BFL13 wrote:
The PM is confused about what it is connected to IMO. You can have low batts (low resistance) but a bad (loose)connection in the wiring (high resistance) between the PM and batts so the PM thinks it is dealing with a battery with high resistance (nearly full) so it goes straight into Absorb or Float except it didn't do its 15 min at boost. (Note that could even be in one of the PM's DC output set-screw type terminals)
EDIT, I also hope that you have fat short wires to the batts from the PM or else it won't do its full amps with long too-thin wires. I have #1 gauge 18" from my 100 amper to the batts. You should have at least #4 no more than say 15" for the 75 amper IMO. Any longer you need fatter wire IMO. (Sorry, I don't remember if you posted about yours earlier.)
When the batts were actually near full, disguising that bad wiring connection high resistance,the PM did its 15 min and then went into Absorb then Float, or at least that is my initial notion, which could turn out to be all wrong :)
Before blaming the PM, maybe haul out a pair of low batts and with nothing on them except the series link, attach the PM to the batt pair's load -taking pos and neg terminals and see if the PM behaves.
If it does, then go back and find what's wrong with your regular set-up for wiring and maybe loose connections.
i have 48" (inches) pos and 24" neg of 4ga cable from pm to batts, 16" of 4ga between each batt for series/parallel, 30" neg and 12" pos of 2ga from batts to inverter, 30" of 6ga for pm to chasis gnd, 18" of 6ga for inverter to chasis gnd, and until i can make up my own heavier cable, 16" of 6ga from batt to shunt. i have a 100a fuse between batt pos and inverter.
... perhaps that (temporary) 16" of 6ga between the shunt and neg batt post is creating high resistance? although, i looked it up, and it should carry the current.
i won't be able to get some 2ga 'til sometime next week. i will definitely check all the connections tomorrow though.
i will check the two-6v-in-series set up as you suggest, however, i will need to hook up the trimetric and shunt as well, in order to get an amps reading.
