I go to Battery University and read that the most comprehensive way to test the health of a lead-acid battery is with a hydrometer. I check every cell of my 3200+ amp/hr battery bank and every cell tops the charts at 13. Yet, my 3200+ amp/hr. battery bank cannot hold a charge AT ALL. My battery bank is made of used batteries that I bought half price after checking them with a hydrometer to insure they were good.
I go to forums and the guy at the end of the bar tells me that used batteries, even with good electrolyte, will not hold a charge very well. No explanation, no physics or chemistry, just personal experience.
From my experience the guy at the end of the bar is right and the authorities at Battery University haven’t the slightest idea where they are or what’s going on.
I’ve got two 48v pv arrays feeding the 24v battery bank through two MTTP controllers. One pv array does 1200 watts and the other does 1400 watts, which equals 2600 watts. Each controller processes a little over 1000 watts at a time.
On a sunny day by 10:00 a.m. the bank is stuffed full with juice at 29v. One controller has cut off to prevent overcharging and the other has reduced output. The icons on my remote MT-50 meters show the batteries blacked out full. I can do about anything with that power: run my 1500 watt deicer in my water tank, run the 1500 watt electric heater in the cabin and operate my household water pump, transfer pump and power tools.
As the sun sets, the voltage drops respectively. At sunset it’s down to 26v and dropping. At that time I cannot use anything that puts a heavy load on the bank. I can’t run my water pump to wash the dishes till the next day unless I run the generator. I actually had to run the generator because a meal I was making in my slow cooker was draining the bank.
At night I use one energy-saving light for the entire cabin. A small 3-amp fridge is the only other load unless I use my computer and modem. That’s with 12 200 amp/hr+ golf cart deep cycle batteries and two giant 12v deep cell batteries from floor-cleaning machines in 4 sets of 24 v series, then in parallel, going through combiner boxes to a 5,000w inverter.
I really want to get a REAL college educated explanation to how lead-acid batteries work. I need to know what chemical reaction occurs as electrons run through lead plates from negative to positive polls in a solution of 75% H20 and 25% sulfuric acid.
The manager of an auto parts store told me that even if the electrolyte is good, sulfated, damaged or consumed plates will prevent the battery from holding a charge. If the plates are sulfated, damaged or consumed, how could the battery retain enough sulfuric acid in the electrolyte? He didn’t know. Neither does the guy at the end of the bar. There must be a reason.