Reviving a sealed lead-acid battery

[Pierre ZFP]

I'm hoping for a little advice from you clever folks out there.

I have a 'car boost starter' thingy which is pretty useless for starting cars but does have a 12v sealed lead-acid battery in it and is/was useful as it had bright lights on it, an electric pump for the tyres and last but not least, a portable 12v supply.

Now it won't take a charge.

It didn't cost a lot (less than €30) but a new battery from fleabay is at least €50

I have got the battery free of the case and it is marked 12v 17AH

The top part of the battery box is well glued on to the base (hence 'sealed' I suppose) but assuming I could cut the top off and get to the cells, can I do anything to revive this battery or am I just wasting my time?  I've looked on You Tube and there is a lot of info but much of it sounds contradictory if not downright dangerous.

All suggestion gratefully received and considered

 

[PaulT]

Buy a decent charger, one that carries out a desulphurisation process (I use an Optimate 6) and that revives batteries well.

[Théière]

Seconded, that's actually a posh term for reverse polarity I believe now where is our frenchman when we need him, he is a whizz on lead acid batteries.

[ericd]

[quote user="Pierre ZFP"]

I have a 12v sealed lead-acid battery in it and is/was useful as it had bright lights on it, an electric pump for the tyres and last but not least, a portable 12v supply.

Now it won't take a charge.

I have got the battery free of the case and it is marked 12v 17AH

The top part of the battery box is well glued on to the base (hence 'sealed' I suppose) but assuming I could cut the top off and get to the cells, can I do anything to revive this battery or am I just wasting my time?  I've looked on You Tube and there is a lot of info but much of it sounds contradictory if not downright dangerous. All suggestion gratefully received and considered [/quote]

Talking about me ??? I have been in the battery (lead-acid) business for nearly 20 years [+o(] so hopefully my bit of advice will be taken on board..... find your nearest recycling bay and get rid of it.

That kind of battery is likely to be of the MSLI type (for Motorcycle) tofit inside your charger and will have failed for a number of reasons mainly a) Chinese made b) poor separation between the plates causing a short c) too little acid in what is supposed to be a MF battery (Maintenance free) d) battery left discharged for too long and Electro/chemist Professors in their 70s I know of are still pondering on the subject without having realy found the solution (they know the reasons though) etc. etc.  

Look at this YouTube video of a battery manufacturer (or more battery repairer) in Nepal http://www.youtube.com/watch?v=MOTFBDLziHI  that's basically what you will have to do ......and that repair will only last a few months because you haven't used the correct alloys or welded the intercell connections good enough.

[ericd]

Check this up, this should be the size of your battery. For what you have to lose (ie. nothing) give it a go. This is of course, valid if your case is as in c) (don't add acid just deionised/distilled water or very clean filtered rain water).

http://www.youtube.com/watch?v=2JIzSxqWids 

 

[Chancer]

I am kicking myself now Eric, I have given loads of "sealed for life" car batteries a new lease of life doing just this but had mistakenly thought that the small sealed lead acid cells that I used, Yuasa, were gel filled.

Mind you I used to make a fortune every couple of years changing them out on access control systems under the maintenance contract, I have a box filled with about 12 1.2ah ones that I used to power my timing beacon for my race car, it hasnt been charged for 10 years now and they were batteries that I had already removed from service, I'll give them a look when I return to the UK, if I can recover them enough to power the thing up to sell it then I will be very happy.

[ericd]

Hey Chancer. I hope you don't bruise easily then.....If they were Gel Batteries, this would (I believe) be displayed on the casing as this is a marketing point. Gel batteries (developped by Sonnenshein in Austria) were originally developped as a safety battery in case of accident (ie. if it were to topple over and get damaged in an accident, the gel would remain within the battery casing and not spill all over as for their Acid filled cousins). Most if not all electric wheel chairs are for exaple, fitted with gel batteries. You can attempt to revive "dead" Gel batteries via a slow charge avoiding high heat at all time. Again, if the gel has dried up, it's a bin job.

Let us know how you get on with your old batteires when you get back to the UK.

[Pierre ZFP]

Thanks all for the replies.  I don't think I'll be going down the super dooper charger route because however good they are, it's not worth it to me to buy a £90 charger for a €30 'toy'

Thanks ericd for your asessment I think of the reasons you gave for failure, well, all of them apply.

I have seen some weird and wonderful magic cures on 'tinterweb,  mainly using magnesium sulphate (why do they persist in calling it Epsom Salts ???) but also using citric acid to 'de acidify the plates ' [8-)]  and even sodium hydroxide !  Add to that the guy who was smoking a ciggy over a charging battery and you can see why I wanted some solid good info.

Since I have nothing to lose, I will attempt to carefully remove the top of the battery and add some distilled water but I can see that it will probably be off to the recycle centre unfortunately

I'll let you all know how I get on, thanks again

[PaulT]

Whilst the charger I referred to is a super dooper £90 one (and seems to do the job) I could not resist a Lidl charger that was under £15 and has a desulphurisation mode - have two batteries I need to keep on charge. So if Lidl France ever have these grab one.

[dave21478]

Interesting - I have a jump start pack that no longers holds a charge - I will try this later this afternoon.

[dave21478]

Nothing else doing today so I made a start.

I bought this jump pack while I was hundreds of Km away from home in a tight spot one day from a Leclerc Auto. I opted for "quality" and bought the dearest one they had, at about 90Euros iirc.

It worked fine, but after a couple of months, became less and less effective, to the point where it would no longer even jump the wee Briggs engined lawnmower.

I would have taken it back, but like the doofus I am, had lost the receipt by then. I tried pleading my case in my nearest Leclerc, but they were having none of it, so it was relegated to the back of the garage.

It came apart very easily - 6 pozidrive screws holding the two halves together, and inside was the usual bundle of disappointment generally found in modern appliances.....a nest of low quality wiring, badly soldered joints and wee sections of pcb hot-glued to the inside of the casing.

With the battery itself removed, it is a sealed thing made by - and I am not kidding! - the "Langfang Donsanxing battery co Ltd."

I got a stanley knife to cut open the top as shown in the youtube video, but noticed straight off that there were ALREADY screwdriver marks around the lid, which just lifted off with no resistance. It has been opened previously - During manufacturing? I doubt it ....I suspect an explanation altogether more French. I would suppose that someone has bought this previously and either fettled it themselves before returning it to the store due to it not working, or the store employees opened it after it was returned as faulty. Either way it was put back together, back into its box and slapped back on the shelves for sale to the next unsuspecting mug - me.

Its been pissing down with rain for months here, so clean rain water was not hard to come by. I have topped up the cells and it is now on charge with my allegedly "intelligent" charger - so we will see how it goes.

[ericd]

As mentioned earlier, Chinese Quack but in the face of it, 99% of all MSLI batteries are made in China/Taiwan due to the size of their local vehicle park and manufacturing equipment investment for those size batteries is specific so Western Companies go shopping there too.

Did you have to add much water? Just tell us exactly where in the Tarn you are ..... just to watch FR3 Midi-Pyrennees tonight to check the size of the crater ! [:D]

[dave21478]

Well, it seems to be kippered.

It took about 30ml of water per cell, it seemed to be completely dry.

It has been on charge all day, and the smart charger keeps shutting down, with the battery showing 13v or so, but as soon as you put a load on it like a 21w brake light bulb, it doesnt even light up and the voltage drops off to nothing. I tried it with an older charger that just puts out a constant power, but that made no difference either.

[ericd]

Short circuit within a few cells ....RIP

[Chancer]

No consolation to you but its made me feel better.

I had thrown away my cheap jump starter pack after the battery failed which is very unlike me, only to learn that maybe I could have recovered it.

I'm sure you have already done the same with sealed for life car batteries before, its not a miracle cure but gives exactly the same results as topping up a partially dry battery in the good old days, I reckon if done in time it can give another 3 years of useable life.

[Pierre ZFP]

Well, I gave it a go. The top came off the battery really easily which gave me access to the cells each with a little rubber cap.  With distilled water and a little funnel I tried to top up each of the cells but they were all full.  24 hours on a charger gave less than a minute with a lightbulb so it's off to the recycler.

Thanks ericd for the advice, you said it was probably dead but  it was worth a try to get it going again