The battery is the first part of an iPhone to wear out. It isn’t a fault: lithium batteries lose capacity with every charge cycle. After two or three years of normal use, it’s common for an iPhone that used to last all day to need charging by mid-afternoon.
The good news is that a battery replacement is one of the simplest and most cost-effective repairs: it restores the battery life of a phone that otherwise works perfectly.
How to tell if your iPhone needs a new battery
1. Check battery health
Go to Settings > Battery > Battery Health & Charging (on older versions, Battery Health). You’ll see maximum capacity, a percentage comparing the current battery with a new one.
- Above 85%: the battery is fine.
- Between 80% and 85%: you’ll start noticing it, but it’s still usable.
- Below 80%: Apple considers the battery degraded and the system usually shows a “Service” notice. Time to replace it.
On recent models you can also see the cycle count under Settings > General > About.
2. Watch for symptoms
- The iPhone shuts down suddenly at 20 or 30%, especially in the cold or when opening the camera.
- The percentage drops in jumps (from 40% to 15% in minutes).
- The phone feels slower than usual. When the battery can’t deliver power peaks, iOS throttles the processor to avoid shutdowns. You’ll see it as “performance management” in battery health.
- The battery gets hotter than usual when charging.
3. If the screen is lifting, don’t wait
If the screen is separating from the frame or there’s a bulge, the battery may be swollen. Stop charging it and get it checked as soon as possible: a swollen battery can damage the screen and, in extreme cases, catch fire. We explain it in what to do with a swollen battery.
Which battery options exist
Basically, two:
- Genuine Apple battery: the same part Apple would fit.
- Compatible (third-party) battery: made by other brands. Good-quality ones work well and are usually cheaper; poor-quality ones may have less real capacity than advertised.
Either way, what matters is that the battery is new and from a reliable supplier, and that it’s fitted carefully: the old adhesive must be removed, the battery mustn’t be bent when taken out, and a new screen seal should be applied.
The “unknown part” notice
For several generations now, iPhones check whether their parts are genuine and paired with the device. If a battery the system can’t verify is installed, iOS may show a notice along the lines of “Unable to verify this iPhone has a genuine Apple battery” and, on some models, stop showing the battery health percentage.
Good to know:
- The iPhone works normally: it charges, lasts and performs the same. The notice is informational.
- On some recent models, genuine Apple parts installed outside Apple can be configured from the iPhone itself so the system recognises them.
- Before replacing it, we explain exactly what will happen with your specific model, so you can decide with all the information.
How much does an iPhone battery replacement cost?
It depends on the model and the type of battery you choose. Apple publishes its official battery replacement price for each model on its website; independent shops are usually cheaper, especially with compatible batteries.
As a guide: a battery replacement is always much cheaper than a new phone, and on an iPhone in good condition it extends its useful life by two or three years.
Tips to make the new battery last longer
- Don’t leave the phone in the sun or in a car in summer: heat is what degrades lithium batteries most.
- Turn on optimised charging (or the 80% limit on models that have it).
- You don’t need to wait until it’s empty to charge. Lithium batteries prefer partial charges.
- Use quality chargers. Very cheap ones can damage the charging circuit — see phone or iPhone not charging.
iPhone battery replacement in Carcaixent and La Ribera
At Systemaxo we do battery replacements and phone repair in Carcaixent, Alzira, Algemesí, Xàtiva and nearby towns (Valencia). Tell us your model and we’ll explain the options and the quote before doing anything.