First Top Charge
I finally got my volt/amp meter wired in to my Mega Watt and started my first Top Charge. Initial battery voltage was 13.2v. Mega Watt was set to 15v. Turn-on voltage was 14.8v @ 33a. It quickly went ...
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Good Looking Setup SJ!
Depending on how fast and -why- specific gravity is slumping on float standby you may or may not need to bump the float voltage up a tenth.
If you've not moved your rig for months and the batteries are floated seemingly at correct voltage for the temperature, chances are it's a matter of stratification. If you suddenly apply bulk charging voltage, the amperage starts out seemingly high but then drops rapidly, trends and tendencies tells me the problem is most likely stratified acid. Time for a top charge. If the bulk charging voltage does not slump right back down then perhaps the batteries are not being floated at a high enough voltage. Sometimes I will zap a battery bank with 16.0 volts (takes a lot of amperage to do this) and watch the cells. They should start bubbling almost immediately. Continue for 15-minuted then cease. If the density of the acid rose appreciably it means the acid had stratified. When you get talented with a good hydrometer you will learn and recognize the behavior of your own bank. Slumping density (at rest, disconnected, no charge) but not a great change is resting voltage is another excellent clue to start looking for stratified acid.
The ultimate goal which is not easy to achieve is to absolutely minimize float AMPERAGE while not allowing the voltage to sag, meaning allowing the battery to drop from full charge to 99, then 98 and on to 97% charge. This is done with voltage control. Try it and see. Full, absolutely full batteries, zero load, how many milliamperes does it take to maintain the batteries? This changes over time, and if the batteries are becoming sulfated. The trifecta: Voltage, milliamperes and the hydrometer. You'll get to be an expert in no time.
Depending on how fast and -why- specific gravity is slumping on float standby you may or may not need to bump the float voltage up a tenth.
If you've not moved your rig for months and the batteries are floated seemingly at correct voltage for the temperature, chances are it's a matter of stratification. If you suddenly apply bulk charging voltage, the amperage starts out seemingly high but then drops rapidly, trends and tendencies tells me the problem is most likely stratified acid. Time for a top charge. If the bulk charging voltage does not slump right back down then perhaps the batteries are not being floated at a high enough voltage. Sometimes I will zap a battery bank with 16.0 volts (takes a lot of amperage to do this) and watch the cells. They should start bubbling almost immediately. Continue for 15-minuted then cease. If the density of the acid rose appreciably it means the acid had stratified. When you get talented with a good hydrometer you will learn and recognize the behavior of your own bank. Slumping density (at rest, disconnected, no charge) but not a great change is resting voltage is another excellent clue to start looking for stratified acid.
The ultimate goal which is not easy to achieve is to absolutely minimize float AMPERAGE while not allowing the voltage to sag, meaning allowing the battery to drop from full charge to 99, then 98 and on to 97% charge. This is done with voltage control. Try it and see. Full, absolutely full batteries, zero load, how many milliamperes does it take to maintain the batteries? This changes over time, and if the batteries are becoming sulfated. The trifecta: Voltage, milliamperes and the hydrometer. You'll get to be an expert in no time.
