car battery charging

[notmyrealnamebutclose]

Hey guys
Hope you're are all keeping well.

So can you charge your car battery in situ rather than disconnecting it. Suppose it may depend on the vehicle an possibly how modern it is.
Never done this b4 but looking on youtube quite few people say it is possible tho some say no don't do it, it will cause all kinda electrical
gremlins, problems. It may also depend on the type of bat charger you use. I have both a pretty ancient bradex 8amp charger and a
(relatively smart) charger bought from Lidl (ULGD 5.0 C1) which has been v useful maintaining my baby 12v scooter battery. This is the one
I plan to use with bat in situ.

Why not disconnect your battery? I envisage you asking, well will it effect my car radio and trigger a code reset and maybe other things when
reconnecting? The cd/radio looks original factory fit. Only just bought the car know very little about it tbh no hand book or anything, it's an 11 plate
renault modus dynamique 1.2 petrol, battery does seems fine atm but not really going that far in it to charge it atm. Thanks...

 

[Sharky]

On all my old cars, last one was a 2002 model, I've always left the battery in place and just connected the crocodile clips. Never had a problem.

My daughters motobility car when it was less than 6 months old, had a flat battery and when the RAC man tested it, said the battery wasn't accepting charge through lack of use, so fitted a new one for us.

On our current car, a 5 Yr old suzuki, on return from having a new clutch fitted, the radio had to reset. The battery would have been disconnected. Didn't know the code initially, but was advised by the original dealer, the the last 4 digits of the chassis number was the radio code. Probably not the same for a Renault, but who knows.

Good luck

 

[T.M.H.N.E.T]

It'll be fine to connect in situ

 

[Drago]

Yes you can.

 

[Bazzer]

And if you find you do need to change your battery, you may find you can use your charger to keep voltage running through the system, while you remove the old battery and fit a new one. Particularly handy if you don't have the radio code, or for more recent cars, when removal of the 12v supply causes an avalanche of error codes.

 

[CXRAndy]

Yes you can charge on the battery in the car. I use Ctek chargers. Only when a battery is really flat, you get a better performance from the charger off the car

 

[ClichéGuevara]

It's probably my ignorance, but wouldn't charging with it connected be just the same as when it's charging through the motor anyway? It should only draw what it needs, and I've not heard of issues due to overcharging on a long run.

 

[notmyrealnamebutclose]

And if you find you do need to change your battery, you may find you can use your charger to keep voltage running through the system, while you remove the old battery and fit a new one. Particularly handy if you don't have the radio code, or for more recent cars, when removal of the 12v supply causes an avalanche of error codes.

That's good to know. I have read you can disconnect the battery momentarily to replace with a new one without needing codes
etc as car ecu's should temporary memorise certain codes for a limited time.

 

[tyred]

I've always charged batteries in-situ.

 

[Jameshow]

I've always charged batteries in-situ.

I had always removed the positive! But thinking about it is it any different to the alternator charging?

 

[notmyrealnamebutclose]

I've always charged batteries in-situ.

have you heard that joke about the bloke who lost his vibrator up his wotsit, the a&e nurse struggled to retrieve it.

oh well, he said, can you atleast change the batteries

 

[Sharky]

When using jump leads to start a dead car, I was told to keep the engine running on the healthy car. Something to do with electrikery flowing back to the dynamo/alternator of the healthy car and doing damage.

No idea if this is true or a myth.

 

[wafter]

I see no reason why you shouldn't, and while I have a solid background with old cars I'm sh*t with electrics while modern cars are pure witchcraft; so please ignore anything I suggest 👍

 

[biggs682]

It should be ok

 

[figbat]

I recall reading some time ago that some new cars need to track battery charging, and that by adding extra from an external source it gets upset. Some even need a new battery to be ‘coded’ to the car.