How to test, Leisure battery charging

When working on a vehicle battery you must take care and wear the appropriate PPE.

The electrolyte in flooded lead-acid batteries contains sulphuric acid. The electrolyte can

not only damage clothes, but it will burn skin if left untreated.

If you come into contact with the battery’s electrolyte, wash and flush the area with water immediately. If it comes into contact with your eyes, flush immediately with water for 15 minutes and promptly seek medical attention.

When performing maintenance on lead-acid batteries, a spark or flame can ignite these

gasses and could cause the battery to explode.

Non-insulated tools or Jewelry can run the risk of arcing if accidental contact is made

between a battery terminal and grounded frame or another terminal. Also, gold or silver

Jewelry can become extremely hot if contact is made. Always wear gloves and use

insulated tools to remove terminals.

There are 3 ways your leisure battery can take a charge whilst fitted to your vehicle and

we are going to show you how to check all 3 are changing.

The first is by 240v hook up cable. The second is by the vehicle engine running and the

third is by solar panel/wind turbine.

To check your 240v hook up is charging, first plug in your lead.

To test this is working, an easy way is to find your consumer unit in the van and press

the rcd/trip switch.

If there is no power there it won't trip, if there is power it should trip.

If you also have a solar or wind charger you should disconnect this charging circuit.

To do this you will need to find your charge controller. You will need to disconnect the

12v negative output cable as this could still be charging the battery during the 240v test.

Now locate your leisure battery and connect your multimeter to the positive and

negative terminals and switch the meter on to the range of 12v dc(usually 20v dc)

You should get a reading of between 12.7v dc(100% charged) and 12.0v dc(25%

charged).

Now reset the rcd/trip switch and the battery should start charging approximately

between 13 and 15 vdc.

To test the vehicle engine charging first disconnect the 240v hook up cable and if

applicable leave the solar charge controller disconnected and check the battery voltage

again.

Start the engine and check the voltage. The results should be similar to the results from

the 240v hook up test.

To test the solar/wind charging circuit now, switch off the engine and make sure the

240v hook up cable is disconnected. Check the battery voltage again and now

reconnect the negative wire into the charge controller output terminal.

You should now get similar charging results as the other two tests.