Just now, james.wilson said:

no it needs to be coming out of the panel so meter the leads with the battery disconnected.

Waiting till the battery has totally failed will usually kill the panel

Thanks James.

Noted about the meter lead needs to be coming out of the panel with the battery disconnected.

 

Battery is usually changed every 3 - 5 years.

Just checking for stable voltage is only half of it, you need to make sure the panel can charge the battery at a decent enough rate.

Measuring the current in and out of the battery with mains on and off.

1 hour ago, CARETAKER46 said:

Thanks.

so i need to have 13.6 volts reading on the battery.

 

Is this without connecting to the panel ?

No not the battery   the leads the battery plugs into 

Thanks  Logan and Sixwheeledbeast