Charging C5 2.2 HDi (2007) battery

[Michel]

Hello all,

I need to charge the battery up in a certain C5 that seems to have limpeted itself to my driveway.

I’ll use the smart charger I bought off Zel a while back - do I need to go through the whole shutdown procedure and disconnect the battery, or can I just attach the charger as is with the battery still connected?
Thanks
Mike

[GiveMeABreak]

It is not absolutely necessary to disconnect the old battery - however, it is an additional safety precaution to do so in case of crossing the terminals / shorting with a tool accidentally. If the battery terminals are disconnected (or at least the negative is), then there is no risk of frying an ECU which we have seen numerous times here and that can be expensive.

If you are going to disconnect the negative - then I would advise following the procedure. If you need access to the vehicle while charging - just manually latch the door lock (s) with a screwdriver, so the RCD circuit will be fooled into thinking the doors are shut and allow the other relevant ECUs to sleep, like the suspension ECU etc.

When I do this, I disconnect the negative terminal and insulate it with some rags so it can't make contact again.

[wheeler]

can I just attach the charger as is with the battery still connected?

As long as you are using a smart charger then yes you can.
It is sensible however once the key is out wait 4 minutes or so to allow the network to go to sleep so there is as low a load as possible on the battery when you connect the charger.

[Michel]

Thanks both

[GiveMeABreak]

Absolutely agree regarding the Smart Charger - I forgot to mention that as it will prevent reverse polarity and over-charging.