This battery (thin and flat like a cell phone battery) is not used except to help the system shut down gracefully when the truck is turned off and the 12VDC goes away.
Could you not just hook to an unswitched point in the battery circuit? Using a switching regulator if necessary.
That would be ideal if knew more about the embedded battery charging circuit, but I'm likely to let the smoke out.
Zener wrote:That is a good idea. As far as a battery, do you want one the same size? If so you should say how big it can be...
And here is the problem I'm facing with NiMH. Lack of a good reference for battery dimensions is hampering my ability to find a suitable replacement.The lithium battery is a common LI-40B, of which I've yet to find in NiMH in an equivalent or smaller package.
All good ideas, thanks for the feedback.