Can anyone help? Eggy smell!!!

[Gingerbunts]

Hello All,

I have a 1986 126 brown who I drive almost everyday and in the last week she's developed a sulphury eggy smell. It becomes noticeable about 20 minutes in to a journey and gets stronger the longer she is on the road.

I've had a good sniff and its not coming from the engine it's coming from the front, I thought it smelt stronger closer to the brake fluid reservoir but my partner wasn't so sure.

I've checked her over and there are no odd passengers (like a stray hard boiled egg.....) that could be causing the smell.

Anyone have any ideas?

Many thanks

Nicky

[dadandlad]

Sounds or smells like the battery is on its way out
You need to check the alternator/Dynamo isn't overcharging and cooking the battery and please whatever you do be very careful making any sparks around the battery as they can blow up with quite devastating effect

This is due to the Hydrogen produced when charging 

If in any doubt to what you are doing take it to a garage

[drcdb15]

Agreed. The smell is not hydrogen (which has no smell) but hydrogen sulphide. Cause is almost certainly from the plates in the battery breaking down and not reacting properly in the (re-)charging process.

Generally no hydrogen sulphide is produced during charging, but when the plates are old and coated with impurities and beginning to - literally - break up and go flaky and blistered, other reactions occur, leading to hydrogen sulphide being produced.

It's not likely there is any explosion hazard, and although hydrogen sulphide is toxic above about 1000ppm it's unlikely your exposure is anywhere remotely close to this. The smell becomes almost unbearable at only around 3-5ppm. At 1000ppm you'd be passing out. But be warned, the danger comes when you CANNOT smell it any more - this means your olfactory sensors have become saturated and your brain can no longer distinguish between total absence of the gas and dangerously toxic levels. In other words, if you can smell it, it's not nice but at least you are safe.

Short answer: your battery is dead. Get a new one. Don't sniff the old one too much!

Bio: 7 years as chemical engineer working on hydrogen sulphide industrial process plant.

[dadandlad]

I cannot argue with a chemical engineer but think it is best to be cautious with battery's in general

I have witnessed two blow apart and been involved twice in writing up reports after charging related accidents

The first being a 72 volt battery pack which blew up just after charging when a fitter created a spark and the lot went up, blew him across a hanger bursting his eardrums in the process and coating a Lear jet in battery acid

The second only a few weeks ago when the fitter drop tested said battery whilst on charge and embedding plastic from the case in his elbow

In both cases the people involved were lucky not to be killed

I found this little piece on the net

Why do batteries explode and how can you protect yourself from injury when your hood is up?

It helps to know a little bit about 12-volt lead-acid batteries. They have six two-volt chambers, called cells, that contain a grid of lead plates submerged in sulfuric acid. Electricity is generated when the acid reacts with the lead plates and water.

One byproduct of the process is gaseous hydrogen, an element so highly flammable that it is used to power rocket engines. Charging a battery also generates hydrogen. And because heat drives up hydrogen output, you can expect more trouble generally in hot weather.

The danger is that hydrogen will explode if a spark occurs nearby. One source of sparks can be the battery itself.

As a battery ages, it loses water, leaving the top of the lead plates exposed to the air inside the battery case. Over time, this can lead to warpage of the plates.

[drcdb15]

I don't disagree regarding hydrogen, my remarks were directed to the OP's query as to what was causing the rotten egg smell. Hydrogen is of course another highly hazardous material, and as you rightly say, proper care is needed when handling any of these things.

However, risk is about probabilities as much as possibilities - certainly batteries *can* explode, and hydrogen *can* ignite, but just because something can happen doesn't mean it is in practice likely to. That begs the question, of course, of just what do we mean by "likely" to happen?

I don't have any statistics to support this, but I'd guess by far the most common accident with batteries is fires caused by sort circuiting the positive terminal to earth, setting fire to the cable insulation as a result together with personal injuries such as burns.

I can imagine simply dropping them on one's foot is another common source of injury.

Whatever the detail, you are of course absolutely right: it's best to be cautious with batteries in general.

PS: curious about your fitter doing the battery drop test - you drop test an acid-filled battery while it's being charged? without any protective screening or scrubber shower?    Is that normal?

[drcdb15]

... fires caused by sort circuiting ...

SHORT circuiting

[dadandlad]

PS: curious about your fitter doing the battery drop test - you drop test an acid-filled battery while it's being charged? without any protective screening or scrubber shower?    Is that normal?

No definitely not normal
The fitter who did it isn't the brightest button in the box shall we say

[Rusty's Uncle]

[quote
No definitely not normal
The fitter who did it isn't the brightest button in the box shall we say
[/quote]

Lucky that he is only working on planes then 

[drcdb15]

ROFL !!! 

Slightly off topic, but true story: a builder friend employed one of his men on a job for me, digging foundation inspection hole, said "you'll need to tell him when to stop". Sure enough, this guy was like a human mechanical digger, never in my life have I seen anyone shift rubble like he did. But builder tells of a job they had to dismantle a (glazed) conservatory. This same chap started by removing all (and apparently it really was "all") of the uprights first, intending to move on to do the roof later...

[Gingerbunts]

Wow, thank you so much everyone! I really appreciate the fast responses.

I've only owned her about 2 months and I am learning fast! Thank you so much for sharing your knowledge, it could've been nasty! But I will to her to a garage and get a new battery fitted tomorrow.

Thanks again, much appreciated 

[dadandlad]

No problem glad we could help

How about putting up a few pictures of her

[ChrisRLewis]

But I will to her to a garage and get a new battery fitted tomorrow.

It's still worth checking that the charging system is not overcharging, which may save the new battery from frying

[Gingerbunts]

I'll attach some pics to this discussion now. I'm new to the forum, is there a particular section that members can upload their pics for others to browse? I'd love to see other members cars.

Oh when I try to attach pics it says my files are too big. I'm a bit of a technophobe, don't know how to make the files smaller but I'll have a fiddle .....bear with....

[drcdb15]

But I will to her to a garage and get a new battery fitted tomorrow.

It's still worth checking that the charging system is not overcharging, which may save the new battery from frying

Sound advice, which got me wondering, exactly how do you do this? There was a time donkey's years ago when I used to know these things but now having a totally worn-out memory I did some interwebbery and discovered it's amazingly quick to check - you don't even need to disconnect anything (it says here...). Just stick a voltmeter across the battery terminals while the engine is running and see what voltage you get.

These couple of items might help. Particularly interesting is the snippet about getting someone to rev the engine while you are testing, in case the fault is only apparent under running revs, but not at idle. Sneaky things, these electrical gremlins.

Yonks ago I read somewhere that well over 90% of vehicle faults were electrical, and well over 90% of them are down to poor connections (unless you have a Reliant like me, in which case it's 347%...). I don't know if it's still true today, but on an elderly vehicle it seems quite probable.

http://www.ehow.co.uk/list_7391992_causes-alternator-overcharge_.html

http://mechanics.stackexchange.com/questions/9602/diagnose-faulty-voltage-regulator-causing-battery-overcharging

If you haven't got a multimeter, get one (that's an order). My son who is a physics chap and knows these things came home with one a few years back which impressed me enormously, until I discovered you can get them on eBay for about a tenner. Money well spent - I've probably used it far more than he ever did (and it was his money too )

http://www.ebay.co.uk/itm/eSecure-Digital-Multimeter-Voltmeter-Ammeter-AC-DC-Meter-OHM/331540457538?_trksid=p2141725.c100338.m3726&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20150313114020%26meid%3D3d95aab800d446f888af7926e40deba2%26pid%3D100338%26rk%3D6%26rkt%3D17%26sd%3D390541469797

[dadandlad]

I have both a test meter and probe
The meters are very good but can also be misleading, for instance you have a reading of 12 volts when connected to a wire but still the bulb etc doesn't work
WHY
Because voltage doesn't light the bulb, amperage does. Voltage is merely what pushes the amperage. Often times a burnt or shorted wire will show 12 volts but the instant you put a load on it that will drop out to nothing. Try testing the voltage with the test light hooked up (as a load) and see if it drops.

So usually my first choice is what I call my light on a stick


http://www.ebay.co.uk/itm/HEAVY-DUTY-6-12V-AUTOMOTIVE-ELECTRICAL-CIRCUIT-TESTER-TEST-LAMP-PROBE-LIGHT-/251778516484?hash=item3a9f2b4604:g:kOMAAOSw~gRV1cyM