battery ignition power supply

[fresnoxl]

Iv'e ordered a 45 hp 1/2 VW from Cassler with  battery ignition. Any suggestions on what type, size, amp hour for the battery, etc..?

[Kamcoman77]

I made my own LiFePO4 battery from 8, 32700 cells. It is somewhere between 12 Ah & 14 Ah capacity. Working voltage is 13.2. It cost me about $50 and I charge it with my RC aircraft charger using the balance wires. This keeps all cells equal without a battery management system. I plan to put a 50-watt solar panel on the wing to keep the battery charged through a little solar charge controller. Your run time will depend on your amperage draw. My electronic ignitions draw about 2-amps so I will have at least 4-hours of run time, even if the charger is not activated. LiFePO4 is currently the safest, high capacity, lightweight battery cell technology. Several LE builders use this technology. Amazon has several 20Ah 12V LiFePO4 batteries that sell for under $75. One caution... they all have a BMS (battery management system). This means if your voltage ever hits the low-voltage limit, the battery shuts off completely!

[fresnoxl]

Thanks for the ideas. I'm also thinking about the electronic ignition option. Luckily I have about 4 months to go before the engine is done.   

[GTS225]

Kamco....that's a heck of an idea.  Is that a flexible panel?
Seems a guy could mount a rigid panel on the top of the tail cone, and maybe even get enough juice to REALLY extend run times.  (Obviously, one would have to be weight-cautious.)

Roger

[Kamcoman77]

This is a flexible panel. I bought it and the charge controller from Aliexpress. My run time will be limited by my 5 gallons of fuel, not my battery life.