On Monday, April 29, 2013 8:08:01 AM UTC-4, Papa3 wrote:
Most of the folks (myself included) who have switched to the LIFEPo4 seem to be using the K2 Energy 12V/10ah with included BMS based on what I see at the charging station at contests. Today, a club member showed me a competing product from StarkPower which is a 12V/12ah including BMS that's about $50 cheaper. I haven't been able to find the technical documentation on either company's Website to do a detailed comparison of their performance specs (especially the discharge curve), but let's assume they are similar. 20% more capacity for 25% less cost seems attractive. Does anyone have any experience with the StarkPower product?

If you have problems, it won't be with the discharge curve.

Of primary importance:
* quality of internal construction
* cells that can pass puncture / crush & short circuit tests without fire, explosion
* BMS with over charge, undercharge, current limit & cell balancing (not all do cell balancing)

Please shop carefully. There are a bunch of cottage industry companies assembling Chinese manufactured LFP tubular batteries (3.3 V / 3300 mAH are typical) into 12V and 24V battery packs with various electronics to manage them.

I looked at Stark Power. IIRC, the BMS that was offered at the time (these products are evolving rapidly) did not do cell balancing.

I bought a 12V / 12 AH LFP battery from another source that (on paper... I can't open it up to look....) met all my requirements. I did a charge / full discharge test using an instrumented battery charger and it maintained 12V under load through 12.1 AH of discharge at room temperature.

In the glider, it works great. Time will tell.

Evan Ludeman / T8