You have had your batteries in your TT for 3, 4, 5 years. You do a voltage check and it shows 12.6Volts (full charge) looks good to me, but what about the Amp Hours of the battery? New it was rated at 84Ah, it is now 4 years old, so how many Ah's does the OLD battery really have?
My first test was performed on an old interstate battery to see what the CURRENT Ah would be. The battery is an Interstate 84Ah battery. It still takes a full charge and sits for months at 12.8VDC, without any charger on it. So to the average camper it looks like a good battery. Why did I do this test? So, I can eventually test my Trojan T-145 batteries, but decided to do a test on my original Interstate that came with the TT.
Battery information: Interstate SRM-24 84Ah (4 years old)
(Mostly used with my office UPS system and electronics projects)
Test Equipment:
Wind Turbine dump load resistor (15Amp load)
Test Information:
After an 8 Hour rest, Battery Voltage 12.98,
Connected battery to the dump load resistor
Test Results:
Voltage start 12.98VDC, Voltage End 10.5VDC
Test Time:
165 minutes
Calculations:
165 minutes / 60 minutes = 2.75 hours
2.75 hours * 15 amps = 41.25Amp Hours (current Ah available at full charge)
Useable Ah = 20.5Ah (not very much when you turn on a heating system or Tv…)
So, now you are curious as to what your current old batteries Ah's really are.
I also posted the test results on the
RVing with SOLAR Social Group.
Don