Costco batteries saved just in time.
I traded in a 5th wheel in early August for a new one. I had two extra batteries kinda illegally mounted in the pass through storage. I removed them for liability reasons and left 2 batteries in the original battery compartment.
I stored these Costco Group 27 batteries in my shop. Changing job locations left little time to care for them. Last week I decided to check them. Voltage read 12.6x on both of them. OK, not down too much for setting for 2.5 months. I removed the caps to check the Specific Gravity. The plates were covered but not deep enough to fill the hydrometer. I added about 1/2 a gallon total to fill them back up. I put them on the 40 amp B&D smart charger (one at a time) and within 30 minutes the charger said they were full and it went into float at 13.2V. Being suspicious of such a short charging time I tested the SG. It was way down on all cells with one end cell being worst than the others. Low cell was 1.200 and all others were 1.225.
I re read MEX's blog on equalizing and the only charger I had capable of 16V was a very old Sears Craftsman wheeled charger. MEX said you also need to control the amps but I had no way to do this nor would I know how to. The charger is capeable of 100 amps but the battery would only accept 2-3 amps at 16.1-3 V. One battery at a time was charged at 16.1-16.3 at about 2-3 amps. When initially turned on the amp meter would spike at about 20 amps but within 5 minutes it was down to less than 5 amps. I checked the SG every hour and after 4 hours, 5 cells were at 1.275 and the 6th cell lagged at 1.265
The process was repeated on the second battery with the same results. batteries were bubbling but not getting warm.
Another hour on the lagging cell would not improve it. 1.265 is just in the green on my hydrometer.
Is this as good as it gets? MEX says one cell will always be the black sheep. Any concern if it is in the green and within .010 of the rest of the cells?
Amperage measured on charger analog amp meter.
Voltage measured with Fluke 87.
SG measured with temperature compensated cylindrical hydrometer.
I stored these Costco Group 27 batteries in my shop. Changing job locations left little time to care for them. Last week I decided to check them. Voltage read 12.6x on both of them. OK, not down too much for setting for 2.5 months. I removed the caps to check the Specific Gravity. The plates were covered but not deep enough to fill the hydrometer. I added about 1/2 a gallon total to fill them back up. I put them on the 40 amp B&D smart charger (one at a time) and within 30 minutes the charger said they were full and it went into float at 13.2V. Being suspicious of such a short charging time I tested the SG. It was way down on all cells with one end cell being worst than the others. Low cell was 1.200 and all others were 1.225.
I re read MEX's blog on equalizing and the only charger I had capable of 16V was a very old Sears Craftsman wheeled charger. MEX said you also need to control the amps but I had no way to do this nor would I know how to. The charger is capeable of 100 amps but the battery would only accept 2-3 amps at 16.1-3 V. One battery at a time was charged at 16.1-16.3 at about 2-3 amps. When initially turned on the amp meter would spike at about 20 amps but within 5 minutes it was down to less than 5 amps. I checked the SG every hour and after 4 hours, 5 cells were at 1.275 and the 6th cell lagged at 1.265
The process was repeated on the second battery with the same results. batteries were bubbling but not getting warm.
Another hour on the lagging cell would not improve it. 1.265 is just in the green on my hydrometer.
Is this as good as it gets? MEX says one cell will always be the black sheep. Any concern if it is in the green and within .010 of the rest of the cells?
Amperage measured on charger analog amp meter.
Voltage measured with Fluke 87.
SG measured with temperature compensated cylindrical hydrometer.
