Recovering neglected batteries

I had one 110Ah size but sat for a year flat, we changed it out of the van ( a long story ) anyway i simply put it in the garden on an old fashioned charger under some polythene and left it on charge for about 4 days, its not in use at moment but is holding a 12.7 V charge, I will probably be told that was the wrong thing to do now (y)

If you bought it locally to you you could always take it back and be honest with them and see what they say
 
An ex AA man told my pal that you can restore any old lead acid battery by turning it upside down and tapping it with a lump of wood to dislodge sludge accumulated on the plates. Then take out the plugs and allow to drain, refill with acid, charge and Bobs your uncle - battery restored.
(You obviously have to wear PPE and be careful about disposal of acid)
Would this work?
 
ghostlymoron said:
An ex AA man told my pal that you can restore any old lead acid battery by turning it upside down and tapping it with a lump of wood to dislodge sludge accumulated on the plates. Then take out the plugs and allow to drain, refill with acid, charge and Bobs your uncle - battery restored.
(You obviously have to wear PPE and be careful about disposal of acid)
Would this work?
Click to expand...
I wouldn't even contemplate doing that. Far to dangerous, and where do you get rid of the acid, even if you can get fresh! Any way your batteries are from all accounts, new so just been sitting for a long time.
Post No. 2 is a better solution. If you have an old style charger, they usually have around a 4 amp max output. Try and get it going as per Chrishcorp's suggestion, follow his advice about covering, and make sure you have a remote switch for the charger, at least until you have a reasonable charge going in. Once (If) it starts to charge you can put it under cover somewhere , garage or what ever, with some ventilation. You may find that on first switch on of the charger the current will be high enough to trip it. Put a 12volt bulb in series until it has some charge. Just take it slow and easy with precautions until you are sure it is safe. Or alternatively take it to a local battery shop/garage and ask advice. You don't say if you are able to check the electrolyte level and top up with de-ionised or distilled water before charging.
 
Last edited:
Alex_Blackwood said:
I wouldn't even contemplate doing that. Far to dangerous, and where do you get rid of the acid, even if you can get fresh! Any way your batteries are from all accounts, new so just been sitting for a long time.
Post No. 2 is a better solution. If you have an old style charger, they usually have around a 4 amp max output. Try and get it going as per Chrishcorp's suggestion, follow his advice about covering, and make sure you have a remote switch for the charger, at least until you have a reasonable charge going in. Once (If) it starts to charge you can put it under cover somewhere , garage or what ever, with some ventilation. You may find that on first switch on of the charger the current will be high enough to trip it. Put a 12volt bulb in series until it has some charge. Just take it slow and easy with precautions until you are sure it is safe. Or alternatively take it to a local battery shop/garage and ask advice. You don't say if you are able to check the electrolyte level and top up with de-ionised or distilled water before charging.
Click to expand...


Not only that - but OP did say SLA ... Sealed Lead Acid.

There are pulse rejuvenator devices you can buy ... I have one ... also many smart chargers have option to rejuvenate ..... BUT as I found - 9 out of 10x .... doesn't work.

Basically what the rejuvenator does is connect + to - and let mA pulses pass to supposedly break up the structure that has built up on plates ..... the process can take days .. week even ... and needs a low rate mains standard non-smart charger if using the separate item ...

Example (this I have) ..

Digital Auto Pulse Car Battery Desulfator Desulphator Lead Acid Batteries 400ah | eBay

It has worked on one battery I was given - 50A/hr Starter Battery .... a Lead Acid that had been left in a locker forgotten. It failed to take charge and get above 7V ... So out with the 4A plain charger and this item. After 1 week - it showed 13.4v on charger ... 12.8v off ... it now provides domestic on one of my boats .. will start engine max 3x before it drops away.
So its not to be relied on for heavy duty - but fine for cabin lights .. light duty ... can be charged along with the primary battery of 90 A/hr.

Summary - Unlikely you can trust the battery for mucjh other than very light demands.
 
Refueler said:
Not only that - but OP did say SLA ... Sealed Lead Acid.
Click to expand...
Yes, but some "SLA" or maybe described as "Maintenance free" Batteries do have a provision for adding water and checking levels. I am not arguing with you but was just covering possibilities. My "Smart" charger has the so called "Recovery" setting but as you say it may or may not work. I much prefer the old transformer rectifier chargers for this type of charging. As I said you can stick a resistance in the circuit (Bulb) and see how they go over a, sometimes, long period. Maybe days.
 
NickRobinson said:
Pulse chargers/epsom salts/batt aid tablets/ etc.. If we could really revive old batteries, why would we buy new ones?
Click to expand...

Totally agree, but these batteries were brand new when they were put into store, never having had a load across them. 4 or 5 years old, yes, but old batteries that have seen countless charge/discharge cycles, no.
 
Alex_Blackwood said:
I wouldn't even contemplate doing that. Far to dangerous, and where do you get rid of the acid, even if you can get fresh! Any way your batteries are from all accounts, new so just been sitting for a long time.
Post No. 2 is a better solution. If you have an old style charger, they usually have around a 4 amp max output. Try and get it going as per Chrishcorp's suggestion, follow his advice about covering, and make sure you have a remote switch for the charger, at least until you have a reasonable charge going in. Once (If) it starts to charge you can put it under cover somewhere , garage or what ever, with some ventilation. You may find that on first switch on of the charger the current will be high enough to trip it. Put a 12volt bulb in series until it has some charge. Just take it slow and easy with precautions until you are sure it is safe. Or alternatively take it to a local battery shop/garage and ask advice. You don't say if you are able to check the electrolyte level and top up with de-ionised or distilled water before charging.
Click to expand...
When I bought a battery for my motorcycle, it arrived dry with the acid in a separate bottle so acid is available separately. Disposal is another matter although I'd try our local waste transfer centre.
 
The alternator diodes on Jissel failed, which ran both batteries completely flat. Fortunately, they didn't stay flat for more than a few days, but the starter battery - a second hand one that had seen service in an ambulance recovered and gave me a few more years good service, while the domestic one, just a few years old, didn't.

It may be that the starter battery had just enough umph to start a well-behaved engine and be recharged ready for the next time, but the much lower, but longer lasting load on the domestic battery was too much for it.
 
ghostlymoron said:
How do you know there's any use in a second hand battery?
Click to expand...

When I buy such - if the guy doesn't have the old big two handle Load Tester to prove its viability - I then only buy on a 72 hour return basis.

Why do I buy such ? Think about it. Till the day that car crashed or failed its MOT / Technical .. it had a battery the owner relied on to start the car to get to work or shops etc. The crash / MOT failure was not the battery. I've seen batterys in Breakers Yards still with the sellers sticker on ..... literally near new.

I have only had one 2nd hand battery not give me years of service, I have average 5yrs or more from them - and that was because my gardener forgot to recconnect power to the boat after needing the power line. The battery ran down and was not charged before a -25C night hit it !! Freezing weather and flat battery do not go well together.

I can get a 80 .. 100 A/hr 2nd hand battery out here for between 20 and 40 euros.
 
ghostlymoron said:
This type of load test doesn't tell you the capacity in Ahr. I've had batteries which maintain voltage for months but go flat quickly under load which is no good for a house battery.
Click to expand...

The Load Tester is more to see the VOLTAGE DROP .. to see if it can deliver the oomph needed to start an engine. Its about the best indicator there is for quick testing .....

20 euro for a load tested battery lasting me 5 yrs is better on my pocket than going to shop buying a new battery that will probably only give me 5 - 7 yrs ....

I actually had one 2nd hand battery go 10yrs ...............
 
Alex_Blackwood said:
I wouldn't even contemplate doing that. Far to dangerous, and where do you get rid of the acid, even if you can get fresh! Any way your batteries are from all accounts, new so just been sitting for a long time.
Post No. 2 is a better solution. If you have an old style charger, they usually have around a 4 amp max output. Try and get it going as per Chrishcorp's suggestion, follow his advice about covering, and make sure you have a remote switch for the charger, at least until you have a reasonable charge going in. Once (If) it starts to charge you can put it under cover somewhere , garage or what ever, with some ventilation. You may find that on first switch on of the charger the current will be high enough to trip it. Put a 12volt bulb in series until it has some charge. Just take it slow and easy with precautions until you are sure it is safe. Or alternatively take it to a local battery shop/garage and ask advice. You don't say if you are able to check the electrolyte level and top up with de-ionised or distilled water before charging.
Click to expand...
Do not top up a flat battery, it will make water as it charges and overflow.
 
Boater Sam said:
Do not top up a flat battery, it will make water as it charges and overflow.
Click to expand...

Its why battery advise is to only top up just over plates ... then you have no overflow.

What actually happens is not water - but reconstitutes the acid and sulphates from the plates .... a volumke change that is less than the change due to heating of the fluid in the charge process.
 
Porthandbuoy said:
Here’s the scenario. Brand new 12v sealed lead acid batteries @ 100Ah sat for around 4 years, so totally flat.
Can they be recovered?
Is it worth trying?
Anyone done it?
Click to expand...

Stick them on charge, if they work afterwards they are Ok, if not, scrap them.

Big difference between "recovering" knackered batteries and recharging flat ones.
 
You must log in or register to reply here.

Other threads that may be of interest

Baggywrinkle
Test run of the Lithium system that has been sitting in my cellar for most of this year.
Replies
14
Views
526
Baggywrinkle
Baggywrinkle

Share this page

Top