Galaxy S21 Ultra Battery, (2024 Upgraded) 6800mAh EB-BG998ABY Li-Polymer Battery Replacement Compatible with Galaxy S21 Ultra 5G SM-G998B/DS SM-G998U with Screwdriver Tool Kit

is been a nice experience, I did change the battery my own, because I want my sister to have a reliable phone, I got the new version, so I can help her with my old, after I full charge it, y pas 10 days and still have the full charge, I was expecting a 70 or less charge, but what surprise, still full. yes is reliable battery from this store.

Seemed fine at first, but by day 3 the battery randomly drops 20% - 30%.

Easy to install, the battery work like a new phone. It last longer than a day, before i have to recharge again. Love it.

This upgraded 6800mAh battery works well once it’s installed. The charge lasts noticeably longer than the original S23 Ultra battery, and the phone runs normally with no overheating or errors. It’s a solid option if your original battery is worn out. The only downside is that installation is a bit tricky. The included tools help, but opening the S23 Ultra takes patience, heat, and careful prying. Once it’s in, though, the battery performs great and holds a strong charge throughout the day. Overall, a good high-capacity replacement, just be ready for a careful install.

Good replacement battery.

The battery is definitely not 6800mAh. It’s closer to ~5200mAh, and it weighs about the same as the OEM Samsung battery. Tests: After fully charging from 0% to 100% and then discharging to 0% and monitoring it with AccuBattery, the battery drew roughly 5200mAh before the device shut off. My old battery (about 2 years use) gave me around 5.5 hours of screen-on time. After the battery replacement, it gave me around 6.5 hours of screen-on time. Results: At best, this is an equal to or slightly better replacement compared to a 5000mAh OEM battery. Verdict: I’m giving it 3 stars because it’s about 1600mAh short of the advertised capacity. If it had been marketed as a 5000mAh battery, it would have earned a full 5 stars. It's a shame because it is a great product, just mislabeled. That said, I’d still recommend the kit since it includes a lot of useful tools for future phone repairs. 12/23/25 review :)

Works great and holds more power than the original, but it's still less capacity than advertised. The picture is what you get, and don't expect screw driver bits to come with it.

The first battery didn't work at all and this battery isn't much better. add a few dollars and get a different brand. Or you can do like I did and cheap out and get two bad batteries in a row. I,m tired of the return process so the only place this crappy battery is going is in the trash can. I'll brake down and spend the extra money and buy a real battery. The return process went very smooth I'm just not doing it twice in a row.