PD converter and 6v battery help

The 4655 and 9260 both charge at the same voltages and either will work beautifully with a pair of GC2.

Otherwise what was the 8855 doing to cook the batteries?

Just last week I replaced the Parallax 7345 in our Minnie with the PD 4645 45 amp converter. The charger has 4 charging modes. The "boost mode" is supposed to bring the batteries to 90% charge in a few hours. The charger then switches to "normal mode" and continues to charge at a lower voltage. The third mode is "float", which maintains the full charge without boiling the batteries. The fourth mode is "desulfation". I bought the converter from Best Converter.

The only issue I had with the install was that the existing positive wire from the batteries to the converter was a few inches too short to reach the terminal on the new 12 volt distribution board. I had to do some rerouting of the wire under the cabinets to get it to reach.

My house batteries were already pretty well charged when I plugged in the shore power, so the new converter started off in normal mode, rather than boost mode. It took about 2 days before it went into float mode.

CentralCoastCampers,

I assume your boondocking at the NASCAR races is on asphalt in the summer? If so, I bet it is hot...and suspect your batteries are hot as well. I am not sure, but I don't think the PD converters have temperature compensation with a remote sensor (that can be mounted on one of the batteries). If they don't have this sensor, you really might be cooking your batteries. I recommend a charger (the RV world calls them converters) that has this feature.
In regards to how big a charger you should get, it might not really matter. Take a look at the wires between the existing charger and batteries. If they are small (like AWG 8 or smaller), then a bigger charger really isn't going to make much difference. With small wires, unless your charger is located within a few feet of your batteries, you will have significant voltage drop (which will help in the heat) and your batteries may never get properly charged. If your wire size is adequate, then the larger charger will charge the batteries faster (and make them even hotter).

Where on the Central Coast? Used to live in SLO.

Steve

Go to the 9260 unless your battery cables are smaller than 6 wag or your charging while using a 1K watt genny or smaller.

Not clear why the WFCO is cooking the batteries. Not clear why any other three- stage converter wouldn't do the same thing in your situation while on shore power.

Not clear how 6v would do you any better than the 12s did when you only boondock for 5 days a year where you have lots of gen time. The 12s should do fine.

6s gas more than 12s so they would "cook" even better :)

Anyway, whatever needs doing, the Forum can help out with it for sure.