Galaxy S8 Plus Battery Replacement: Cost & DIY
Galaxy S8 Plus battery replacement in a nutshell
A Samsung Galaxy S8 Plus battery replacement runs about $79–$99 at an authorized service center, roughly $60–$90 at an independent repair shop, or $15–$30 in parts if you do it yourself. The S8+ arrived in April 2017, so any unit still in service runs a nine-year-old cell cycled well over a thousand times. If the phone that once lasted a full day now taps out by mid-afternoon, the answer is a fresh 3500 mAh battery — not a new flagship.
There's also a safety angle specific to this phone. The S8+ wraps a curved Gorilla Glass back over a large 3500 mAh cell. As that cell ages and swells, it presses outward against the curved rear glass, and on a curved panel that pressure can crack or lift the back — which makes a puffy, aging S8+ battery a job to handle now, not later. Below is how to check the cell, spot the failure signs, and decide between paying a shop and doing it at your own bench.
How to check your Galaxy S8 Plus battery health
Samsung never gave the S8+ a plain "maximum capacity" percentage like an iPhone, so you have to read the signals it does show:
- Open Settings → Battery and device care → Battery to see current charge, an estimated runtime, and which apps are draining power.
- Look at screen-on time after a full charge. A healthy S8+ with its big 3500 mAh cell should still clear five hours of screen use; if you're falling short of three, the battery is worn.
- Notice how fast the percentage drops under light use — a 12–18% fall from casual browsing signals a worn cell.
Because there's no true health figure baked into the S8+, the honest way to gauge wear is a third-party app. AccuBattery is the tool most repair techs rely on: it measures the actual charge flowing into the pack across several full cycles and estimates real capacity against the factory 3500 mAh. It's an estimate, not a lab measurement, and it needs a few charge sessions to stabilize — but it's far more useful than guesswork. If AccuBattery pegs your S8+ at only 2,300–2,600 mAh, the battery is the bottleneck.
Signs your Galaxy S8 Plus battery is failing
Lithium cells decline gradually, then drop off a cliff. Watch for these:
- Galaxy S8 Plus battery draining fast — you lose 15–20% just scrolling, or the phone bleeds charge overnight while idle.
- Random shutdowns at 30–40%, especially in the cold, when an aged cell can't push current.
- Galaxy S8 Plus not charging or charging slowly — sometimes a worn cell, sometimes a dirty USB-C port worth cleaning first.
- Heat during light tasks or on the charger.
- Swelling — the safety-critical sign, and it hits the S8+ hard because of that curved glass back. If the rear panel lifts at the edges, the display bulges, or the phone rocks on a flat table, stop charging immediately. On a curved rear panel a swelling cell can crack the glass. Never press, bend, or puncture a swollen battery; replace it promptly and recycle the old pack at a proper e-waste drop-off.
Galaxy S8 Plus battery replacement cost
Here's the realistic 2026 picture. The S8+ is now a legacy device, so some authorized centers treat it as an older-model repair — call ahead first.
| Option | What you get | 2026 price |
|---|---|---|
| Authorized service (Samsung / uBreakiFix) | Genuine part + labor + limited warranty | $79–$99 |
| Independent repair shop | Aftermarket part + labor, same-day | $60–$90 |
| DIY (part only) | Replacement 3500 mAh cell + adhesive | $15–$30 |
Nearly all of that spread is labor — the shop charges most of its fee for about 40 minutes at the bench. That's why people search "galaxy s8 plus battery replacement near me," get quoted $85, and decide to buy the part and do it at home.
The exact replacement battery
The Galaxy S8 Plus uses a single 3500 mAh lithium-polymer pack, Samsung part number EB-BG955ABE, rated at 3.85V. The same cell fits every regional variant — the phone shipped as SM-G9550, SM-G955A, SM-G955F, SM-G955FD, SM-G955N, and SM-G955P — so there's no model code to chase down; one S8+ battery covers all of them. Don't confuse it with the smaller standard S8 cell (the 3000 mAh EB-BG950ABE). When you shop for a Galaxy S8 Plus OEM battery or a quality equivalent, look for the full 3500 mAh rating, a fresh adhesive strip, and ideally a zero-cycle cell that's never been charged. You can check stock and pricing on our Galaxy S8 Plus battery listing, or browse the full replacement batteries collection to confirm the right fit first.
How to replace a Galaxy S8 Plus battery yourself
Here's the step overview. The S8+ has a glued glass back and a glued-down cell, so read the whole thing before you begin.
- Power down and gather tools: a heat source (hair dryer or heat pad), suction cup, thin plastic picks, a Phillips #00 driver, tweezers, and isopropyl alcohol.
- Warm the rear glass evenly to soften the perimeter adhesive, then use a suction cup and picks to work the back panel loose. Move slowly near the top edge — the wireless-charging coil and NFC antenna sit inside that cover.
- Remove the midframe screws and plastic plate to expose the battery and its flex connector.
- Disconnect the battery flex first, before touching anything else, to cut power to the board.
- Free the old cell. Work a little alcohol under the edges to dissolve the adhesive, then lever it out with a plastic card. Never use a metal tool against the cell body, and never bend or crease it.
- Seat the new 3500 mAh battery on fresh adhesive, reconnect the flex, and power on to test before sealing anything up.
- Re-adhere the glass back with new perimeter adhesive and let the phone rest under light pressure while the glue cures.
Honest difficulty rating: 7/10 — moderately hard. The swap itself is straightforward; the real test is removing that tall, curved glass back in one piece without cracking it or tearing the charging-coil flex. If you've opened a glass-backed phone before, you'll manage. First-timer? Budget an unhurried hour, plan to buy replacement back-cover adhesive, and watch a full teardown video first.
After the swap
Samsung doesn't lock the S8+ out with a "genuine part" warning, so you won't get a nag screen after fitting a quality aftermarket cell. What you should do is calibrate: charge to 100%, then run the phone down to near-empty once or twice so Android relearns the true full-to-empty range. The percentage may read erratically for the first day — that's the fuel gauge recalibrating, not a fault. Reinstall AccuBattery afterward and the estimated capacity should climb back toward 3500 mAh, confirming your S8+ is back to all-day runtime.
Repair vs. upgrade: keep the Galaxy S8 Plus alive
A new large-screen phone is $500 and up. A Galaxy S8 Plus battery is around $20 in parts and an hour of your time. That gorgeous curved Infinity Display, the dual speakers, and a still-capable camera don't stop working just because the original cell is tired — a fresh battery makes a nine-year-old flagship feel whole again. It's also the greener call: roughly 70% of a smartphone's lifetime carbon footprint is baked in at manufacturing, so every extra year on a device you already own beats buying new. That's the whole reason PhonePartPro exists — repair, don't replace, and keep working electronics out of the landfill.
FAQ
How much does a Galaxy S8 Plus battery replacement cost?
Expect $79–$99 at an authorized service center, $60–$90 at an independent shop, or $15–$30 if you buy the 3500 mAh part and install it yourself. DIY is the cheapest by far because you're paying only for the cell and adhesive, not bench labor.
How do I replace a Galaxy S8 Plus battery?
Power off, warm the rear glass to loosen the adhesive, lift the back cover with a suction cup and picks (mind the wireless-charging flex), remove the midframe plate, disconnect the battery, dissolve the glue under the old cell with isopropyl alcohol, pry it out with a plastic tool, seat the new 3500 mAh battery on fresh adhesive, reconnect, test, and reseal the glass. It's a moderately hard 7/10 repair that takes about an hour.
Why is my Galaxy S8 Plus battery draining fast?
After nine years and well over 1,000 charge cycles, the original cell holds a fraction of its factory capacity. A rogue app or weak signal can add to it, but if a fully charged S8+ no longer lasts a workday, the battery itself is worn and a fresh 3500 mAh cell restores the original runtime.
My Galaxy S8 Plus is not charging — is it the battery?
Not always. First clean the USB-C port with a dry brush and try a different cable and charger, since lint and worn cables cause most "won't charge" cases. If it still won't take a charge or shuts down at 30–40%, a degraded battery is the likely cause and a new cell will fix it.
Does a Galaxy S8 Plus use an OEM battery I can buy?
Yes. The S8+ takes one 3500 mAh cell (Samsung EB-BG955ABE) across every variant — SM-G955F, SM-G955U, SM-G9550 and the rest. You can buy a genuine-spec OEM or a quality zero-cycle aftermarket replacement; just confirm it's rated at the full 3500 mAh and ships with a new adhesive strip.
Is it safe to replace a swollen Galaxy S8 Plus battery myself?
You can, but take extra care, because the S8+'s curved glass back can crack under a swelling cell. Stop charging a puffy phone immediately, never bend or puncture the battery, and pry only with plastic tools. If the swelling is severe or the pack has ruptured, let a professional handle it and recycle the old battery at an e-waste facility rather than in the trash.
Ready to fix it? Grab the exact cell from our Galaxy S8 Plus battery listing, browse the full replacement batteries collection, or find your device in our battery replacement by model guide.