Classic cars forum & vehicle restoration.

[Kelsham]

Hi all,
the battery on my 1968 landcrab exploded under the bonnet on Sunday. The car carried on regardless.
When I arrived home I put a voltmeter on the battery terminals. I had a steadily increasing level of volts. when it got to 17 volts I switched off.
It looks like a faulty voltage requlator. any comments? It took two hours to clean the engine bay. and the top of the battery was blown out.

regards Kels.

[Nic Jarman]

Was it a sealed battery? If not then maybe the vent has blocked. After you lost an amount of acid in the battery the voltage ( potential ) will rise as there is a decreased current flow so the increase in voltage is not in itself a problem. However if you put a new battery on and you still have a high voltage then your regulator may be faulty. I am old school when I fit a new battery, charge it over night before hitting the start button. Good luck.
_________________
1936 Morris 8 Series 1
1973 MGB roadster
1977 MG Midget 1500
Dax Rush

[peter scott]

Hi Kels,

Bad luck with the battery. Getting rid of acid spill is very difficult. It gets into all the seams of metalwork. Clearly you need to neuralise it with alkali but this just tends to run off. I've found that pouring thick Domestos over the affected area and just leaving it there for a few weeks is quite effective.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[victor 101]

If your running a dynamo it's the regulator at fault, if it's an alternator its probably down to a replacement unit unless you can source the individual bits and rebuild your own. 14.5v is the about the most you want to be producing. At 17+ it must have boiled your battery. If you know someone with a steam cleaner I would consider wrapping all electrics in plastic bags and blasting it of under the bonnet.

[Kelsham]

Hi all thanks for the comments, I bought a new regulator it has a dynamo.
When I fitted it, I tried it on the old battery, probably foolish.

When I started the engine the charge rate was 13.8 volts with some fluctuation but not excessive.
However I saw smoke rising from the resistors at the back of the regulator?? .
Naturally switched off instantly. Am going to collect a new battery tommorow. Will try that. I am trying to convince myself the smoke was residue burning off the resistors. Further comments welcome.
regards Kels.

[ukdave2002]

Hi Kelsham

Your post is a great reminder to all of us who have dynamo's and control box's, why battery maintenace is important !! I think we all have got a bit compalcent with modern charging systems and sealed batteries.

I did a post on this some time ago;
The dynamo and control box system is a bit crudeand as a consiquence the battrey will often get over charged and gas, which is why they should checked often and topped up, and the control box checked and adjusted as part of routine maintenance.

For this reason you should never fit a sealed for life battery on a dynamo vehicle. as it will gas, but you have no way of topping it up. Moden cars with sopisticated charging and battery conditioning circuits don't cause any overcharging or gassing so sealed maintenance free batteries are fine.

The wire would resistors on the control box's are pretty robust, probably got hot because you more than lightly have shorted cells in the old batttery.

let us know how you get on

Cheers

Dave

[Kelsham]

Thanks for all your comments.
I believe that all is now OK. I think that prior to fitting the regulator it had laid on the bench,where it picked up some contamination on the resistor.

The smoke was as it burned off.

I have run it again and it seems alright with fairly steady voltage control.

regards Kels.