Quote:
Originally Posted by MikeWestern400
Hey guys,
I searched for a while looking for the exact numbers to a full charge on my western 400 42v.
I am estimating that a full charge is 6.35 (1 6v battery) x7(batteries)=44.45
and 90% is 40.00. (multiplied 44.45x.90). Am I on the right track?
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Welcome to BGW!
Getting the "exact" numbers is more or less an exercise in futility since a deep-cycle lead-acid wet-cell battery isn't fully charged until the Specific Gravity (SG) of the electrolyte ceases to increase while a charging current is passing through it.
When you add 0.845 to the cell's SG, you get VPC (Volts per Cell), so voltage can be used to estimate SoC (State of Charge), but it takes time for the electrolyte's SG to reach an equilibrium after charging or discharging, so to get a reasonable accurate SoC estimate the voltage must be measured about 12 hours after charging or about half an hour after discharging.
Since slight variations during manufacturing do occur, the voltage of adjacent cells in the same battery may vary slightly when "fully" charged.
Then you have to toss in the fact that different battery manufacturers use different acid concentrations (SG) in their batteries.
The Voltage vs SoC charts typically use test data from the Trojan Battery company, which is an average of hundreds of test conducted on hundreds of batteries. The voltages for other brand batteries may be slightly higher, but I'm not aware of any that would be lower since Trojan uses the lowest acid concentration typically used for this type battery.
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I'm curious. What is your reason for wanting to find out the "exact numbers to a full charge"?
I ask because there are three separate sets of numbers. On-Charge, Under-Load and At-Rest, and each set is used in different ways.
Are you are trying to determine how high of a voltage to charge your batteries to, to get a "full" charge?