In short and in plain language
Is your phone flat by lunchtime? You may not need a new phone. The article shows what often helps.
A few settings make a difference. These include brightness, location and apps in the background. An app is a small program on your phone.
Heat harms the battery more than any app. Make sure your phone does not get too warm.
Sometimes the battery itself is worn out. Then a new battery can be worth it.
We check your battery and set up your phone with you.
It is half past three and the phone shows twelve per cent. Again. Brightness down, apps closed, socket hunted - and by evening the thought has settled that a new device is due. Usually it is premature. A battery that gives up by lunchtime after two years has not been a fact of life since 20 June 2025: new smartphones sold in the EU must survive at least 800 full charge cycles and still deliver 80 per cent of their capacity afterwards (European Commission). And the device in question is hardly a niche item - 90.8 per cent of households in Germany had a smartphone in 2024 (Federal Statistical Office). This guide sorts out what really drains the battery, which settings make a measurable difference - and how to tell that the cell itself has reached the end of its service life.
Key takeaways
- Since 20 June 2025, new smartphones sold in the EU must survive at least 800 full charge cycles and still deliver 80 per cent of their capacity afterwards (European Commission).
- The switchable charge stop at 80 per cent is no longer a workaround but a required function of new devices (European Commission).
- Heat costs more battery than any app: the manufacturer names 16 to 22 degrees as the comfortable range and warns about environments above 35 degrees (Apple).
- The often quoted 83 per cent after 500 charge cycles is not a general requirement but a condition for manufacturers who supply replacement batteries only to professional repairers - the yardstick at the counter remains 800 cycles at 80 per cent (European Commission).
- From 18 February 2027, device batteries must be built in so that end users can remove and replace them themselves (European Union).
Why the battery gives up at lunchtime
A lithium-ion battery loses capacity as soon as it is used - that is chemistry, not a defect. The EU counts in full charge cycles: one cycle equals one complete fill, spread over a day or a week. The yardstick for new devices is 800 charge cycles with 80 per cent of capacity left afterwards (European Commission). The frequently quoted 83 per cent after 500 charge cycles sits elsewhere in the text: it is a condition for manufacturers who hand replacement batteries to professional repairers only - not a bar a new device can fail (European Commission). The manufacturer of the most widespread closed system names 500 charge cycles to the 80 per cent mark for older iPhone models (Apple), and 1,000 charge cycles for the iPhone 15 (Apple). Charging once a day puts you at roughly 700 cycles after two years, so a phone that is empty by lunchtime after eighteen months rarely has a capacity problem - it has a consumption problem. The same distinction leads to the same result on computers: what feels slow is often just badly set up (Slow PC? What helps without buying new).
The single biggest consumer is the display, by a wide margin. For the label test the EU explicitly prescribes 200 candela per square metre with automatic brightness switched off - a medium brightness, not a full one (European Commission). Behind it come mobile data and Wi-Fi, then background services, then location. The order rarely matches people's assumptions: the weather app everyone suspects costs less than twenty minutes of bright screen with weak reception. The breakdown sits in the device itself, in the battery settings, split by app and by screen time. That list is exactly what we look at together in our smartphone courses before a single switch is flipped.
An empty battery is not the same as an old battery
What has applied to new devices since 20 June 2025
The ecodesign regulation for smartphones and slate tablets has applied since 20 June 2025 (European Commission). It is why more is moving on batteries now than in the ten years before, and why repairs add up again (Right to repair: what applies to broken devices). The requirements apply to devices placed on the market from that date, so a phone from 2022 does not get better because of them. The figures still work as a yardstick for your own device - and as an argument at the retailer if a newly bought device clearly falls short.
- 800 full charge cycles with 80 per cent remaining capacity afterwards - the lower limit for new smartphones (European Commission).
- 1,000 full charge cycles where the manufacturer builds the battery in permanently and uses the exemption (European Commission).
- 83 per cent of rated capacity after 500 full charge cycles - not a general requirement but the condition for supplying replacement batteries to professional repairers only (European Commission).
- At least 12,000 insertion cycles for the charging port where the manufacturer combines it with microphone, speaker and buttons into one assembly - at one charge per day, more than three decades (European Commission).
- 45 drops without a case must leave a new smartphone fully functional (European Commission).
- Five years of free operating system updates after the model stops being sold (European Commission).
- Seven years of spare part availability after the end of sales, explicitly for end users (European Commission).
- Five working days maximum delivery time for spare parts in the first five years (European Commission).
Battery
Cycle count, remaining capacity and a switchable charge stop at 80 per cent of full capacity are mandatory features of new devices, not extras (European Commission).
Software
Five years of free operating system updates after the end of sales often extend usable life more than a new battery does (European Commission).
Spare parts
Seven years of availability and a five working day delivery limit in the first five years make a battery replacement plannable (European Commission).
Charging port
At least 12,000 insertion cycles apply where the charging port is built as part of a combined assembly - if the cable wobbles sooner, lint in the port is usually the reason (European Commission).
Charger
Since 28 December 2024 every new phone in the EU has the same port, and a charger delivers up to 100 watts over USB Power Delivery (European Union).
Manufacturing
Phones, cordless phones and slate tablets across the EU-27 consumed 39.5 terawatt hours of primary energy over their life cycle in the 2020 reference year (European Commission).
The four settings that do the most
During a battery check-up we work through the same order every time, sorted by effect rather than effort. The first two points take two minutes; the last two need a little patience. Change one switch at a time and wait a day - otherwise nobody knows afterwards which change did the work. If you feel unsure, our article on accessibility settings walks through the same menus.
- Lower the brightness and switch the automatic on. For the energy label the EU measures at 200 candela per square metre with the automatic off (European Commission) - in daily use the automatic is better, because it stays well below that in dim rooms.
- Activate the charge stop at 80 per cent. New devices must offer the option to end charging at 80 per cent of full capacity (European Commission). For phones that hang on the cable overnight, this is the most effective single switch.
- Thin out background refresh. Android throttles rarely used apps by itself down to one ten-minute session per day (Google) - the same effect can be set by hand for apps you only open deliberately.
- Set location to "while using". Hardly any app needs your position permanently; you will not notice the change in use, but you will see it in the battery graph.
- Prefer Wi-Fi over mobile data. With weak reception the radio turns up its transmit power, so a stable home network saves noticeably (Slow Wi-Fi? Fixing dead spots at home).
Why the energy label figure is not your day
Heat costs more battery than any app
The most underestimated factor is temperature. The manufacturer names 16 to 22 degrees as the comfortable range for operation (Apple) and warns about environments above 35 degrees, because capacity can suffer permanently there (Apple). The dashboard in summer, the windowsill, the sun lounger, charging under the duvet: those are the places where batteries age, not the apps. If you rarely put the device down you will notice little of this; clamped to the windscreen for navigation you certainly will. Older people often leave the phone on the radiator during the day because that is where it is found again - a point we raise first during tech help for seniors.
- 16 to 22 degrees is the comfortable range for everyday operation (Apple).
- Above 35 degrees capacity can suffer permanently - the phone belongs neither in a parked car nor in direct sun (Apple).
- Around 50 per cent of capacity is the right charge level for a device that sits in a drawer for months (Apple).
- Up to 80 per cent of capacity devices charge briskly, after which they switch to slow trickle charging - which is why the last twenty per cent take disproportionately long (Apple).
- Take the thick case off while charging if the device becomes noticeably warm - especially overnight or while streaming on the charging stand (Streaming 2026: the overview).
Cold behaves differently from heat
What the device handles on its own
Much of the former manual work is now handled by the devices themselves. New smartphones may only top up again once they fall below 95 per cent of their maximum charge capacity (European Commission) - leaving the cable plugged in overnight is far less harmful than its reputation suggests. Low power mode announces itself at 20 per cent and 10 per cent of remaining charge (Apple). Background services are throttled once an app has not been opened for a while. The same shift is under way in home technology, where access rights and automations are changing (Smart home data: new rights from September 2026). The table below sorts the symptoms we meet most often.
| What you notice | Common cause | What helps first |
|---|---|---|
| Battery drops fast in the morning, slowly in the afternoon | Bright screen outdoors, automatic off | Switch automatic brightness on, lower the maximum |
| The device gets warm while charging | Thick case, brisk charging up to 80 per cent (Apple) | Take the case off, charge overnight with the 80 per cent stop |
| Ten per cent disappears overnight | Background services and permanent location access | Thin out background refresh, set location to "while using" |
| The indicator jumps from 30 to 1 per cent | Aged cell, drifted capacity gauge | Read the maximum capacity, then decide about a replacement |
| Only drains fast when out and about | Weak mobile reception, high transmit power | Prefer Wi-Fi, use flight mode in dead spots |
| Worse since the last update | Re-indexing and background downloads | Wait two or three days, then measure again |
The fourth row is the only one that ends in a spare part; the others can be sorted out in half an hour at the kitchen table. Tablets differ in one respect: they more often sit unused for months, and then the charge level when you put them away matters more than any setting (tablet courses).
When a battery replacement pays off
The EU has defined the point at which a battery counts as worn out: as soon as it delivers only 80 per cent of its rated capacity (European Commission). Most devices show that figure under "maximum capacity" or "battery health". If the figure is still high and the device still does not last, a replacement is the wrong tool; if it is close to or below 80 per cent, a replacement is usually the cheapest extension - provided the device still receives updates. A complete backup belongs before any such work (Backing up photos and data: a strategy that holds).
The timing is easier to plan than it used to be. Spare parts must be available for seven years after the end of sales, explicitly for end users too, and a maximum delivery time of five working days applies during the first five years (European Commission). From 18 February 2027, device batteries must be built in so that end users can remove and replace them themselves (European Union). Waiting does not pay off for a device causing trouble today, but it shapes the choice of the next one. An orderly data backup is the precondition either way.
- Read the maximum capacity in the settings and write it down with the date.
- Look at screen time and per-app battery use across a full week, not a single day.
- Apply the four settings, then measure for a week without changing anything else.
- Only ask for a battery replacement quote once the battery health display shows a clear loss of capacity or recommends service.
- Make a complete backup before the appointment and test the restore once.
- If you change devices, prepare the move instead of improvising in the shop (Data transfer to a new device).
Your rights at purchase and with the old device
If a newly bought device is noticeably weak after a few months, that is a case for the statutory liability for defects, not goodwill. During the first year after handover it is presumed that a defect already existed at handover (German Civil Code), so the buyer need not prove the device was faulty from the start. The limitation period for claims based on defects is two years from delivery (German Civil Code). Document the condition early: a photo of the capacity display with a date is enough. If you hand the old device on, wipe it properly first (Selling an old device and erasing data safely).
One return rule is little known: larger distributors with an electrical goods range must take back old appliances with an edge length of up to 25 centimetres even without a new purchase, limited to three old appliances per appliance category (German Electrical Equipment Act). A phone falls under that. Behind it stands a collection target: 63 per cent of waste portable batteries are to be collected by 31 December 2027, rising to 73 per cent by the end of 2030 (European Union). Unsure what data is still on the device before you return it? We go through that during the appointment (contact).
If, within one year of the passing of risk, a material defect becomes apparent, it is presumed that the goods were already defective when risk passed, unless this presumption is incompatible with the nature of the goods or of the defect.
In daily life that simply means: keep the receipt and write down the capacity figure once a quarter. Two dated numbers are worth more at a retailer than any description. If you want your paperwork in order anyway, our article on digitising paperwork shows the route - the phone receipt is a good case to practise on.
How we work in your own home
Stocktake
We read out the maximum capacity, look at the battery graph of the last ten days and note both with the date. Without that starting point nothing can be said later about whether a change did anything.
Settings
Brightness, charge stop at 80 per cent, background refresh and location - in that order, one at a time, with a short explanation of each switch. You decide every point yourself.
Everyday test
We work through the three tasks you use the device for most often and check whether the changes get in the way. Anything that does is reverted - a setting that complicates daily life rarely lasts a week.
Decision
At the end one sentence is on paper: the settings are enough, or the battery has reached its end. In the second case we name the route to a replacement.
A battery check-up rarely takes longer than an hour and needs no extra accessories. If you want to carry on yourself, we show the menus so you find them again - that is the real content of our smartphone courses. What an appointment costs and what it includes is on our pricing page.
Sources and studies
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