So, I need to get my shuttle bus road worthy. Haven't started it in months and the batteries are dead. I hook up my charger to each one and after a couple of hours of high amp, nothing. Take them to the auto parts store, they charge for an hour and then proclaim the batteries dead. Which is a shame since I bought them and haven't driven the truck 50 miles since installing. I tried to exchange one at Walmart, but they say it's past the warranty. Turns out these two were warranty replacements for the first two I bought a couple of years ago. So, I went ahead and bought one replacement while I was there.

But then, I read online about methods to recover batteries, and one post said to put it on a trickle charger - the lower the amps the better, and let it sit for several days. So, I turn my charger to it's lowest setting and try again on the remaining dead battery. After one day, the charger says 12v and 47%. Day 2 its up to 52%. Then it starts moving a little faster, and finally on day 3, it now gives me a green light and 100% charge, but only at 12v still.

What do you think the chances are that this battery is good again? I read that it may rate 12v, but still have no cranking amps.

 

I hope others have some success stories. I have never been able to recover a bad (let alone a dead) battery.

 

Is there an easy way to load test this one? From reading, it sounds like the auto parts stores use a device that doesn't really load test.

 

A carbon pile tester will do a rudimentary load test (show the voltage when a set amperage draw is introduced). Using them, it is best to match the tester with the battery cca rating (ie test at 1/2 the cca rating).

The best testing (IMO anyway) is at a battery/alternator store (I know folks at a local shop where they service the oil industry). We have an Interstate Battery store locally. They are good also, or at least the head guys there know their stuff.

I am sure Jack (or others) will provide a better answer.

 

I'll google to see what's near me. Dang, now it's Saturday; may have to wait until Monday.

 

The Autozone or Advance do an acceptable job.

I maintain a dozen automotive size batteries for home and farm. Luckily, about half are used on equipment that really only need a small garden tractor size, so I can get away with batteries that are past their time automotive wise.

I've gotten batteries back to a state for use, but never fully dead or fully recovered. But to do so you need a charger that has a de-sulfate mode or reconditioning mode, I have two. I have several trickle chargers, they ain't going to do it. The only battery that has perplexed me to bring back to some life is an AGM for my dump trailer. In several threads, I've documented how I test and recently charge, but even over 5 decades of doing this, I'm still in learning mode and I'm starting to look at battery health more at the resistance of a battery then what the CCA says it is. Not sure the path will not have a dead end.

My historic test had been using a visual specific gravity test, which I also use for coolant. But I've moved over to a simple electronic tester due to the many batteries that are now sealed. When you have funds I think it has been a good tool for me, not only during the testing over a batterie's life but to find the best battery in the litter when I buy new. I have this one.








Here is my latest charger purchase, and it has worked well including the battery restoration mode. Notice it says you need a minimum of 2 volts.







Here is one that I know works well for less money, but with a smaller amp output, so way longer time to charge. They have higher output versions for more money.






I've highlighted some good features, and as noted, the rare ability to charge even with a zero volt battery. Most chargers will not do that. If I was doing what you do, a tester and charger would be part of the tool kit you are missing. I can't imagine trying to recharge an 850 battery with a 1 amp charger.

My latest thread where I covered what I just wrote but included some examples. And talked about the consideration of looking at resistance, as futile as that may be, Jean-Luc.


https://www.ford-trucks.com/forums/1...batteries.html

 

I have tried to restore 3 batteries with the Noco Genius 7200 and it did not work on any of them. In all 3, the restore mode produced bubbles on 5 of the 6 cells. Nothing from one cell. With this latest battery I was charging, the most I could get was 75% charge. I then got mad at it and left it on recover for a long time. Now I get no better than 25% charge (I am sure I overheated the battery.

 

I've never tried to recover a dead cell battery Mark. I'm not sure you could as my understanding is a dead cell has the oxide flakes built up on the bottom of the cell. shorting the plates. The reconditioning or de-sulphation I've done before a battery gets really bad and the other de-sulphation charger that I've mostly used isn't sold anymore. What I've read on other sites is that type is supposed to be the best at bringing them back to life whereas the electronic ones do not. I think that's the problem for many though, trying to recondition with a bad cell.

The next time I'm at the farm I'll take a picture of the battery in my 1953 Allis HD9. I put that on de-sulphation once every year as it's a battery I do not care to replace. When it goes, I probably go to 4 850s in the twin battery boxes.

 

Hit or miss on recovery if batteries are left in a discharged state or left partially charged as the soft battery plate sulfate turns to hardened crystalline form and no amount of "wave / shock action" (as provided by most desulfators) will work. Basically the remaining active plate material which has suffered plate sulfation is HIGH RESISTANCE to charging.

Some manufacturers are using black-carbon graphite foam in their plate pastes to prevent sulfation -- so so performance there also.

Battery conductance testers (e.g Midtronics) are infinitely superior to load testers which often provide inconclusive / erroneous results (but they're great for remote BBQ'ing, roasting marshmallows if you don't have juice handy)

 

I found a Batteries Plus store near me. They have a proprietary(?) test device that the guy says does a load test. I don't know, and honestly, I don't think he knows much either, except how to operate the machine, which seemed pretty easy; just input the CCA. I didn't see any sign that the machine heats up, if that is a clue. Anyway, it says the battery is good. It's a 750 but tested at 835CCA. He also says it was over 13v, whereas my charger always said 12v. SYK, my charger has been acting a little different recently - the different lights don't always light up, so it's hard to tell whether/what amp it's charging at.

So, I'll now have one brand new battery and one that I've maybe brought back. Not ideal, but for now, it'll work. Next up: the real issues.

 

There are a few things they should note, but they typically just give a CCA rating. CCA, Volts, State of charge (%), State of health (%), and resistance.

 

That is a conductance type tester. Midtronics makes a full line of them. They are handy, and often used for Warranty service.

The advantage, compared to the standard carbon-pile load test, is that they are very quick to use and are said not to require a completely charged battery to make the test , nor much interpretation of the results, and do not require re-charging the battery yet again after testing.

So long as the battery in question reads at least 8 to 9 volts it will supposedly make a Go/NoGo determination. What these do electronically is take a portion of the battery voltage and convert it to a high frequency AC signal and feed it back through the plates, and determine the health and CCA of the battery through some kind of jiggery-pokery. If they indicate a battery is "Bad" I've no doubt that this is the case, if on the other hand they indicate a battery is "Good" it might be, or "should" be. There's no substitute for a true load test.

 

Agreed. I’d prefer the carbon pile, but these are easy.