if you have a newer gel or agm battery with no capacity try this.

[kc8adu]

a neighbor has a small cheap handicap scooter that i suspect he has been using a dumb charger on.the onboard charger had gone bad and i repaired it.
he bought a new battery because the less than a year old mk agm would not get him around the block.i decided to try adding a bit of distilled water thinking he gassed it away with his dumb car battery charger.
he went to batteries plus and got robbed before asking me though.
he once worked for exide and should have known better anyway.
so the test surprised both of us.this is a 32ah battery and the test is a standard minutes at 25a reserve test.

[kaboom]

Re: if you have a newer gel or agm battery with no capacity try this.

Beautiful!

They don't call them "starved electrolyte" for nothing!

[Toasty]

Re: if you have a newer gel or agm battery with no capacity try this.

Success! A 3+ year old set in an APC SmartUPS 1400 ran its "self-test" on Saturday and failed. Red light, chirping alarm, and would test and re-alarm every 12 hours for 30 seconds. Manual test gave same results.

Pulled the pack today and figured I'd try this. Added DW with a syringe to each cell. About 20 ml. (2/3 oz.) per cell gave me just shy of 1/4" over the top of the plates as measured with a wooden Q-tip stick.

Let it be for 15 minutes and ran the manual test. Red light cleared and no alarm. Let it charge for an hour and pulled the plug. Ran fine for 5 minutes and still had 4 of 5 green LEDs lit. Draw is ~700w with 3 systems and monitors on it.

Thanks for the tip KC!

[kc8adu]

Re: if you have a newer gel or agm battery with no capacity try this.

trick is to just rehydrate.add a little at a time and stop when it doesnt soak in anymore.the seperator will stay a bit wet looking and not flat white.stop at that point.standing water not needed or good.
i just got 2 #27 agm from a pallet jack.about 2 years old and no longer run a full shift on a charge.i have an esr tester for batteries and these were checking poorly.
gave each cell a dose of water and now they test like new.
about $600 worth of batteries for free.
well i got them for installing the replacements.the lift truck place wanted to charge my customer $300 to come out and replace them.thats with him already having the new batteries there.was already there fixing a cnc so no big deal.

[Krankshaft]

Re: if you have a newer gel or agm battery with no capacity try this.

I always thought the reason they wouldn't hold a charge anymore was due to sulphation and not loss of electrolyte via hydrogen gassing. Then again the chargers in the Back UPS series aren't the best and probably overcharge the batteries.

Interesting I'll try this on my 7 ah UPS SLAs the next time one fails.

Luckily prying the plastic cover over the cell caps off is easy since the Chinese don't use much glue .

[kc8adu]

Re: if you have a newer gel or agm battery with no capacity try this.

ones left dead a while will sulphate.
floated for a long time will lose water and get grid corrosion.
better quality batts hold off the corrosion longer.but the recombination in the catalytic vent caps isnt 100%.even worse if the float is a bit high.btw i have an east penn/deka 8d gel i have been using over 14 years.
it powers stuff at hamvention every year.deep cycled and fast charged 3 days in a row.used at field day 24 hours running 2 100w hf rigs that get pounded on 24hours straight.and when not in use for those events its on my home workbench ups which floats it around 13.4v.
gets intermittant use for testing big linear amps and boom car amps.
still seems to be in perfect shape.
a neighbor bought a "fullriver" 8d agm 2 years ago and set his float the same.
his has grid corrosion already.the posts are pushing up out of the case.
its next destination is my recycling pallet.
so gel/agm are variable in quality and reviveability.
very few 7ah ups batts are fixable.if they are way dead i wont even try to charge them unless they are new.if they load test ok i keep them for selling at hamfests to the qrp guys.

[kc8adu]

Re: if you have a newer gel or agm battery with no capacity try this.

just got a free power on board hid spotlight.would run 5 minutes and shut off.
pulled out the "sunnyway" battery figuring it was shot.failed the load test.
popped the top and added a bit of water to each cell.load test improved immediatly.
added a bit more to get the right look to the seperators.now test close to a new one.

[ben7]

Re: if you have a newer gel or agm battery with no capacity try this.

I keep meaning to ask this, but, I got an AGM sitting in junk pile (don't worry, it doesn't even have a volt on it!).

Pick it up, it feels very light. shake it, and you can hear what sounds like sand inside. I think this thing is dried up. Would there be any chance of reviving it?

[kc8adu]

Re: if you have a newer gel or agm battery with no capacity try this.

its probably a goner.
rattling is usually crumbled plates and interconnects.
you can try.

[larrymoencurly]

Re: if you have a newer gel or agm battery with no capacity try this.

Pick it up, it feels very light. shake it, and you can hear what sounds like sand inside.

I've had even brand new batteries in APC backups make that sound when shaken.

[smason]

Re: if you have a newer gel or agm battery with no capacity try this.

Hmm I'm sure I posted this about 3 hours ago. I'll try again.

Maybe I should try some distilled water in these.
Had a server and router disappear on the weekend. Sent someone out to look and they found the UPS chirping with all lights flashing and not powering anything.
Got it in today, and pried (literally needed 2 screwdrivers) these out:

[kc8adu]

Re: if you have a newer gel or agm battery with no capacity try this.

those hit thermal runaway.those are toast.pardon the pun!

[kc8adu]

Re: if you have a newer gel or agm battery with no capacity try this.

just did an exide orbital(spiral agm)
it seems to be ok now.it would just barely start my neighbors pickup.now it load tests like new and starts like it did new.added 1 oz to each cell.
peeled the top label and pulled out the 2 plastic cap strips.removed the rubber valves and injected water with a ink kit syringe.used sams club bottled water this time as it was handy.the owner had figured it was getting replaced and there was nothing to lose.i figured most bottled water was closeto or better than distilled.
this is a expensive battery new and i would be dissapointed to get only 3 years out of it.
then again this one seems marketed to ricers with its glittery x label and "purple haze"
that may be the reason it cost 250.00!

[kc8adu]

Re: if you have a newer gel or agm battery with no capacity try this.

just did this to a neighbors goldwing battery.its his only wheels right now and i was going to loan him the battery from mine as i have parked it for the season.tried the distilled water trick.went from turning half a turn and clicking to starting normally.
these bikes are pretty demanding of the 18ah battery.
it has to crank up a 1500cc 6.

[bluto]

Re: if you have a newer gel or agm battery with no capacity try this.

I tried this two weeks ago on a double BP12-12 pack out of an APC SmartUPS 1200. The batteries were failing to self test and had been sitting for two months tops. They still read 12v for each. After refilling and re-installing, the self tests passed initially. But fastforward two weeks and they are failing again with the beeping every 12 hours
It was worth a try though.