My BCM shows 100% capacity and immediately after the sun goes down it drops to 80%. I am using an Outback FM60 that has been set with battery manufacturers(Rolls) settings. The charger will show that it is floating prior to the sun going down. The battery bank capacity is 700AH. Any idea why I get the drop? Thank you
a few specifics about the batteries and the FM settings would help us diagnose the problem but I will wager a guess that you do not have a long enough Absorb time, as you have Rolls batteries
What are the jumper settings on the BCM ? Stock ?
What is the absorb voltage on the FM60 set for and what is its Absorb time set for ?
Do you have temperature compensation on the FM60 ? If so and the batteries are
a lot warmer than 77 degrees F, the charge voltage will come down from your
default absorb voltage.
boB
The BCM is set for flooded batteries(no jumper). The absorb voltage is set at 30V and the absorb time is set at 2.5 Hrs. Currently the temp is slightly above freezing during the day. Thank you all again.
have you ever done an EQ on those batteries, particularly when they were first put into service?
My initial reaction is that you need to lengthen the absorb time, possibly to 4 hours, and then do an EQ.
What charger do you have as a generator supplied BULK/ABSORB charge may be needed before floating by PV and then into EQ.
Which model of Rolls battery do you have?
hth
Quote from: RickR on January 04, 2013, 09:32:05 AM
The BCM is set for flooded batteries(no jumper). The absorb voltage is set at 30V and the absorb time is set at 2.5 Hrs. Currently the temp is slightly above freezing during the day. Thank you all again.
Those do seem to be good settings.
Do you find that the voltage is really staying at 30 volts for that amount of time ?
boB
is the power varying from time to time. that is, does the power changes by morning, afternoon and evening. if it is so then there is problem with your battery backup.