Forum Discussion
BFL13
Jun 07, 2017Explorer II
Doing 50-90s or 50-80s, a voltmeter cannot tell you when to stop the generator when charging, which is where an ammeter is so useful.
However you can watch the voltage as the PD70 gets the battery voltage up to 14.4 and then just allow some more time for an absorption stage. Time2roll suggests an hour for that, thinking 35 amps on 220AH for a 50-90. With 70 amps on four batts you would have the same time.
A 70 amper on 440AH doing a 50-90 would take about two hours at 70 amps constant to reach 14.4 at 80% (all Bulk stage), then another hour of tapering amps Absorption stage to get from 80 to 90. Total three hours of gen time. You can save an hour of gen time by doing 50-80s instead if you can love with than many AH and you can get the batts fully charged not too long after doing a few of those. It makes for more sulfation to only reach at 80 than to hit 90.
So that only takes a voltmeter and a clock.
EDIT--you can run short wires from the converter over to the inverter and then use the longer fat wires from there to battery. You can still use the 70s second set of terminals for something.
However you can watch the voltage as the PD70 gets the battery voltage up to 14.4 and then just allow some more time for an absorption stage. Time2roll suggests an hour for that, thinking 35 amps on 220AH for a 50-90. With 70 amps on four batts you would have the same time.
A 70 amper on 440AH doing a 50-90 would take about two hours at 70 amps constant to reach 14.4 at 80% (all Bulk stage), then another hour of tapering amps Absorption stage to get from 80 to 90. Total three hours of gen time. You can save an hour of gen time by doing 50-80s instead if you can love with than many AH and you can get the batts fully charged not too long after doing a few of those. It makes for more sulfation to only reach at 80 than to hit 90.
So that only takes a voltmeter and a clock.
EDIT--you can run short wires from the converter over to the inverter and then use the longer fat wires from there to battery. You can still use the 70s second set of terminals for something.
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