Battery under guarantee, now flat, advice given by seller

[IanA2]

The battery (Bosch S4) was bought in April.

Despite being on trickler for several weeks, a couple of days ago, it was flat.

I tried two different jump packs, car would not start.

Changed trickler to a charger which read 00V.

Connected seller, who told me to use a multimeter which I don't have.

Told him the reading on charger is 00V and he then came back with this:

Please try the following to re-charge your battery:

1. Connect flat battery to any other battery with jump leads

2. Leave for 10 mins and then connect charger to flat battery at same time.

3. Turn on charger and charge like this for 1 hour.

4. Then take off jump leads and charge battery normally with charger for minimum of 12 hours.

This will then bring the battery up to 12.73v (100% Capacity)

So my question is, if I could find a way of following his instructions (there are reasons I can't).

Would it work?

Thanks

[littleredrooster]

Sounds reasonable. Many modern chargers need to detect something above 6v before they will start charging, so connecting a 12v supply (another battery) would allow charging to start.

You sound as if you want the seller to replace it because it's gone flat?

[IanA2]

littleredrooster said:

Sounds reasonable. Many modern chargers need to detect something above 6v before they will start charging, so connecting a 12v supply (another battery) would allow charging to start.

You sound as if you want the seller to replace it because it's gone flat?

So are you saying it will work?

On all other occaisons I've had flats, a jump starter pack has worked.

That's why I think something is different here.

Also, is this normal for a battery that has been on continual trickle for a month?

[GreenV8S]

If you aren't monitoring the charging voltage or current, it's impossible to know whether the charger has actually been charging it.

The fact the charger won't charge it now probably is because the battery voltage is too low, as your seller seems to be suggesting. It is usually possible to overcome that by connecting to another 12V battery to bring the voltage up slightly, or by connecting it to a dumb battery charger for a while.

Note that if the battery has been deeply discharged to the point that a battery charger won't recognise it, it will almost certainly have been damaged. This can cause an internal short within internal cells such that they don't charge subsequently, and reduced capacity for the other cells.

It's most unlikely that the battery went flat because of a defect in the battery so I wouldn't count on getting it replaced under warranty, but if you have that option I'd definitely take it.

[IanA2]

GreenV8S said:

If you aren't monitoring the charging voltage or current, it's impossible to know whether the charger has actually been charging it.

The fact the charger won't charge it now probably is because the battery voltage is too low, as your seller seems to be suggesting. It is usually possible to overcome that by connecting to another 12V battery to bring the voltage up slightly, or by connecting it to a dumb battery charger for a while.

Note that if the battery has been deeply discharged to the point that a battery charger won't recognise it, it will almost certainly have been damaged. This can cause an internal short within internal cells such that they don't charge subsequently, and reduced capacity for the other cells.

It's most unlikely that the battery went flat because of a defect in the battery so I wouldn't count on getting it replaced under warranty, but if you have that option I'd definitely take it.

Agree that it's difficult to know if the trickler had actually been charging as it was not monitored. That said it does have warning functions and none showed. Also I know they work as we've swapped them around and they all appear to be functioning correctly.

The two things I can't figure out is why the complete discharge and why the jump packs won't work.

We'll give his instructions a whirl, but I don't think there's a cats chance in hell of the warranty being honoured.

[GreenV8S]

Are you connecting jump leads and charger directly onto the battery posts?

[IanA2]

GreenV8S said:

Are you connecting jump leads and charger directly onto the battery posts?

Yes.

[rustednut]

Very unusual for a bad battery to read 0v. It is usually only 1 cell, or 2 that fail and more likely to give a reading of 10/11v area after standing.

Seller knows this, and I think he suspects it has been drained and not necessarily faulty. It can only be tested when (ideally fully) charged, so he wants you to confirm this before going furhter. Which also means he knows, if so, that any fault is not necessarily the battery either.

Too late for you, but batteries are 1 item I would always buy locally, purely in case of any warranty issues. No doubt it was a lot cheaper to buy online, but what price is inconvenience? A local seller may well have been able to lend you another used battery whilst doing a full test on yours.

[GreenV8S]

IanA2 said:

Yes.

That's a shame - a wiring / fusible link issue would have been a very convenient explanation.

From your first post I understand you tried to jump start the engine using two different jump starter battery packs and they both failed. That's worrying. Did you get any sign of life at all when you tried starting with them connected?

I think it will be difficult to get any further without being able to measure the battery voltage. It would be well worth getting a volt meter - they aren't expensive.

[IanA2]

GreenV8S said:

IanA2 said:

Yes.

That's a shame - a wiring / fusible link issue would have been a very convenient explanation.

From your first post I understand you tried to jump start the engine using two different jump starter battery packs and they both failed. That's worrying. Did you get any sign of life at all when you tried starting with them connected?

I think it will be difficult to get any further without being able to measure the battery voltage. It would be well worth getting a volt meter - they aren't expensive.

It's the failure to start the car with the jump packs that worries me. There were no signs of any life whatsoever.

I've ordered a new battery and will be trying the seller's directions. If it revives the battery, (which I don't think it will), then fine.

If it does not then it will be returned for "examination". If they decide it was caused by an "external fault" then I can whistle warranty blues.

I'm expecting to be whistling, but at least the car will be running and there'll be a spare battery in the garage!

[GreenV8S]

IanA2 said:

I'm expecting to be whistling, but at least the car will be running and there'll be a spare battery in the garage!

And a volt meter?

[IanA2]

GreenV8S said:

IanA2 said:

I'm expecting to be whistling, but at least the car will be running and there'll be a spare battery in the garage!

And a volt meter?

Given the current plan of action, I'm not sure what a voltmeter would bring to the party....

[Chris32345]

Was it a smart charger or a dumb type that constantly charges?


If the latter you've probably cooked the battery constantly putting power into it

[IanA2]

Chris32345 said:

Was it a smart charger or a dumb type that constantly charges?


If the latter you've probably cooked the battery constantly putting power into it

Smart. No cooking involved.

[GreenV8S]

IanA2 said:

Given the current plan of action, I'm not sure what a voltmeter would bring to the party....

It would give you a means to measure the actual state of charge of any battery in future so you can confirm the charger is doing what you think, and enable you to diagnose this type of not starting/possible flat battery/wiring fault type of problem.

[IanA2]

GreenV8S said:

IanA2 said:

Given the current plan of action, I'm not sure what a voltmeter would bring to the party....

It would give you a means to measure the actual state of charge of any battery in future so you can confirm the charger is doing what you think, and enable you to diagnose this type of not starting/possible flat battery/wiring fault type of problem.

Possibly, but by following the seller's instructions I can establish if the battery is of any use to me, I suspect it will not be and it will be returned to the seller for refusal of warranty.

In the alternative, his instructions work, and I have a spare battery.

Meanwhile I have a driveable vehicle.

All done without a voltmeter :-)

[GreenV8S]

IanA2 said:

All done without a voltmeter :-)

The voltmeter tells you a lot about the condition and charge of the battery and helps to diagnose starting problems. Notice how the first question from your supplier was about the voltage?

If you're planning to diagnose problems like this yourself in future, it should be on your Christmas list.

[IanA2]

GreenV8S said:

IanA2 said:

All done without a voltmeter :-)

The voltmeter tells you a lot about the condition and charge of the battery and helps to diagnose starting problems. Notice how the first question from your supplier was about the voltage?

If you're planning to diagnose problems like this yourself in future, it should be on your Christmas list.

Shortly before discovering the flat battery, I threw out an old voltmeter as I I'm trying to clear stuff out and had not used it for years.

I'll not be buying another unless absolutely necessary.

[AW10]

IanA2 said:

I'll not be buying another unless absolutely necessary.

wow. pretty fundamental piece of kit when troubleshooting electrics. whether fuses, batteries, mains supplies, cables, etc.

[GreenV8S]

IanA2 said:

I'll not be buying another unless absolutely necessary.

That's an odd attitude for somebody to have who was asking for advice about an electrical problem. I take it that you won't be planning to understand or diagnose any electrical problems yourself in future, then.