Hello, I think my battery is on it's last legs. Only charges to 90 % and today just as it started the starter was clicking like when the battery is dead. The truck sits for 2-3 weeks at a time in the winter. I have a big deep cycle battery for my boat that I use in the summer for trolling that is brand new. Will this work in my truck or cause issues to the truck or battery. The physical size is very similar.

 

I didn't receive a response to my post, anyone please.

 

the only concern is agm batteries don't like charge rates over 14.4 volts for extended periods. newer vehicles that use agm batteries have intelligent battery sensors that charge agm batteries appropriately. older vehicles don't.

older vehicle charging rates usually sit around 14.4 but can vary from 13.5 to 15.5volts. with it work, yes. will it damage the vehicle; no. will it damage the battery; probably not
if you are going to try it; make sure the battery hold down fits the battery. If it doesn't...get the proper battery.

you should be putting a charger on the battery if the vehicle sits for that long. I have a 06 Taurus with no parasitic draws problems and a new lead acid battery. I have to charge it every 3 weeks. Cold weather can reduce battery capacity 50%. I charge it regularly to protect my $200 battery.

 

Thanks for the reply. To be clear, the battery is a conventional deep cycle, not an AGM. Agreed it should be charged more often, the battery has done well given the circumstances.