Alternator..: battery off-gassing

[varesecrazy]

Hi.

Ok.. got a weird one.

Diesel mj 1.3.. had horrible fumes.. mechanically seems ok.

Then had a thought about battery 'boiling'

Sure enough its low on fluid

Only does local trips generally.. so might normally stay under-full charge wise.

But 2 hours of m.way nearly gassed us

My last similar issue was on a 1978 fiesta van.. alternator was overcharging.. cooked 2 batteries in 2 weeks.. lesson learned


Ok.. so on the Grande.. will the lack of fluid make it off.gas anyway ( lack of absorption capacity)

Or is it definitely an overcharging alternator..?
(The grandes seem to be prone to alternator issues.. so dont want to meddle..)

Opinions please

 

[chris3234]

Battery gas has a pretty strong sulfur smell in my experience smell it a lot at with forklift battery's so you know if it was that

 

[varesecrazy]

I will update as things progress

 

[DaveMcT]

Check your system voltage. When the alternator voltage regulator fails, the battery will see far too much voltage so it gets overcharged, overheated and wrecked.

 

[varesecrazy]

Battery gas has a pretty strong sulfur smell in my experience smell it a lot at with forklift battery's so you know if it was that

Probably...

(We have a busy road junction in the valleys that smells of sulphur..)

When the clothes you wore reek of the stuff a few days later.. its probably not good

 

[varesecrazy]

Check your system voltage. When the alternator voltage regulator fails, the battery will see far too much voltage so it gets overcharged, overheated and wrecked.

How much is too much?

Back in the Fiesta days I didnt own a meter..

 

[g8rpi]

Anything over 14.6V is too much. A modern car without stop start should be about 14.4V at fast idle and no lights etc on. Should not drop below 13.8V with all lights on.

Robert G8RPI.

 

[varesecrazy]

Its an 07 multijet. Fairly primitive.

Topped up battery.. but its probably toast..
3 cells with exposed plates


Just want to gauge the alternator output..
Rather than cook a replacement battery.

 

[varesecrazy]

Ok.. some progress.

Old battery refilled with demin.

Hydrometer showed cells 3,5,6 80% charge

Others were flat.

A brief charge showed 12.4 v.. but did nothing in the vehicle.. Just ran the lift pump.. but attempting to crank just bounced the dash needles

Coupled to a sound 12v battery.. same result

Then fitted a sound ( but old and undersize..ex seicento..) battery.

Fired instantly.. charging @ 14.48 v

Had a short drive around the block.. seemed ok

Will do some local journeys .. and see how it goes.

Thinking back.. the car had glowplug
issues when purchased.. so has had a relatively hard time..

Then lots of infrequent use : short trips

So there is a possibility it was a battery rather than alternator fault..

The fumes..?

Time will tell.

 

[portland_bill]

Been away from teh forum for a few days, so just catching up.

A failing battery can cause the cells to gas. As teh electrolyte diminishes, the problem accelerates.

An overcharging alternator will cause excess gassing and kills the battery if not sorted quickly. Then as the electrolyte drops, will kill the battery anyway.

So chicken or egg?

If charging rate is good, battery is the problem. Needs a new battery anyway, so fit one, and check the charge rate frequently for a few days until the paranoia reduces.

 

[s130]

Anything over 14.6V is too much. A modern car without stop start should be about 14.4V at fast idle and no lights etc on. Should not drop below 13.8V with all lights on.

Robert G8RPI.

Correct. More specifically

Charge Voltage "absorption" = 14.4V
Charge Voltage "float" = 13.7V
Charge Voltage "storage/maintenance" = 13.2V

 

[varesecrazy]

Thanks all.

My temporary battery will do for a weeks running around.. if I happen to cook it.. better than a new £70 one..

In the meantime.. I have ordered a ciggy lighter socket digital voltage gauge.

Should give me a headstart on managing the battery life..


On the bright side..
Better prospective fumes fix than the diesel injector seals.. that looked REALLY time consuming