Disregard: Sealed Lead Acid Battery Longevity Log

Edit: ACTUALLY, NEVERMIND

It’s now June of 2020, and I figure it’s time to put a big “disregard” in the title of this post.

While my objectives were indeed grand, there’s a fundamental flaw in my methodology:

Most of the UPSes in question do not perform battery self-tests. As such, I really only find out about bad batteries when there’s an actual power failure. And those happen very inconsistently, and infrequently. (Which is good for me overall, but bad for this “log”.)

For example, my power just flickered briefly and one UPS shut down as soon as the power went off. The batteries were dated as replaced on 2017-12-10. However, that UPS survived the last power outage some months ago, at least until I shut it down.

SLA batteries don’t usually fail catastrophically. They’ll lose their ability to hold a charge over time. So when did those batteries go “bad”? And moreover, what exactly do I consider “bad”?

As I wrote below, “a decent battery should last 3 years”. So clearly those batteries didn’t. It was more like 2.5 years at best. So they’re not very good, but what about batteries that fail after the 3 year mark? Did they fail in 2 years, and I just didn’t notice until 3 years had passed? And if they got me through a brief 5 minute outage at the 3 year mark, are they still “good”?

I’ve updated the info below with that latest failure, but the below data is going to be incredibly approximate, and will really only end up highlighting some of the bad batteries that completely give up the ghost in under 3 years as being brands to avoid.

Atypical Post

This post isn’t only for you, but also for me. I have roughly sixteen 120V 1300-1500VA UPSes in my basement of various ages. They each take two SLA 12V ~8Ah batteries.

As such, I need to replace those batteries periodically. Being a cheap bastard, I don’t buy the branded APC or CyberPower packs, but go for inexpensive generics from eBay or Amazon. In theory there’s no difference, but in practice some cheap batteries are, well, cheap. I’m attempting to figure out which off-brand brands work best.

This Log

Hence I’m going to start logging battery replacements to get an idea of which brand(s) represent the best value and longevity. This will always be a work in progress, because a decent battery should last 3 years. A good one should last 5 or more. Unfortunately I only started labeling them a couple of years ago.

So, uh, stay tuned.