My Screwy 31
First off let me say I am not stressing over this. It's just a battery, it is only money, it is meeting my overnight needs, but it is displaying strange behavior, and I am curious as to why. So th...
Forum Discussion
landyacht318 wrote:
Just checked SG after the amperage required to hold 14.6v fell below 1 amp and amp hour counter said 1 A/h from full.
1.250 on all 3 easily checkable cells.
The regimen for the last 2 weeks has been 14.6 absV and 14.7 float/finish, and enough sun and time to get them to the float/finish stage every day. Mostly before 1pm. Often before 11 am.
No schumacher. A few mornings of short lived 50+ amps from the alternator.
Just switched all loads to AGM battery. Changed solar acceptance and float to 15.9v. 6+ amps were required to bring voltage to 15.9v. Now 5 minutes later 4.2 amps to hold 15.9v.
Max overnight amp hours removed since last report( 2 weeks ago) have averaged about 25 with a max of 35 and a minimum of 12.
Battery seems to level off at 12.2 volts under various loads around 11pm. I've not been checking rebound voltage with all loads removed.
Edit: 1.5 hours later, SG is 1.270 on all 3 cells. 15.9 volts, taking 4.2 amps. Aggressive bubbling. Lots of gurgling.
Edit2: 2 hours after beginning eq cycle, all three cells at 1.275. 15.9v, taking 3.84 amps.
Edit3: 2:50 after beginning eq cycle, all cells at 1.275, 15.9v taking 3.4 amps.
Terminate EQ cycle
So there you have it... somewhere between 2 and 2.5 hours at 15.9V for that battery gets things topped off on the battery acid levels... although, wait until the following day to read the SG.... cells do wonky things to the SG overnight after giving a full equalization, sometimes the SG pops up a full 5 or 10 points to 1.280 or so.
Good job on treating that battery right and getting 'er truly topped off.
Now then, when was the last time you Equalize charged it? How many days ago?
6 amps for a group 31, with 120 Ah rating.... is 5% charge rate. I think Mex prefers a 10% charge rate for EQ... either way, it just takes a little bit longer at 6 amps to get 'er done. No substitute for that almost 16.0v capability from a charger to equalize all the cells properly.
