Battery flat - Immobiliser

[JB89]

Hey Everyone,

With the pandemic happening my wife and I ran away from London to my in laws house in Germany, which happens to be where I keep my SL280Auto.
Thinking it might relieve some of the anxiety to go for a little drive as the weather here is nice and sunny, I then realised when it was dropped off it wasn't put on its trickle charge.
We had an immobiliser installed which has helped keep it safe in London, but now Im not sure how to charge the battery or jump start it with the immobiliser on?
Or wether I need to change the battery completely (What I did last time this happened)
Hoping there is a way to get it running.

Any thoughts greatly appreciated

Thanks,

J

[Cees Klumper]

There is a possibility that your battery has 'expired' since, unless it is a deep-cycle one, it is not made to be fully discharged and sitting for an extended period without any charge can ruin it.
That said, you may be able to bring it back to life with the right charger. I would start with whatever charger you have, after disconnecting the immobilizer (however check the manual for that, if you have it someplace) so the battery is isolated from the car + immobilizer. If that does not produce result (in my experience, a battery may not respond to a charger if totally flat) then a special charger may be needed. I have had good results with my 80 Watt solar panel charger, that for some reason was able to resuccitate flat batteries that other chargers could not. Maybe you can take it to a garage to have them give it a try (although I might not take the additional risk that brings of getting infected).

[MikeSimon]

There are small, inexpensive chargers available (here in the U.S., at least) that have a "desulfating" setting. It will revive deep discharged batteries in most cases.