Twin 914'2 w dual batteries

I would not hesitate to use a lithium battery. The brand EarthX is endorsed by Rotax. There are certainly many thousands and probably millions of these batteries in service in snow machines, ATVs, motorcycles etc. Everybody that I personally know with an experimental aircraft is now using a LiFePO battery.

Here's a link to a good article in KitPlanes, although it seems like the main sources of info were the EarthX folks, themselves:

https://www.kitplanes.com/understanding-lithium-batteries/

"Builders must be able to read the documentation and understand the limitations of a battery with an onboard battery management system (BMS). For example, consider overvoltage protection. Some E/A-B airplanes use an automotive style internally regulated alternator. It is possible for those regulators to fail in such a way that drives the field current up, which causes the alternator to deliver its maximum output. Builders have known about this for years, and most have incorporated some means of absolute field control, along with crowbar overvoltage protection."

Bottom line is, battery-management systems for these things are essential.

You might want to check with Lockwood to see what their current thinking is with regard to the AirCam electrical system and its batteries.

All,

Thank you for the replies and suggestions.  

Tim