I have just installed a BatteryProtect in my 4WD to protect the second battery (100Ah start/semi-cycle). The BP is located right next to the battery with both the input and ground wires connected directly to the battery. The only thing connected to the load side of the BP is the cable to the fridge, located at the rear of the vehicle.
When I first connected the fridge it would not turn on until I started the vehicle, which I thought was odd. Upon arriving at my destination I have removed the fridge so there is no load on the BP.
Over several days I have noted each morning the second battery is down around 10.5V (it is always around 12.5V each night after driving around during the day) and the BP hasn’t disconnected the “load”, which is an empty cable running to the rear of the vehicle. The BP is set to disconnect at 11.5V.
I have disconnected the BP from the battery at night and in the morning the battery is still around 12.5V, so the battery is holding charge OK. I have put an amp meter between the two and it is drawing 1.3mA.
I don’t understand how a 1.3mA draw from the BP can drop a 100Ah battery from 12.5V to 10.5V in 12 hours. Also the BP not disconnecting at the set 11.5V is odd. Could this be a sign my BP is dead even though I have only just installed it?
Thanks, Mike.
