⚡ Quick Answer
The most common causes are an ageing battery (2+ years old), background apps, high screen brightness, and heat. If your phone dies below 30% or the back panel is swelling, you likely need a battery replacement — a 30–60 minute job at a repair shop.
How long should a phone battery last?
Most lithium-ion phone batteries are designed for 300–500 full charge cycles — roughly 2 years of normal use. After that, capacity drops noticeably and the phone drains faster even with the same usage.
7 common reasons your battery drains fast
- 1.Ageing battery — the #1 cause after 2 years of use.
- 2.Background apps — social and location apps running silently.
- 3.High brightness & 120Hz display — the screen is the biggest power draw.
- 4.Weak signal areas — your phone burns power searching for network.
- 5.Heat — gaming or charging in hot conditions degrades the battery faster.
- 6.Software bugs — a bad update can cause abnormal drain.
- 7.Swollen battery — if the back panel is bulging, stop using the phone and get it replaced immediately; it’s a safety risk.
When do you actually need a battery replacement?
If your phone shuts down above 20%, drains visibly in minutes, overheats during normal use, or the battery is swollen — software tricks won’t help. A genuine battery replacement restores day-one backup and typically takes under an hour.
How much does phone battery replacement cost?
It depends on your model. At our Nandgram shop, you get a free diagnosis and an upfront quote before any work begins — no hidden charges.