Restore Resurrect Battery?

[FJRider]

Good on you Neels.

It is possible to zap a dead battery with a welder using a diode apparently but it sounds a bit dangerous to me. Plus electronics is not my strong suit.


For everyone who says just buy a new one - yeah, understood. But there are supposedly 98 million wet cell batteries dumped every year in the world and that offends the conservationist in me. Plus...I like a challenge. Over and above that, the specific battery I'm annoyed with belongs to a tractor and costs $300 to replace. That's a lump of change for something only used a few times a year - and consequently only lasts a year. My bike battery has the same problem but somewhat cheaper.

Either buy a battery minder ... or start a "start-up routine" for it .... every week or two, start the tractor up .... and a short drive.

[Winston001]

Thanks Trevor and a battery minder is on the plan.

So here's my experiment which may be a waste of time but interesting to try. Apart from the big tractor battery I have two others to play with too.



1. Empty the acid into a 3 litre bottle through a paper towel and funnel.

2. Turn the battery upside down and flush with a hose.

3. Fill the battery with water.

4. Charge it overnight.

5. Discharge by directly connecting the terminals, or through a headlight.

6. Charge again, then discharge. And again.

7. Mix up 250g of Epsom Salts in 500ml of hot water = 700ml by volume.

8. Put most acid back in battery but leave enough room for the Epsom salt mix which is then added too.

9. Charge battery and use it.

[Winston001]

Warning: sulphuric acid is nasty stuff. Work near a tap or hose to wash because small splashes are hard to avoid.

When a battery is charging, hydrogen gas is produced. One spark into an open cell will cause a bang. For that reason I leave the caps off and fill each cell to the top with water so the H disperses.

Discharging using jumper leads generates substantial heat. I had to let the leads cool down 4 times. Using a headlight setup would be slower and safer.

Using only water the tractor battery already holds a substantial charge and takes in 4 amps on the trickle charger. Looking hopeful.

Just out of curiosity, today I discharged the big battery into a smaller marine 12v battery. The marine one is 4 years old, appears to be looked after but will barely take a charge. It got very excited to join the tractor battery: one cell almost boiled and the whole case heated up. But all 6 cells should show activity so its a work in progress.

One slight downside of flushing and charging with water is the sulphate dissolved by the water (which is what I'm trying to do) is lost once the battery is finally emptied, before returning the acid. Consequently the acid will be a bit weak. Might try a hydrometer but I don't think its critical - I don't expect a renewed battery, simply an extended useful life.

[Kickaha]

That's a lump of change for something only used a few times a year - and consequently only lasts a year. My bike battery has the same problem but somewhat cheaper.

You need a battery tender for it

[Macontour]

Good ideas but just a repeat of the warnings. I used to work in a business manufacturing Battery Chargers and Testers and had 2 or 3 batteries explode on me!! Not nice at all. The acid is obviously not healthy for eyes or skin and the clothes I was wearing fell apart in days.

The Hydrogen produced while charging is very explosive, sufficient to split a battery in half!!

Take care with naked flames(preferably none) and sparks....easy to generate for example if connecting or disconnecting a charger or the electrical connectors with the ignition still on.

Also pays to do it with plenty of ventilation around to remove the gas and also as said earlier, access to water is a good idea if the battery does split.

[bsasuper]

Do the quick fix if you want to, but it will only work for so long.ME, I dont want to be stranded in the middle of nowhere, so I replace with NEW.The Shorai's are awsome, I use because of the extra long cranking ability they have, but are not needed If you want for a every day commuter.

[Winston001]

Time for a thread dredge and update. Happy New Year to everyone.

The experiments I tried above were not ultimately successful which was a shame but live and learn.

Nevertheless I gave it another try.

Took the old batteries to the recycling centre a few days ago. Noticed a few which looked pretty clean so out of curiosity tested them with a multi meter. To my surprise there were four at 11.5 - 12.5 volts so took them home to play with.

Didn't bother with emptying and flushing this time, just tipped them over, shook them around, topped off with some acid from the last lot, and put them on the charger.

Only checked three with the tractor so far (which demands a heavy draw ) but good news - two worked. In fact the most dungery battery has the most charge.

So I'm a happy man. Of course they may not hold their charge but what the heck.

[Winston001]

In summary here's what I reckon:

When summer arrives people discover dead batteries in motorcycles, ride-on mowers, boats, 4WDs, and caravans. Often they throw them out because they want a functioning battery now. To be fair batteries don't like sitting unused and its easier to buy a new one than shag around for a day waiting to see if recharging will work.

Plus battery dealers want to sell a fresh battery which is understandable.

I have purchased a 7 stage battery charger from Repco which rejuvenates tired batteries. Seems to work so far.

[Winston001]

A bit of context: until fairly recently I spent $500/year and more on batteries. Cars, rideon lawnmowers, motorcycles - there was always a flat battery. Very frustrating.

So rejuvenating someone elses throwaway is a bonus.

[unstuck]

Dead batteries are worth from $5-$10 at the scrap yard in Mataura.
Do not get caught taking them from the recycling station in Invers, they are a little testy about that, it helps fund the xmas function.
Solar trickle chargers are good for batteries that sit doing nothing and are getting cheaper by the year.