Thread: Disconnect the Battery while away?

Personally I leave mine on charge when not using it for more than a couple of weeks (I use a ctek mxs 5.0). That way you're guaranteed to have a fully charged disco on your return.

If it is only 4 weeks I would leave or, as suggested get a little ctek maintenance charger. If you leave it connected, your clock, radio, etc. settings will not have to be reset.

Hi Dan, and for a 4 week break, I personally would remove the negative cables clamps from both batteries.

If you can, give the batteries a good overnight charge first.

A couple of things

What is the impact of disconnecting the negative terminals.


I have read it is not good to leave the car on charge for extended periods, longer than 4 weeks, I think.

Would it be worth using a timer so the charger comes on say once week for a day?

Sorry about changing threAd a bit

Richard

Out of interest Tim, why would you disconnect as opposed to leaving the vehicle on a proper trickle charger ?

I leave my van (2 x 100ah deep cycle) on trickle whenever it is not in use.

If you are using an automatic charger, get one that will restart after a power outage. I recently found this after returning from 7 weeks overseas. I'd left the Rangie on charge but when I got home the battery was dead flat. There had been a blackout a few days after we left and the charger didn't start up again after power was restored, it sat there in voltage monitor mode.

The battery was so flat that none of my smart chargers would charge the battery, they all indicated the battery was short circuit. I recovered the battery with an old dumb charger and am still using the battery.

Originally Posted by wbowner

What is the impact of disconnecting the negative terminals.

One usually removes the ground/earth leads first because, if the spanner contacts the chassis, there won't be short circuit. On any modern car that means removing the negative leads. On older Land Rovers (and most, if not all older British cars), the positive lead was the one that was connected to chassis, i.e., positive earth.

Originally Posted by p38arover

The battery was so flat that none of my smart chargers would charge the battery, they all indicated the battery was short circuit.

Probably insufficient battery voltage to allow the charger to confirm that the charger was connected with correct polarity. To overcome this I temporarily connect a good battery in parallel using jumper leads then disconnect it as soon as the charger starts.

Yep. I can't remember the voltage but it was down near zero. An hour with the dumb charger brought it up enough for the smart charger.

The P38A is not a car you can leave for extended periods without a charger attached.