Unpopular opinion: you should always test the backup battery with a full system load

I keep seeing guys just check the battery voltage and call it good. Last month in a Cincinnati apartment job, a battery read 13 volts but died in 4 minutes when the sirens were going. The spec sheet said it should last 48 hours. I test every battery now by pulling the main power and letting the whole system run on backup for an hour. Who else does this, or is it a waste of time?

3 comments

3 Comments

kelly_ramirez964mo ago

It's like people who buy a generator but never start it until the power's out.

ryan_kim634mo ago

Guilty as charged with my generator.

markl752mo agoMost Upvoted

My neighbor ran his generator for 3 hours last week and then threw a party to celebrate that it actually started. Now he's got a gas can in his garage that he swears is "just in case" but it's been sitting there since 2019. I tried to borrow it once and he looked at me like I asked for his kidney. Funny how people will buy a $500 backup plan and treat it like a museum piece until the power flickers.