4mo ago

How usable is an old lithium battery with less capacity?

I have an older robot vacuum that has finally shown some age in its battery. The charger will charge for about 15 mins and then gets an error, but it's enough to do a decent vacuuming of the room if I charge then vacuum, then repeat once more. I can't leave it on the charger now due to the error repeating, so basically I run it dead until the next time.

So my question is, can I continue doing this since it works well enough, or is there potential problems/danger with the battery being at less capacity? I could buy a new battery, they aren't terrible in price, but if it works and is safe, why not continue what I'm doing until it completely gives out?

6 comments

I've never seen a dead battery that didn't eventually go full "spicy pillow," but until then they're as safe as new (assuming no physical damage to the battery). That being said, it wouldn't hurt you to take it to a certified battery recycler and get a new one.
- Good point. It looks fine so far, but apparently not only overcharging (which I think isn't a problem since the charger seems to detects current flow) but deep discharging could lead to this. So my running it down until it stops could eventually get things unstable. And it's enclosed so I'd have to literally remove the cover regularly to make sure it's okay. I guess that was what I was looking for, something that might be a problem down the road. Thanks.

I did that for like a year until I broke down and bought a replacement battery. Weird thing was that it didn't act like it had lost any capacity. Still took the usual amount of time to charge and cleaned for about 30 minutes on the high setting.
Would just let it charge until it started error-beeping, pull it off the charger, and then turn it off with the physical switch until I needed it again (if I didn't do that, it would periodically wake up, crawl back on the charger, and then start beeping lol).
Kind of defeated the convenience purpose of it, but it was still good for cleaning under the furniture and such. I just had to make sure it was off the charger before I went to bed or else it would beep all night.
- I didn't think of using the switch to hold a charge. Might be a good test, to see if the battery can hold what little it takes. I'm just mainly concerned about the lithium overheating more than anything. If it gets tedious then I'll spend some money.

I'd be more concerned that it could be a faulty charger.
- I actually have two robot vacs and tested that first thing, switching them out to see if the error followed the robot.

6 comments