Re: [Electric Boats] Picking batteries - NiFe
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
|
Zebra Battery - molten sodium aluminumchloride (NaAlCl4),
On the subject of batteries, molten electrode are looking like a promising technology because of the high availability of their component elements.
They have similar numbers to Lithium based systems.. but should potentially be cheaper because of lower cost raw materials.
NaS high temp batteries seem to be the technology of choice for multi-megawatt utility storage systems that are coming online.. problem is they operate at up to 700 Celsius.
Sodium aluminumchloride (245 Celsius) are already in use in some electric vehicles in Europe (see ) .. has anyone heard anything about them in the States or perhaps got any idea about reliability or pricing.
They seem suitable for a boat with a constant charge source (wind/solar/shore power).
Thoughts or comments?
ZEBRA battery
Molten salt battery
ZEBRA Na-NiCl2 battery, Museum Autovision, Altlu?heim, Germany
specific energy 90 Wh/kg[1]
energy density 160 Wh/l[1]
specific power 155 W/kg, peak power 335 C [2]
Energy/consumer-price 3.33 Wh/US$
Self-discharge rate 18%/day [2]
Time durability >8 years
Cycle durability ~3000 cycles
Nominal cell voltage 2.58 V
The ZEBRA battery operates at 245 ¡ãC (473 ¡ãF) and utilizes molten sodium aluminumchloride (NaAlCl4), which has a melting point of 157 ¡ãC (315 ¡ãF), as the electrolyte. The negative electrode is molten sodium. The positive electrode is nickel in the discharged state and nickel chloride in the charged state. Because nickel and nickel chloride are nearly insoluble in neutral and basic melts, intimate contact is allowed, providing little resistance to charge transfer. Since both NaAlCl4 and Na are liquid at the operating temperature, a sodium-conducting β-alumina ceramic is used to separate the liquid sodium from the molten NaAlCl4. This battery was invented in 1985 by the Zeolite Battery Research Africa Project (ZEBRA) group led by Dr. Johan Coetzer at the Council for Scientific and Industrial Research (CSIR) in Pretoria, South Africa, hence the name ZEBRA battery. In 2009, the battery had been under development for more than 20 years. The technical name for the battery is Na-NiCl2 battery.
The ZEBRA battery has an attractive specific energy and power (90 Wh/kg and 150 W/kg). For comparison, LiFePO4 lithium iron phosphate batteries store 90¨C110 Wh/kg and the more common LiCoO2 lithium ion batteries store 150¨C200 Wh/kg. Nano Lithium-Titanate Batteries store energy and power of (116 Wh & 72 Wh/kg) and (1,250 W & 760 W/kg)[3].
The ZEBRA's liquid electrolyte freezes at 157 ¡ãC (315 ¡ãF), and the normal operating temperature range is 270 ¡ãC (518 ¡ãF) to 350 ¡ãC (662 ¡ãF). The β-alumina solid electrolyte that has been developed for this system is very stable, both to sodium metal and the sodium aluminumchloride. The primary elements used in the manufacture of ZEBRA batteries, Na, Cl and Al have much higher worldwide reserves and annual production than the Li used in Li-ion batteries.[4] Lifetimes of over 1500 cycles and five years have been demonstrated with full-sized batteries, and over 3000 cycles and eight years with 10- and 20-cell modules.
Vehicles powered by ZEBRA batteries have covered more than 2 million km. Modec Electric Van uses ZEBRA batteries for the 2007 model. The Th!nk City also uses ZEBRA batteries.[5]
When not in use, ZEBRA batteries are typically left under charge so that they will remain molten and be ready for use when needed. If shut down and allowed to solidify, a reheating process must be initiated that may require up to two days to restore the battery pack to the desired temperature and impart a full charge. This reheating time varies depending on the state-of-charge of the batteries at the time of their shut down, battery-pack temperature, and power available for reheating. After a full shut down of the battery pack, three to four days will usually elapse before a fully-charged battery pack loses enough energy to cool and solidify.[citation needed]
|
[Electric Boats] Re: New Electric Cat
Hi Pierre,
According to Torqeedo spec sheets, the 26-104 battery is 26V and 104Ah at 100% depth of discharge. The company claims 800 cycles to 100% DoD resulting in capacity loss of 25%.
I would typically rate a battery to only 80% DoD, if only to have some sort of emergency reserve, but that's just me.
Fair winds,
Eric
Marina del Rey, CA
toggle quoted message
Show quoted text
--- In electricboats@..., "qc_ca_666" <qc_ca_666@...> wrote:
Hi all!
If you want the latest news on Torqeedo products, here's a link to a 30 minutes podcast with Steve Trkla, the Torqeedo President.
Interesting note at 19 min 15 sec: the 26-104 battery is 104 AH usable.
Enjoy!
Pierre
|
Re: [Electric Boats] Picking batteries - NiFe
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
|
Re: [Electric Boats] Picking batteries - NiFe
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
>
|
[Electric Boats] Re: New Electric Cat
Is there supposed to be video with that? No. Audio only in MP3 format. Pierre
|
[Electric Boats] Re: New Electric Cat
Is there supposed to be video with that?
toggle quoted message
Show quoted text
--- In electricboats@..., "qc_ca_666" <qc_ca_666@...> wrote:
Hi all!
If you want the latest news on Torqeedo products, here's a link to a 30 minutes podcast with Steve Trkla, the Torqeedo President.
Interesting note at 19 min 15 sec: the 26-104 battery is 104 AH usable.
Enjoy!
Pierre
|
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 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
>
|
Re: [Electric Boats] Picking batteries - NiFe
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!
|
[Electric Boats] Re: New Electric Cat
--- In electricboats@..., "Don Parsons" <tdparsons@...> wrote:
That link was so good I added it to my Favorites list.
They look damn seaworthy too!
Thanks Michael.
--- In electricboats@..., "Mike Allison" <mysloop@> wrote:
Higher than I was thinking too.
Guess I'll keep looking at and mabe build one myself.
Me too. The only thing I'd change would be the glue he uses to epoxy. Plus, by building it you could put any type of motors in you like and you could have a deck pod. Blue Planet Catamarans makes you set out in the open and that could be a real pain if the weather gets bad on a trip. Just my take on it though. If all you want is to use it from time to time in only good weather and have 150k, guess it would be great. Michael Allison <myloop@...> Michael Allison
|
Re: [Electric Boats] Picking batteries - NiFe
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 >
|
[Electric Boats] Re: New Electric Cat
Hi all!
If you want the latest news on Torqeedo products, here's a link to a 30 minutes podcast with Steve Trkla, the Torqeedo President.
Interesting note at 19 min 15 sec: the 26-104 battery is 104 AH usable.
Enjoy!
Pierre
|
Re: [Electric Boats] Picking batteries - NiFe
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
|
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 <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
|
[Electric Boats] Re: New Electric Cat
That link was so good I added it to my Favorites list.
They look damn seaworthy too!
Thanks Michael.
toggle quoted message
Show quoted text
--- In electricboats@..., "Mike Allison" <mysloop@...> wrote:
Higher than I was thinking too.
Guess I'll keep looking at and mabe build one myself.
Michael Allison
|
[Electric Boats] Re: New Electric Cat
Hi Mike,
I have come across used Gemini's from $25,000 to $75,000. That would leave $75,000 to $125,000 to by E-pod, refurb boat and pay cruising expenses for a long while instead of the Blue Planet 32.
I dont want to put it down. I would love a bunch of used ones to flood the market in 5 to ten years. I might be able to swing that.
Here is a link to a Gemini owner who dumped the diesel for the
E-pod.
Don
toggle quoted message
Show quoted text
--- In electricboats@..., "Mike Allison" <mysloop@...> wrote:
Higher than I was thinking too.
Guess I'll keep looking at and mabe build one myself.
Michael Allison
|
Quote: Has anyone had experience with the Torqeedo motors getting dunked?
I have a customer who uses an 801 Travel to move his daysailer in calms. He has had it fail twice due to saltwater-related issues.
He now keeps a plastic bag over the tiller.
He also bought a 2 Hp Honda to keep operational when the Torqueedo is in the shop.
His is an early model, I understand. Might not be a problem anymore.
-Tom
|
[Electric Boats] Re: New Electric Cat
Higher than I was thinking too.
Guess I'll keep looking at ?and
mabe build one myself.
?
Michael Allison
|
Re: [Electric Boats] Picking batteries - NiFe
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!
|
[Electric Boats] Re: New Electric Cat
Hi Eric, Sally and all,
I got an E-mail from Gene at Planet Blue Catamarans but still sparse on specs.
They are targeting $149k for basic version with many options for electronics, additional batteries, generators, solar/wind power, kites, amd custom interiors.
Hulls 4' wide, bridge deck just under 8' and demountable.
Gene says interior woodwork is nearly done and looks magnificent... semi-gloss teak, etc. Test drives can be scheduled off his dock in Beaufort, North Carolina in December.
It is more pricey than I hoped.
Don
toggle quoted message
Show quoted text
--- In electricboats@..., "Eric" <ewdysar@...> wrote:
Hi Sally,
It's good to hear that a major supplier has broken the $1.00/Wh barrier for the latest generation of mainstream high-tech batteries.
I am curious about the voltage that they use to rate their batteries. My Thundersky cells are rated as 3.2V and they do have a resting voltage of 3.31V three months since their last charge. But in use, the voltage usually closer to 3.1V at any regular loads. With 16 cells, I could rate my battery pack as it's resting voltage of 53V, but I use 50V to be conservative. That choice means that I rate my capacity at 8kWh instead of 8.5kWh @ 53V/pack or 8.2kWh @ 3.2V/cell. So I wonder what the specifics are around their 25.9V rating. I know that it is just a nit-pick kind of thing, but since they got so specific...
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@..., Sally Reuther <smreuther@> wrote:
We spoke with Torqeedo at IBEX and went to their "unveiling" of the new
Power 26-104. The specs are:
2.7 kWh (25.9 v, 104 Ah)
44 lbs
Dimensions are: 8.0" x 21.3" x 9.4"
Price: $2,499.00
Pretty nice - if you can afford the price.
|
dpyakker