Car battery charger problems

[JamesEB]

My car battery went entirely flat and the household battery charger would not begin to put any charge in.

The household insisted this is a fairly new high quality charger and is made to only input charge when there is a small amount of charge left in which it does.

The AA who came said this is rubbish and needs throwing away and I would have thought when the battery was entirely flat was when you needed a charger the most.

Is this true and if I was to buy a new charger what is a good quality, reliable model please?

Thanks
JamesEB

 

[wotan]

Try connecting jump leads across the battery to be charged and a good battery, then connect charger to flat battery, it then should start charging. Carefully remove jump leads, and the charging of the flat battery should continue.

Wotan

 

[JamesEB]

Try connecting jump leads across the battery to be charged and a good battery, then connect charger to flat battery, it then should start charging. Carefully remove jump leads, and the charging of the flat battery should continue.

Wotan

Thanks but I don't have any jumps, no way of getting any and would not be able to use them.

I really do need to know what to do about the existing battery charger and whether it is true that a good battery charger will not charge a completely flat battery but needs some in to start charging or whether this is wrong and it can be thrown away.

Also I would like some advice if I buy a new charger what is a good quality reliable model.

Thanks
JamesEB

 

[wotan]

My battery charger has electronic sensing and will not start charging a completely flat battery, however if you dummy it by connecting another battery in parallel for a few minutes, then it will charge.

Just googled best car battery charger, and came up with
RAC Battery Charger, though not cheap £50 ish
it has had some good reviews, and looks to be of good construction.
But the best charger in the world will not charge a battery that's life expired, would hate you to spend money on a good charger only to find you need a new battery.


Wotan

 

[Whitworth]

Have a look at C-TEK chargers. Some of these and indeed other manufacturers have the facility to charge deep drained batteries. Be prepared to pay though. Round about £60 I think.
TTFN

 

[snapoff]

My car battery went entirely flat and the household battery charger would not begin to put any charge in.

The household insisted this is a fairly new high quality charger and is made to only input charge when there is a small amount of charge left in which it does.

The AA who came said this is rubbish and needs throwing away and I would have thought when the battery was entirely flat was when you needed a charger the most.

Is this true and if I was to buy a new charger what is a good quality, reliable model please?

Thanks
JamesEB

Its the AA man talking rubbish, some chargers do need to see a residual voltage before they will charge.

 

[Peter.N.]

I don't know about all this modern high tech stuff but I do know that a completely flat battery exhibits a very high resistance and will probably not show any current flow when the charger is first connected, if the battery is any good it should start showing a charge if left connected for some hours, if it doesn't, the chances are that the battery is no good. Leaving a lead acid battery flat for any length of time will very often kill it especially if its old. The plates both turn to lead sulphate so you end up with two negative plates - hence, no charge.

Peter

 

[JamesEB]

Thanks everybody. It's a new high quality Bosch battery but went flat while I was away on holiday although disconnected while away. It was then found that the household charger does not have the facility to charge a completely flat battery and I want to buy another one that does.

Can someone please tell me a good quality reliable battery charger that does not require a residual voltage to start charging and how you can tell by looking at the description as I can't.

I'm still a bit puzzled as I would only ever need a charger if the battery was flat and it seems odd that some don't do that and why anyone would want one that doesn't.

Thanks
James EB

 

[djrock]

Thanks everybody. It's a new high quality Bosch battery but went flat while I was away on holiday although disconnected while away. It was then found that the household charger does not have the facility to charge a completely flat battery and I want to buy another one that does.

Can someone please tell me a good quality reliable battery charger that does not require a residual voltage to start charging and how you can tell by looking at the description as I can't.

I'm still a bit puzzled as I would only ever need a charger if the battery was flat and it seems odd that some don't do that and why anyone would want one that doesn't.

Thanks
James EB

What voltage was the battery showing? Since flat could mean about 10.5volts but sounds like it could be below this.

I think you have to be careful charging a discharged lead acid. Since if the battery voltage is too low and you give it too much amps you can kill it.

I think a simple option is get yourself a cheap or you might have one kicking around wall wart transformer that outputs 12v, 500ma or higher. Now this won’t fully charge the battery (if left to) since it need to be about 14v output but should bring the voltage up enough for you to swap to you’re good charger.

 

[Peter.N.]

I can't understand why a new battery should go flat while you were away on holiday if it was disconnected, unless you were away for six months or more. If there was genuinely no load on it for that time I would suggest that it's faulty.

Peter

 

[JamesEB]

What voltage was the battery showing? Since flat could mean about 10.5volts but sounds like it could be below this.

I think you have to be careful charging a discharged lead acid. Since if the battery voltage is too low and you give it too much amps you can kill it.

I think a simple option is get yourself a cheap or you might have one kicking around wall wart transformer that outputs 12v, 500ma or higher. Now this won’t fully charge the battery (if left to) since it need to be about 14v output but should bring the voltage up enough for you to swap to you’re good charger.

Sorry, but this is all a bit above me.

I have to buy my own battery charger and would be grateful if someone could please tell me a good quality reliable battery charger that does not require a residual voltage to start charging and how you can tell by looking at the description as I can't.

Thanks
JamesEB

 

[Mursal]

All good quality chargers need power from the battery to ensure you have the leads on correctly (not crossed)

Some cheaper ones may not have this safe guard and will blow the fuse in the front cover if you connect up incorrectly

Sealey or Draper Chargers will be OK

Try http://www.amazon.co.uk/Sealey-Battery-Charger-12V-230V/dp/B000RA0YYU

Or E-Bay for the above chargers

I hope this is of some help

 

[djrock]

What voltage was the battery showing? Since flat could mean about 10.5volts but sounds like it could be below this.

I think you have to be careful charging a discharged lead acid. Since if the battery voltage is too low and you give it too much amps you can kill it.

I think a simple option is get yourself a cheap or you might have one kicking around wall wart transformer that outputs 12v, 500ma or higher. Now this won’t fully charge the battery (if left to) since it need to be about 14v output but should bring the voltage up enough for you to swap to you’re good charger.

Sorry, but this is all a bit above me.

I have to buy my own battery charger and would be grateful if someone could please tell me a good quality reliable battery charger that does not require a residual voltage to start charging and how you can tell by looking at the description as I can't.

Thanks
JamesEB

OK.

Rereading again I think your charger is telling you the battery has dropped to a level that has started to damage it. The longer the battery is left the more damage is done to it.

As Peter.N. said maybe the battery is faulty to start with.

A dumb charger, which you can pick up cheap should charge it.

This one will very slowly charge it.Could take a week plus to fully charge it if its flat. Good for keeping it topped up if its going to sit for a while.
http://cgi.ebay.co.uk/12V-ATV-CAR-Q...06?pt=UK_Motorcycle_Parts&hash=item1c17d93bea

This one should work and charge it faster. But might damage the battery if it supply's too much amps to the discharged battery.
http://cgi.ebay.co.uk/4AMP-CAR-VAN-...2156?pt=UK_Recovery_Tools&hash=item1e64792e2c

 

[snapoff]

As 'Whitworth' suggested check the Ctek range here, http://www.ctekchargers.co.uk/?gclid=CNGaps7twqkCFYob4Qodlyv4EA not the cheapest but good.

 

[JamesEB]

OK.

Rereading again I think your charger is telling you the battery has dropped to a level that has started to damage it. The longer the battery is left the more damage is done to it.

As Peter.N. said maybe the battery is faulty to start with.

A dumb charger, which you can pick up cheap should charge it.

This one will very slowly charge it.Could take a week plus to fully charge it if its flat. Good for keeping it topped up if its going to sit for a while.
http://cgi.ebay.co.uk/12V-ATV-CAR-Q...06?pt=UK_Motorcycle_Parts&hash=item1c17d93bea

This one should work and charge it faster. But might damage the battery if it supply's too much amps to the discharged battery.
http://cgi.ebay.co.uk/4AMP-CAR-VAN-...2156?pt=UK_Recovery_Tools&hash=item1e64792e2c

Thanks but I do need to buy a good reliable battery charger that does not require a residual voltage to start charging and I need to know how you can tell by looking at the description as I can't.

JamesEB