Thread: Battery Voltage, State Of Charge.

Hi Tim,
Using your chart, how do you recommend putting a load on the battery to perform a loaded battery voltage reading? Does it matter how many amps are being drawn? In my isolated camper, would turning on the lights be enough?

Hi Ranga, when you are out camping, if the battery has not had a load on it over night, then you should run the lights for a few minutes, taking a measurement when you first turn the lights on and again, just before you turn them off.

If there is a fair bit of difference between the two readings, leave the lights on and see if the voltage either stables out or if it keeps dropping.

If you have a compressor fridge connected to the battery, you can pretty well take a reading at any time, but best while the fridge is running.

If the battery is at home and has not been used for a while, again, taking a measurement when you first turn the lights on and then leave the lights on until the voltage stabilise.

This could take anything up to an hour for LED type lights and up to 30 minutes for a SMALL standard type globe.

If it is a battery at home and has not been used for a while, if you have a 55w globe, just connect it to the battery and wait till the voltage stabilises and that will give you a fairly close SoC of the battery.

With a 55w globe, it should stables in 5 to 10 minutes.