Testing a Car batery

[Alex_G60_Fanatic 0]

Hi all!

 

I have recently put my car in for an MOT and found that the battery that has been on trickle charge for 6 months didn't work. It would charge to a point and then loose it's charge after a day.

 

Checked the electrolyte levels and It was almost empty... I think my trickle charger was passivating the water in the electrolyte (turning H2O in to H and O)

 

I got some distilled/ionised water and topped up the cells and popped it back on to trickle charge.

 

I'm measuring a Voltage of 13v across the battery last night and 13.7v this morning.

 

My question is... How can I test the battery for current (amps)? I want to see if it holds it's charge now I've topped it up a bit. I don't have my Corrado at the moment as it's at the garage so I can' t plug it in to that. Also, what's the chances that I've fudged the battery?? It was on trickle charge for 6 months almost! just bubbling electrolyte away...

 

BTW I tried to take it back to the shop (6 month old battery with 2 year warranty) and they said they wouldn't do that because I had let the electrolyte get to low :(

[RowanVW 0]

Just had this problem!

 

http://the-corrado.net/showthread.php?57529-New-Battery-Keeps-Draining-Help-identifying-why

[Alex_G60_Fanatic 0]

yes but it would seem that you didn't find the problem and didn't check the electrolyte levels... you just bought a new battery! :lol:

 

that's hardly helping me! I want a new battery but i can't really afford the £60!

[RowanVW 0]

The problem was the battery was not holding charge, in my experience once a battery has gone theres no bringing it back and a quick bit of research confirms this so why would I bother trying to fix it!

 

The problem is when batterys go past a point, i.e a deep discharge you damage it beyond repair! I explained the problem clearly in my thread I had left the boot light on and I wrecked it beyond the maintenance things such as electrolyte and trickle charging.

 

Sorry for trying to help! haha

[RW1 0]

Charge it up right through to full with your charger. ie if 60 amp hr and using a 4 amp charger = 60 / 4 = 15hours.

 

Then leave it off the car for a day and where does the voltage settle?

 

12.75 volts = 100% charge

12.50 volts = 75%

12.25 volts = 50%

12.00 volts & below.

 

If its good, then it will sit somewhere between 12.75 volts & 12.50 volts.

 

If its below 12.50 volts...... past its sell by date due to internal discharging.

 

Next test with a Battery tester. Could always take it to a local factors who may have one. That will give you the start current capacity to deliver when starting.

 

.

[Alex_G60_Fanatic 0]

yes but i didn't have that problem... read the 1st post

 

the battery has been on trickle charge since it came off the car... I over charged it!

 

If you undercharge the battery then at about 25% charge the lead plates start to distort and buckle and this can eventually cause shorts. My battery didn't have this happen to it at any point it wasn't even in the car at the time.

 

---------- Post added at 11:24 AM ---------- Previous post was at 11:11 AM ----------

 

Charge it up right through to full with your charger. ie if 60 amp hr and using a 4 amp charger = 60 / 4 = 15hours.

 

Then leave it off the car for a day and where does the voltage settle?

 

12.75 volts = 100% charge

12.50 volts = 75%

12.25 volts = 50%

12.00 volts & below.

 

If its good, then it will sit somewhere between 12.75 volts & 12.50 volts.

 

If its below 12.50 volts...... past its sell by date due to internal discharging.

 

Next test with a Battery tester. Could always take it to a local factors who may have one. That will give you the start current capacity to deliver when starting.

 

.

 

That's ideal mate thanks, I've taken it off trickle charge now and we'll see where it settles down. I'm picking my car up tonight so I'll take the battery with me. Hopefully the garage has a tester I can use... If i could save the £60 that would be great. Last thing I want is to have less to spend on fixing the car.

 

Sorry for trying to help! haha

sorry if it sounded like i was having a go BTW, Im not annoyed at you... I'm annoyed at Autosave for not taking my battery back and giving me a refund...

[Supercharged 2]

Just take it to Halfords mate - they'll test it for free on a Bosch tester

[RW1 0]

Ah OK, haven't had my breakfast yet, dozy me. Its goosed, end of story and in a dangerous state if connected to the car. Read below. A cell has gone as you have observed.

 

Go and stuff the shop. The battery has failed in a recognised way. Tell them that a cell has gassed. A common failure mode for a battery which results in the cell level going down. And you would not have had any chance of realising unless you checked the battery daily (unreasonable demand). If the guarentee is with the battery maker, not the shop, ring them and report your mega dissappointment to honour their guarentee.

 

AND I wouldn't fit that battery back on the car and run the engine. It could explode. Once saw a battery in a Golf Mk3 go at Inters without warning on the sprint line and the bonnet hit the windscreen and there was no front left between the wings. All blow away with a hell of a crack which hurt my ears at 100m away. THere was nothing left where the battery was other than the two terminals clamped in the car's cables.

 

.

[RowanVW 0]

No worries mate, I wouldn't intentionally offer bad advice though! I would be really annoyed in your position aswell so fair enough!

 

Some good advice in the comment above I think, I would take that knowledge back to where you bought it from and 'kick off'

 

:)

[Alex_G60_Fanatic 0]

Ah OK, haven't had my breakfast yet, dozy me. Its goosed, end of story and in a dangerous state if connected to the car. Read below. A cell has gone as you have observed.

 

Go and stuff the shop. The battery has failed in a recognised way. Tell them that a cell has gassed. A common failure mode for a battery which results in the cell level going down. And you would not have had any chance of realising unless you checked the battery daily (unreasonable demand). If the guarentee is with the battery maker, not the shop, ring them and report your mega dissappointment to honour their guarentee.

 

AND I wouldn't fit that battery back on the car and run the engine. It could explode. Once saw a battery in a Golf Mk3 go at Inters without warning on the sprint line and the bonnet hit the windscreen and there was no front left between the wings. All blow away with a hell of a crack which hurt my ears at 100m away. THere was nothing left where the battery was other than the two terminals clamped in the car's cables.

 

.

 

This explosive quality you speak of... hydrogen and oxygen building up in the battery I can comprehend would go BOOM eventually. But I have a open battery, not a sealed one. So the hydrogen and oxygen just come off and dissipate in the air. How would the battery "gas" without me charging it?

 

Also, do you know of any literature on-line that would help me prove this to the shop!

 

Thanks BTW, this conversation was a great help!

[RW1 0]

Literature.... no. My own experiences with numerous battery failures over the years and nursing them. And those were VW supplied. I can recall two doing this with cell failures.

 

One gassed on the car as I drove over a ramp in a car park gentle like. Stank like hell and the bonnet area looked as though the rad header tank had blown or a rad hose. White vapour all over the place.

 

My friend has just one go with two cells gassing two nights ago. Another VW battery been on the car about 18 months.

 

As I said, its a common failure mode.

 

The explosion is not necessarily the gas igniting. The battery literally just blows up like a balloon with the gassing and pops with one almighty bang.

Cap off may stop that but you will be loading the alternator and therefore running things continually at higher current output which will put strain on the alternator.

 

Just searched on car battery gassing.... http://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

 

.

Edited August 19, 2011 by RW1

[Alex_G60_Fanatic 0]

Literature.... no. My own experiences with numerous battery failures over the years and nursing them. And those were VW supplied. I can recall two doing this with cell failures.

 

One gassed on the car as I drove over a ramp in a car park gentle like. Stank like hell and the bonnet area looked as though the rad header tank had blown or a rad hose. White vapour all over the place.

 

My friend has just one go with two cells gassing two nights ago. Another VW battery been on the car about 18 months.

 

As I said, its a common failure mode.

 

The explosion is not necessarily the gas igniting. The battery literally just blows up like a balloon with the gassing and pops with one almighty bang.

Cap off may stop that but you will be loading the alternator and therefore running things continually at higher current output which will put strain on the alternator.

 

.

 

I wish you lived near me... I could do with you coming to Autosave to shout at them for me... I'll never remember all this stuff. Maybe I'll ring Autosave up (their main office if they have one) and see what they say. Failing that I'll have to drive to Aberdeen.. they have 3 shops there. Thing is I've topped up the electrolyte now, It looks like a normal duff battery now :)

[RW1 0]

They wouldn't survive in the shop with me. Thats what RW stands for as a nick-name.

 

Fact you've topped it up doesn't matter. It should fail on test at their premises where ever you decide to go.

 

Just say.... "The battery is gassing a in cell. Won't hold charge very well. I don't think its safe to used anymore on my car. Also, I've tried trickle charging it with no improvement." Keep it simple.

 

The fact the cell is full now is ocs you topped it up having tried to trickle charge it. If they know their beans, that will immediately be a recognisable fault to them.

 

End of the day, what are they protecting??? A warranty is a warranty and if it can be tested to fail, then its an asbsolute case. The parent company expects a statistical return of batteries due to early failure inside the warranty period. They've budgeted for that in the "ex-works" price.

 

.

Edited August 19, 2011 by RW1

[Alex_G60_Fanatic 0]

They wouldn't survive in the shop with me. Thats what RW stands for as a nick-name.

 

Fact you've topped it up doesn't matter. It should fail on test at their premises where ever you decide to go.

 

Just say.... "The battery is gassing a in cell. Won't hold charge very well. I don't think its safe to used anymore on my car. Also, I've tried trickle charging it with no improvement." Keep it simple.

 

The fact the cell is full now is ocs you topped it up having tried to trickle charge it. If they know their beans, that will immediately be a recognisable fault to them.

 

End of the day, what are they protecting??? A warranty is a warranty and if it can be tested to fail, then its an asbsolute case. The parent company expects a statistical return of batteries due to early failure inside the warranty period. They've budgeted for that in the "ex-works" price.

 

.

try telling that to the guy at this shop! You'd think it was his £60 i was asking for back... Thing is I've been in there twice now with this battery and they want take it. I'll have to phone some ones boss...