How to Increase Battery Capacity

rfloyd99 wrote:
OP here.

2oldman wrote:
We don't know what converter you have.

The converter is a WFCO model WF8735-P. Says "converter output 13.6V DC, 35A"

If I recall, the threads I was reading said that you needed 14.6 - 14.8V to get 100% charge. I think it said that at 13.6 the best you could get was 90%. If that's true, I would still be better off with a 90% charge of two 6V batteries than what can be gotten from any single 12V battery.

In a previous reply in this thread it was suggested to run a heavy gauge charging line from my truck alternator to the batteries. Does anyone know what output this would have?

Thanks!

Reading your post it appears you do not have a generator, so the convertor is not really a significant issue. When you hook up to power it's going to be for at least 12 hours so the slow charging is not a big deql.
The easiest way to go is to buy an AGM battery, they charge easier at low voltages. Idle your tow vehicle on it for an hour or two once a day with booster cables attached. It's far from optimal, but if you want to keep costs way down as your post says loud and clear and since boondocking is not a regular thing you do that's the cheap way to go and still have some power on. Golf cart batteries are also good in that they will take longer to run down from a full charge, but will be more work to install and when charging off an alternator the low voltage is just not going to get much charge in unless you idle for several hours, no fun. If you have a newer vehicle some of their alternators I'm told do a not too bad job, with the voltage going up well over 14 if required almost like a charger.
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