The S25 Ultra has a 5,000mAh battery (part number EB-BS938ABY) with 45W wired and 15W wireless charging. It launched in early 2025, so first owners are now past the one-year warranty and some are seeing the battery health number slide.
What it costs
| Option | What you get | Cost |
|---|---|---|
| Samsung (out of warranty) | Genuine battery, certified tech | About $109 |
| Samsung Care+ | Battery repair once capacity is 79% or less | Covered, service fees may apply |
| uBreakiFix (authorized) | Genuine parts, 1-year warranty, price match | Quote after free diagnostic |
| Independent shop | $10 to $19 part plus about $60 labor | Around $70 to $80 |
| DIY, genuine part | Samsung parts store | $16.11 |
| DIY, aftermarket part | iFixit, part only | $32.99 |
Samsung doesn't post its battery price on a public US page, so the $109 comes from The Droid Guy's April 2026 price roundup. Confirm when you book. uBreakiFix doesn't list a price either but says it'll beat a local competitor's published price by $5.
First, rule out the July 2026 drain bug
After Samsung's July 2026 update (One UI 8.5), many S25 Ultra and S24 Ultra owners reported heavy battery drain and overheating. Notebookcheck cited one owner losing 5% to 7% an hour while idle, and 9to5Google noted one user traced their drain to WhatsApp stuck in a backup loop. Samsung hadn't acknowledged the issue in those reports. A new battery won't fix a software bug, so check this first:
- Install the newest update and restart.
- Open Settings > Battery and see which app is at the top of usage.
- Force stop and update any app that's misbehaving. WhatsApp backup is a known suspect.
- If the phone is hot while doing nothing, that points to software, not a worn cell.
Check battery health
- Settings > Battery > Battery information (where Samsung enables it) shows health and cycle count.
- Samsung Members > Support > Phone diagnostics gives Normal, Weak or Bad. Normal roughly means 80% or better.
- Below 80% with real usage, a replacement is worth booking.
DIY
The S25 Ultra is on Samsung's US self-repair list with an official manual, and the genuine battery is $16.11 on Samsung's parts store. iFixit rates its battery guide as Moderate, 1 to 2 hours, and its aftermarket cell is $32.99 without adhesive. You'll need to get through the back glass and its adhesive, and the phone loses its factory water seal unless you reseal it properly.
Genuine vs aftermarket batteries
An aftermarket cell can be fine, but quality varies a lot, and some phones flag non-genuine parts in settings, which can matter when you sell. A genuine Samsung battery costs a shop very little extra at wholesale, so it's reasonable to insist on one. If you have Care+, Samsung uses genuine parts and certified techs for every repair.
What to ask the shop
- Genuine Samsung battery or aftermarket?
- Will you replace the back glass adhesive and reseal for water resistance?
- What warranty is on the battery?
- Will my data be untouched? (Back up anyway.)
Is it worth replacing?
Easily. For around $70 to $109 you get a flagship back to full-day battery life,. Just make sure it's the battery and not the software. For screen damage, see the S25 Ultra screen repair cost guide and the Galaxy S25 Ultra repair page.
Prices checked October 15, 2026.
