House batteries not up to ah rating
Bought 2 new Interstate SRM-24 group 24 RV/Marine batteries a few months ago. I have used the MH 4 times on trips lasting from 3-6 days. Never going below 40 amps before recharging. The rating is 85ah each. The batteries have been on the Intellipower charge wizard converter/charger for 6 days and advanced thru the 3 stages to float. They should be fully charged when I began my test.
Based on the amount of amps drawn so far, the corresponding voltage indicates a higher % of consumption from ah capacity
Example:
Ran some lights and fans, at point where
Xantrex Battery monitor showed 17.3amps consumed.
overnight rest with no draw, the voltage at batteries was 12.54v = 85%
17.3amps is 15% of 120ah not 170ah as advertised
Continuing test
Drew off to total of 30 amps
rest batteries for 4 hour, no draw
30 amps consumed
voltage at batteries is 12.45v=75%
30 amps equal 25% of 120ah again.
Final test
drew off total of 60 amps
rest batteries for 4 hours
60 amps consumed
Voltage at batteries is 12.25v=50%
60amps equals 50% of 120ah again
To further check batteries SOC, I removed them and tested SG
Results of SG were 1.189
Confirms battery ah capacity is 60ah each, not 85ah.
The SOC from voltage figures come from the flyer that came with the batteries RV/Marine Deep Cycle batteries
The temperature here in LA is in the low 80's. So temperature isn't reducing my ah capacity.
Any thoughts? If I take them back where I bought them, they will say they are fine.
Based on the amount of amps drawn so far, the corresponding voltage indicates a higher % of consumption from ah capacity
Example:
Ran some lights and fans, at point where
Xantrex Battery monitor showed 17.3amps consumed.
overnight rest with no draw, the voltage at batteries was 12.54v = 85%
17.3amps is 15% of 120ah not 170ah as advertised
Continuing test
Drew off to total of 30 amps
rest batteries for 4 hour, no draw
30 amps consumed
voltage at batteries is 12.45v=75%
30 amps equal 25% of 120ah again.
Final test
drew off total of 60 amps
rest batteries for 4 hours
60 amps consumed
Voltage at batteries is 12.25v=50%
60amps equals 50% of 120ah again
To further check batteries SOC, I removed them and tested SG
Results of SG were 1.189
Confirms battery ah capacity is 60ah each, not 85ah.
The SOC from voltage figures come from the flyer that came with the batteries RV/Marine Deep Cycle batteries
The temperature here in LA is in the low 80's. So temperature isn't reducing my ah capacity.
Any thoughts? If I take them back where I bought them, they will say they are fine.
