If your iPhone is dying by 3pm, shutting down at 30%, or running hot during normal use, the battery's worn out. We replace iPhone batteries on every model from the 6 through 17 Pro Max with OEM-quality cells, 24-hour turnaround, and a 12-month warranty. We've done over 316 of these and we're honest about when it's worth doing — and when you'd be better off saving the money for a phone upgrade in six months.
How to tell if you actually need a new battery
Go to Settings → Battery → Battery Health & Charging. The "Maximum Capacity" number is the headline metric. At 100% the battery holds as much charge as it did new; at 80%, it holds 80% of the original capacity and Apple's iOS automatically starts applying performance throttling. Below 80% is when most people feel the impact — daily runtime drops noticeably, the phone might shut down at 20-30% remaining, charging gets slower, and the CPU is being held back to prevent crashes. If your number is 79% or lower, replacement is genuinely worth it.
The percentage isn't the only factor. We also see batteries fail before the percentage drops — sudden unexpected shutdowns at high charge levels, phones running hot during normal use, swelling that pushes the screen up at one edge, or "Service" messages that appear even on a relatively new phone. Any of those, regardless of what Battery Health says, means the battery is misbehaving and needs to come out.
Why iOS throttles old iPhones (and why it's not a conspiracy)
This is worth understanding because there's a lot of bad information around it. Lithium-ion cells lose their ability to supply peak electrical current as they age — even when there's still 30% charge sitting in the cell, a worn-out battery physically can't deliver the burst of power the CPU needs to run at full speed during demanding tasks. Without intervention, the phone would unexpectedly shut down during things like opening apps, using GPS, or firing the camera flash.
Apple's performance management slows the CPU just enough to stay within what the worn battery can actually supply. It's a genuine engineering solution to a genuine problem. A fresh battery removes the throttle automatically because the new cell can supply full peak current. The whole controversy from 2017 was that Apple didn't tell anyone they were doing it for a few years, not that doing it was wrong. The honest fix for a throttled iPhone is a new battery — not turning the throttle off via a jailbreak or a software hack.
The "Service" message: what it means and what it doesn't
On iPhone XR, XS and every model after, Apple pairs each battery to the phone's serial number using a chip embedded in the battery itself. When a battery gets fitted that wasn't paired to that specific phone — including a genuine Apple battery transferred from another iPhone — iOS displays "Important Battery Message: Unable to verify this iPhone has a genuine Apple battery."
Here's the honest read: the battery works completely normally. The phone runs at full speed, the battery charges and discharges as expected, and there's no actual functional limitation. What you lose is the Battery Health percentage display in Settings (it just says "Service" instead of showing a number), and some of Apple's peak performance management features. We'll always tell you upfront when you call whether the battery we're fitting will trigger this message or not. For some iPhone models we can source genuine pairing-preserving batteries that don't display the message; for others, particularly the most recent generations, that's not economically possible. The cost difference matters: a pairing-preserving genuine battery can cost 2-3x more than an OEM-quality non-paired battery for the same model.
Why we won't fit a $30 eBay battery
This is the one place we draw a hard line, because we've seen what happens. Cheap aftermarket iPhone batteries are the leading cause of battery swelling, screen-lift damage, and lithium fires that come through our workshop. The protection circuitry inside a battery — over-voltage protection, over-current protection, thermal cut-off, pressure relief — is what separates a safe lithium cell from a dangerous one. Bargain-tier batteries cut costs by simplifying or omitting this circuitry.
We've seen DIY-replaced iPhone batteries swell to twice their original thickness inside a phone over 6-12 months, lifting the screen off the frame entirely. We've seen two catch fire on customers' bedside tables overnight. We've seen others vent gas and corrode the surrounding components. We use OEM-quality cells with intact safety circuitry. The cost difference between a quality battery and an eBay one is genuinely small at retail; the risk difference is enormous. If you want more detail on this, our article on fake iPhone batteries covers what to look out for if you're considering a DIY replacement anyway.
How we do it
The work is straightforward but careful. Phone opened, screen lifted off (the Face ID flex on the back of the screen stays attached to the phone — we don't disturb it), battery connector unclipped from the logic board, adhesive strips that hold the battery to the back chassis carefully pulled to release the battery. New battery seated with fresh adhesive, connector reseated, phone reassembled, full functional test before handover. Bench work is 30-45 minutes for most models. The rest of the 24-hour turnaround covers diagnosis, the QA pass (charge/discharge cycle, peak current under load, temperature monitoring), and final hand-back.
Battery work on the iFix bench.
Models, turnaround, pricing
We replace batteries on every iPhone from the 6 through the 17 Pro Max. 24-hour standard turnaround on every model. Price varies — older iPhone batteries (6, 7, 8 series) are at the cheaper end; current Pro Max generations with larger-capacity batteries are at the higher end. Call us on (02) 4311 6146 with your specific model and we'll quote you exactly. We'll also tell you on the phone whether the battery we'd fit triggers the "Service" message and what the price difference is for a pairing-preserving option if one's available for your model.
Outside the Central Coast? Post it to us
We receive iPhones for battery replacement by post regularly. Call or message first to confirm your model and quote. Ship the phone tracked and insured for its full replacement value via Australia Post Express or similar. We replace the battery within 24 hours of arrival and ship it back tracked the same day. Round-trip is typically 4-5 business days.
How to make a new battery last
A few habits genuinely extend battery life. Avoid charging to 100% overnight every night — letting the phone sit at 100% on a charger for 7-8 hours daily ages the cell faster than partial charging. Most iPhones have an "Optimised Battery Charging" feature in Settings → Battery → Battery Health that learns your sleep schedule and holds at 80% until just before you wake up; leave that on. Avoid charging in direct sunlight or in a hot car — heat is the single biggest accelerator of battery wear. Use the supplied (or any genuine MFi-certified) cable and a brand-name charger rather than the cheapest one you can find.
Get a quote for your iPhone battery
Call our Erina workshop with your iPhone model or book online. We'll quote exactly and tell you whether to expect the "Service" message before you commit. 24-hour standard turnaround.
Call (02) 4311 6146 Book OnlineCommon questions
When is it actually time to replace my iPhone battery?
The honest threshold is below 80% maximum capacity (check Settings → Battery → Battery Health). Below 80% is when iOS starts throttling and you feel the runtime drop. Also consider replacement if you're getting sudden shutdowns at 20-30% remaining or if the phone is unexpectedly hot during normal use.
Will I lose my data, apps, or settings?
No. Battery replacement is purely physical — internal storage, apps, photos, accounts and settings all stay exactly as they were. Everything is right where you left it when you collect the phone.
Will Face ID still work?
Yes. Battery work doesn't disturb the Face ID flex on the back of the screen — Face ID, Touch ID, and any other paired biometric hardware all work after the repair as long as they worked before.
What about the "Service" message in Battery Health?
The battery works completely normally — same speed, same runtime. What you lose is the percentage number display and some peak performance management features. We'll tell you on the phone before you commit whether the battery we'd fit triggers this message or whether a pairing-preserving option is available for your model.
How long does the new battery last?
A quality lithium-ion cell holds 80% capacity for around 500 charge cycles. For most users that's 1.5-2 years of daily use before noticeable degradation; heavy users (gaming, hot environments) see it sooner, lighter users later. Our 12-month workshop warranty covers manufacturing defects in the cell itself.