How much weight will a firewall j16 battery save from stock position behind passenger seat in a pa-12 as far as cable weight? Thinking to do a relocate when we put a lightweight starter on next week.

Put 31’s on and a j16 in the back to save some weight but weight crept up to 1202lbs. I usually fly with a passenger and a survival bag stuffed in the far rear of the ext baggage so CG isn’t too bad.

I don't know much about the weight you'd be saving based on cable, I'd think a couple of pounds. I have my j16 battery located on the floor, bolted down into a metal box, in the front seat between the legs. Works out well for me there, but I'd prefer the firewall though, allows the battery to get warm during a preheat in the winter. I typically use a heater in the cockpit for about an hour or two prior to flying in the winter.

First thing I’d do is verify you have space in a good location for a firewall mount.

You’ll likely save five or six pounds or maybe a bit more. But the bigger benefit of shortening cables is a lot better cranking power, from less cable loss.

Another benefit is keeping battery warm with engine, but Odysseys tend to tolerate cold pretty well.

Check with your mechanic on approvals. Probably need to field approve. Also consult with your mechanic about which battery bracket to buy…..Atlee’s is an “approved part”…others may not. That may or may not be an issue.

Good luck.

MTV