I was reviewing the settings and history statistics on my battery
monitor because of a high number of high voltage alarms. It seems I had it set too close to the nominal value for the highest charge voltage. I've never seen the voltage exceed that value, so I presume it was entirely a programming error on my part.
I also reviewed the battery
specs in the course of this process and discovered one error in the temperature compensation. I left it at the nominal value which was a percentage of AH capacity, while the battery
spec was in millivolt/deg C. I did a little math an reduced my temp compensation significantly. I don't think this is a huge factor because my batteries are either charging or discharging most of the time and that keeps the temperature in the typical range in cooler temperatures. Temps are higher in the summer despite the lower loads. I plan to add some 1/2" spacers between the batteries for better cooling in warmer temperatures.
212 DAYS OF RECORDS.
Average Discharge (AH): -57.3 AH
Avergaer Discharge %: (recalculated after ea. sync): -14.9%
Deepest Discharge (AH): -286 AH
Deepest Discharge (%): -74.9%
Total AH Removed: 8049 AH
Total AH Charged: 9873 AH (temp compensation explains difference)
Number of Cycles: 20
Number of Sync's: 93 (A sync means the battery was fully charged)
Number of Full Discharges: 0
Noteworthy, is the one time I left my refrigerator
on AC using the inverter. It ran my battery down until the alarm sounded. This is one reason I want to switch to a Danfoss type compressor DC fridge
when my fridge
starts to give out.
During this time my batteries have only "cycled" about a dozen times. In actuality they cycle a small amount every day. I am guessing the definition of a cycle is 50% or greater discharge. I don't know how they count cycles, but obviously it is of little value to me if the number is so low. We know that discharging less than means longer life. One of my friends lives in an RV. He went overboard on capacity and his batteries rarely discharged more than 25% and lasted 11 years. He paid a big penalty in weight
, and is generally carrying an insane amount of weight
for a 350 motor. He's blown the motor in his RV three times.
Below is a good example of battery life in a stationary application:
Battery life is twice as long if discharged to 25% compared to 50% discharge. But if they in an RV, you are carrying around all this extra weight
. Is it better to change batteries every three years or every six for someone who daily cycles batteries?
Based on this, if I keep my discharge numbers at 15% I should get more than 3000 cycles out of them. Possibly 10 years of life.
One of the reasons I'm a huge fan of solar
panels and solar
charging, is it keeps the batteries topped up and maximizes their life. People forget to charge batteries. Prompt charging (daily in the case of solar
panels) is the best method, IMHO.