|
Myles,
You make a good point. Once cycle life gets to be about 500 cycles, the chances of having the batteries expire from cycle age are pretty low for pleasure boaters like most of the people here. That said, I know that for many boaters (me included) FLA batteries often die with low cycle counts from mis-management. With their higher self-discharge rates, FLA batteries will sulfate if not kept on a consistant charging routine.
AGM batteries seem to survive inattention for longer periods without significant degradation.
Lithium batteries, LiFePO4 batteries specifically, have a much longer shelf life, and should be able to survive 6 months of sitting without any noticible loss of capacity.
Of course, with the considerable investment for any battery bank, having an automated charging system, either plugged in or renewable, will help any battery live closer to its potential.
So my takeaway from this is that cycle life is not as critical for most of our applications. Attributes like size, form, energy density, the ability to deliver more of the stored energy, and cost could be more important factors in choosing your battery bank.
======================================
Even though FLA are obviously cheaper than our other major battery types, I believe that they are least efficient for their size and weight. I find AGM to be a good compromise between cost and delivered energy. And finally, Lithium are half the volume and weight as either lead acid type and usually deliver more Wh per charge for the same Ah ratings, for a consdierably higher cost.
I have found that a rough rule of thumb is that AGM cost about twice as much as FLA for the same size, weight, and Ah rating. They will deliver more range in our typical use cases. Lithium batteries cost about 50% more than AGM for batteries that will deliver the same range, but are rated 20% lower in Ah, and are 60% smaller and lighter than AGM or FLA. This rough estimate includes BMS modules that will prevent any high or low voltage event and help keep the individual cells balanced with each other.
Everyone here gets to decide what is most important to them. I picked LiFePO4 batteries for many of the reasons listed above, but mostly size and weight. Cycle life was not a consideration.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., "Myles Twete" <matwete@...> wrote:
Interesting note on cycle life.
It would take me 150years to go thru 6000 charge/discharge cycles with my
boat.
Even if you were to use your boat every single day, it'd take over 15yrs to
reach that cycle count.
Not even the manufacturers of these batteries advertise them to last 15yrs,
let alone 150yrs.
Cycle life is meaningless to me and my boat except that if I were using
Lithium cells, one overcharge or one over-discharge and the cycle life goes
from awesome to pitiful.
-Myles
|
Thanks Eric.? That should
inform folks who don’t understand the tradeoffs.? My point is just
that having more than a 500-1000 cycle battery charge life is great
advertising, but is pretty useless for a seldom used boat.? And given this
infrequent usage, I personally cannot justify even buying new flooded PbA
batteries, let alone AGM, let alone Lithium of any chemistry.? My 6 used
T105’s cost me $120 total…even though the really only deliver less
than 100ah at this point, I expect they will last another 3 years at least and for
me, this scenario cannot be beat.
Indeed everyone will weigh the
tradeoffs differently…and should I personally get into a more financially
stable situation, I might be tempted to add a string of Lithium to? the boat.
?
It’s really great seeing so
much more activity on this list these days with very very constructive and
informative dialog.? It truly helps to share your experiences out there so
that new folks coming here realize that they’re not crazy after all in
wanting to go electric.
Thank you all!
?
-Myles Twete, Moderator, Electric
Boats
?
From:
electricboats@... [mailto:electricboats@...] On
Behalf Of Eric
Sent: Saturday, November 13, 2010 10:17 AM
To: electricboats@...
Subject: Re: [Electric Boats] Picking batteries
?
?
Myles,
You make a good point. Once cycle life gets to be about 500 cycles, the chances
of having the batteries expire from cycle age are pretty low for pleasure
boaters like most of the people here. That said, I know that for many boaters
(me included) FLA batteries often die with low cycle counts from
mis-management. With their higher self-discharge rates, FLA batteries will
sulfate if not kept on a consistant charging routine.
AGM batteries seem to survive inattention for longer periods without
significant degradation.
Lithium batteries, LiFePO4 batteries specifically, have a much longer shelf
life, and should be able to survive 6 months of sitting without any noticible
loss of capacity.
Of course, with the considerable investment for any battery bank, having an
automated charging system, either plugged in or renewable, will help any
battery live closer to its potential.
So my takeaway from this is that cycle life is not as critical for most of our
applications. Attributes like size, form, energy density, the ability to
deliver more of the stored energy, and cost could be more important factors in
choosing your battery bank.
======================================
Even though FLA are obviously cheaper than our other major battery types, I
believe that they are least efficient for their size and weight. I find AGM to
be a good compromise between cost and delivered energy. And finally, Lithium
are half the volume and weight as either lead acid type and usually deliver
more Wh per charge for the same Ah ratings, for a consdierably higher cost.
I have found that a rough rule of thumb is that AGM cost about twice as much as
FLA for the same size, weight, and Ah rating. They will deliver more range in
our typical use cases. Lithium batteries cost about 50% more than AGM for
batteries that will deliver the same range, but are rated 20% lower in Ah, and
are 60% smaller and lighter than AGM or FLA. This rough estimate includes BMS
modules that will prevent any high or low voltage event and help keep the
individual cells balanced with each other.
Everyone here gets to decide what is most important to them. I picked LiFePO4
batteries for many of the reasons listed above, but mostly size and weight.
Cycle life was not a consideration.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@...,
"Myles Twete" wrote:
>
> Interesting note on cycle life.
>
> It would take me 150years to go thru 6000 charge/discharge cycles with my
> boat.
>
> Even if you were to use your boat every single day, it'd take over 15yrs
to
> reach that cycle count.
>
> Not even the manufacturers of these batteries advertise them to last
15yrs,
> let alone 150yrs.
>
> Cycle life is meaningless to me and my boat except that if I were using
> Lithium cells, one overcharge or one over-discharge and the cycle life
goes
> from awesome to pitiful.
>
> -Myles
>
|
One cell that seems to get neglected on this list is Nickel-Iron.? I
believe they are likely the best of all batteries even though they are
an old tech. Some battery banks still in use are over 50 years old.?
They don't care much how they are charged or discharged.? They don't
care if they are left to discharge and over charge or complete
discharge fails to bother their life.? Most of the time when they don't
supply as rated a simple replacement of the electrolyte will put them
back in original condition.
It is true that they self discharge but this looks to me to be of
little importance and this is why:
A lead acid battery must be kept maintained with a trickle charge. This
process plates the plates with the antimony that strengthens the
plates.? Nickel Iron can be left unattended and charged before you need
to use your boat. Constant current charger is all that is needed to
charge the nickel-iron battery because it can be overcharged without
worry. This leads to lower charger expenditures.? Nickel Iron is not
cheep!? But what is? Subtract High dollar equalizers and 3 stage
chargers and the price seems more manageable.? Take the maintenance
chargers out of the picture and thinks may even look better.? The fact
that alkaline solution is used as an electrolyte and factor that the
batteries will not be replaced in your lifetime and maybe your
children's, and the two times you do need to be replaced and nickel
iron looks very good.? I bring this up because some are now looking at
lithium batteries as an option.? The thought scares me because they are
so easily destroyed, and the price is out of this world.? Edison
developed the battery with an eye to electric vehicles, what are we
thinking?
Kevin Pemberton
On 11/13/2010 11:47 AM, Myles Twete wrote:
?
Thanks Eric.? That
should
inform folks who don’t understand the tradeoffs.? My point is just
that having more than a 500-1000 cycle battery charge life is great
advertising, but is pretty useless for a seldom used boat.? And given
this
infrequent usage, I personally cannot justify even buying new flooded
PbA
batteries, let alone AGM, let alone Lithium of any chemistry.? My 6
used
T105’s cost me $120 total…even though the really only deliver less
than 100ah at this point, I expect they will last another 3 years at
least and for
me, this scenario cannot be beat.
Indeed everyone will
weigh the
tradeoffs differently…and should I personally get into a more
financially
stable situation, I might be tempted to add a string of Lithium to? the
boat.
?
It’s really great
seeing so
much more activity on this list these days with very very constructive
and
informative dialog.? It truly helps to share your experiences out there
so
that new folks coming here realize that they’re not crazy after all in
wanting to go electric.
Thank you all!
?
-Myles Twete,
Moderator, Electric
Boats
?
?
?
Myles,
You make a good point. Once cycle life gets to be about 500 cycles, the
chances
of having the batteries expire from cycle age are pretty low for
pleasure
boaters like most of the people here. That said, I know that for many
boaters
(me included) FLA batteries often die with low cycle counts from
mis-management. With their higher self-discharge rates, FLA batteries
will
sulfate if not kept on a consistant charging routine.
AGM batteries seem to survive inattention for longer periods without
significant degradation.
Lithium batteries, LiFePO4 batteries specifically, have a much longer
shelf
life, and should be able to survive 6 months of sitting without any
noticible
loss of capacity.
Of course, with the considerable investment for any battery bank,
having an
automated charging system, either plugged in or renewable, will help
any
battery live closer to its potential.
So my takeaway from this is that cycle life is not as critical for most
of our
applications. Attributes like size, form, energy density, the ability
to
deliver more of the stored energy, and cost could be more important
factors in
choosing your battery bank.
======================================
Even though FLA are obviously cheaper than our other major battery
types, I
believe that they are least efficient for their size and weight. I find
AGM to
be a good compromise between cost and delivered energy. And finally,
Lithium
are half the volume and weight as either lead acid type and usually
deliver
more Wh per charge for the same Ah ratings, for a consdierably higher
cost.
I have found that a rough rule of thumb is that AGM cost about twice as
much as
FLA for the same size, weight, and Ah rating. They will deliver more
range in
our typical use cases. Lithium batteries cost about 50% more than AGM
for
batteries that will deliver the same range, but are rated 20% lower in
Ah, and
are 60% smaller and lighter than AGM or FLA. This rough estimate
includes BMS
modules that will prevent any high or low voltage event and help keep
the
individual cells balanced with each other.
Everyone here gets to decide what is most important to them. I picked
LiFePO4
batteries for many of the reasons listed above, but mostly size and
weight.
Cycle life was not a consideration.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@...,
"Myles
Twete" wrote:
>
> Interesting note on cycle life.
>
> It would take me 150years to go thru 6000 charge/discharge cycles
with my
> boat.
>
> Even if you were to use your boat every single day, it'd take over
15yrs
to
> reach that cycle count.
>
> Not even the manufacturers of these batteries advertise them to
last
15yrs,
> let alone 150yrs.
>
> Cycle life is meaningless to me and my boat except that if I were
using
> Lithium cells, one overcharge or one over-discharge and the cycle
life
goes
> from awesome to pitiful.
>
> -Myles
>
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
As a off grid solar installer, I agree with you.
NiFe batteries are available at
and
Steve Spence
Renewable energy and self sufficiency
toggle quoted message
Show quoted text
On 11/13/2010 03:25 PM, Kevin Pemberton wrote:
One cell that seems to get neglected on this list is Nickel-Iron. I
believe they are likely the best of all batteries even though they are
an old tech. Some battery banks still in use are over 50 years old.
They don't care much how they are charged or discharged. They don't
care if they are left to discharge and over charge or complete discharge
fails to bother their life. Most of the time when they don't supply as
rated a simple replacement of the electrolyte will put them back in
original condition.
It is true that they self discharge but this looks to me to be of little
importance and this is why:
A lead acid battery must be kept maintained with a trickle charge. This
process plates the plates with the antimony that strengthens the
plates. Nickel Iron can be left unattended and charged before you need
to use your boat. Constant current charger is all that is needed to
charge the nickel-iron battery because it can be overcharged without
worry. This leads to lower charger expenditures. Nickel Iron is not
cheep! But what is? Subtract High dollar equalizers and 3 stage
chargers and the price seems more manageable. Take the maintenance
chargers out of the picture and thinks may even look better. The fact
that alkaline solution is used as an electrolyte and factor that the
batteries will not be replaced in your lifetime and maybe your
children's, and the two times you do need to be replaced and nickel iron
looks very good. I bring this up because some are now looking at
lithium batteries as an option. The thought scares me because they are
so easily destroyed, and the price is out of this world. Edison
developed the battery with an eye to electric vehicles, what are we
thinking?
Kevin Pemberton
On 11/13/2010 11:47 AM, Myles Twete wrote:
Thanks Eric. That should inform folks who dont understand the
tradeoffs. My point is just that having more than a 500-1000 cycle
battery charge life is great advertising, but is pretty useless for a
seldom used boat. And given this infrequent usage, I personally
cannot justify even buying new flooded PbA batteries, let alone AGM,
let alone Lithium of any chemistry. My 6 used T105s cost me $120
totaleven though the really only deliver less than 100ah at this
point, I expect they will last another 3 years at least and for me,
this scenario cannot be beat.
Indeed everyone will weigh the tradeoffs differentlyand should I
personally get into a more financially stable situation, I might be
tempted to add a string of Lithium to the boat.
Its really great seeing so much more activity on this list these days
with very very constructive and informative dialog. It truly helps to
share your experiences out there so that new folks coming here realize
that theyre not crazy after all in wanting to go electric.
Thank you all!
-Myles Twete, Moderator, Electric Boats
*From:* electricboats@...
[mailto:electricboats@...] *On Behalf Of *Eric
*Sent:* Saturday, November 13, 2010 10:17 AM
*To:* electricboats@...
*Subject:* Re: [Electric Boats] Picking batteries
Myles,
You make a good point. Once cycle life gets to be about 500 cycles,
the chances of having the batteries expire from cycle age are pretty
low for pleasure boaters like most of the people here. That said, I
know that for many boaters (me included) FLA batteries often die with
low cycle counts from mis-management. With their higher self-discharge
rates, FLA batteries will sulfate if not kept on a consistant charging
routine.
AGM batteries seem to survive inattention for longer periods without
significant degradation.
Lithium batteries, LiFePO4 batteries specifically, have a much longer
shelf life, and should be able to survive 6 months of sitting without
any noticible loss of capacity.
Of course, with the considerable investment for any battery bank,
having an automated charging system, either plugged in or renewable,
will help any battery live closer to its potential.
So my takeaway from this is that cycle life is not as critical for
most of our applications. Attributes like size, form, energy density,
the ability to deliver more of the stored energy, and cost could be
more important factors in choosing your battery bank.
======================================
Even though FLA are obviously cheaper than our other major battery
types, I believe that they are least efficient for their size and
weight. I find AGM to be a good compromise between cost and delivered
energy. And finally, Lithium are half the volume and weight as either
lead acid type and usually deliver more Wh per charge for the same Ah
ratings, for a consdierably higher cost.
I have found that a rough rule of thumb is that AGM cost about twice
as much as FLA for the same size, weight, and Ah rating. They will
deliver more range in our typical use cases. Lithium batteries cost
about 50% more than AGM for batteries that will deliver the same
range, but are rated 20% lower in Ah, and are 60% smaller and lighter
than AGM or FLA. This rough estimate includes BMS modules that will
prevent any high or low voltage event and help keep the individual
cells balanced with each other.
Everyone here gets to decide what is most important to them. I picked
LiFePO4 batteries for many of the reasons listed above, but mostly
size and weight. Cycle life was not a consideration.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@...
<mailto:electricboats%40yahoogroups.com>, "Myles Twete" <matwete@...>
wrote:
Interesting note on cycle life.
It would take me 150years to go thru 6000 charge/discharge cycles
with my
boat.
Even if you were to use your boat every single day, it'd take over 15yrs to
reach that cycle count.
Not even the manufacturers of these batteries advertise them to last 15yrs,
let alone 150yrs.
Cycle life is meaningless to me and my boat except that if I were using
Lithium cells, one overcharge or one over-discharge and the cycle life goes
from awesome to pitiful.
-Myles
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
I see on the beutilityfree site that the cell Ah specs are given at the 100hr rate. That got me thinking about Peukert effect losses with this chemistry. Anybody know how these cells perform at high discharge rates, say C/5 and C/2?
-Tom
toggle quoted message
Show quoted text
--- In electricboats@..., Steve Spence <steve@...> wrote:
As a off grid solar installer, I agree with you.
NiFe batteries are available at
and
Steve Spence
Renewable energy and self sufficiency
On 11/13/2010 03:25 PM, Kevin Pemberton wrote:
One cell that seems to get neglected on this list is Nickel-Iron. I
believe they are likely the best of all batteries even though they are
an old tech. Some battery banks still in use are over 50 years old.
They don't care much how they are charged or discharged. They don't
care if they are left to discharge and over charge or complete discharge
fails to bother their life. Most of the time when they don't supply as
rated a simple replacement of the electrolyte will put them back in
original condition.
It is true that they self discharge but this looks to me to be of little
importance and this is why:
A lead acid battery must be kept maintained with a trickle charge. This
process plates the plates with the antimony that strengthens the
plates. Nickel Iron can be left unattended and charged before you need
to use your boat. Constant current charger is all that is needed to
charge the nickel-iron battery because it can be overcharged without
worry. This leads to lower charger expenditures. Nickel Iron is not
cheep! But what is? Subtract High dollar equalizers and 3 stage
chargers and the price seems more manageable. Take the maintenance
chargers out of the picture and thinks may even look better. The fact
that alkaline solution is used as an electrolyte and factor that the
batteries will not be replaced in your lifetime and maybe your
children's, and the two times you do need to be replaced and nickel iron
looks very good. I bring this up because some are now looking at
lithium batteries as an option. The thought scares me because they are
so easily destroyed, and the price is out of this world. Edison
developed the battery with an eye to electric vehicles, what are we
thinking?
Kevin Pemberton
On 11/13/2010 11:47 AM, Myles Twete wrote:
Thanks Eric. That should inform folks who don't understand the
tradeoffs. My point is just that having more than a 500-1000 cycle
battery charge life is great advertising, but is pretty useless for a
seldom used boat. And given this infrequent usage, I personally
cannot justify even buying new flooded PbA batteries, let alone AGM,
let alone Lithium of any chemistry. My 6 used T105's cost me $120
total…even though the really only deliver less than 100ah at this
point, I expect they will last another 3 years at least and for me,
this scenario cannot be beat.
Indeed everyone will weigh the tradeoffs differently…and should I
personally get into a more financially stable situation, I might be
tempted to add a string of Lithium to the boat.
It's really great seeing so much more activity on this list these days
with very very constructive and informative dialog. It truly helps to
share your experiences out there so that new folks coming here realize
that they're not crazy after all in wanting to go electric.
Thank you all!
-Myles Twete, Moderator, Electric Boats
*From:* electricboats@...
[mailto:electricboats@...] *On Behalf Of *Eric
*Sent:* Saturday, November 13, 2010 10:17 AM
*To:* electricboats@...
*Subject:* Re: [Electric Boats] Picking batteries
Myles,
You make a good point. Once cycle life gets to be about 500 cycles,
the chances of having the batteries expire from cycle age are pretty
low for pleasure boaters like most of the people here. That said, I
know that for many boaters (me included) FLA batteries often die with
low cycle counts from mis-management. With their higher self-discharge
rates, FLA batteries will sulfate if not kept on a consistant charging
routine.
AGM batteries seem to survive inattention for longer periods without
significant degradation.
Lithium batteries, LiFePO4 batteries specifically, have a much longer
shelf life, and should be able to survive 6 months of sitting without
any noticible loss of capacity.
Of course, with the considerable investment for any battery bank,
having an automated charging system, either plugged in or renewable,
will help any battery live closer to its potential.
So my takeaway from this is that cycle life is not as critical for
most of our applications. Attributes like size, form, energy density,
the ability to deliver more of the stored energy, and cost could be
more important factors in choosing your battery bank.
======================================
Even though FLA are obviously cheaper than our other major battery
types, I believe that they are least efficient for their size and
weight. I find AGM to be a good compromise between cost and delivered
energy. And finally, Lithium are half the volume and weight as either
lead acid type and usually deliver more Wh per charge for the same Ah
ratings, for a consdierably higher cost.
I have found that a rough rule of thumb is that AGM cost about twice
as much as FLA for the same size, weight, and Ah rating. They will
deliver more range in our typical use cases. Lithium batteries cost
about 50% more than AGM for batteries that will deliver the same
range, but are rated 20% lower in Ah, and are 60% smaller and lighter
than AGM or FLA. This rough estimate includes BMS modules that will
prevent any high or low voltage event and help keep the individual
cells balanced with each other.
Everyone here gets to decide what is most important to them. I picked
LiFePO4 batteries for many of the reasons listed above, but mostly
size and weight. Cycle life was not a consideration.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@...
<mailto:electricboats%40yahoogroups.com>, "Myles Twete" <matwete@>
wrote:
Interesting note on cycle life.
It would take me 150years to go thru 6000 charge/discharge cycles
with my
boat.
Even if you were to use your boat every single day, it'd take over 15yrs to
reach that cycle count.
Not even the manufacturers of these batteries advertise them to last 15yrs,
let alone 150yrs.
Cycle life is meaningless to me and my boat except that if I were using
Lithium cells, one overcharge or one over-discharge and the cycle life goes
from awesome to pitiful.
-Myles
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
The edison cell has a peukert value of about 1.
you can see how this works out at
Steve Spence
Renewable energy and self sufficiency
toggle quoted message
Show quoted text
On 11/14/2010 12:00 AM, Tom wrote:
I see on the beutilityfree site that the cell Ah specs are given at the
100hr rate. That got me thinking about Peukert effect losses with this
chemistry. Anybody know how these cells perform at high discharge rates,
say C/5 and C/2?
-Tom
--- In electricboats@...
<mailto:electricboats%40yahoogroups.com>, Steve Spence <steve@...> wrote:
As a off grid solar installer, I agree with you.
NiFe batteries are available at
and
Steve Spence
Renewable energy and self sufficiency
On 11/13/2010 03:25 PM, Kevin Pemberton wrote:
One cell that seems to get neglected on this list is Nickel-Iron. I
believe they are likely the best of all batteries even though they are
an old tech. Some battery banks still in use are over 50 years old.
They don't care much how they are charged or discharged. They don't
care if they are left to discharge and over charge or complete discharge
fails to bother their life. Most of the time when they don't supply as
rated a simple replacement of the electrolyte will put them back in
original condition.
It is true that they self discharge but this looks to me to be of little
importance and this is why:
A lead acid battery must be kept maintained with a trickle charge. This
process plates the plates with the antimony that strengthens the
plates. Nickel Iron can be left unattended and charged before you need
to use your boat. Constant current charger is all that is needed to
charge the nickel-iron battery because it can be overcharged without
worry. This leads to lower charger expenditures. Nickel Iron is not
cheep! But what is? Subtract High dollar equalizers and 3 stage
chargers and the price seems more manageable. Take the maintenance
chargers out of the picture and thinks may even look better. The fact
that alkaline solution is used as an electrolyte and factor that the
batteries will not be replaced in your lifetime and maybe your
children's, and the two times you do need to be replaced and nickel iron
looks very good. I bring this up because some are now looking at
lithium batteries as an option. The thought scares me because they are
so easily destroyed, and the price is out of this world. Edison
developed the battery with an eye to electric vehicles, what are we
thinking?
Kevin Pemberton
On 11/13/2010 11:47 AM, Myles Twete wrote:
Thanks Eric. That should inform folks who don't understand the
tradeoffs. My point is just that having more than a 500-1000 cycle
battery charge life is great advertising, but is pretty useless for a
seldom used boat. And given this infrequent usage, I personally
cannot justify even buying new flooded PbA batteries, let alone AGM,
let alone Lithium of any chemistry. My 6 used T105's cost me $120
totaleven though the really only deliver less than 100ah at this
point, I expect they will last another 3 years at least and for me,
this scenario cannot be beat.
Indeed everyone will weigh the tradeoffs differentlyand should I
personally get into a more financially stable situation, I might be
tempted to add a string of Lithium to the boat.
It's really great seeing so much more activity on this list these days
with very very constructive and informative dialog. It truly helps to
share your experiences out there so that new folks coming here realize
that they're not crazy after all in wanting to go electric.
Thank you all!
-Myles Twete, Moderator, Electric Boats
*From:* electricboats@...
<mailto:electricboats%40yahoogroups.com>
[mailto:electricboats@...
<mailto:electricboats%40yahoogroups.com>] *On Behalf Of *Eric
*Sent:* Saturday, November 13, 2010 10:17 AM
*To:* electricboats@...
<mailto:electricboats%40yahoogroups.com>
*Subject:* Re: [Electric Boats] Picking batteries
Myles,
You make a good point. Once cycle life gets to be about 500 cycles,
the chances of having the batteries expire from cycle age are pretty
low for pleasure boaters like most of the people here. That said, I
know that for many boaters (me included) FLA batteries often die with
low cycle counts from mis-management. With their higher self-discharge
rates, FLA batteries will sulfate if not kept on a consistant charging
routine.
AGM batteries seem to survive inattention for longer periods without
significant degradation.
Lithium batteries, LiFePO4 batteries specifically, have a much longer
shelf life, and should be able to survive 6 months of sitting without
any noticible loss of capacity.
Of course, with the considerable investment for any battery bank,
having an automated charging system, either plugged in or renewable,
will help any battery live closer to its potential.
So my takeaway from this is that cycle life is not as critical for
most of our applications. Attributes like size, form, energy density,
the ability to deliver more of the stored energy, and cost could be
more important factors in choosing your battery bank.
======================================
Even though FLA are obviously cheaper than our other major battery
types, I believe that they are least efficient for their size and
weight. I find AGM to be a good compromise between cost and delivered
energy. And finally, Lithium are half the volume and weight as either
lead acid type and usually deliver more Wh per charge for the same Ah
ratings, for a consdierably higher cost.
I have found that a rough rule of thumb is that AGM cost about twice
as much as FLA for the same size, weight, and Ah rating. They will
deliver more range in our typical use cases. Lithium batteries cost
about 50% more than AGM for batteries that will deliver the same
range, but are rated 20% lower in Ah, and are 60% smaller and lighter
than AGM or FLA. This rough estimate includes BMS modules that will
prevent any high or low voltage event and help keep the individual
cells balanced with each other.
Everyone here gets to decide what is most important to them. I picked
LiFePO4 batteries for many of the reasons listed above, but mostly
size and weight. Cycle life was not a consideration.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@...
<mailto:electricboats%40yahoogroups.com>
<mailto:electricboats%40yahoogroups.com>, "Myles Twete" <matwete@>
wrote:
Interesting note on cycle life.
It would take me 150years to go thru 6000 charge/discharge cycles
with my
boat.
Even if you were to use your boat every single day, it'd take over 15yrs to
reach that cycle count.
Not even the manufacturers of these batteries advertise them to last 15yrs,
let alone 150yrs.
Cycle life is meaningless to me and my boat except that if I were
using
Lithium cells, one overcharge or one over-discharge and the cycle life goes
from awesome to pitiful.
-Myles
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
I agree with you Kevin,
but feel the need to point out the difference
between what is available in NIFE from Be Utility Free or any other source and what is no longer made by Eagle-Picher who supplied the batteries for the Dodge T-van.
The Eagle-Picher battery pack in the T-van weighed 1650 lbs. 30-6 volt
units of 200AH making 180 volts. An equivilent pack of NIFE from what is available today would weigh over 3000 lbs and also would be way bulkier. Both negatives for installation in boats.
Now I know most boats don't need 180 volts, so a modest setup of NIFE could still be worked out in a monohull, but personally I need a light power source for a multihull sailboat.
We need a battery geekoid or a tech wiz from the former Eagle-Picher
to leak the chemistry of that battery and tell us how to make them ourselves.
Reread John Paramore's post from 07/2009(type NIFE into the search box.)
I have an interesting link on the T-van battery pack
This guy has or had 3 sets of NIFE for sale a while back.
I was seriously thinking about it. But didn't have an extra $12,000
laying around.
NIFE has potential, I hope someone gives it a good try and posts
the results here.
Don Parsons
toggle quoted message
Show quoted text
--- In electricboats@..., Kevin Pemberton <pembertonkevin@...> wrote:
One cell that seems to get neglected on this list is Nickel-Iron. I
believe they are likely the best of all batteries even though they are
an old tech. Some battery banks still in use are over 50 years old.
They don't care much how they are charged or discharged. They don't
care if they are left to discharge and over charge or complete discharge
fails to bother their life.
|
A Peukert exponent of 1.00 means that there is no Peukerts effect at all and that the battery will deliver the same amount of energy at any discharge rate. I would guess that the Peukert's exponent for Nickel Iron batteries is higher than 1.00
Eric
toggle quoted message
Show quoted text
--- In electricboats@..., Steve Spence <steve@...> wrote:
The edison cell has a peukert value of about 1.
you can see how this works out at
Steve Spence
Renewable energy and self sufficiency
On 11/14/2010 12:00 AM, Tom wrote:
I see on the beutilityfree site that the cell Ah specs are given at the
100hr rate. That got me thinking about Peukert effect losses with this
chemistry. Anybody know how these cells perform at high discharge rates,
say C/5 and C/2?
-Tom
|
Not significantly.
Steve Spence
Renewable energy and self sufficiency
toggle quoted message
Show quoted text
On 11/14/2010 03:19 PM, Eric wrote:
A Peukert exponent of 1.00 means that there is no Peukerts effect at all
and that the battery will deliver the same amount of energy at any
discharge rate. I would guess that the Peukert's exponent for Nickel
Iron batteries is higher than 1.00
Eric
|
I was also going to mention the weight factor. running some quick calculation from the spec sheets that were on the provided links, the NiFe batteries seem to be between 8 to 10Wh per pound. Compare that to 20Wh/lb for Odyssey PC1800 AGM, 22Wh/lb for T-105 FLA and 40Wh/lb for Thundersky LiFePO4.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., "Don Parsons" <tdparsons@...> wrote:
I agree with you Kevin,
but feel the need to point out the difference
between what is available in NIFE from Be Utility Free or any other source and what is no longer made by Eagle-Picher who supplied the batteries for the Dodge T-van.
The Eagle-Picher battery pack in the T-van weighed 1650 lbs. 30-6 volt
units of 200AH making 180 volts. An equivilent pack of NIFE from what is available today would weigh over 3000 lbs and also would be way bulkier. Both negatives for installation in boats.
Now I know most boats don't need 180 volts, so a modest setup of NIFE could still be worked out in a monohull, but personally I need a light power source for a multihull sailboat.
We need a battery geekoid or a tech wiz from the former Eagle-Picher
to leak the chemistry of that battery and tell us how to make them ourselves.
Reread John Paramore's post from 07/2009(type NIFE into the search box.)
I have an interesting link on the T-van battery pack
This guy has or had 3 sets of NIFE for sale a while back.
I was seriously thinking about it. But didn't have an extra $12,000
laying around.
NIFE has potential, I hope someone gives it a good try and posts
the results here.
Don Parsons
|
>A Peukert exponent of 1.00 means that there is no Peukerts effect at all and that the battery will deliver the same amount of energy at any discharge rate. I would guess that the Peukert's exponent for Nickel Iron batteries is higher than 1.00
>Eric
No doubt.? References online claim virtually no Peukert effect for any of the Nickel chemistries including NiCd, NiZn, NiMH. I’m sure he just was parroting these.? Worse, the weblink he offered drawing folks to his personal Peukert calculator page does not provide any support for the 1.0 Peukert exponent claim. ? From the brief looking I’ve done, I’d guess that the effective Peukert exponent for NiFe is below 1.05, and once you’re down that low, unless you’re drawing high-C loads, I don’t think you have to worry much about it. ? I think the major beefs against NiFe batteries are: ·???????? Cost ·???????? Relatively high self-discharge rates ? And those weigh enough against them that we don’t appreciate the uber-long life of them.? Charge/discharge inefficiency isn’t much of an issue for many of us, but high initial cost and self-discharge rates are. ? -Myles Twete ?
|
Myles,
Fair enough, I use 1.03 for LiFePO4 batteries. It does show up in electric car conversions but they often operate with loads above 1C.
Eric
toggle quoted message
Show quoted text
--- In electricboats@..., "Myles Twete" <matwete@...> wrote:
A Peukert exponent of 1.00 means that there is no Peukerts effect at all and that the battery will deliver the same amount of energy at any discharge
rate. I would guess that the Peukert's exponent for Nickel Iron batteries is
higher than 1.00
Eric No doubt. References online claim virtually no Peukert effect for any of
the Nickel chemistries including NiCd, NiZn, NiMH.
I'm sure he just was parroting these. Worse, the weblink he offered drawing
folks to his personal Peukert calculator page does not provide any support
for the 1.0 Peukert exponent claim.
From the brief looking I've done, I'd guess that the effective Peukert
exponent for NiFe is below 1.05, and once you're down that low, unless
you're drawing high-C loads, I don't think you have to worry much about it.
-Myles Twete
|
If you read battery chemistry engineering books, you would know that
Nickel based batteries have a peukert of virtually 1.00. I do not
"parrot", I do research and practical experimentation. I've lived off
grid for 6 years, and have over 25 years in electronics. I resent the
implications otherwise. My calculator is accurate.
Steve Spence
Renewable energy and self sufficiency
toggle quoted message
Show quoted text
On 11/14/2010 03:36 PM, Myles Twete wrote:
*>*A Peukert exponent of 1.00 means that there is no Peukerts effect at
all and that the battery will deliver the same amount of energy at any
discharge rate. I would guess that the Peukert's exponent for Nickel
Iron batteries is higher than 1.00
Eric No doubt. References online claim virtually no Peukert effect for any
of the Nickel chemistries including NiCd, NiZn, NiMH.
Im sure he just was parroting these. Worse, the weblink he offered
drawing folks to his personal Peukert calculator page does not provide
any support for the 1.0 Peukert exponent claim.
From the brief looking Ive done, Id guess that the effective Peukert
exponent for NiFe is below 1.05, and once youre down that low, unless
youre drawing high-C loads, I dont think you have to worry much about it.
I think the major beefs against NiFe batteries are:
Cost
Relatively high self-discharge rates
And those weigh enough against them that we dont appreciate the
uber-long life of them. Charge/discharge inefficiency isnt much of an
issue for many of us, but high initial cost and self-discharge rates are.
-Myles Twete
|
toggle quoted message
Show quoted text
On Nov 14, 2010, at 12:25 PM, "Eric" < ewdysar@...> wrote:
?
I was also going to mention the weight factor. running some quick calculation from the spec sheets that were on the provided links, the NiFe batteries seem to be between 8 to 10Wh per pound. Compare that to 20Wh/lb for Odyssey PC1800 AGM, 22Wh/lb for T-105 FLA and 40Wh/lb for Thundersky LiFePO4.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@..., "Don Parsons" wrote:
>
> I agree with you Kevin,
> but feel the need to point out the difference
> between what is available in NIFE from Be Utility Free or any other source and what is no longer made by Eagle-Picher who supplied the batteries for the Dodge T-van.
> The Eagle-Picher battery pack in the T-van weighed 1650 lbs. 30-6 volt
> units of 200AH making 180 volts. An equivilent pack of NIFE from what is available today would weigh over 3000 lbs and also would be way bulkier. Both negatives for installation in boats.
> Now I know most boats don't need 180 volts, so a modest setup of NIFE could still be worked out in a monohull, but personally I need a light power source for a multihull sailboat.
> We need a battery geekoid or a tech wiz from the former Eagle-Picher
> to leak the chemistry of that battery and tell us how to make them ourselves.
> Reread John Paramore's post from 07/2009(type NIFE into the search box.)
> I have an interesting link on the T-van battery pack
>
>
>
> This guy has or had 3 sets of NIFE for sale a while back.
> I was seriously thinking about it. But didn't have an extra $12,000
> laying around.
>
> NIFE has potential, I hope someone gives it a good try and posts
> the results here.
>
> Don Parsons
>
>
>
|
Myles,I agree partially,
The exception being for a home powerbank they are the answer even with their high cost and lower performance. In the long run you will save.
What pisses me off is we are being cheated out of their potential.
Not even future potential, but 1970's potential!
That 70's patent is way past expiration but is being held from us. Why.
Our military supposedly is sitting on 40 year old technology. The notion is absurd.
The Be Utility Free Chinese made NiFe is old technology compared
to the Eagle-Picher technology and that is now 40 years old.
Where could NiFe be now if Excide hadn't shelved it.
Sadly we may never know.
If any of you can get your hands on the T-van batteries then I think they would be worth a try in a boat.
I believe there was a post in 2009 by a member who said he had some dead T-van batteries he was going to try to revive. If you read this let us know if they worked.
Hope I didn't rant too much.
Don Parsons
toggle quoted message
Show quoted text
--- In electricboats@..., "Myles Twete" <matwete@...> wrote:
A Peukert exponent of 1.00 means that there is no Peukerts effect at all and that the battery will deliver the same amount of energy at any discharge
rate. I would guess that the Peukert's exponent for Nickel Iron batteries is
higher than 1.00
Eric
No doubt. References online claim virtually no Peukert effect for any of
the Nickel chemistries including NiCd, NiZn, NiMH.
I'm sure he just was parroting these. Worse, the weblink he offered drawing
folks to his personal Peukert calculator page does not provide any support
for the 1.0 Peukert exponent claim.
From the brief looking I've done, I'd guess that the effective Peukert
exponent for NiFe is below 1.05, and once you're down that low, unless
you're drawing high-C loads, I don't think you have to worry much about it.
I think the major beefs against NiFe batteries are:
. Cost
. Relatively high self-discharge rates
And those weigh enough against them that we don't appreciate the uber-long
life of them. Charge/discharge inefficiency isn't much of an issue for many
of us, but high initial cost and self-discharge rates are.
-Myles Twete
|
No arguments here…definitely was a conspiracy and capitalism at its finest that led to patent ownership that kept companies from producing large size NiMH batteries for EV use.? Thank you Ovonics and Chevron!? And in my opinion they shot us all in the foot---the head start they had in this was squandered by their keeping this technology from the market and allowed investments in lithium cell technology to jump ahead leaps and bounds.? Few folks rave about NiMH batteries anymore, particularly since the cost of lithium keeps dropping and more and more manufacturers are switching to the easier to make lithiums instead of the NiMH batteries. ? I had a set of NiMH batteries from an EV1----some of the cells were too dead to be revived. I gave them to another fellow EVer here in Portland as I couldn’t trust them and didn’t want to get into mixing/matching cells and having to reband them to the right tension.? My experience with those and smaller scale NiMH batteries led me to not be a big fan of NiMH. I’m not a big fan of lithium either though. ? Waiting to be convinced by quality and pricing. ? -Myles ? ? ?
toggle quoted message
Show quoted text
From: electricboats@... [mailto:electricboats@...] On Behalf Of Don Parsons
Sent: Sunday, November 14, 2010 1:16 PM
To: electricboats@...
Subject: Re: [Electric Boats] Picking batteries? ? Myles,I agree partially,
The exception being for a home powerbank they are the answer even with their high cost and lower performance. In the long run you will save.
What pisses me off is we are being cheated out of their potential.
Not even future potential, but 1970's potential!
That 70's patent is way past expiration but is being held from us. Why.
Our military supposedly is sitting on 40 year old technology. The notion is absurd.
The Be Utility Free Chinese made NiFe is old technology compared
to the Eagle-Picher technology and that is now 40 years old.
Where could NiFe be now if Excide hadn't shelved it.
Sadly we may never know.
If any of you can get your hands on the T-van batteries then I think they would be worth a try in a boat.
I believe there was a post in 2009 by a member who said he had some dead T-van batteries he was going to try to revive. If you read this let us know if they worked.
Hope I didn't rant too much.
Don Parsons
--- In electricboats@..., "Myles Twete" wrote:
>
> >A Peukert exponent of 1.00 means that there is no Peukerts effect at all
> and that the battery will deliver the same amount of energy at any discharge
> rate. I would guess that the Peukert's exponent for Nickel Iron batteries is
> higher than 1.00
> >Eric
>
>
>
> No doubt. References online claim virtually no Peukert effect for any of
> the Nickel chemistries including NiCd, NiZn, NiMH.
>
> I'm sure he just was parroting these. Worse, the weblink he offered drawing
> folks to his personal Peukert calculator page does not provide any support
> for the 1.0 Peukert exponent claim.
>
>
>
> From the brief looking I've done, I'd guess that the effective Peukert
> exponent for NiFe is below 1.05, and once you're down that low, unless
> you're drawing high-C loads, I don't think you have to worry much about it.
>
>
>
> I think the major beefs against NiFe batteries are:
>
> . Cost
>
> . Relatively high self-discharge rates
>
>
>
> And those weigh enough against them that we don't appreciate the uber-long
> life of them. Charge/discharge inefficiency isn't much of an issue for many
> of us, but high initial cost and self-discharge rates are.
>
>
>
> -Myles Twete
>
|
The claim was made: "The edison cell has a peukert value of about 1.? You can see how this works out at ____”. Yet no support for this claim was offered except a link to a capacity calculator at the poster’s own website. ? Extraordinary claims (in this case, Peukert Exponent of 1 for NiFe battery chemistry) demand extraordinary proof. A P.E. of 1 effectively requires a battery with zero internal resistance and no irreversible electro-chemical losses. For years, people have claimed P.C. of 1.0 for Lithium also, often parroting "Peukert only applies to Lead Acid".? Only recently has this been disputed. e.g. Peukert Exponents of 1.036 (Valence) and 1.056 (ThunderSky) estimated for . ? Is 1.03-1.06 a Peukert Exponent “about 1”?? That depends of course on your usage---i.e. %C that you will pull current out at.? EV-scale Lithium batteries were claimed for years as having ZERO Peukert effect (Peukert Exponent of 1.0) and yet now we know otherwise.? So why should I (as an Engineer of 30yrs and EV enthusiast for 17yrs) believe an unsupported claim that effectively Peukert doesn’t apply to NiFe?? Sorry, credentials notwithstanding, I am skeptical. ? What do we find on the Web regarding NiXX chemistry and Peukert? It doesn’t take long with resources online to find evidence that NiMH batteries (eg this Panasonic curve below from research paper ) display the Peukert effect---this one with a Peukert Exponent of about 1.035.? Given this for modern NiMH, why should we believe claims that Edison (NiFe) batteries exhibit zero Peukert effect? ?Modern NiFe are somehow better than modern NiMH? ? I can’t tell you the number of times that I’ve heard “Peukert only applies to lead chemistries”. The problem with this: The Peukert Equation was not derived based on the chemistry involved at all.? It was simply based on detailed observations of reduced capacity as a function of current draw and a simplified exponential mathematical model found that matched it pretty well.? Nothing to do with constraining its applicability to lead-acid or that if a battery’s internal resistance is small or zero that the effect doesn’t apply.? Given its empirical basis, the way you “prove” a battery type doesn’t exhibit the effect is to show the data for your new battery type!? You don’t prove it by simply making a claim that the Peukert exponent is about 1.0.? Having said this, sure, a Peukert Exponent of 1.035 is very very good!? And that should be celebrated. ? -Myles ?
toggle quoted message
Show quoted text
-----Original Message-----
From: electricboats@... [mailto:electricboats@...] On Behalf Of Steve Spence
Sent: Sunday, November 14, 2010 12:58 PM
To: electricboats@...
Subject: Re: [Electric Boats] Picking batteries ? If you read battery chemistry engineering books, you would know that Nickel based batteries have a peukert of virtually 1.00. I do not "parrot", I do research and practical experimentation. I've lived off grid for 6 years, and have over 25 years in electronics. I resent the implications otherwise. My calculator is accurate. ? Steve Spence Renewable energy and self sufficiency http://www.green-trust.org http://arduinotronics.blogspot.com/ ? ? ? On 11/14/2010 03:36 PM, Myles Twete wrote: >? > > *>*A Peukert exponent of 1.00 means that there is no Peukerts effect at > all and that the battery will deliver the same amount of energy at any > discharge rate. I would guess that the Peukert's exponent for Nickel > Iron batteries is higher than 1.00 >>Eric > > No doubt.? References online claim virtually no Peukert effect for any > of the Nickel chemistries including NiCd, NiZn, NiMH. > > I’m sure he just was parroting these.? Worse, the weblink he offered > drawing folks to his personal Peukert calculator page does not provide > any support for the 1.0 Peukert exponent claim. > >? > > From the brief looking I’ve done, I’d guess that the effective Peukert > exponent for NiFe is below 1.05, and once you’re down that low, unless > you’re drawing high-C loads, I don’t think you have to worry much about it. > >? > > I think the major beefs against NiFe batteries are: > > ·???????? Cost > > ·???????? Relatively high self-discharge rates > >? > > And those weigh enough against them that we don’t appreciate the > uber-long life of them.? Charge/discharge inefficiency isn’t much of an > issue for many of us, but high initial cost and self-discharge rates are. > >? > > -Myles Twete > >? > > ? ? ------------------------------------ ? Yahoo! Groups Links ? <*> To visit your group on the web, go to: ??? http://groups.yahoo.com/group/electricboats/ ? <*> Your email settings: ??? Individual Email | Traditional ? <*> To change settings online go to: ??? http://groups.yahoo.com/group/electricboats/join ??? (Yahoo! ID required) ? <*> To change settings via email: ??? electricboats-digest@... ????electricboats-fullfeatured@... ? <*> To unsubscribe from this group, send an email to: ??? electricboats-unsubscribe@... ? <*> Your use of Yahoo! Groups is subject to: ??? http://docs.yahoo.com/info/terms/ ?
|
I said about 1, not 1. I also said you can see how this works out using the calculator. The calculator allows you to play with peukert numbers to see what the effects are. at low c values, changing the peukert exponent has no effect. you can prove that with the calculator as well.
Steve Spence
|
When we talk Peukert effect we fail to remember one thing.? As our lead
acid batteries age the Peukert factor changes.? This is not true with
Nickel Iron.? When new the two compare favorably but in time the polish
of an old tech appears to shine. The catch 22 of lead is to keep the
battery maintained we must limit it's ability to deliver over time.?
Any charging continues to plate the plates reducing their ability to
release the charge stored in the plates.?
This is expressed in many ways. We can start with the statement that we
must not mix different age batteries.? We can further show the implied
limits of lead acid by looking up how many times on this list alone, an
age factor with impaired distance traveled, can be cited.
I can see the cost thing, but I was thinking the reliable operation due
to simplicity in design.? Not the battery, but the entire support
thing. No battery I can think of other than NiFe can be abused the way
they can and survive.? One mistake or failure of a charger can
eliminate a complete battery pack while you are getting a nights sleep
with all the other high priced batteries.? One shorted cell in lead
acid can bring down many batteries in your pack. The Iron battery
company down under has smaller Ah batteries that seem a better fit for
some systems.? Don't know what importing them would cost.? I have been
looking more at hybrid than all electric anyhow so don't know how they
fit for most here.? I can bypass the controller with a knife switch to
get in with a NiFe system because I would not need to worry about abuse
and battery failure.
I have started my savings earmarked for NiFe pack.? I have found large
capacity banks just cost more to replace and as was stated, for house
use may be a good option, and that is what I am doing first. In the
future I can add to the bank without concern over battery age so it
will be a win win for me.? I am sorry to have brought up the NiFe, I
did not intend for it to turn into a debate.? My intent was to
re-introduce a battery type as I wished someone had done here earlier.
The house bank in my motor-home lasts just about 2 years (over 700
cycles), this bank needs replacement often in my book.? My brother
reports maintenance on his house battery claims it in 3 years.? For him
I recommended optima batteries because they are pure lead plates and
will be what he needs, but still at close to 200 big ones for the
optima,? NiFe may still be a good bet.
Kevin Pemberton
On 11/14/2010 01:36 PM, Myles Twete wrote:
?
>A
Peukert exponent of 1.00 means that there is no Peukerts effect at all
and that the battery will deliver the same amount of energy at any
discharge rate. I would guess that the Peukert's exponent for Nickel
Iron batteries is higher than 1.00
>Eric
No doubt.?
References online claim virtually no Peukert effect for any of the
Nickel chemistries including NiCd, NiZn, NiMH.
I’m sure he just was
parroting these.? Worse, the weblink he offered drawing folks to his
personal Peukert calculator page does not provide any support for the
1.0 Peukert exponent claim.
?
From the brief
looking I’ve done, I’d guess that the effective Peukert exponent for
NiFe is below 1.05, and once you’re down that low, unless you’re
drawing high-C loads, I don’t think you have to worry much about it.
?
I think the major
beefs against NiFe batteries are:
·????????
Cost
·????????
Relatively
high self-discharge rates
?
And those weigh
enough against them that we don’t appreciate the uber-long life of
them.? Charge/discharge inefficiency isn’t much of an issue for many of
us, but high initial cost and self-discharge rates are.
?
-Myles Twete
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
dpyakker
