Oh wise ones….
Charging question. Actually, a trickle charging question.
Road Ranger has two batteries, an older 65 size under the hood, and a pretty good size pretty new marine battery in the toolbox. They are wired together in parallel with a disconnect switch to the one in the box. I only disconnect it when I use the strobe lights and such if I have to stop and shut the truck off. 99% of the time they are connected. Point is they both charge together.
I have more vehicles than I can drive, so I’ll leave them on trickle chargers for the most part. As you might imagine, I don’t drive the Road Ranger as much as the others. When I leave this battery combo on a trickle charger, it does not maintain charge. It will drop to about 65% over a couple weeks. BTW, truck will still start, but it cranks slowly.
I initially assumed it was my cheap Chinese trickle charger, but then I tried a Battery Changer Jr., and most recently I had it on a very good diehard smart charger/maintainer;
Same result, it will drop to about 65% over a week or two.
I am assuming my problem is simply that the main battery under the hood is an old battery, but when I charge it by itself, it will go to a 95% charge. I haven’t tried trickle maintaining it separately. It’s when I have the two batteries together that the voltage drops over time.
Do you think my problem is an old battery under the hood? Or is my problem that the batteries are different? Note, I don’t have this problem on my 96 7.3 F250, but they are identical batteries that were installed at the same time.
I already ordered a new battery, but I’m wondering if I’m going to have the same problem. I could set it up so I have two trickle chargers and I switch the batteries apart when I’m not using it, but I don’t see why they shouldn’t charge together.
?????
EDIT: more info. When I check it with this thing, the marine battery comes up #2 “fair” and the battery under the hood comes up #1 “poor.”