Not necessarily. Open circuit voltage isn't a good indicator of battery health. It may show 12+ volts, but the real test is if it can maintain that under a load.
Flooded Lead Acid Revitalization.
- Thread starter MONBEL
- Start date
Oh, I see. That means the battery should not be more than two years old. I will check the review about the product.
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,451
All cells see equal current, and low cells need to charge longer. That over charges cells that weren't as low. This is done with an elevated voltage to equalize. See if you can find a manual on-line for your battery. If not, find one for a similar battery (pure lead, or lead-calcium, etc. for similar chemistry.) Voltage, current, time, maybe a maximum allowed temperature.
To equalize you need a charger able to deliver constant voltage at an elevated voltage. As water is lost, need to keep adding so plates don't get exposed. Hydrogen is released, so well ventilated, and do NOT wiggle connectors or otherwise make sparks. Wear protective gear and wash your hands after touching.
I'm not sure that 12.5V (resting with no charger attached for several hours) is a fully charged reading for your FLA battery. For my AGM, I want a bit higher. A manual would tell you.
To equalize you need a charger able to deliver constant voltage at an elevated voltage. As water is lost, need to keep adding so plates don't get exposed. Hydrogen is released, so well ventilated, and do NOT wiggle connectors or otherwise make sparks. Wear protective gear and wash your hands after touching.
I'm not sure that 12.5V (resting with no charger attached for several hours) is a fully charged reading for your FLA battery. For my AGM, I want a bit higher. A manual would tell you.
sunshine_eggo
Happy Breffast!
The last 48 hours is encouraging in that the voltage at least went up.
12.5V is too low. The battery needs to be able to hit 14.X volts or whatever the peak voltage of the charger is.
Again, please check specific gravity. It's the best way to determine the health of the battery. It documents its current state and changes document any progress.
This is cheezy, but it's easy to read and WAY better than nothing:
Hard to read if you have mid-40s eyes or older, but .005 accurate:
Many auto parts stores carry them as well.
Please direct me to a source that conducts independent before and after capacity testing.
I don't know how independent these guys are. But here's some scientific(?) research papers. I have also used it to moderate success on some used batteries I picked up. It has also failed on really old batteries.
https://www.researchgate.net/public...or_of_lead_electrodes_for_lead_acid_batteries
https://www.degruyter.com/document/doi/10.1515/eetech-2018-0007/pdf
Texas-Mark
Solar Addict
- Joined
- Aug 4, 2021
- Messages
- 1,280
Have you checked the specific gravity of each cell? From the voltage indicated, it sounds like you may have a shorted cell. I have found that if an equalization session does not bring it up to a "normal" voltage, the battery is probably not salvageable.
sunshine_eggo
Happy Breffast!
Those are two sources for the same paper.
Conclusions:
- Expected to reduce the formation of large sulfate crystals. - no data presented to support this. It's a speculative statement.
- Presence retards the formation of of hydrogen at the lead electrode - demonstrated.
- Drop in impedance of the electrode (demonstrated, but concentration is critical) is expected to reduce the total resistance of the electrode, which is expected to enhance charge acceptance and life of battery - two more speculative statements for which there is no supporting data.
I get that you have anecdotal evidence that this works, but if you didn't test the actual capacity, you can only say you restored voltage and some capacity. The reality is that equalization charges consistent with those recommended by Trojan and Rolls are amazingly effective in restoring batteries that are not degraded past a certain point. Once batteries are past that certain point, they're gone.
I have personally done before/after testing on about a dozen batteries ranging from small automotive batteries to large deep cycle batteries by Rolls and Trojan. I used the reserve capacity (RC) rating to establish the before and after results. The most noteworthy was a Interstate 24 series deep cycle battery. It was only six months old, but hadn't been charged. It would rest at 12.4V and almost immediately hit 14.4V under charge. It originally tested at 40% capacity (25A discharge to 10.5V to measure reserve capacity) with low specific gravity. Following a single equalization charge to 16.2V until the SG stopped rising (about 4 hours), the post-equalization charge test was at 92% capacity. Improvements in neglected T-1275 batteries were on the order of 7-20%
I've also tried pulse chargers, and I see no evidence that they provide any meaningful benefit to degraded batteries. There is some evidence that maintenance charging with pulse chargers may slow the rate of degradation.
Last edited:
I meant to post two different papers. At any rate, you can do and say anything you want about all that. And you're right that most additives are snake oil. But my anecdotal evidence is backed by measurements. It won't recover all batteries. And a paper I read but haven't found again yet, did some research that showed cadmium or magnesium or aluminum sulfate additives are work best before any sulfation formed and helped prevent damage. Lots of testing out there says pulse chargers don't do anything either. It's all dependant on the exact nature of the failing battery.
I never understood why anyone would want to try to rely on weak or dead batteries. If they won't or don't charge fully and hold a charge they need to be replaced. Period.
A lead-acid battery does not well tolerate complete discharge - that means anything under about 11.8 volts and even if they will fully charge they'll never be the same and they'll never last their intended lifespan.
And why oem batteries in cars and motorsports vehicles don't generally last very long if they've sat on a showroom floor and allowed to discharge. They have to be kept fully charged.
A lead-acid battery does not well tolerate complete discharge - that means anything under about 11.8 volts and even if they will fully charge they'll never be the same and they'll never last their intended lifespan.
And why oem batteries in cars and motorsports vehicles don't generally last very long if they've sat on a showroom floor and allowed to discharge. They have to be kept fully charged.
sunshine_eggo
Happy Breffast!
I have too much evidence to the contrary, but I'm willing to expend a lot of time to find that out, i.e., I'm weird. I bought 14kWh of Trojan T-1275 for 25% of market price, and the only reason they didn't last is because I didn't visit often enough and let one string of batteries go dry. They gave me 2 years of services, and I still have the other string as "backup" if my NMC battery goes bad without engulfing everything in fire.
This is way overstated unless qualifying it by saying it applies to "starter batteries." Typical deep cycle batteries have a 100% DoD rating of 250-500 cycles, and they'll do it... lasting their rated lifespan.
Drain an automotive battery to extreme states of deep discharge by letting them sit for a few months @ <6V, absolutely - severe and permanent damage.
Definitely.
Yes, particularly starting batteries, but lots and lots of RV/marine batteries have been killed by running them dead too many times - BTDT got the tee-shirt. I find all those machinations are an effort in futility - just when you really need them they're dead.
And yeah, you might get away with deep dead on a Trojan, but you might find it won't hold up either after a short life. Sometimes these batteries will recover, I've done it too, but it's like playing roulette - you never know when it's just gonna die on you. Cheaper ones, pretty much anything besides a Trojan, Crown, or Rolls, will surely give up the ghost.
For my rigs they HAVE to work, so I don't mess with them - they have to be in tip-top shape.
EDIT: I have had batteries that tested fully charged at 12.6V or so, only to drop to nothing as soon as a load is put on them. I tore the starter down three times on a yamaha before trying a different battery. Gee wizz I can be hard-headed. LOL
And yeah, you might get away with deep dead on a Trojan, but you might find it won't hold up either after a short life. Sometimes these batteries will recover, I've done it too, but it's like playing roulette - you never know when it's just gonna die on you. Cheaper ones, pretty much anything besides a Trojan, Crown, or Rolls, will surely give up the ghost.
For my rigs they HAVE to work, so I don't mess with them - they have to be in tip-top shape.
EDIT: I have had batteries that tested fully charged at 12.6V or so, only to drop to nothing as soon as a load is put on them. I tore the starter down three times on a yamaha before trying a different battery. Gee wizz I can be hard-headed. LOL
sunshine_eggo
Happy Breffast!
I think it's worth pointing out the difference between cycling and neglect or less favorable circumstances.
If you daily cycle a deep-cycle to near empty/empty and charge it back to full the next day, you will get rated 100% DoD cycle life out of it. If circumstances are such that an accidental discharge to empty or insufficient conditions to fully charge each day, then yeah... shit goes sideways. Let's say you leave your propane fridge on AC power overnight, and it nearly taps out the battery. If you can fully charge it the following day normally, you'll never see a difference in cycle life. If you do that several days without charging to full, then yeah... things get way worse.
Your need for operability is also totally justified... My goal was to get something that worked for really cheap, and it had some redundancy. It only had to perform really well a 4-6 days a month when I was on-site. If my needs had been greater, I would have taken a more reliable approach.
Bro... I feel your pain on the Yamaha starter, though I didn't have to go to those lengths, and I gave the battery more scrutiny up front, but still got shafted. I have a '97 GMC 2500 HD long bed with the 454... has a somewhat 700 CCA battery in it. One day, the starter would just click with the occasional hit and spin. I 100A load tested the battery - right at the bottom of green. I had another big 12V that I jumped it with + a 50A boost starter - click.
Replaced the starter.
Click.
WTF???!!!! Click, Click, Click, Click,Click,Click... finally, having no desire to pull and test the starter...
Replaced the battery... VROOOM.
Bastard did it again in a HD parking lot a year later. Tried to jump start it it with a running diesel - click.
This time I just yanked the battery and replaced it under warranty - VROOOM.
I learned the lesson the second time. While both passed the load test, I put a digital tester that directly measures IR on the second one... it was about 2.5X the resistance of the new one and reported notably lower CCA, so I've put one of those testers in every car I have. ;P
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,451
Sable was having trouble starting.
I replaced battery and it was better for a while.
I replaced cable, and it was better for a while.
I replaced starter, and it is great now.
Probably some windings shorting. Not that far from exhaust manifold.
Saab 99, starter got fried. Manual showed a heat shield. I made one out of coffee can and fiberglass.
K2500, was cranking slow, 2x Optima was 10 years old so I retired them, replaced with Odyssey. (D*mn, that's a lot of money!)
I used to keep batteries until they rolled over and died, but I now replace at the first sign of seepage around terminals, to avoid corroding cables.
These AGM batteries need a different charging voltage, correct? And with internal regulator, not much we can do about that. Should I add PV charger?
Thats the company that makes the chargers I have. As mentioned in another post desulfinators normally dont really work that well from my experience but the ones I have from pulsetech do from my experience.
The easiest way to tell is by looking into the cells for floating material after using them as it gets pretty nasty on batteries that are bad off.
Pulsetech is what the military uses a good bit to maintain their vehicle batteries. They are not cheap but I have had great results personally with the chargers.
That said I have not had 100% rate of success reviving a battery. I had one battery that was left in a ford excursion of mine that would show full charge and volts until you opened the door. Instant 6 volts or less with any draw at all on it. So it had volts but no amps. I tried several chargers on it with no changes.
I put a pulsetech on it. It killed it. DEAD.
But if you looked down in the cells afterwords it looked like icebergs floating in the acid. I wish I had cycled the acid out to see if it could of been saved but I never got around to it. I think I still have that battery at my old house. I may try again doing that one day. The point is it worked as far as desulfating the battery but it was so far gone it killed it off completely when it broke it loose from the plates charging it.
They are great for maintenance too. I use one on a f250 superduty truck that has a dual battery setup in it with 99% pure lead plate batteries in it. They are over 12 years old now and still have full capacity as far as I can tell. Still cranks the diesel engine up fast on the coldest days. So Im kind of hooked on the chargers myself. But to each their own.
FWIW Here is my story. Stored my RV outside as always. Normally we get a few days of snow and a couple of weeks above freezing. The solar panels keep the batteries charged, things, smoke , propane, CO detectors, radio keep alive, etc etc are parasite loads. But this winter was a *itch. Lots of LONG lasting snow (all winter) cold down to -43. I walked into the RV lot and checked things. Totally frozen coach batteries(6v CG-2), swollen up like a pumpkin. Removed them and took them home.
Put them in a heated garage for 2 days. Then turned the heat up to 65 and used cargo straps and wood blocks to unswell the batteries. I figured that the plates and stuff should be moved back to normal location before charging. I used 3 different standard FLA chargers both 6v and 12v with 0 results. The batteries would charge to 4 volts or 8v and drop to 0 when the charger was removed or the charger cut off for a bad battery.
I remembered my LifePo4 charger had a FLA button and a "repair" function. Put the batteries in series and hooked up this charger for 12hr of "repair". Bingo 12.5v even after 1hr rest. Then I charged them at 10 amps on normal FLA setting. Load tested them and got 200ah. I chickened out about taking them to full discharge.
https://www.amazon.com/Battery-10A-...harger&qid=1682485964&sprefix=,aps,160&sr=8-8
Clueless as to what "repair" does and to future battery life span.
As always your mileage may vary.
Put them in a heated garage for 2 days. Then turned the heat up to 65 and used cargo straps and wood blocks to unswell the batteries. I figured that the plates and stuff should be moved back to normal location before charging. I used 3 different standard FLA chargers both 6v and 12v with 0 results. The batteries would charge to 4 volts or 8v and drop to 0 when the charger was removed or the charger cut off for a bad battery.
I remembered my LifePo4 charger had a FLA button and a "repair" function. Put the batteries in series and hooked up this charger for 12hr of "repair". Bingo 12.5v even after 1hr rest. Then I charged them at 10 amps on normal FLA setting. Load tested them and got 200ah. I chickened out about taking them to full discharge.
https://www.amazon.com/Battery-10A-...harger&qid=1682485964&sprefix=,aps,160&sr=8-8
Clueless as to what "repair" does and to future battery life span.
As always your mileage may vary.
Tomthumb62
Solar Wizard
- Joined
- Sep 25, 2022
- Messages
- 1,871
Yep. We killed $1000 in AGMs in just a few years doing just that, because we didn’t know any better at the time. And by “killed” they never really could get us through a whole 24 hours, because they were always undercharged. Our solar charging was just not adequate nor was our shore charger. Didn’t know the high current charging needs of AGM, but do now. Wish we had jumped on lifepo4 from the get go, but then we would’ve missed out on the lesson lol.
What digital tester might this be?
sunshine_eggo
Happy Breffast!
Ouch!
If I have to buy one...
If I have to put one in every vehicle:
It doesn't correlate with my other equipment that the Antec model does, BUT they are diagnostically accurate enough, i.e., if they report high mΩ or low health, I know the battery is bad.
Thanks for the beautiful advice. The battery has charged up to 13.5 volts. The 20-amp automatic charger was awesome.
