Help with bmv battery monitor please


New member
31 Jul 2011
So I have a bmv 600s monitor, to monitor 1 bank of 300ah.

The problem is that I don't think it is set up right.
The manual says that you should set the charge voltage parameter at a voltage slightly below where the battery is considered fully charged. It then goes on to say that this is normally 0.2-0.3v below the float stage voltage.

Now the battery charger is a mastervolt mass combi. According to the manual..

"The bulk phase is followed by the absorption phase. Absorption charging starts when the voltage on the batteries has reached 14.4V (12V models) / 28.8V (24V models) @ 25°C / 77°F, and ends when the battery is completely full. Battery voltage remains constant at 14.25V (12V models) / 28.5V (24V models) @ 25°C / 77°F throughout this stage, and the charge current depends on the degree to which the battery was initially discharged, the battery type, the ambient temperature, and so on. With a wet cell battery this stage lasts some four hours, with gel and AGM around three. Once the battery is 100% full, the Mastervolt charger automatically switches over to the float phase.
During the float phase the Mass Combi switches to 13.25V (12V models) or 26.5V (24V models) @ 25°C / 77°F and stabilises this voltage to maintain the batteries in an optimum condition. Connected DC loads are powered directly by the charger. If the load is higher than charger capacity, the required additional power comes from the battery, which will be progressively discharged until the charger automatically switches back to the bulk phase. Once consumption decreases, the charger goes back to normal operation of the three-step charge system."

At present I have set the charge voltage parameter to 13.2 volts (just below the float stage voltage). This means that at present the battery monitor is showing as 100% charged. However, the battery is still charging and is still putting 8amps in during the absorption phase.

So the question I have is, do I set the charge parameter voltage to 14v? (0.2v below what the charger considers the batteries charged)



Well-known member
13 Jul 2002
The trouble will be that if the charge voltage parameter is set higher the battery monitor will see is as being less than 100% charged during the float stage.

Perhaps the answer is to experiment and eventually settle on what seems to be the most useful to you.