I use the Aerovotz lithium-iron battery on my Kitfox 912uls and so do many other Kitfox owners. It cranks very well down to 30F so far. It has many advantages:
- Very light weight. Saves about 10 lbs over conventional gel cells.
- Holds a charge almost forever. I don't use any kind of trickle charger (battery minder) and it still has full charge weeks later.
- Small size, easy to mount.
- the lithium-iron technology is MUCH safer than lithium-ion (LIPO) and does not have the tendency to burst into flame if overcharged or impacted.
A few disadvantages:
- Somewhat more expensive, but not too bad.
- Cranking power is just fine, but it does not seem to have the "staying power" that a conventional battery has. If you are having a hard time starting the engine and doing a lot of cranking, it seems to lose power faster than others.
- You must use a balancing type of battery charger once in a while, say every 6 months, to keep the cells balanced. Aerovoltz sells this type of charger for about $70, and they are available from others.
To me the weight saving is worth the few disadvantages. The "staying power" issue can be solved by just going to the next size larger which still saves a ton of weight and physical size.
