This might sound really stupid to some but I have 2 lead acid 12v batteries hooked in parallel. According to the battery manufacturer, Interstate, they each have 64 amp hours. But their chart also says (RC) Mins @ 25 amp = 100. This sounds like each battery can give out 25 amps for 100 min making 2500 total amps available. I know I am not reading this right, can someone explain. The reason I am asking is because I am programing a Battery Monitor and it asks me to put in total amp available. So I put in 65 since I have 2 lead acid but don't want to go below 50%.
Confused about amp hours
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Amps, amp-hours, amp minutes.
"25 amps for 100 min making 2500 total amps available"
Not "Amps", but "Amp minutes"
2500 amp-minutes / 60 minutes per hour = 42 amp-hours.
This is less than 64 amp hours (probably measured at 20 hour or 24 hour rate) because of Peukert effect; at high amperage draw rate, can't get as many amps before voltage drops too low.
Peukert seems to be partly just series resistance (you could immediately reduce current draw to 25 amps an still operate for a while), but also rate of chemical reactions. If you let the battery sit for a while, may once again be able to deliver high current for a little while. e.g. sometimes if you can't crank engine after battery got run down, just shut everything off and wait a while, then try again.
65 amp hours is the proper entry. 50% may be another parameter you can also set.
"25 amps for 100 min making 2500 total amps available"
Not "Amps", but "Amp minutes"
2500 amp-minutes / 60 minutes per hour = 42 amp-hours.
This is less than 64 amp hours (probably measured at 20 hour or 24 hour rate) because of Peukert effect; at high amperage draw rate, can't get as many amps before voltage drops too low.
Peukert seems to be partly just series resistance (you could immediately reduce current draw to 25 amps an still operate for a while), but also rate of chemical reactions. If you let the battery sit for a while, may once again be able to deliver high current for a little while. e.g. sometimes if you can't crank engine after battery got run down, just shut everything off and wait a while, then try again.
65 amp hours is the proper entry. 50% may be another parameter you can also set.
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