The Xantrex monitor issues don't seem to apply to my victron monitor.
There was another thread within that one on victron but it didn't seem to quite address my issue, at least so I could understand it! Something about resetting the monitor? It said the monitor will reset upon reaching 100% which we were at within the last 5 days.
Overnight the SOC dropped to 70% and the voltage read 11.7 volts. Specific gravity was not good, around 1125. According to Calder SOC is ZERO!
UPDATE:
Talked to Victron, required to MANUALLY reset the monitor. That isn't in the supplied manual. Thanks Victron for helping destroy my $1000 battery bank by hiding important information.
There has been much written here and elsewhere about the NEED to do manual resets and properly program the battery monitor for Peukert, CEF, when the full reset occurs and what triggers it etc. etc.. These are not set it and forget it devices and they need human assistance..
SG and voltage only work well on fully rested batteries which often takes 12-24 hours. Was there a load on the batteries when you noted the 11.8V reading? If so then there is a possibility the monitor was closer to correct than you think. With standard lead acid batteries as the SOC drops the ability to hold a voltage under load also changes.
The EASIEST way to re-set a monitor is when you "assume" the bank is full to turn ALL ship loads 100% off. This includes turning off the inverter and DC panel main breaker, solar etc., then run the charger or alternator for 10+/- minutes to get beyond the "inrush" and let it stabilize. Now check the "I" screen and see how much current is flowing into the bank. If that current is below 2% of bank capacity then you are safe to do a manual re-set. While 2% is not "chuck full" it is about as close as you'll get when off cruising and a safe point to do a manual re-set.. It is important that this is at your ABSORPTION voltage not FLOAT voltage. This is why using a battery charger that has been on a while is not a good idea unless you re-start it so it goes to 14.4V +/- when taking this reading.
Manual re-sets, as OFTEN AS POSSIBLE, prevent counting errors in the monitor. Solar especially, can trick these devices into reading "FULL" when they are not and the monitor needs to be programmed to minimize this but it don't feel it can always be 100% prevented..
Next time it reads "FULL" do the acceptance test. You can't use solar for this you need a stable charge source with plenty of current behind it for this test. If the current, with no loads on, is not below 2% of the 20 hour capacity of the bank it is not full......
Battery monitors are only as smart as they can be and external factors can trick them. You as the programmer/human need to be smarter...
So for a 900Ah bank less than 18A flowing into the bank at 14.4V +/- would be a safe re-set range. Personally, I use less than 1.5% as my reset but with solar I can do this as it gets to full every week. I manually re-set my battery monitor every week and it takes no time to do this test. While the motor is warming up I do the "acceptance" test....
