I had an unusual indication of a bad battery some years ago in my fiver. It contained two 12 volt batteries connected in parallel (typical wet cell types).
For some unknown reason the propane leak detector kept going off for no apparent reason. Upon checking both coach batteries I discovered one was essentially dead. Replacing that battery stopped the propane detector from misbehaving.
I’m not sure why the propane detector was going off, but possibly it wasn’t receiving the proper voltage because of the bad battery and maybe the remaining good battery had become marginal. Anyway, there were no further problems after the replacement.