I just can't figure this out and it's driving me nuts. There are similar posts but never a working solution?
I have two 6v Golf Cart batteries connected in series. 230 Ah. System settings and wiring below.
Victron reports 10.4 amps used, and says that's 97.2% of 230 amps. (is that not 95.4%?)
But when you take their 97.2% of 230, that SHOULD BE 6.44 Amps used?
HOW DOES THAT WORK?! What am I missing here?
What I've done:
- Fully charged the batteries to 100%.
- I then let them let sit for 2 days to stabilize voltages (Completely disconnected all power leads - only thing connected was the BMV 712 - just the little power wire)
- Battery read 12.8v after the two days (The little BMV power wire was still connected)
- I did as the manual states to set zero current:
A zero current calibration is (almost) never needed. Only perform this procedure in case the battery monitor shows a current while you are absolutely sure that there is no actual current flowing. The only way to be sure of this, is to physically disconnect all wires and cables connected to the side of the shunt. Do this by unscrewing the shunt bolt and remove all cables and wires form that side of the shunt. The alternative, which is switching off loads or chargers, is NOT accurate enough as it does not eliminate small standby currents.
- To me, it should not matter the state of the battery when you set Zero Current?
(There is NO current flowing as the battery is disconnected)
Can someone explain it like I'm 5? LOL
So far everything else seems to work like it should, but I'm still confused as to what my battery state really is?
Battery reports full when I believe it to be from the converter (and also the MPPT charger on the solar reports the battery to be full as well)
At the VERY LEAST, what is more accurate, the percentage, the amps used or the voltage?
(So far, I've been following Amps and watching the Voltage reading and trying to make an educated guess that way) Voltage will read 12.1v when the percent still reads in the low 70's? Is that not empty? So confused :(
To me the percentage is so far out of wack that it make ZERO sense. This battery monitor DOES NOT help me monitor my batteries :(
The battery is manufactured by East Penn MFG also called (DEKA) its a GC15.
Two batteries connected in series will be 230Ah. (130Ah useable)
- Reserve Capacity at 25A is 448 Minutes
- RC at 75A is 120 minutes
- The Peukert’s coefficient for most use cases for this battery is 1.24
What is the recommended Bulk, Absorb, Float, Equalize and maintainer parameters?
- Bulk charge to 2.35 volts per cell and hold for Absorption. (14.1v for two in series)
- Float charge at 2.25 volts per cell. (13.5v for two in series)
- To compensate for battery temperature not at 20°C:
- subtract 0.005 V/cell for each 1°C above 20°C;
- add 0.005 V/cell for each 1°C under 20°C.
- An Equalization charge can be done at 15.5 volts.
Max bulk charging current is <=30A per 100 Ah (C20). So for this 230 Ah battery, that's 69 amps. (If charging a pair in series, it's still 69 amps.)