Battery issues.. (A little long)

No, it's a complete load of bollocks.

Your batterys knackered amd they should replace it. However getting that to happen may take more time than it's worth.

John

be the battery but the garage who I bought it from and the supplier are telling me that the battery is fine..

started to go flat if the car was not used for 5 days.. If I drove the car every second day it would be fine..

12.6v.. Started the car and it went up to 13.9v.. Switched the lights on, the front and rear fog lights on, the rear window heater and the radio.. The lowest I could get it to go was 13.2.. all this was at idle.. reved the car up a little and the it went to 13.3 and sat there.. So I would think the alternator is fine..

about 2 days at various times I tested it with an amp meter in series on the positive terminal.. The load was 0.08A or 80mA.. This to me seems normal but the garage was not convinced and said they would need to have the car booked in to test the electrical system.. (or to word it another way, they want to charge me to tell me there is nothing wrong with my car!!)

bulb to it, I disconnected the car from the battery so the load was ONLY the small bulb.. The load on the bettery from the bulb was 0.130A (130mA).. In theory a 40Ah battery should last about 12 days with this load and I think my battery is over 60Ah so it should last at least 2 weeks.. Over the following days I tested the voltage and the results are below..

problem with this battery?? and how can I convince the supplier that there is a fault?? His gizmo says the battery is fine..

dispute that but it should not go flat so quickly..

to deliver 14.9v and over 15A to charge it.. Does this sound valid?? I would have thought 14.9v would start destroying circuts in the car..

Nope, either it wasn't fully charged when you started the test or it's knackered. & if it needs 14.9V to charge it then he's sold you a battery that's not fit for the purpose you bought it for.

Battery has shorted cell. Replace it. Charging system is fine (according to your measurments)

Tim..

Thanks John,

I think I will write a letter to the complaints department of the battery supplier and see where that gets me..

Its become a mission now..

Thanks again..

I drove the car for over an hour the day before I started the test and I then ran it for 10 mins just before I disconnected it from the car..

So I think as you have commented the battery is screwed..

Thanks..

It does sound like a dud battery, but your 'experiment' is a little flawed as an hours drive can't be certain to fully charge the battery.

That's nowhere near enough long enough to charge the battery. I tend to agree with the view that the battery is knackered but to be absolutely sure you need to either charge it fully (disconnected from the car) using a mains charger and repeat your discharge test or fit it in another car with a known good system and see what happens in that.

knackered. & if it needs 14.9V to charge it then he's sold you a battery that's not fit for the purpose you bought it for.

ran it for 10 mins just before I disconnected it from the car..

Ah that won't be fully charged, try either charging it with a charger for 24 hours & then discharge it at about 10Amps,

Any suggestions on what to use to put a 10A load on it?

Couple of headlight bulbs

One of those naff incar "heaters"

??

Tim..

Have they tested the battery in front of you with a heavy drop(discharge)tester? if so, what did that test show? it sounds like they are denying that it's U/S, but I can't properly understand why, since presumably if they replaced it for you under warranty, they would get a replacement also under warranty from their suppliers. It ought to be no skin off their nose, unless they have changed suppliers or the manufacturer of your battery has gone bust, something like that. That would mean they would be standing the loss and would explain their reluctance. I agree with all the others who have said the battery is u/s. I would say 99% certain.

A good idea might be to take it to a different supplier and ask them to test it without explaining why. See what they say.

HTH

Steve

They're pulling your plonker. The only type of lead acid battery that requires special charging arrangements is the genuine sealed type which uses a gel instead of liquid electrics, and these aren't fitted to cars. In any case, they require a *lower* peak voltage than the normal type to prevent the electrolyte overheating.

Go to an auto electrician and get a heavy discharge test done - this will show up the probable faulty cell.

I think they have done a heavy discharge test and I guess it passed.. The problem seems to be to do with it holding charge with a light load (the cars standard load of alarm and stuff +-80mA) on it.. in this senario the battery is dead after a 4-5 days..

Maybe thats why they keep telling me its fine..

Thats a good idea, I will have to find an auto electrician who should know a little more than the Joe at the battery supplier who does not believe there to be a problem..

If you can remove the filler plugs, look at the electrolyte while the heavy discharge test is taking place. A dead cell will 'boil' furiously.

It's possible the battery is starting out half discharged though due to short journeys with lots of load on. An external charge followed by your tests would be more accurate, but remember a battery is effectively dead at just under 11 volts on a light load.