Originally Posted by trosenthal20
Just measured the voltage at all 5 batteries with the multimeter. 12.78 at the shunt battery and 12.73 at the others. Monitor shows 12.9 dropping to 12.78 and inverter/charger shows 13.0-13.3. I've always left the charger enabled on the inverter. Everything seems to have topped out and monitor appears to be giving accurate voltage from the batteries. What next?
I do not know how can you say that everything is "topped out/up" if you have not seen batteries reach proper charging
voltage (about 14.4V) when the charger is on and the genset is running. It is your boat and your time; I can only suggest you start as follows:
1) You say that the "inverter/charger shows 13.0-13.3". Check is that if that is the actual voltage at the inverter-charger or at a "device with a screen" that is reading voltage somewhere else (find where).
2) Trace the voltage drop between in the positive wire the inverter-charger and the batteries, all before the current
changes significantly. Then same thing on the negative wire. You will have to make a little drawing showing all the peices of wire that an electron has to go through between battery and inverter-charger. Measure the voltage between ends of each pice of wire and they should add up to 0.2-0.5 (difference between 13.0 or 13.-3 and 12.8). That drop (around 3% of 12V) is acceptable drop for rated inverter current
(250A or so in your inverter, chosen because it is higher than the 150A rated charger current) but I bet you are not charging more than 100A because the reading tells me that there is little current flowing, hence drop should be almost nil. . Therefore something needs improvement until voltage drop between battery and inverter-charger is no more than 0.4V WHILE YOU ARE DRAWING MAXIMUM INVERTER OUTPUT, or a proprotionally lower number with lower inverter draws or charger currents. Ideally you do this same test when running the inverter full tilt with microwave and hair dryer to reach 2000-2500VA inverting and with the genset off..
Note: if you write down the length and gauge of each piece of positie and negative wire between inverter-charger and battery that will help explain how much is due to length and gauge of wires an dhow much is due to bad connections.
3) Most importantly, you have to find a way to get your charger to deliver charger´s rated capacity in bulk (early) stage (150A) and battery´s desired charging voltage (14.4 or so) in absorption (later) stage. First action is to reboot the charger and keep an eye on a) current that leaves the charger (ideally measured with a DC ammeter clamp on one of the fat wires connected to the inverter-charger) clamp and b) voltage between the two terminals where the fat wires are attached to inverter-charger. If you do not have a clamp turn off all loads and solar
, set the inverter-charger to "charger only" and read amps and volts in the battery monitor.Record the values every minute for 10 minutes and report back.. You will have to do this test for both bulk an dabsorption stages, which means either charging or discharging batteries as required.. This point is with solar off and inverter-charger in "charge only" mode .