motorhome coach batteries

full_mosey wrote:
Hi KendallP;

I see you are back with your anti-AGM dis-information campaign.

Always a fun read that belongs in the fiction section.

Settled science?; that's a good chuckle.

HTH;
John

Heh heh heh. You still livin' in your fantasy world, mose?

We don't need another long thread for this. Just ask Mexicowanderer or another engineer like Bigfootford. Bigfoot was a Lifeline guy. Still might be. He and I had this conversation way back when. He had to concede.

The following is a canned response of mine on this. It begins with one example of a test that Bigfootford and Reddog1 performed. That's about as high a charge rate as you will ever see in RVing; A single 100 Ah Lifeline charged by a 55A IOTA and then a 60A PD.

So you call 2 1/2 hours with a better than C/2 charger to get from 40-90% fast?

Okie doke.

BFL13 regularly achieves that... at a slower charge rate... on his Golf Cart batteries.


My canned response... with evidence...

(Note: The "wo/Boost on the PD is a typo. The PD was in "Boost.")


I have yet to see any test results on an AGM that when charged at any fast rate with a typical converter at say 14.4V or so... doesn't begin to force the current to taper long before 90% SOC.

Here's one that is being charged at about C/2. The IOTA dropped out of boost at 15 minutes or so, but notice that the current still began to taper at just 10 minutes in. These are typical RV converters. This is how a Lifeline reacts to them in real life. Even at C/2 it took over 2 hours to go from 40% to 90%. The IOTA 2 1/2 hours.

(Below the Lifeline chart is BFL13's infamous "ugly graph" that shows it took 129 minutes to do a 50-90 on a pair of 6V GC2s at only C/3. And as we all know (or should know)... with typical RV converters... the 40-50% portion of the charge is definitely the easy part... AGM or flooded. It only added about 10 minutes to the Lifeline's charge. So the speed winner here is actually the GC2s. At best it's a draw... even at a slower charge rate for the GC2s.)

(And at the bottom of the page is Fisherguy's graph. 2 hours or maybe 2:15 to do a 47-90 at C/3 using another typical converter.)





BFL13's Ugly Graph