Charging a car battery.?

RegoR

Can I charge my car battery while it is still connected to the car, I have had advice on two different ways, 1. disconnect the earth cable. 2. disconnect both cables. Any electronic experts out there...

goldspanners

it depends. why do you want to charge it? is there something on the car draining your battery? it would be better to disconnect it, but you only need to disconnect one of the leads.

RegoR

The car has been sat in the garage for over a week now and today it would not start (Flat Battery). It needs a good charge , So which lead do I disconnect.

goldspanners

give it a jump start and take it for a drive.i presume thats why you want to start it?

if you really want to charge it then you can take whatever lead you like off. some folk say the negative is the safest for the car. but bear in mind you might loose your radio code if its coded.

Inactive

RegoR wrote: »

The car has been sat in the garage for over a week now and today it would not start (Flat Battery). It needs a good charge , So which lead do I disconnect.

If your battery will not hold charge for a week, it probably needs replacing.

RegoR

I have not got the means to jump start, if I did I have a foot of snow up the long drive and I would probably end up stalling.
To be on the safe side I think it best to disconnect both leads rather than take a chance with one and give it a good charge.

intranix

simply disconnect both to be on the safe side. it is no effort?

but generally you can charge without disconnecting.

exup

it depends on the charger - alot of modern chargers will allow you to charge the battery while it is still connected - If its an older unsealed battery then you may need to removed the covers to avoid gas build up - but these are pretty rare now - most are sealed, which means they also need a sealed battery charger (again - most that are for sale now will be for sealed batteries).
Unless you have really sensitive electronic equipment on your car then I dont think you will have to disconnect the battery to charge it.

jackieb

How long does a car battery usually last before it needs replacing?

goldspanners

RegoR wrote: »

To be on the safe side I think it best to disconnect both leads rather than take a chance with one and give it a good charge.

why, what chance are you taking?

Inactive

jackieb wrote: »

How long does a car battery usually last before it needs replacing?

That is a bit of a " how long is a piece of string " question.;)

My Daughter has a year 2000 Mazda 323, she has just replaced the original battery.