[deckofficer]

Hi all.

My first post on the forum. I'm here because Forest joined the forum that I am on, The Cruiser's Forum. We share LiFePO4 batteries in common. On the Cruiser's Forum we have a thread that has over 3400 posts on this battery technology. My background is building and racing electric vehicles and prior to that installing off grid power systems for remote home sites. I've used batteries from the simple and cheap 6 volt golf cart batteries, L16s, 2 volt 700 a-hr AGM, 2 volt 2400 a-hr Rolls, and now LiFePO4 cells.

To sum up those 3400+ posts of cruisers using these cells as house banks on their sailboats, they are 100% happy about the upgrade. To date on that forum about 40 members have made the switch. They make economic sense for full time cruisers who spend more time on the hook in an anchorage than at marinas. The same would apply to full time RVers that boondock a lot.

Their attributes though would be appreciated by folks that aren't full timers. These are of course less weight, no acid, venting or terminal corrosion. The ability to cycle down to 80% DOD and still give over 2000 cycles. Also excellent charge acceptance maximizes charging sources such as solar, gen set, and inverter charging to minimize charge time. Able to discharge at a 1C rate with very little voltage sag. And since they earn their a-hr rating differently than lead acid, I can assure you from 1st hand experience that whatever a-hr lead bank you have, if you switch to LiFePO4 you will only need 1/2 the a-hr rating. A lead acid battery is rated for a-hr on a very easy 20 hour rate, so the rating is assigned to a 400 a-hr lead acid battery if it can power a 20 amp load for 20 hours. As you all know, to get decent cycle life from lead acid (400 cycles) you should not cycle below 50% DOD. That same lead acid battery that got a 400 a-hr rating in the 20 hour test would provide less than 200 a-hr in a 1 hour test pulling a 1 C load instead of a 0.05 C load due to Peukert effect. A LiFePO4 cell gets its a-hr rating in a brutal 1 hour (1 C load) test, and this test is only run to 80% DOD, leaving 20% in the cells.

My latest LiFePO4 project was for my electric kayak. 60 lbs worth of lead AGM battery was replaced with the same weight of lithium cells and the range of the kayak in calm waters has gone from 18 miles to 80 miles. Here are the two packs I put together for the kayak. Each weighs 30lbs.