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We're occasionally experiencing some short outages (few minutes at most or even seconds) so batteries in UPS almost never get below 90-80%. Is it advised to sometimes (eg. once half a year) perform some deeper discharge eg. to 30% in order to force deeper recharge cycle?

Question comes from fact that consumer devices sometimes get improper battery charge sense if they experience tiny discharges over extended period of time so in the end after actual disconnecting they loose power in few minutes instead of few hours as they're supposed to.

Does it also affect professional UPSes or are they prepared for such scenarios? UPS in question is APC-SMT3000I

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    No. Batteries used in UPSes are lead-acid batteries. They should be kept fully charged at all times and NEVER allowed to run down all the way. They are almost exactly the same as the battery in your car. That’s a far different technology then batteries used in modern consumer devices. – Appleoddity Dec 22 '17 at 15:23
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No, you should not deep discharge UPS without good reason.

At least not the overwhelming majority of small UPS devices, including those sold by APC. They are generally using lead–acid batteries, neither designed nor expected to endure many full discharge-recharge cycles.

Such batteries are not significantly affected by memory effect performance degradation that is said to occur in various consumer electronics. The (commonly misattributed into the same category) effects of over-charging or merely approaching their maximum recharge cycles are not relevant for UPS either, as the charging mechanism are already configured to maximize the batteries utility over the respective promised lifetime.

The only reason you would ever want to deep discharge an UPS is to test whether your setup really works as expected. Even then, do not overdo it:

Only perform runtime calibrations on your UPS one or two times a year, if necessary. Some of our customers want to check their systems to verify that their runtime is sufficient. However, consistently performing these calibrations can significantly decrease the life expectancy of your APC battery. -- APC FAQ 158934

If you do such, check the manual for your specific device - it may recommend that for testing purposes, you only use the devices self-test program, collecting data about the batteries remaining quality in order to correctly perform functions such as "send shutdown signal to attached machines when remaining energy lasts for X minutes".

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