ZeroLemon battery case for Samsung Note 9 not working properly?


Golden Member
Apr 20, 2013
I bought a ZeroLemon 10,000 MaH battery case for my Samsung Note 9 128 GB,
thinking that it would help extend my battery life on my phone. is the one I have.

The case doesn't seem to be working properly.
(I thought that it would add its 10,000 MaH capacity to the 4,000 MaH capacity of my Note 9's built-in battery, and give me at least 5 days between charges.)

Do you have to charge the case's battery fully(5 hours or so is what I heard.) before it will properly work?
Mar 11, 2004
Its just functioning as an external power bank that will recharge your phone's internal battery, so its less that it combines the two and instead just recharges the phone's internal battery. Which isn't optimal for either I believe, plus you'll lose some of that capacity due to the charging. If your stock phone battery is already pretty worn out, its not gonna help that much and might even exacerbate things depending on how it charges.

It is possible its just the ZeroLemon not living up to its potential though. Those large battery packs are pretty iffy. I believe from the onset you're supposed to fully charge the ZeroLemon (which will take a long time, more than 5 hours even, I think generally they say like 10+ hours, at least overnight) so that it'll fully charge. I think they say to let it go through almost a full discharge/recharge for the first few as well. I know a lot of people have had issues ever getting the claimed battery life out of them even following that though.

I actually had the ZeroLemon 10,000 battery for my Note 3 and it really did provide like 3x the battery life (but it also fully replaced the internal battery). I'd let it get low then fully charge it, and it held up well for like a solid year or more. Once I gave that phone to my sister though it went bad fast, not sure why exactly but she is awful about charging (let it fully deplete and then would only charge it to like 30% before she'd start using it again). I bought a different brand one for my LG V10 as ZeroLemon had stopped selling (or maybe never did?) a similar battery for it. It was ok for like 6 months, but now it powers down if the battery hits 50% and I don't think it offers even the worn stock 3000 LG battery battery life (I had been swapping between two of the stock batteries as I got an extra one free when I bought the phone).