Battery Maintainer with Desulphator

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peakbagger

Minister of Fire
Jul 11, 2008
8,775
Northern NH
My Unimogs normally use two 12 volt truck batteries in series. They weigh a ton and not suited very well for off road, as they can leak electrolyte which rots out the battery trays. I think its a Nato requirement as civilian versions use 12 volt systems. Both of mine are parked all winter and used sporadically in late spring summer and fall. One of mine came with Optima AGM batteries and they have lasted several years with no issues. It has a battery cut off switch that cuts off all power. The other one came with a couple of marginal truck batteries that needed replacement. I decided to bite the bullet and put in two Optima batteries. They were great for two years but this spring one was low and the other lower, this truck also has a battery cut off but there are a few circuits that I think bypass it. I gave it a charge and things were fine for my spring wood hauling. I was busy with other things this summer so didnt use this truck for about 2 months. When I turned it over this fall, no start. I checked the volts and one battery was 7 volts and the other 4. Not good. I hooked up my high tech Century (lincoln electric) charger and it gave me an error code "bad battery". I have another Schumacher charger and that also did not seem to want to charge the battery but didnt turn off.

I have a portable solar trailer with two large 48 volt forklift batteries on it. It is hooked to my house so the only time the batteries have to do any work is on the rare occasions that the power goes out. They are probably $4K each so definitely want to keep them alive as long as possible. I have read that one of the keys to long battery life in "float" service is using something called a desulfator. It zaps the battery occasionally with an AC pulse that breaks down sulfation that can form on the battery cells. I have one on each of my big batteries that run continuously. I had not tried one on regular car batteries as I assumed that when they will not take a charge and tester says its bad, its time for new one. The warranty was up a few months ago on the Optimas so I decided to try to save them. The rigs on my 48 volt batteries are battery powered so no good but over the years these brand battery maintainers seem to get a good reputation Amazon product ASIN B00Q3CM2QY . I had read and I think the instructions said it may take awhile. I hooked up one and overnight it came up from 7 volts to 11.5 volts. I left it going for a couple of days and it came up 12.4 volts. I hooked up the other one and it came up from 4 volts to 12.3. A friend of mine offered to do some testing so we hooked up a dump load ( a long piece of steel fence wire) and it pulled 20 amps for about 20 minutes with no voltage drop once the load was off, That looked positive and then one of his friends stopped by and offered up battery load tester that a mechanic had given him. This one pulled an 80 amp load and the meter showed both to be good batterys.

The Unimogs just got parked for the winter using one set of batteries being swapped around so I havent tried starting either one with the salvaged batteries but at this point I am sold. New batteries would be about $450 for the pair, so the $60 spent looks to be worth it. My friend the electrical genius said this it typical, in order to break up the sulfation the charger has to charge against a high resistance and most chargers just assume its a shorted cell. This rig just trickle charges while pulsing it with AC to break up the resistance until it will take a normal charge. No guarantees, sometime a battery is just shot but worked for me.
 
They do work good and if you can save one battery they are worth it. If you ever get one so low the smart charger won't recognize it, I've had good luck with hooking up a good battery with jumper cables for a few hours. It charges enough to get the charger going. Another tip if your batteries are serviceable is to put a teaspoon of Epsom salt in each cell, shake it up, let it sit awhile then recharge. I've brought many motorcycle batteries back from the dead.
 
Hey peakbagger, have you ever considered rigging a battery tender or other maintainer to each of those batteries for winter? I use them on my mower and trailer batteries, both which sit out in sub-freezing all winter, and although I’ve never set up a proper experiment to verify they really extend life, I seem to be having pretty good luck with them. They’re supposed to do a pulse charging that delays sulfication, although you’d still need a separate desulfinator to reverse the effect on an existing battery.

Since my trailer sits outdoors away from a power source, I just use a large solar version of the tender on that. I bought it mostly for cold-weather protection, as we get regular teens-F and even occasional sub-zero.
 
I hauled them indoors for the winter and will probably rotate the maintainer between the four of them. All my power comes from net metered solar so indirectly they are solar maintained;)

VW used to ship cars from Europe with a solar panel suctioned cup on the windshield to keep the battery charged enough so the computer would not lose its memory. I have seen several cars over the years with them still installed in the rear window, I also so them listed on E bay.
 
I've had a re-conditioning battery charger for a decade or so, for me they've worked ok for recovering some useful storage in deep cycle batteries but I've never got any lasting success for high CCA starting batteries.
 
The small little .2amp maintainer/chargers work great for keeping the batteries toped up and maintained. Its the winter cold that is killing the batteries not so much the small draw that may be on them . Where ever you are buying your group 31 batteries off you are getting ripped off. I sell AGM group 31 all day long for under $150 CAD and they are a good battery out of several hundred i have sold over the last 4 years i have a return rate of less than 1%. Do not buy group 31 from a automotive shop go to your local Truck shop as they will have the most reliable batteries. Last thing they want is a pissed off truck driver with new batteries and a dead truck..
 
cheaper to buy a new batterie
Maybe 1 battery, I have many batteries I have to maintain across my "fleet" of vehicles and mowers etc...

I ended up buying an open box DC stick welder at Harbor Freight last night, got a good deal on it so I will be trying this approach on my diesel mower battery that no longer starts my mower this weekend. Will report back the results.
 
Maybe 1 battery, I have many batteries I have to maintain across my "fleet" of vehicles and mowers etc...

I ended up buying an open box DC stick welder at Harbor Freight last night, got a good deal on it so I will be trying this approach on my diesel mower battery that no longer starts my mower this weekend. Will report back the results.
Curious to see your results but it seems a lot of batteries short out cells which can't be fixed. I've found that "bad batteries" can be fixed by using a battery brush to clean the terminals. Surprising how they can appear fine but make it seem like the battery is dead.

I have an Optima and knock-off as well that both are supposed to de-sulphate batteries. From my usage, including a 250amp Associated charger, there is no bringing back dead batteries, at least not to a useful long term state.
 
Problem is as you desulphanate the crud drops to the bottom, builds up causes short. onl;y answer to that is to dump acid rinse out reinstall acid. plenty of ytube vids on this reclaim stuff. and Ya not all will respond. as to the glass mat/ gel cel l units not sure if this works on those. In my experience after Globe union bought optima, things have gone down hill. Snow plowing is tough on batteries. I have retired from that about 5 years ago. that is where I was using the optima units.
 
I have a plethora of battery maintainers / rejuvenators that I have bought over the years, they work with limited success so I am hopeful that this method will work. I did plenty of research on it as I was skeptical but it makes sense as long as you follow the steps correctly. If I can make a battery last for just one more year that to me is a win, if I get more than that it is a bonus.
 
I am waiting on a DC stick welder to go on sale for Black Friday, going to use that to desulfate my batteries.



Good way to blow yourself up.

Had a guy at work try that, put a 24 volt booster back on a 12 volt battery. Over volting the battery produces huge amounts of hydrogen gas. He went to adjust the cables, created a spark, and boom. Blew up the battery in his face sending sulfuric acid everywhere including into his eyes.

Out came the eyewash kit and off we went to the hospital. He's lucky to still have eyesight.

Not worth it IMO.
 
I have a face shield I wear doing things like this, same I use for grinding along with other PPE. Not saying everyone should do this by any means.
Given the potential for excitement, no matter how unlikely, please get video! ;lol
 
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Good way to blow yourself up.

Had a guy at work try that, put a 24 volt booster back on a 12 volt battery. Over volting the battery produces huge amounts of hydrogen gas. He went to adjust the cables, created a spark, and boom. Blew up the battery in his face sending sulfuric acid everywhere including into his eyes.

Out came the eyewash kit and off we went to the hospital. He's lucky to still have eyesight.

Not worth it IMO.
yes definitely to dangerous.. I would rather spend the money on maintainers and run them when the units were down for the season, and replace batteries as needed.. All my lawnmowers and toys that have batteries i have never replaced batteries in them since i started disconnecting battery's at the end of the season and swap the maintainer every week or so to another battery.. At one point i has at least a dozen pc of heavy equipment and trucks.. Never replaced a battery in 8 years
 
No explosions, no craziness, just lots of bubbling.

Yesterday I tested the DC stick welder on 2 deep cycle batteries and a standard battery that needed some love. All 3 are now back to full charging status, the deep cycles are circa 2015 and the standard battery is from 2017. The deep cycles had been relegated to powering my 12v air compressor and water pump when needed so they had no bad cells but did no longer would hold a full charge.

I did the 5 min on and 15 min off for 5 cycles. I started out at 15 amps and ended up at 60 amps for the last charge. I then stuck the batteries on my maintainer to top them off and check to see how much charge they would take. Before doing this the deep cycles would sit on the maintainer for over a day before the maintainer would give up and shut off charging, they fully charged now in under 30 minutes.

It got dark before I could test the standard battery that was failing to start my diesel mower, plus it was in the 20's yesterday with wind chill so I will test it on a warmer day 🥶😮‍💨

I did do a video on the last battery of the day that I use on my mower: https://1drv.ms/v/s!Av3MLjR7Oj5kkJQ7JHrIkASSGk40wA?e=PaggJV
 
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Wow… been replacing the batteries on my trailer winch two at a time, at pretty substantial cost. Now this morning 18F, my truck barely turned over. Maybe it’s time to look for a cheap DC welder.
 
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Yea my 7.3 yesterday gave me a fit trying to start in the freezing weather, once I did finally get it running I let it idle for a while but the batteries in it are from 2019 so I probably need to pull those and give them a good bubbling and top up the water in them.
You're turning a serious motor, mine's just a little 5.7L Hemi gasser. But what's funny is that my 2005 Ram 1500 had the original battery still in it when I sold it in 2017. Yeah... 12 years on one battery! It was turning over a little slower on 15F mornings, but not so bad that I was worried about it.

The current battery is factory in a 2017 Ram 1500, same 5.7L Hemi. It turned over okay, but so slowly that I initially thought I might be driving a different vehicle this morning. Going to load test it after things cool back off tonight.

I remember my father's diesel, which had dual batteries, used to blow up a battery about every 2nd year. Always exciting, and always took some hood liner with it, when one would go off.
 
don't forget no one said this but if you keep the battery charged all the time it will be good for a while. a charged battery the acid in it doesn't do anything to it. if you have a discharged battery the acid will eat at the plates inside of it. that video the shows the guy running his welder on it that is pushing it. the reason that he said do this outside is that the battery when it's bubbling is giving off hydrogen gas and it's very flammable. i had a motorcraft battery in my 96 e250 that before i changed the thing it was 13 years old. another car that my friend owned a 88 crown vic had a motorcraft battery for 11 years before it was changed. as long as you keep it charged the battery can go a long time. my truck was used everyday so it was charged all the time it lived. sometimes a wet cell can lose a piece of one of the plates and it sits down on the bottom of the cell and the when it moves and shorts out the cell the battery will make so much hydrogen gas because it is bubbling that it explodes. if two of the cells start losing pieces of it's plates and doesn't explode the welder trick won't work.

when i was in electronics class many moons ago the teacher taught us about ni cads. and to break a cell that would not take a charge we would zap the battery quickly with voltage of a opposite source neg to positive and positive to neg and on a ni cad that would work it used to break up the gas that formed around the positive post of the battery but this will not work on a wet cell.

just putting in my 2 cents worth
frank
 
Yea my 7.3 yesterday gave me a fit trying to start in the freezing weather, once I did finally get it running I let it idle for a while but the batteries in it are from 2019 so I probably need to pull those and give them a good bubbling and top up the water in them.
When i had my 7.3 for some reason it was on a 3 year rotation and i could never figure it out. One year i would replace starter, next alternator, next batteries and then it would start all over again... Luckily everything had lifetime on it so all i was paying was the pro rated charge for the battery's.
 
My father briefly owned one of those terrible diesel Olds Cutlass’s they put out in the late 1970’s or early 1980’s. It would explode one of its two batteries at random, without warning, about once per year. Always very exciting when one would go “boom”, and it happened enough that it just became part of our family routine and conversation, after the first two.