Charging with the pm4b last evening, I brought the bank to 9.2a @ 14.64Vabs. Amps plateaued there early on during the 2 1/2 hour charge. It was getting late, so I shut things down for the night.Today, in an effort to do a more complete charge, I am continuing to charge at 14.64Vabs. After 1 1/2 hours, bank was accepting 8a. Two hours later, 8.3a. Another two hours later, 8.8a. Another one hour later 9a.I opened the battery cabinet to take a look. No excessive heat, anywhere. All four 6's sharing the voltage evenly, to two decimal places. All cells gently bubbling. Only load draw is the Trimetric (which is turned off) at about 0.15-0.2a. Ambient temps are in the high 70's, and it's been cloudy and rainy.? Is it possible Vabs is too low? Don't think so... 10 days ago, I brought them to 5.7a @14.66v, when ambient temps were about 68F.? Is there a load on? Only things hooked up are the inverter, which is off and reads 0a on the clamp meter, and the Trimetric, at ~ 0.2a.? Is there a reading discrepancy? No. Turned on Trimetric and confirmed current.Any other ideas???Thanxx!

"And the hydrometer ran away with the fiddle"Sort of like selecting a tapeless measuring device to make your way in pitch blackness.....Instead of using a flashlight...

WAG theory-- they are spotty in sulfation and are gaining in acceptance because their capacity is growing as they get cleaned up inside better as the recharge progresses? The increasing capacity makes it like the charger is on an ever bigger bank and is sliding back in SOC accordingly( or treading water for SOC) so acceptance is higher? Might be a sign you need a good deep cycle and big amp recharge to get them back in proper shape and maybe a good desulfation too?I said it was a WAG!

Yes, newer SG's are forth coming. At last check, on April 26th, they were as such:A1 1.285, 1.275, 1.275(prodigal cell)A2 1.275, 1.275, 1.275(prodigal cell)B1 1.285, 1.280, 1.280B2 1.285, 1.280, 1.285Those were taken 14 hours after a 10 hr charge at 15.0Vabs, the day prior, that started at 12.49v ocv, and, at some point after 8 hrs, dropped to the modded pm4b's float voltage, and finished at 4.1a @ 14.6v. At the time of the SG readings, ocv was 12.84v, with even voltages across the bank.

BFL, I considered that last year, when ocv's would drop as a result of using higher Vabs. Between the 10hr charge above, and today's charge, I have done a couple of other charges (but not on a heavily depleted bank); one as high as 15.4v for about an hour and a half, and got the usual results.But this is (almost) totally new. The only other time I've seen amps go up was when EQ'ing individual 6's with the cv/cc gopher.

A nearly dead battery will not accept many amps, but when being recharged, it slowly takes more and more amps in till it gets up to the charger's current limit. Then the recharge goes normally and amps taper after the bulk as usual.My 100 amper starts out on a 50% SOC bank at about 98 amps and works its way up to 103 amps after a few minutes. I think that is battery warming up or something and not the charger ramping up, but it might also be wire connections getting better with warming, no idea. I found a couple poor connections recently, so the next use of the 100 amper should be interesting for that.My 6s don't act right if they haven't done a deep cycle to about 50% lately. They need that action! :) Sitting on shallow solar cycles a long time hides what is going on.Or :) - you are a spaz and it is all Measurement Error!

Amps Rising not tapering During Abs Charging? | Good Sam Community

35 Replies

BFL13
Explorer II
May 10, 2015
A nearly dead battery will not accept many amps, but when being recharged, it slowly takes more and more amps in till it gets up to the charger's current limit. Then the recharge goes normally and amps taper after the bulk as usual.

My 100 amper starts out on a 50% SOC bank at about 98 amps and works its way up to 103 amps after a few minutes. I think that is battery warming up or something and not the charger ramping up, but it might also be wire connections getting better with warming, no idea. I found a couple poor connections recently, so the next use of the 100 amper should be interesting for that.

My 6s don't act right if they haven't done a deep cycle to about 50% lately. They need that action! :) Sitting on shallow solar cycles a long time hides what is going on.

Or :) - you are a spaz and it is all Measurement Error!
jrnymn7
Explorer
May 10, 2015
BFL,

I considered that last year, when ocv's would drop as a result of using higher Vabs. Between the 10hr charge above, and today's charge, I have done a couple of other charges (but not on a heavily depleted bank); one as high as 15.4v for about an hour and a half, and got the usual results.

But this is (almost) totally new. The only other time I've seen amps go up was when EQ'ing individual 6's with the cv/cc gopher.
jrnymn7
Explorer
May 10, 2015
Yes, newer SG's are forth coming.

At last check, on April 26th, they were as such:

A1 1.285, 1.275, 1.275(prodigal cell)

A2 1.275, 1.275, 1.275(prodigal cell)

B1 1.285, 1.280, 1.280

B2 1.285, 1.280, 1.285

Those were taken 14 hours after a 10 hr charge at 15.0Vabs, the day prior, that started at 12.49v ocv, and, at some point after 8 hrs, dropped to the modded pm4b's float voltage, and finished at 4.1a @ 14.6v. At the time of the SG readings, ocv was 12.84v, with even voltages across the bank.
BFL13
Explorer II
May 10, 2015
WAG theory-- they are spotty in sulfation and are gaining in acceptance because their capacity is growing as they get cleaned up inside better as the recharge progresses? The increasing capacity makes it like the charger is on an ever bigger bank and is sliding back in SOC accordingly( or treading water for SOC) so acceptance is higher?

Might be a sign you need a good deep cycle and big amp recharge to get them back in proper shape and maybe a good desulfation too?

I said it was a WAG!
MEXICOWANDERER
Explorer
May 10, 2015
"And the hydrometer ran away with the fiddle"

Sort of like selecting a tapeless measuring device to make your way in pitch blackness.....
Instead of using a flashlight...

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Amps Rising not tapering During Abs Charging?

35 Replies

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