Charging Batteries

[CaptnJohn]

I have 2 batteries (12 volt deep cycle) in parallel. The Cougar has a battery shut off that allows a lot of parasitic draw so a real cut off switch has been installed.
When leaving the last trip both switches were left on to allow the truck to maintain a charge ~~ but I did not shut them off on our return. Now batteries are dead.
How should a charger be attached to charge both at once?

[chuckster57]

Positive lead on one end and the negative on the other end.
Use the posts that have the feed to the trailer.

[MBD]

Don't ask me to explain why, but if you take your batteries out (or take them out of series/parallel) they will charge faster

[CaptnJohn]

Thank you... always took them out and charged individually but they get heavier every year. Besides, it gets a little close in there.

[WaltBennett]

First off, your two should have one batteries positive connected to your coach and the other's negative connected to ground (usually the frame), with the two batteries pos. and neg. connected to each other. Ours didn't have this originally and this won't charge or discharge them equally. The cable connecting them together should be as short as possible and be equal gauge.

Second, until you can install a for real cut off, you need to disconnect the positive lead to the coach when you're not using the thing as several things aren't disconnected by that Keystone 'cut off'. I guess they think things are better that way, but your batteries will go dead in a month or so if you don't.

Finally, if they are dead, make certain you check you water/acid level before trying to charge them, and check it after about an hour or two. If your charger isn't a three stage one, it will probably boil them trying to charge too quickly.

[Desert185]

Deltran, maker of Battery Tender chargers, advised me to charge the dual batteries in my pickup individually for optimum effect as one battery may be weaker than the other.

[spokedintheeye]

Originally Posted by Desert185

Deltran, maker of Battery Tender chargers, advised me to charge the dual batteries in my pickup individually for optimum effect as one battery may be weaker than the other.

Battery minder is the same. Instructions say two 12v wired in parallel are to be charged on the controller separately. Which threw me off, because my old 6v were in series but had to be charged together with positive on the one battery and negative hook up on the other.

Originally Posted by WaltBennett

First off, your two should have one batteries positive connected to your coach and the other's negative connected to ground (usually the frame), with the two batteries pos. and neg. connected to each other. Ours didn't have this originally and this won't charge or discharge them equally. The cable connecting them together should be as short as possible and be equal gauge.

Second, until you can install a for real cut off, you need to disconnect the positive lead to the coach when you're not using the thing as several things aren't disconnected by that Keystone 'cut off'. I guess they think things are better that way, but your batteries will go dead in a month or so if you don't.

Finally, if they are dead, make certain you check you water/acid level before trying to charge them, and check it after about an hour or two. If your charger isn't a three stage one, it will probably boil them trying to charge too quickly.

Sent from my SM-G870W using Tapatalk

[Timon]

Originally Posted by Desert185

Deltran, maker of Battery Tender chargers, advised me to charge the dual batteries in my pickup individually for optimum effect as one battery may be weaker than the other.

I think this really only comes into play if the batteries are not always connected together, i.e., chassis and aux. If they are always hard connected and were put in at the same time with basically the same date code you'll generally not have an problem.

The converters 5th wheels, and MHs, usually don't make good battery chargers for lead acid or age batteries as most are not multi stage chargers. However they can make good chargers for LiFePO4 systems since they only need a single stage, i.e., bulk, charger since charge control is handled by the BMS.