Whizbang Junior Vs MNBCM who to believe???

[mooseandpebs]

I have the Whizbang Junior installed and the MNBCM installed. The Whizbang Jr. says the SOC,(State Of Charge) is 94% and the MNBCM says the SOC is 50%. Which one is right?
Thanks!

[Vic]

In general,  battery Monitoring devices can only be as accurate as is the setup information about the system as has been entered into them.

Rate of discharge and charge of the battery affects the actual capacity,  and there are many other variables that really require a fairly accurate mathematical model of the actual battery being monitored.

The WBjr is a very useful tool,  and very inexpensive,  at that.   In general,  these monitors  give a quick rough approximation of the SOC.   The WBjr  keeps very accurate count on the AH removed and returned to the battery.   How these factors affect the ACTUAL SOC is fairly difficult to derive,   IMO.

FWIW,   Vic

[CDN-VT]

Whizbang Junior over the MNBCM , but you need to make sure all the correct settings are in the menu 3 of the WBjr . the BCM is a quick  look from afar,.

[boB]

Yeah, if the WB Jr. invormation is correct and the charger has gone from Absorb to Float,
the WB Jr. should be more accurate I would think.

The MNBCM only looks at battery voltage so is just an approximation.

The main reason for the BCM is to show the user that the batteries did not
get a full charge (Absorb actually) within the last week or two but looking at the voltage
and time.

boB