Battery dies after a while

[Denverdean1]

My battery stays at 12.5v for good while when riding and then stops charging randomly leaving me stranded. The stator is good and has new wires. I am using a Rick's reg/rec for lithium-ion batteries and an Antigravity 4 cell. I thought the battery was bad so I bought a new one but it does the same thing. Once it dies I switch out the battery and the new one charges fine for a while then dies as well. I'm fairly certain my bike is charging because I don't think a small battery like that would hold 12v for 30km or more. Bike is a 1979 xs400, and has a brand new wiring harness that I made.

 

[CaptChrome]

Once you put in your own wiring harness and components, you are kind of on your own. It is sort of difficult to help without knowing exactly what you have and how it was done.

 

[Buddha]

Once you put in your own wiring harness and components, you are kind of on your own. It is sort of difficult to help without knowing exactly what you have and how it was done.

I concur with CaptChrome
May I suggest getting an automotive volt meter gauge, wiring it up to the battery and temp mounting it so that you can see whats happening real time while you're riding.

 

[Denverdean1]

The issue is the rick's reg/rec. For some reason the voltage point is set too low and won't charge past 12.5v and my battery doesn't like it after a while. It's the second one I've had, both didnt work. I put on a cheap Chinese one and it charges up to 14v.