Exploding Battery

Hi - long story short - brought a 1992 200tdi defender couple of days ago. guys tells me that sometimes the 'starter motor' doesn't run, but try it a couple of times and normally ok.

get to the point where the starter is just spinning and today replaced the starter motor and started first time.

during this time I had the battery on charge on a ctek 9.0 on recond. Later in the day new starter installed cranks first time - of round the block for 10mins park up.

get back in turn the key starts - the bang! All dead. Looked at battery has exploded.

Now...

Just wanted to check could I do anything really stupid when changing the starter motor that would cause that - or could it just be the battery was going to go pop soon?

Thinking I'll replace it with new battery (AGM?) and hope its all good unless anyone has insight on what else could cause it?

Note also that I drove it yesterday for about 4 hours down from north wales.

Any help/advice/answer greatfully received.

Thanks

Jim

jim_m_kidd said:

Hi - long story short - brought a 1992 200tdi defender couple of days ago. guys tells me that sometimes the 'starter motor' doesn't run, but try it a couple of times and normally ok.

get to the point where the starter is just spinning and today replaced the starter motor and started first time.

during this time I had the battery on charge on a ctek 9.0 on recond. Later in the day new starter installed cranks first time - of round the block for 10mins park up.

get back in turn the key starts - the bang! All dead. Looked at battery has exploded.

Now...

Just wanted to check could I do anything really stupid when changing the starter motor that would cause that - or could it just be the battery was going to go pop soon?

Thinking I'll replace it with new battery (AGM?) and hope its all good unless anyone has insight on what else could cause it?

Note also that I drove it yesterday for about 4 hours down from north wales.

Any help/advice/answer greatfully received.

Thanks

Jim

Click to expand...

Batteries explode when the hydrogen gas generated inside under normal charging gets ignited.

This can be done during jump starting when the leads are taken off the wrong way road i,e. the assisting battery should be taken off first, (negative lead), followed by the jumped battery negative lead then the same with the positives...

Its basically a spark that's caused it, the only other time I have come across is on heavy plant where a serious short has occurred across the battery, (usually a foreign metallic object like a pry bar), causing rapid gassing and overheating of the battery and boiling of the acid ...but that is unlikely in this case ...

Its sounds like possible the charging circuit might have been too high causing excess gassing followed by a bad connection on the battery igniting the gas, I think maybe the vent for the battery was blocked or the tube from it kinked ...

I blew one up several years ago by overcharging it.

West Slope Rover said:

I blew one up several years ago by overcharging it.

Click to expand...

I can get quite feisty when I'm overcharged anorl

Ok - new batery this morning - also took some time to clean up battery box and also to replace the old terminal connectors with some new ones.

All fitted - turned over - ran for 10 mins kept eye on it and fine.

Stop - go away and tidy up for 10mins come back key - ignition - click. then key nothing - dead again.

Open up battery box and this time it didn't explode but the positive terminal connector had been severed and the negative post has damage on it again





So looks like it wasn't a duff battery - either some preexisiting condition or something I did when changing the starter motor.

Some thoughts...

1) That sort of damage occurs when there is a short - or other circumstances?

2) Could when I fitted the wiring back on the starter in some way earthed the connectors to the engine somewhere instead of the terminal - its a tight fit.

3) Could the wiring be fine and actual its the starter motor/solonoid that is causing the problem.

4) There were three positive cables in the car - the thick red to starter - then a thinner brown which I think I can account for in the wiring diagram - (feeds the unswitched live?) - then there was a even thinner (like speaker wire) it's black and there was brown sheathing on it - I am not sure what this is at all - any ideas? Was also in place when I picked it up and drove it home - might be spurious - just like to know!

The only other electical fault I'm aware of is a corroded tail light holder.

Any other thoughts? Thanks!

Just going to go do a simple test - if it is a short I should get continueiety between the battery leads?

Okay - so the main cables show a continuiety (070 on my multimeter) the smaller brown and small black cables don't have any.

Quick picture up at my starter motor terminals...



It looks like the main starter cable is touching on the inlet manifold - earthing that cable straight back to the battery - would this be the cause?

Should I have no continieuty between the main battery leads - if so this is what I'll test before exploding another battery!

I would expect to see a large spark when trying to connect if the fault is there all the time.

Yes if + ve is earthing through manifold that is the cause.

sounds like a short to me. it'll be on the unfused pos cable.

looking at the pics it looks like you've wedged the red cable lug on the manifold. you need to be careful that it doesn't move when tightening.

as said above

btw, you need to now check that pos cable to make sure you haven't knackered the wire or melted the insulation off any of it.

also might be worthwhile sticking a protective sleeve over the end, like the brown ones. or some leccy tape. saves dummies shorting it out

Don't use quick disconnect terminals on your main (starter) battery terminals, they aren't rated anywhere near the 700/800 amps the starter will draw. Fit some proper bolt on ones and you should be fine.

Yeah!

(Fingers crossed)

Okay so on the basis of the pictures - got access underneath and took the main cable of the starter - another picture I took and you can see where it had arced against the manifold.

Removed - taped up the exposed bits and refitted taking care on positioning the cable as I tightened it...

New non QR battery clamps as suggested.

Key in - ignition - start!

Drove it round for five minutes - parked up - haven't been back out yet to try and start it again - may wait until morning! - But I think this is it for now.

Pain of a job/troubleshoot for my first job!

Thanks for help.

Jim

jim_m_kidd said:

Yeah!

(Fingers crossed)

Okay so on the basis of the pictures - got access underneath and took the main cable of the starter - another picture I took and you can see where it had arced against the manifold.

Removed - taped up the exposed bits and refitted taking care on positioning the cable as I tightened it...

New non QR battery clamps as suggested.

Key in - ignition - start!

Drove it round for five minutes - parked up - haven't been back out yet to try and start it again - may wait until morning! - But I think this is it for now.

Pain of a job/troubleshoot for my first job!

Thanks for help.

Jim

Click to expand...

keep an eye on the battery, you might have killed it.. and it just doesn't know yet