charge battery in situ

Ant555

Is it OK to charge a car battery with all leads still connected to the car?

I have a battery charger and a long lead to reach my drive but no tools at the moment to take the battery out.

I let the battery go flat at the weekend and I don't think my 40 minute drive each morning/evening is charging the battery fully as each start since the weekend has been a bit laboured.

Thanks

force_ten

some will say you need to disconnect the battery to charge it and others will say that you dont need to disconnect anything, I would say have a look at the cars handbook and follow that advice as i am sure you will get mixed advice

if i wanted to keep the car connected to a charger when the car is parked up at home i would buy a trickle charger and plug that in at home as they are designed to keep the battery topped up

if the battery is struggling to hold charge there may be other underlying issues causing the problem

Ant555

Thanks for the reply.

I intend to charge for 5 or 6 hours from when I get home to just before I go to bed - just checking if its best practice to disconnect - I can get a screwdriver for terminals but not a socket set to remove battery completely.

I am resigned to getting a new battery but am happy to try charging first if this is what is required. I have jump leads and easy access to a jump start both at home on the drive and at work in worst case scenario so as long as I dont stall on the way home then I should be OK until the weekend.

reddwarf2002

As long as charging rate is less than 6 Amps and handbook does not advise otherwise, I would charge it in situ.

EdGasketTheSecond

Be careful you dont blow any electronics; not all 12v chargers are the same. Some have smoothed output and some have noisy output with voltage spikes that have th epotential to damage electronics. On balance it is safer to diconnect the battery but you may lose radio information and the ecu may have to relearn the sensors afterwards so be running inefficiently for a while. On some cars (Mercedes) just connecting the battery can blow electronics; the whole thing is a nightmare these days.

societys_child

Just remove a battery lead, no need to remove the battery from the car.

Steve_KK

Ant555 wrote: »

I let the battery go flat at the weekend and I don't think my 40 minute drive each morning/evening is charging the battery fully as each start since the weekend has been a bit laboured.

It sounds like you have another issue as a 40 minute drive should be plenty to keep a battery charged.
It could be the battery is slowly dying, or your alternator isn't supplying enough current to keep the battery charged. Another issue could be you have something that is draining the battery, for example an interior light that is staying on after the doors are closed.
Finally are you locking the car when you leave it? Some modern cars will not properly shut down all systems unless locked, so that could drain a battery over time.

Regards,
Steve

stator

Disconnect the wires and then charge the battery in situ

shaun_from_Africa

societys_child wrote: »

Just remove a battery lead, no need to remove the battery from the car.

stator wrote: »

Disconnect the wires and then charge the battery in situ

If you do this then for safety reasons make sure that you disconnect and reconnect the leads in the following order:

Disconnect the negative lead first then the positive and when reconnecting, put the positive on first then the negative.

Ant555

Thanks for all the replies - I will disconnect the battery in the car, charge it, and give it a go.

All started as I accidentally left the keys in the car on the drive with the ignition on at the weekend - about 2 hours. Its a diesel Corsa.
Connected jump leads to another car and it started immediately.
Since then I have had the feeling that the battery is on the way out when starting - either I must have done something to it to tip it over the edge by leaving ignition on, or its coincidence and generally showing problems due to cold weather.

David_Aston

Although the handbook for our Honda Jazz does say that it is recommended to disconnect the wires, I have been connecting up a trickle charger with all wires connected, for a couple of years or so, and no probs, up to now.