Spinning off a new topic so as not to pollute the other thread.
Like Tony, I am using the NOCO Genius charger (model G7200).
I have used it to desulfate 2 functioning AGM batteries and it did improve charge absorption on both. Meaning the float charge was higher after desulfation – the batteries absorbed more energy and delivered more energy measured by the voltage in the morning after running the fridge all night. One web page I read said if your resting voltage after charging (and cooling a bit) is 12.6 or lower consider desulfating.
My refrigerator runs off a 115 amp hour battery and solar panels, the car alternator or shore power (whatever is available). I have to recharge daily. Solar is no problem on sunny days, I limp by on cloudy days and especially a week of heavy clouds. It’s a downward spiral. Some days the alternator looks tempting. But for a few years now I have successfully survived on solar. I like the excitement of living on the edge and hand wringing is a form of exercise…
Corrections appreciated:
My amateur understanding is – all lead acid batteries sulfate meaning Sulfur comes out of the Sulfuric acid and collects on the lead plates reducing the lead plates ability to contact the acid reducing capacity and in some cases making the battery useless. Good news – this is reversable. You can get the Sulfur off the plates and back into the acid where it belongs (desulfation) or something like that.
https://relionbattery.com/blog/lithium- ... ld-weather
http://www.batteryminders.com/avoid-battery-sulfation/
My understanding is a heavily used battery that is fully recharged immediately after use is ideal for keeping sulfation low.
Contributors are leaving an idle battery not fully charged, low charge, not recharging quickly, and partially charging. My teardrop has at least some of those going on continuously. I have it on a light switch in the garage in the winter so when I turn on the light – it partially charges (but not fully). Driving the car charges the battery with the alternator but not to 100%. Since I am on solar – cloudy days partially charge the battery, on and on. In the real world I get to charge my battery to 100% when the sun is shining for about 5 hours.
I desulfate when the battery appears to be lacking – maybe 4 times a year. If the voltage in the morning after running the fridge all night is drifting lower I give it a good desulfate when I get to shore power. It takes my battery about 4 to 6 hours to disulfate with the charger. Just press the button. Noco claims they use some sort of high frequency input to the battery to blast the sulfur off the plates. Reviews on Amazon showed many batteries were saved using this option. Of course not all batteries were saved. https://amzn.to/2ZVU5AM Affiliate link
There are lots of opinions on how to desulfate. Some chargers do it. A friend says putting a load on will do it (a load on the battery of course). In days of old called this “burning the wisker’s off the plates”. I have done the load thing with the Harbor Freight battery tester and it does seem to help. I used the tester 3 times in a row for about 10 seconds. The tester gets quite hot. https://www.harborfreight.com/100-amp-6 ... 61747.html I think the Genius charger does a better job.
The take away here is if you have a battery or a bank of batteries and one is not up to par or considered dead as Tony pointed out it might be worth trying a desulfate to see if it revives.
I purchased an impedance meter which claims to bring science to predicting battery health by measuring internal resistance of the battery. Its a relative reading. You read the battery when its new and charged and look for higher impedance as it ages. I am testing it on Eneloop AA batteries and have no conclusion yet since its only a week old.
=Cosmo