|Topic Review (Newest First)|
|03-04-2008 09:48 AM|
Originally Posted by ArgleBargle View Post
|03-03-2008 08:25 PM|
Torqeedo makes a 77 Ah (at 24 V!) marine LiMn battery that weighs only 18 kg and can be essentially fully discharged without loss of life-cycles. It is intended for their "power" 6 hp electric outboard.
and click on technical data
is their nothing those crazy germans can't do?
|03-03-2008 11:12 AM|
The biggest LiFePO4 battery I could find with a price attached is this one from eBay:
That's a 48V, 20Ah pack that sells for $429 FOB China (plus $95 shipping).
I can't vouch for the quality though -- as Red Green says "Nothing says 'poor craftsmanship' like lumpy duct tape."
Rewired this would be 12V @ 80 Ah. Similar to a Group 24 lead acid battery. Quoted weight is 20 lbs vs. 45 for a Group 24 lead acid. So you could save 25 pounds per battery.
A cheap lead acid is maybe $75 at your local big box store.
These things have a nominal cell voltage of 3.60 V, so four cells in series will give 13.4 V, a little bit above regular lead acid. Charging voltage is 4.20 V per cell, so a 12V pack would need a charging voltage of 16.8 V. Standard alternators are regulated at about 14.1 V, so it appears they couldn't charge one of these LiFePO4 batteries.
When mass production brings the prices down and provides the charging technology, LiFePO4 will probably give lead acid a run for its money. At current prices, installing them on a boat would just be another expensive hobby.
|03-03-2008 11:00 AM|
Does that mean that the cost for a nominal 300Ah capacity with this new technology will be the same as or lower than Lead-Acid?
|03-03-2008 10:57 AM|
All I can find on this technology is a 12V pack which supplies 10ah's for around $400!!! That would make the price of a group31 battery around $4000 bucks.
The Odyssey batteries seem like the best bang for the buck currently in available technology for full time cruisers looking for quick charging and high cycle life.
|03-03-2008 10:22 AM|
|camaraderie||falconev...please point me to someplace I can buy one of these batteries in a 12V size with enough amp hours to be used on a boat (20 hour rate/100+a/h's).|
|03-03-2008 10:17 AM|
|sailingdog||Just curious, who said I was pissing on them.. Can you point to the chargers and inverters that are marine grade and made or support the LiFePO4 battery technology. If not, STFU. I'm stating the facts , and you don't seem to like it... what is your relationship to LiFePO4 batteries anyways... and why do you need to go through an e-mail anonymizer??? That's what NYMS.NET is.|
|03-03-2008 10:10 AM|
yes, and yes.
but you can't afford them anyway, so why piss on them.
|03-03-2008 08:56 AM|
|sailingdog||Yes, but what are the initial costs of the batteries. Many people aren't willing to shell out the bucks, especially on an unproven, in the marine environment, technology. Also, is the infrastructure to support the batteries available. Can you get chargers and inverters that will work with them. I don't think so.|
|03-03-2008 08:01 AM|
costs are not a factor in using LiFePO4 packs.
1/2 the weight, 5+ X's the life cycles, higher output per smaller volume, flatter discharge curve, no negative impact on environment like lead, any voltage, Ah, ....what else you need to know ?
more Q & A offline at 9zulu9 at nyms dot net
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