How to restore an uninterruptible battery

My uninterruptible power supply turned 15 this year, over the years it has already worked its value several times: twice it saved the computer from increased voltage in the network (varistor flew out), once it took over the consequences of a lightning strike. And how many times there were minor problems ... (power outages at the most inopportune moment ...).

In 15 years, I have changed 4 batteries. Each new battery nursed 3-4 years until the battery life was reduced to a couple of minutes. Never bothered with any recovery methods. I just threw it away and bought a new one...

Last year, when the “fluffy animal” came to the next battery, I decided to get confused and tried to restore the battery to its full working capacity.

I listened to a lot of Soviets, read / viewed a bunch of megabytes of information.

And here's what I did:

Using a screwdriver, I opened the top cover of the battery.

6 filler holes closed with stoppers became available to me. Studying the experience of restoring such batteries by participants in various forums, bloggers, I found very contradictory ways. First of all, I was interested in: “what should be poured into battery banks?” Distilled water, acid electrolyte and even alkali were advised.

Completely confused in the recommendations, I turned for advice to a familiar video blogger who repairs Chinese mopeds. The fact is that mopeds have the same batteries. Surely he already has practical experience in restoring the capacity of moped batteries.

I will say right away - I did not lose with the choice of an adviser. Konstantin (that's his name) advised to pour ONLY distilled water into each jar!

Just enough water is poured into each jar so that it slightly covers the plates. No more and no less! If the cause of the loss of capacity was the drying of the gel-like filler, then this method will most likely help. If the plates fell down, then ... the battery can be disposed of.

And now his main secret! After filling the cans, he takes a 100 microfarad electrolytic capacitor, rated for at least 200 V, and charges it with 100 V. Disconnects the charged capacitor from the power source and discharges it to the battery, while observing the polarity: + to +, - to -.

This procedure is repeated 3 times. This action raised doubts in me: “Will the plates fall off?” But Kostya claims that he has been using this technique for a long time. The result is positive.

After that, he puts it on charge, loading it with a current equal to 20% of the declared battery capacity. Those. if the capacity is 9 Ah, then the charging current is 1.8 A.

Every half an hour checks the voltage at the battery contacts. If the voltage rises, then there is a chance that the charging is proceeding normally.

Upon reaching a value of 13.5V, charging stops and connects the load in the form of an incandescent bulb. Discharges until the voltage drops to 11V. Knowing the current consumption and the discharge time, you can calculate the capacity of the battery. If the calculated value of the capacity was at least 70% of the original value, this is a victory.

Subsequent charges should be carried out with a current equal to 10% of the battery capacity for 10 hours.

Primary charging (on the table) is performed with the caps of the cans open. When the battery has gone through the recovery procedure, the plugs should be closed, but the cover should not be “planted” on the glue. Secure it with tape. Now it has become serviceable.

So what about my battery? It's been half a year since I restored it in a similar way and it works safely as part of an uninterruptible power supply.