|
Kevin,
Based on your criteria, the NiFe batteries do seem like a reasonable alternative. But I have always been concerned with weight in any mobile installation. I do agree that they seem excellent alternatives for home and business installations.
I don't know how heavy your current RV battery bank is, but do you really want to increase that weight by 100 to 150 percent for the same rated capacity? Battery volume will also be a concern, do you have space for battery bank that is twice the physical size?
Many of the converted boats here have battery banks that are around 10kWh and weigh about 500 pounds. At 1000 pounds or more, NiFe will start having a bigger negative effect on performance, not only in electric range, but sailing performance too (if applicable). For me, the cost, lifecycles and fault tolerance are lesser concerns than size and weight. Most car and boat manufacturers that are venturing into this market seem to agree.
That said, if your conversion is spec'ed for these batteries, then more power to you (no pun intended). I'm looking forward to your actual observed performance data when you finish your boat.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., Kevin Pemberton <pembertonkevin@...> wrote:
...I can see the cost thing, but I was thinking the reliable operation due
to simplicity in design....
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
|
Eric,
According to this page batteries supplied by Ironcorebatteries
100Ah weigh almost 100lbs
for 12v pack. T 105 6v about 67lbs.? No problem discharging NiFe to
80%, big problem discharging the T 105 to 80% over the long haul.? Was
two optima blue tops. 120 lbs for 100Ah when large discharges are not
figured in.? Where is weight a problem?
mount in wood mount because fumes are non corrosive, can be mounted
anyplace if vented outside. Size becomes no problem.
And yes I see the weight problem with anything other than batteries
easily distroyed by over charge or over discharge.
Kevin Pemberton
On 11/15/2010 01:31 PM, Eric wrote:
?
Kevin,
Based on your criteria, the NiFe batteries do seem like a reasonable
alternative. But I have always been concerned with weight in any mobile
installation. I do agree that they seem excellent alternatives for home
and business installations.
I don't know how heavy your current RV battery bank is, but do you
really want to increase that weight by 100 to 150 percent for the same
rated capacity? Battery volume will also be a concern, do you have
space for battery bank that is twice the physical size?
Many of the converted boats here have battery banks that are around
10kWh and weigh about 500 pounds. At 1000 pounds or more, NiFe will
start having a bigger negative effect on performance, not only in
electric range, but sailing performance too (if applicable). For me,
the cost, lifecycles and fault tolerance are lesser concerns than size
and weight. Most car and boat manufacturers that are venturing into
this market seem to agree.
That said, if your conversion is spec'ed for these batteries, then more
power to you (no pun intended). I'm looking forward to your actual
observed performance data when you finish your boat.
Fair winds,
Eric
Marina del Rey, CA
.
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
I was interested enough in this to do some research on NiFe.? I
decided to compare them to the T-105 6v.
To get 450Ah with T-106 you need 4 of them. Total cost?? $600, total
weight 248lbs, total volume 1.86 CubicFeet, life span 4years avg
To get 450Ah with NiFe you need 10 of them.? Total cost $3160, total
weight 485lbs, total volume 6.07 CubicFeet, life span 100+ years
So at this Amp Hour level, NiFe is 2 times the weight, 3 times the
volume and 5 times the cost.
For taking a house off the grid, its a NO BRAINER. NiFe all the way!
For a boat, a bit of a hard sell but maybe.
Now if you were building a new boat and could incorporate the weight
and placement of the NiFe batteries into the ballast somehow, now
that would be a major plus.? If they never need to be replaced, as
claimed, seems completely doable to me.....
That thought process with a diesel-electric system to charge and use
for propulsion seems like a win-win if you can afford it.
William
toggle quoted message
Show quoted text
?
Eric,
According to this page batteries supplied by
Ironcorebatteries
100Ah weigh almost 100lbs
for 12v pack. T 105 6v about 67lbs.? No problem
discharging NiFe to
80%, big problem discharging the T 105 to 80% over the
long haul.? Was
two optima blue tops. 120 lbs for 100Ah when large
discharges are not
figured in.? Where is weight a problem?
mount in wood mount because fumes are non corrosive, can
be mounted
anyplace if vented outside. Size becomes no problem.
And yes I see the weight problem with anything other than
batteries
easily distroyed by over charge or over discharge.
Kevin Pemberton
On 11/15/2010 01:31 PM, Eric wrote:
?
Kevin,
Based on your criteria, the NiFe batteries do seem
like a reasonable
alternative. But I have always been concerned with
weight in any mobile
installation. I do agree that they seem excellent
alternatives for home
and business installations.
I don't know how heavy your current RV battery bank
is, but do you
really want to increase that weight by 100 to 150
percent for the same
rated capacity? Battery volume will also be a concern,
do you have
space for battery bank that is twice the physical
size?
Many of the converted boats here have battery banks
that are around
10kWh and weigh about 500 pounds. At 1000 pounds or
more, NiFe will
start having a bigger negative effect on performance,
not only in
electric range, but sailing performance too (if
applicable). For me,
the cost, lifecycles and fault tolerance are lesser
concerns than size
and weight. Most car and boat manufacturers that are
venturing into
this market seem to agree.
That said, if your conversion is spec'ed for these
batteries, then more
power to you (no pun intended). I'm looking forward to
your actual
observed performance data when you finish your boat.
Fair winds,
Eric
Marina del Rey, CA
.
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
Kevin,
I did the math with the data on the link that you provided. One 100Ah 1.2V cell weighs 4.9Kg (dry weight?), so 10 dry cells would weigh 49Kg which is 107.8 pounds. That battery would be rated for 1200Wh which is 11.1 Wh/lb. But the page says that you need to add distilled water to make them work, and of course the link doesn't say how much. If a 100Ah cell takes only 2 cups of water, then one cell is close to 12 pounds and we're back to 10Wh/lb. Looking at the 200Ah cells, they are 26.4 pounds dry or 264 pounds for a dry 200Ah 12V (2400kWh) battery. Add water and you're probably past 280 pounds or 8.5Wh/lb.
Alternatively, a T-105 weighs 62 pounds (according to Trojan) and is rated for 225Ah @ 6V or 1350Wh. That works out to 21.8 Wh/lb. Take two in series and you've got a 225Ah 12V battery that weighs 124 pounds.
Are you really sure that size doesn't matter? Lets compare the 200Ah 12V NiFe to the 225Ah 12V T-105s
2400Wh NiFe = 13.2" x 32" x 13.6" = 5745 cu. inches, 280 pounds
2700Wh T-105 = 10.4" x 14.3" x 10.7" = 1591 cu. inches, 124 pounds
The NiFe battery is more than 3 times the volume of the two T-105s for 10% less rated capacity.
I'm not passing any judgement, just doing the math so that people can decide for themselves.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., Kevin Pemberton <pembertonkevin@...> wrote:
Eric,
According to this page batteries supplied by Ironcorebatteries
100Ah weigh almost 100lbs
for 12v pack. T 105 6v about 67lbs. No problem discharging NiFe to 80%,
big problem discharging the T 105 to 80% over the long haul. Was two
optima blue tops. 120 lbs for 100Ah when large discharges are not
figured in. Where is weight a problem?
mount in wood mount because fumes are non corrosive, can be mounted
anyplace if vented outside. Size becomes no problem.
And yes I see the weight problem with anything other than batteries
easily distroyed by over charge or over discharge.
Kevin Pemberton
|
A t-105 may have 1350 watt hours, but it's not all available. only about 50% is useable if you are trying to get maximum life. The NiFe has over 80% of it's theoretical wh capacity available without degradation.
Steve Spence
toggle quoted message
Show quoted text
On 11/16/2010 03:47 AM, Eric wrote:
Kevin,
I did the math with the data on the link that you provided. One 100Ah
1.2V cell weighs 4.9Kg (dry weight?), so 10 dry cells would weigh 49Kg
which is 107.8 pounds. That battery would be rated for 1200Wh which is
11.1 Wh/lb. But the page says that you need to add distilled water to
make them work, and of course the link doesn't say how much. If a 100Ah
cell takes only 2 cups of water, then one cell is close to 12 pounds and
we're back to 10Wh/lb. Looking at the 200Ah cells, they are 26.4 pounds
dry or 264 pounds for a dry 200Ah 12V (2400kWh) battery. Add water and
you're probably past 280 pounds or 8.5Wh/lb.
Alternatively, a T-105 weighs 62 pounds (according to Trojan) and is
rated for 225Ah @ 6V or 1350Wh. That works out to 21.8 Wh/lb. Take two
in series and you've got a 225Ah 12V battery that weighs 124 pounds.
Are you really sure that size doesn't matter? Lets compare the 200Ah 12V
NiFe to the 225Ah 12V T-105s
2400Wh NiFe = 13.2" x 32" x 13.6" = 5745 cu. inches, 280 pounds
2700Wh T-105 = 10.4" x 14.3" x 10.7" = 1591 cu. inches, 124 pounds
The NiFe battery is more than 3 times the volume of the two T-105s for
10% less rated capacity.
I'm not passing any judgement, just doing the math so that people can
decide for themselves.
Fair winds,
Eric
Marina del Rey, CA
|
All this?"Math" forgets using 50% of charge on T105s and using 80 to 100% on Nife.
?
Lets complete the math. ?
To: electricboats@... From: ewdysar@... Date: Tue, 16 Nov 2010 08:47:47 +0000 Subject: Re: [Electric Boats] Picking batteries - NiFe
?
Kevin,
I did the math with the data on the link that you provided. One 100Ah 1.2V cell weighs 4.9Kg (dry weight?), so 10 dry cells would weigh 49Kg which is 107.8 pounds. That battery would be rated for 1200Wh which is 11.1 Wh/lb. But the page says that you need to add distilled water to make them work, and of course the link doesn't say how much. If a 100Ah cell takes only 2 cups of water, then one cell is close to 12 pounds and we're back to 10Wh/lb. Looking at the 200Ah cells, they are 26.4 pounds dry or 264 pounds for a dry 200Ah 12V (2400kWh) battery. Add water and you're probably past 280 pounds or 8.5Wh/lb.
Alternatively, a T-105 weighs 62 pounds (according to Trojan) and is rated for 225Ah @ 6V or 1350Wh. That works out to 21.8 Wh/lb. Take two in series and you've got a 225Ah 12V battery that weighs 124 pounds.
Are you really sure that size doesn't matter? Lets compare the 200Ah 12V NiFe to the 225Ah 12V T-105s
2400Wh NiFe = 13.2" x 32" x 13.6" = 5745 cu. inches, 280 pounds
2700Wh T-105 = 10.4" x 14.3" x 10.7" = 1591 cu. inches, 124 pounds
The NiFe battery is more than 3 times the volume of the two T-105s for 10% less rated capacity.
I'm not passing any judgement, just doing the math so that people can decide for themselves.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., Kevin Pemberton wrote: > > Eric, > > According to this page batteries supplied by Ironcorebatteries > 100Ah weigh almost 100lbs > for 12v pack. T 105 6v about 67lbs. No problem discharging NiFe to 80%, > big problem discharging the T 105 to 80% over the long haul. Was two > optima blue tops. 120 lbs for 100Ah when large discharges are not > figured in. Where is weight a problem? > > mount in wood mount because fumes are non corrosive, can be mounted > anyplace if vented outside. Size becomes no problem. > > And yes I see the weight problem with anything other than batteries > easily distroyed by over charge or over discharge. > > Kevin Pemberton >
|
Hey Eric,
Thanks for doing the math.? I already did it. I also consider the fact
that 50% of the T105 is dead weight, also for my application, as anyone
with a MH knows you can't fill all the storage space without going over
weight.? I regularly weigh my RV on the scales and have the weight
capacity for 100Ah of NiFe. The heat battery will take more space than
the NiFe battery.
The cost of going NiFe has already been spent on Lead in the past, and
I am close to the cross roads that determine my next course of action.?
I personally know the folly of lead acid investment.
Cruising on the boat that was dry, with serious weather the bilge pump
had to run more often.? Electronics failed under these conditions.? I
wonder about lithium batteries on a cruising boat, but that is only my
opinion, (Well, OK, backed up by an engineer friend that designs
lithium backup supplies for consumer electronics). Now it is easy for
the week ender to avoid times when waves are crashing over the decks,
but 15 or more days on the pond can't be predicted. We are lucky when
the weather predictions are good for 5 days let alone 15 or more, if
you could find such a prediction.
As I have stated with my specs there are more things to consider than
weight and space. I understand the need to stay light with multi hulls,
and a multi hull can make a passage much shorter than with a mono.?
Maybe enough to stay within the weather prediction window, but cruisers
typically find weight less important than convenience over time.? The
water line keeps raising with every year they spend on their boats.?
Soon the multi hull dream of go fast, gives way to a better life, at
close to mono hull speeds.
This may be the reason experience gives way to desiring a mono hull
rather than a multi.? The desire for space gives way to trollers rather
than multi hulls.? All that said if I were to build or buy a gunk holer
it would likely be a multi.? If I were to build or buy a seasonal boat
it may likely be a multi hull.? If I were to go back to cruising, it
would likely be a mono with hybrid power.? It would be without sail but
not a troller.? If it were a power boat however, here is no way it
would be any other kind of of boat but a troller.? Mono hull Sail boat
modified to be a power vessel would likely be my pick.
Kevin Pemberton
On 11/16/2010 01:47 AM, Eric wrote:
?
Kevin,
I did the math with the data on the link that you provided. One 100Ah
1.2V cell weighs 4.9Kg (dry weight?), so 10 dry cells would weigh 49Kg
which is 107.8 pounds. That battery would be rated for 1200Wh which is
11.1 Wh/lb. But the page says that you need to add distilled water to
make them work, and of course the link doesn't say how much. If a 100Ah
cell takes only 2 cups of water, then one cell is close to 12 pounds
and we're back to 10Wh/lb. Looking at the 200Ah cells, they are 26.4
pounds dry or 264 pounds for a dry 200Ah 12V (2400kWh) battery. Add
water and you're probably past 280 pounds or 8.5Wh/lb.
Alternatively, a T-105 weighs 62 pounds (according to Trojan) and is
rated for 225Ah @ 6V or 1350Wh. That works out to 21.8 Wh/lb. Take two
in series and you've got a 225Ah 12V battery that weighs 124 pounds.
Are you really sure that size doesn't matter? Lets compare the 200Ah
12V NiFe to the 225Ah 12V T-105s
2400Wh NiFe = 13.2" x 32" x 13.6" = 5745 cu. inches, 280 pounds
2700Wh T-105 = 10.4" x 14.3" x 10.7" = 1591 cu. inches, 124 pounds
The NiFe battery is more than 3 times the volume of the two T-105s for
10% less rated capacity.
I'm not passing any judgement, just doing the math so that people can
decide for themselves.
Fair winds,
Eric
Marina del Rey, CA
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
On 17/11/10 01:21, john briese wrote:
All this"Math" forgets using 50% of charge on T105s and using 80
to 100% on Nife.
Lets complete the math.
Some where in the pile of doco I have about my T145s Trojan say
they rated them for 80% DOD. Yes they recomend 50% for optimum life,
but the cycle rating given is for 80% usage.
My T145s will die of old age before they die of excessive cycles
even if I took them to 80% every use, which I don't. I think the
most I've even taken them to is 60%. My usage is relatively low
though. My boat spends more time sitting on a trailer than any thing
else.
To: electricboats@...
From: ewdysar@...
Date: Tue, 16 Nov 2010 08:47:47 +0000
Subject: Re: [Electric Boats] Picking batteries - NiFe
Kevin,
I did the math with the data on the link that you provided.
One 100Ah 1.2V cell weighs 4.9Kg (dry weight?), so 10 dry
cells would weigh 49Kg which is 107.8 pounds. That battery
would be rated for 1200Wh which is 11.1 Wh/lb. But the page
says that you need to add distilled water to make them work,
and of course the link doesn't say how much. If a 100Ah cell
takes only 2 cups of water, then one cell is close to 12
pounds and we're back to 10Wh/lb. Looking at the 200Ah
cells, they are 26.4 pounds dry or 264 pounds for a dry
200Ah 12V (2400kWh) battery. Add water and you're probably
past 280 pounds or 8.5Wh/lb.
Alternatively, a T-105 weighs 62 pounds (according to
Trojan) and is rated for 225Ah @ 6V or 1350Wh. That works
out to 21.8 Wh/lb. Take two in series and you've got a 225Ah
12V battery that weighs 124 pounds.
Are you really sure that size doesn't matter? Lets compare
the 200Ah 12V NiFe to the 225Ah 12V T-105s
2400Wh NiFe = 13.2" x 32" x 13.6" = 5745 cu. inches, 280
pounds
2700Wh T-105 = 10.4" x 14.3" x 10.7" = 1591 cu. inches, 124
pounds
The NiFe battery is more than 3 times the volume of the two
T-105s for 10% less rated capacity.
I'm not passing any judgement, just doing the math so that
people can decide for themselves.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@...,
Kevin Pemberton wrote:
>
> Eric,
>
> According to this page batteries supplied by
Ironcorebatteries
>
100Ah weigh almost 100lbs
> for 12v pack. T 105 6v about 67lbs. No problem
discharging NiFe to 80%,
> big problem discharging the T 105 to 80% over the long
haul. Was two
> optima blue tops. 120 lbs for 100Ah when large
discharges a re not
> figured in. Where is weight a problem?
>
> mount in wood mount because fumes are non corrosive,
can be mounted
> anyplace if vented outside. Size becomes no problem.
>
> And yes I see the weight problem with anything other
than batteries
> easily distroyed by over charge or over discharge.
>
> Kevin Pemberton
>
|
I tend to agree with Miles and Matthew on using some type of lead acid batteries. AGM's make the most sense for my needs. But, I do find the discussions here very informative no matter what the type. Since I am also working on some energy projects at my house too. As I said AGM's are my choice. But, I wonder about flooded and nickel iron battery use on a monohull sailboat. While under sail such a boat may be healed over under sail for a long time. I wonder if there is a danger the plates might be exposed to air (and sulfated) if they are not kept topped up completely when sailing. Just curious. Sent from on board BIANKA
http://biankablog.blogspot.com
From: Matthew Geier <matthew@...>
Sender: electricboats@...
Date: Wed, 17 Nov 2010 06:04:24 +1100 To: <electricboats@...> ReplyTo: electricboats@... Subject: Re: [Electric Boats] Picking batteries - NiFe
?
On 17/11/10 01:21, john briese wrote:
All this?"Math" forgets using 50% of charge on T105s and using 80
to 100% on Nife.
?
Lets complete the math.
?Some where in the pile of doco I have about my T145s Trojan say
they rated them for 80% DOD. Yes they recomend 50% for optimum life,
but the cycle rating given is for 80% usage.
?My T145s will die of old age before they die of excessive cycles
even if I took them to 80% every use, which I don't. I think the
most I've even taken them to is 60%. My usage is relatively low
though. My boat spends more time sitting on a trailer than any thing
else.
?
?
To: electricboats@...
From: ewdysar@...
Date: Tue, 16 Nov 2010 08:47:47 +0000
Subject: Re: [Electric Boats] Picking batteries - NiFe
?
Kevin,
I did the math with the data on the link that you provided.
One 100Ah 1.2V cell weighs 4.9Kg (dry weight?), so 10 dry
cells would weigh 49Kg which is 107.8 pounds. That battery
would be rated for 1200Wh which is 11.1 Wh/lb. But the page
says that you need to add distilled water to make them work,
and of course the link doesn't say how much. If a 100Ah cell
takes only 2 cups of water, then one cell is close to 12
pounds and we're back to 10Wh/lb. Looking at the 200Ah
cells, they are 26.4 pounds dry or 264 pounds for a dry
200Ah 12V (2400kWh) battery. Add water and you're probably
past 280 pounds or 8.5Wh/lb.
Alternatively, a T-105 weighs 62 pounds (according to
Trojan) and is rated for 225Ah @ 6V or 1350Wh. That works
out to 21.8 Wh/lb. Take two in series and you've got a 225Ah
12V battery that weighs 124 pounds.
Are you really sure that size doesn't matter? Lets compare
the 200Ah 12V NiFe to the 225Ah 12V T-105s
2400Wh NiFe = 13.2" x 32" x 13.6" = 5745 cu. inches, 280
pounds
2700Wh T-105 = 10.4" x 14.3" x 10.7" = 1591 cu. inches, 124
pounds
The NiFe battery is more than 3 times the volume of the two
T-105s for 10% less rated capacity.
I'm not passing any judgement, just doing the math so that
people can decide for themselves.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@...,
Kevin Pemberton <pembertonkevin@...> wrote:
>
> Eric,
>
> According to this page batteries supplied by
Ironcorebatteries
>
100Ah weigh almost 100lbs
> for 12v pack. T 105 6v about 67lbs. No problem
discharging NiFe to 80%,
> big problem discharging the T 105 to 80% over the long
haul. Was two
> optima blue tops. 120 lbs for 100Ah when large
discharges a re not
> figured in. Where is weight a problem?
>
> mount in wood mount because fumes are non corrosive,
can be mounted
> anyplace if vented outside. Size becomes no problem.
>
> And yes I see the weight problem with anything other
than batteries
> easily distroyed by over charge or over discharge.
>
> Kevin Pemberton
>
|
John,
Let's do that. We'll even double the number of T-105s to get the weight closer to the 200Ah 12V NiFe array.
2400Wh NiFe = 13.2" x 32" x 13.6" = $1760 FOB
5745 cu. inches, 280 pounds, 1920Wh usable @ 80% DoD
5400Wh T-105 = 10.4" x 28.6" x 10.7" = $600 delivered
3182 cu. inches, 248 pounds, 2700Wh usable @ 50% DoD
The four T-105s have 40% more usable capacity, are 44% smaller, are 11% lighter and and are 1/3 the cost of the 200Ah 12V NiFe bank. Even running the NiFe batteies to 100% DoD gives less capacity than the T-105s at 50% DoD. Using a 50% DoD on the FLA batteries also gives you a bigger reserve in case of an emergency.
But as I've said before, everyone needs to figure out what is most important for themselves, every choice comes with tradeoffs. The cool part is that we each get to build our boats any way we like. I'm looking forward to hearing how the first NiFe boat in this group turns out.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., john briese <goodguyforsure@...> wrote:
All this "Math" forgets using 50% of charge on T105s and using 80 to 100% on Nife.
Lets complete the math.
To: electricboats@...
From: ewdysar@...
Date: Tue, 16 Nov 2010 08:47:47 +0000
Subject: Re: [Electric Boats] Picking batteries - NiFe
Kevin,
I did the math with the data on the link that you provided.... Looking at the 200Ah cells, they are 26.4 pounds dry or 264 pounds for a dry 200Ah 12V (2400kWh) battery. Add water and you're probably past 280 pounds or 8.5Wh/lb.
Alternatively, a T-105 weighs 62 pounds (according to Trojan) and is rated for 225Ah @ 6V or 1350Wh. That works out to 21.8 Wh/lb. Take two in series and you've got a 225Ah 12V battery that weighs 124 pounds.
Are you really sure that size doesn't matter? Lets compare the 200Ah 12V NiFe to the 225Ah 12V T-105s
2400Wh NiFe = 13.2" x 32" x 13.6" = 5745 cu. inches, 280 pounds
2700Wh T-105 = 10.4" x 14.3" x 10.7" = 1591 cu. inches, 124 pounds
The NiFe battery is more than 3 times the volume of the two T-105s for 10% less rated capacity.
I'm not passing any judgement, just doing the math so that people can decide for themselves.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@..., Kevin Pemberton <pembertonkevin@> wrote:
Eric,
According to this page batteries supplied by Ironcorebatteries
100Ah weigh almost 100lbs
for 12v pack...
Kevin Pemberton
|
Hi Kevin,
I'm with you about multihulls, weight is a killer. I didn't convert my F-27 trimaran to electric for exactly that reason. While not exactly a passage maikng cruiser, my trips have been limited to no more than 3 days of blue water racing at a time. With a new 9.8 Tohatsu outboard with 40nm of fuel that all together weighs less than two group 27 batteries, I've been able to keep my performance up. A month ago, I was racing back from Catalina after staying aboard for a long weekend with three people onboard and we were sailing at 12+kts in 15kts true wind. Add another 300 pounds and the boat only hits 8kts in the same conditions (I know this from day sails with 2 more guests).
For my Bermuda 30 Ketch electric conversion, space has been my biggest challenge. An old sailboat design (H28 knockoff with narrow beam and wineglass hull), there was little enough locker space available before I started, I'm trying to get the entire drive including batteries to fit within the same space as the old engine and fuel tank, while retaining some level of accessability. The 8kWh of LiFePO4 batteries that I purchased are making that goal possible. And yes, the battery bank is equiped with BMS modules that will prevent any over or under-voltage condition. My friends with 48 cell LiFeO4 banks (24kWh) in their electric cars haven't lost a cell yet in over 500 cycles using the same components. I know that I am taking a risk in a marine environment, but I won't be tackling any 2 week passages in this boat anyway.
We'll have to compare notes of how our boats perform after both of our conversions are complete.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., Kevin Pemberton <pembertonkevin@...> wrote:
Hey Eric,
Thanks for doing the math. I already did it....
As I have stated with my specs there are more things to consider than
weight and space. I understand the need to stay light with multi hulls,
and a multi hull can make a passage much shorter than with a mono.
Maybe enough to stay within the weather prediction window, but cruisers
typically find weight less important than convenience over time. The
water line keeps raising with every year they spend on their boats.
Soon the multi hull dream of go fast, gives way to a better life, at
close to mono hull speeds....
Kevin Pemberton
|
Nickel Iron does not sulfate, The fill lines are above the plates and
the orientation can eliminate any possable exposure to the air.
Kevin Pemberton
On 11/16/2010 03:52 PM, Capt. Mike wrote:
I tend to agree with Miles and Matthew on using some type of lead
acid batteries. AGM's make the most sense for my needs. But, I do find
the discussions here very informative no matter what the type. Since I
am also working on some energy projects at my house too. As I said
AGM's are my choice. But, I wonder about flooded and nickel iron
battery use on a monohull sailboat. While under sail such a boat may be
healed over under sail for a long time. I wonder if there is a danger
the plates might be exposed to air (and sulfated) if they are not kept
topped up completely when sailing. Just curious.
Sent from on board BIANKA
--
Ubuntu10.04, Acer AspireOne, Virgin Mobile 3G Broadband2go.
Doesn't get any better than this!
|
