Charging AGM Batteries

MEXICOWANDERER wrote:
I have to believe that folks are not going to wake up at dawn on 4 July in Bad Water Death Valley and run outside and charge their batteries. "Yeah I found out the hard way that 13.6 was too high a float voltage at 50C"

Most folks are definitely not happy camping where battery temperatures start out at 35C.

So I abbreviated my answer. For 90% of campers 14.7 is fine.

If I must I'll repeat it again:

If time is not an issue, limit the charging voltage down from 14.7. When I discharge a flooded battery 20% in less than 24 hours and then connect to public power to recharge, I will limit charge rate to FIVE PERCENT of A/H capacity until 15.0 is reached then reduce to float. Of course I adjust for temperature if I see camels or penguins outside.

It's when the aggregate total price, the total cost of "babying" batteries with a reduced voltage limit threatens to cost more than the purchase price of the batteries is when I crank the voltage up to 14.7 It doesn't take long for the price of fuel, generator wear out, and GOING TO GET MORE FUEL adds up to more than purchase price the batteries.

Yes, good stuff!

But, when I say I use 13.5V on 110F AGMs and 15V on cold AGMs it doesn't mean I do it myself. The Temp-comp chargers do it for me while I sit back and enjoy the R in RV.

When I do get out the genny, it is for bulk and some Abs charging while I go back to the R in RV until the genny idles down. Then I shut the genny down and let the solar finish the job. Many penguins and camels, however, I don't need to take notice as the temp-comp automatically deals with that.

Are you saying I should go out of my way and override my setup to use 14.7V on my AGMs when they are 110F? This is a normal, daily condition right in my driveway as I have AGMs in the van in the summer sun. I just let the solar charger take care of this.

HTH;
John