Mex's 20% AGM Rule Sucks.

pianotuna wrote:
JimBollman,

What is your camping style?

How much capacity were you intending to add?

30 amps charging would easily service 150 amp-hours of battery bank.

I got tired of laying in the snow to check my flooded. I'd NEVER switch back.

As the batteries charge they start to "push back" and limit the charge rate automatically.

On a flooded jar that happens at 85% state of charge--limiting the rate to 15 amps per 100 amp-hours of battery bank. On an AGM the number is higher--tapering of charging probably happens at 92% soc.

There is at least one member here who uses a 'stock' PD converter and it successfully charges his agm bank.

As for the rest of us battery nuts, we love to "dance on the needles".

The majority of our camping is single nights and then 4-8 hours of driving before we stop again. Most of the time we stop in campgrounds but not always and not always with electricity. Anytime we are camping for more than a day we are connected to power accept once a year in early October when we camp 4 days without power and generators are a no no. Our new rig has a compressor frig and my first thought was to have enough power to get us through but decided that was not reasonable and probably not worth the cost of solar for once a year so we will probably just go with an ice chest for that trip.

With computers to charge and normal camper needs I figured two batteries will get us through the 4 day without any problem, that is what our old rig had. For years we scraped by with one. I need to measure how big the existing box is and I figured I would get two AGM batteries of that physical size, I see no reason to go smaller than the space available. I'm not trying pinch pennies.

The frig draws about 3.5amps when running. Unless we have a really warm October, I'm guessing it would only have a 25-40% cycle rate. So the frig would need 85-135 amp-hours all by itself for 4 days, if we used it.

I have converted to LED lighting and we don't use much light while camping anyway.