It is almost certain you wrongly charged your phone

According to hvg.hu, your smartphone lasts for a short time not just because there is not a big enough battery in it. Behind the phenomenon is partly that almost everyone incorrectly charges it.

Don’t charge it fully

The website Battery University, which is owned by a battery company, warns that lithium-ion batteries do not require a full charge – neither at the first charge before the first power-up, nor after that. Indeed you do the right thing, if you always just charge somewhat, but not until 100%

Don’t leave charging at night (either)

The previous advise allows you should not let the battery on the charger for a longer period of time: however, if it is kept plugged into, there will be always charged, but the more times the battery is fully charged, the less it holds on in the long run.

The graphic shows that the capacity (green line) reduces almost to zero even after 200 charges, while the capacity of a battery, which is not fully-charged, reduces only by about 20% even after 400 charges. The point is:  do not leave it unattended charging for too long: 80-90% charge will be plenty enough, hvg.hu said.