How should I clean the mess made by battery acids  - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: September 23, 2022, 04:33:42 pm
content: When I opened a UPS stored for a long time, I found that its acids got leaked. I can't wash it with hot water as its PCB is inside.What other method can i use to clean it? please refer to images

author: james_s
author_rank: Super Contributor
timestamp: September 23, 2022, 04:37:31 pm
content: Neutralize it with baking soda dissolved in water, then scrub it with a brush or scouring pad.

author: Yusuf Alsaedi
author_rank: Newbie
timestamp: October 01, 2022, 03:24:07 am
content: Going off of what james_s said, Definitely neutralize the acid with baking soda and water. I would also make sure to afterwards, scrub it well with white distilled vinegar, using something like a dish sponge.

author: antenna
author_rank: Frequent Contributor
timestamp: October 01, 2022, 06:01:19 am
content: My first question would be: "what kind of battery leaked?". Lead-acid will obviously need a base like bakin' soda to neutralize, but if that was caused by a notoriously leaky alkaline Duracell, what leaked might be a hydroxide and need an acid to be neutralized!

author: Ian.M
author_rank: Super Contributor
timestamp: October 01, 2022, 06:07:27 am
content: Don't use vinegar. Vinegar is useful for neutralizing alkaline electrolyte spills from Alkaline, NiCd and NiMH batteries, not sulfuric acid from Lead Acid batteries.Follow James' advice above then wash off the baking soda neutralizing solution with water, and finally dry as much as possible with tough paper towel then hot air, paying particular attention to any joints and crevices.If the corroded areas are significantly pitted, you may need to treat them with a phosphoric acid based rust remover, then an etch primer to prevent rapid rusting.@Antenna: UPS batteries that have swelled and leaked are almost invariably Lead Acid batteries.

author: antenna
author_rank: Frequent Contributor
timestamp: October 01, 2022, 06:44:55 am
content: I had to hit like button because I 100% agree with the fact that UPS batteries are almost always lead acid (or at least sla), but I've never seen one leak... If you live in the good old US of A where gullible people buy garbage products on the regular, then you would be intimately familiar with the decline in Duracell AA and D cell quality, which my personal experience in prompted my response. I have had so many duracell AA batteries leak, sometimes in an audible manner. Duracell used to be king in my opinion, now they suck in comparison to energizer. There is no comparison.If a lead-acid battery leaks, the user fucked up, not the manufacturer. This typically happens when people add waterbeforecharging forgetting that the solution expands upon charging...Look, all I'm saying is that not all batteries leak acids. Some leak bases. And from my experience, it is the batteries with bases that leak unprovoked. Hence, my curiosity...

author: Ian.M
author_rank: Super Contributor
timestamp: October 01, 2022, 07:03:34 am
content: It takes severe abuse for aSLA (Sealed Lead Acid) batteryto leak, but the high float voltage and extremely high charge rate used by design in many consumer UPSes, combined with poor ventilation resulting in excessive battery temperature, IMHO verges on severe abuse.Its not uncommon for failing SLA batteries to bulge to the point where they jam in the UPS frame, and if they aren't mounted terminals up, if the internal pressure rises high enough, they can vent electrolyte gel displaced from between the plates. Rarely, poorly designed mounting hardware may rupture the case of a swollen SLA, also resulting in electrolyte leakage.

author: magic
author_rank: Super Contributor
timestamp: October 01, 2022, 07:18:27 am
content: Sulphuric acid, iron sulphate, maybe some lead sulphate.I guess water and scrubbing.It will never look perfect because the steel has been partly etched by acid.

author: antenna
author_rank: Frequent Contributor
timestamp: October 01, 2022, 07:19:33 am
content: Quote from: Ian.M on October 01, 2022, 07:03:34 amI'll take your word for it, but for the record, I will say that I have NEVER seen a swollen SLA UPS battery, like NEVER, not once ever! I've seen countless SLA batteries fail due to sulfation and refuse to take a charge, but I have never ever ever ever ever seen one bulge like a neglected automotive battery on a cold winter day. Bulging happens when the electrolyte becomes so low of dissolved ions that its melting point is above ambient temperature (I live in northern Minnesota where -40°F happens whether you plan for it or not). Just saying, I've seen batteries bulge overnight, and SLA's, in a warm home..... nope.Batteries may suffer from plate wear from overcharging and loss of electrolyte which results in uneven plate wear, but the only way a lead acid battery will bulge is if it freezes in an uncharged state, which requires neglect (or significant age) AND cold temperatures.

author: Ian.M
author_rank: Super Contributor
timestamp: October 01, 2022, 07:42:10 am
content: No need to take my word for it. Seehttps://www.google.com/search?q=swollen+ups+batteries&tbm=ischIf you haven't encountered a swollen SLA UPS battery you are either very lucky or don't have much experience with UPSes.Quote from: antenna on October 01, 2022, 07:19:33 amThe SLA bulging mechanism is very different to a flooded ('wet') lead acid battery, as the electrolyte typically has thickeners making it a gel so can exert significant force if gas bubbles form as it doesn't flow freely, and there is likely to be minimal 'headspace' in the cell as its designed for use in any orientation.However I agree that its rare to see a bulging SLA *NOT* from a UPS.

author: nightfire
author_rank: Frequent Contributor
timestamp: October 01, 2022, 11:44:45 pm
content: In addition to the tips of Ian.M, I would like to add that after rinsing with water to get the various stuff out of the system, rinse with IPA to get the water out- makes drying a bit easier and leaves less residue if you used tap water for this procedure.In regard to bulging UPS batteries, I also have seen sealed batteries in the range of 50Ah with round poles, that began to corrode. (80kVA UPS behind that, so batteries were placed in a separate battery rack)

author: james_s
author_rank: Super Contributor
timestamp: October 02, 2022, 01:01:21 am
content: Quote from: antenna on October 01, 2022, 06:01:19 amHe said right in the post that it's a UPS, the battery is obviously lead acid.

author: SeanB
author_rank: Super Contributor
timestamp: October 02, 2022, 07:01:03 pm
content: Plpenty of bulging and cooked SLA batteries in gate motors, garage doors and alarm systems, anywhere which both run the battery nice and toasty, and then have a constant 14V4 float voltage on them to first of all cause gas generation, which then vents the cells. The liquid generally is caught in the felting in the vent cavity in most cases, and the liquid gradually dries out, and then you get an open circuit battery. If you are unlucky a cell shorts out, and then most chargers cook the remaining ones nicely, so they boil, and then soften the case and cause it to bulge out. Other faults are the terminals rotting off from venting acid eating through the lead terminal seal, and eroding the copper push on blade, and then the wiring attached, and you get the battery with 6 bulges where the cells are. Also got them so dry that they will still read 12V open circuit, just draw 20mA, and see the voltage drop to 1V or less. And those that rattle when shaken.Then of course the fake ones, where the cells contain 2 lead plates, and the rest of the volume is taken up with a block of recycled polystyrene foam to provide pressure on the plates, to keep the acid gel in contact with the plates. Normally the 7Ah brick should be around 1.2kg, though some that have been cooked nicely, as in 6 split cells in the case, with all of them bulging out and venting white powder, came in at under 1kg.