LiFePO4 / LFP battery experience (w/ pics)

After wrecking a not-that-good sealed lead acid battery, I decided to try something more robust (and hopefully with a longer life) to handle my lighting needs on my '99 street legal TE610. After a lot of reading, it seemed that LFP (or LiFePO4) was the best way to go. The one negative seemed to be that over-charging and over-discharging would shorten the life of the cells, which meant a protection circuit was in order as cheap insurance... which also meant worries about vibration on the protection circuit, etc. The other negative is just how they work in really cold weather, but since the bike is a kick start it shouldn't affect things much.

Here's what I ended up with: 6.8Ah LiFePO4 setup in an aluminum enclosure, and an encapsulated / potted protection circuit. It's held up nicely thus far, and weighs a lot less than the 5.6Ah SLA the bike had before.

If the cells hold up to their advertised values, they should be good for 2000+ cycles from 80-100% which is far, far, far more than SLA boasts.

Handful of pictures, including 1280x960 sizes: My TE610 Wiring and Battery Page

Thanks Nachoman. Great write up with pics and all.

KTM Hardparts have a similar set up for around $500.

Just curious how much it cost you for everything?

Someone needs to offer these. Motosportz? Uptite?

Theres a write up about the Ebatt units for the smaller 450 battery on TT right now. Very timely.

Mike,
The total setup ran about $100, pre-potting. I had potting compound left over and used that, so if you did the whole thing with shipping and potting, figure in the $120 range.

Now, this is a lot bigger than the E-Batt offering (2.3Ah by E-Batt - this is 6.8Ah) so you could definitely do smaller for a bit less money depending on your needs. Cell costs on the internet tend to be somewhat linear pricing - meaning, you don't get much more bang for the buck when you get a larger battery so it's cost effective to buy a smaller one. The 8 x 3.4Ah batteries (2 sets of 4 for a 6.8Ah 12.8V battery) fit really nicely in a foam padded aluminum box which was alluring to me. Eventually I may drop down to a 3.4Ah assembly, or smaller, but want to experiment with different lighting combinations in the future and see how the 6.8Ah model holds up for at least the first year, so the 6.8Ah was the choice.

BatterySpace has a near identical setup for $95.95. http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=4959. It looks basically ready to go, PCB and all, but could definitely stand to be potted/encapsulated to resist vibration and moisture on the protection circuitry.

I see they also have a 3.4Ah one, like I may move to in the future, for just $60. No idea how the PCB is wedged in there though so you may want to unwrap the setup, pot/encapsulate, and repackage it somehow, if you go that route.

Thanks rajobigguy!

As Motosportz mentioned, these are pretty new and thus not necessarily failproof. Though, after reading all the tests that are performed on the cells themselves - drop test, crush test with 2900lbs of weight, etc - and with the protection circuitry attached as well, I'm not too worried. The big things that shorten the life of these cells is over-charging, over-discharging, and charge rate. If you can handle the first two with a protection circuit and the last by knowing your bike's wattage outputs and sizing accordingly, you should get good life from the cells. With being rated at over 2000+ charge cycles, hopefully it's a winner for my daily commuter.