How to charge a car battery?!

gilbert_and_sullivan

Lulu58 wrote: »

Thanks gilbert and sullivan. I did quite a bit of research and the CTEK came out on top. A Lidl brand also came out high, and at half the price, but they are no longer available at present.

It's a weird connector, which I've not seen before. I more used to the red clipon/over ones. This is really defeating me. I'm off to have 2 shredded wheat to gain a bit of muscle and then I'm going to tackle it again!

I have a CTEK and the Lidl's equivalent, though appearing different the operation including the light sequence of the two are identical, not coincidence methinks.

Your CTEK should have a second set of leads with a safe connector that you can semi permanently connect to the battery making a monthly or whatever you want reconnection much easier.

Once you've got the shredded wheat down your neck all will become apparent.:)

maninthestreet

A battery showing a voltage of 12+ volts when tested with a multimeter doesn't indicate that the battery is OK. The battery's voltage needs to be tested under load - a special meter is required that does this, which any half-decent garage should have. Did the garage in question use such a meter to test the battery AFTER it had been charged??

Strider590

Lulu58 wrote: »

Thanks for your post, Strider590. Perversely, the battery appears fine and shows 12+ volts. It has a complicated history as to why it sometimes goes flat, but the garage suggested I get a good overnight charge in it rather than a surface charge and see what happens. They have also suggested that I regularly use the CTEK charger to keep it 'topped up' as it's a very low mileage car.

Yes that's quite possible, but ive explained this before.... The important factor is it's current capacity, the voltage can be 12v but as soon as you try to start the car it's incapable of supplying the cracking current to turn the engine over.

The plates inside a battery sulfate when left in a discharged state, this coating of gunk covers the plates.



Sulfated




Putting the theory of protons and electrons into laymans terms.
If you think of these plates as the shower head on your shower, which is gunked up with limescale after years of use, you still have the water pressure there (if you measure it at the mains), but with the blockage when you turn it on, you simply won't get the flow.

Pew_Pew_Pew_Lasers!

Strider590 wrote: »

Lead acid batteries produce hydrogen gas during charging, when you try to use the battery it can cause a spark either internally or externally (the plates or the terminals), this ignites the hydrogen gas and BOOM your cars covered in battery acid.... 30 minutes later and your paintwork is soft to the touch down to bare metal.

Maybe if you live in Antarctica, but not in the UK.

Strider590

Pew_Pew_Pew_Lasers! wrote: »

Maybe if you live in Antarctica, but not in the UK.

Happened to me..... Charged my battery over night, reconnected it in the morning, tried to start it 5 min later and it was like a bomb going off..... It sprayed acid all over the front wings, the garage door and the windows at the side of the house. The engine bay had to be hosed out to prevent acid corrosion and the paintwork was ruined.

Looked something like this...

skiddlydiddly

Which bit of Antarctica do you live in then .?

Lulu58

maninthestreet wrote: »

Did the garage in question use such a meter to test the battery AFTER it had been charged??

Thanks for your post maninthestreet. Believe, my battery has been tested to within an inch of its life!! In brief, I plugged an iPod adaptor into my cigarette lighter and everything went downhill from then on in. My local garage have been brilliant and told me that there was nothing wrong with (even though I went in asking for a new battery) and suggested the CTEK or similar to give it a proper charge then monitor it. They also gave me the name of an car electrical chappie who has also been really good and tested everything.

Lulu58

gilbert_and_sullivan wrote: »

I have a CTEK and the Lidl's equivalent, though appearing different the operation including the light sequence of the two are identical, not coincidence methinks.

Your CTEK should have a second set of leads with a safe connector that you can semi permanently connect to the battery making a monthly or whatever you want reconnection much easier.

Once you've got the shredded wheat down your neck all will become apparent.:)

Thanks for your post gilbert and sullivan.

Awesome stuff that Shredded Wheat!! The red thingy which wouldn't budge yesterday came off in one clean sweap revealing the metal below :T I attached the leads and switched the unit on ... everything is tickety boo and it's charging quite happily

The CTEK unit does have a second set of leads, which I may investigate once I get the battery charged and see how it performs. Thanks for that.

Lulu58

Strider590 wrote: »

Happened to me.....

Wow ... that's scary stuff. I hope you were ok after the explosion :eek:

Lulu58

Strider590 wrote: »

Yes that's quite possible, but ive explained this before.... The important factor is it's current capacity, the voltage can be 12v but as soon as you try to start the car it's incapable of supplying the cracking current to turn the engine over.

Forgot to say that the garage did a drop test (I think that's what they called it); put on all the lights, radio etc and tested; tested it from cold during the snowy weather etc. It seems that there was a short caused by the iPod adaptor which affected the battery along with some of the electrics.

All of that has been checked, repaired etc and is now working ok.

We are just trying to ascertain whether the battery is ok or not now.