Tablet PC CWI538 battery

Recently, my Tablet PC CWI538 needs to be recharged after using it for 1 hour, sometimes it is turned off without using it, and it can be used after turning it on, especially in winter. What is going on?

You do not indicate if the battery percentage drops rapidly or if it is turned off with sufficient battery according to the Windows meter.
The first thing you have to do is calibrate the battery, a process that you must perform a couple of times, and that consists in completely depleting the battery to recharge it up to 100%.
As we do not know if the percentage shown by Windows is correct, you can have it downloaded, until it turns off from the Bios screen, pressing Esc intermittently when turning on.
The Bios screen will be displayed and you just have to leave it that way until the tablet turns off. Once it has turned off, try turning it on to make sure it is fully discharged.
Put the charger and let it charge 100%.

If this does not solve the problem, you should consider changing the battery.

I know your situation, you can try to blow it with hot air, it should be effective.

Your tablet has been used for a long time, it should be that the battery is aging. If you have the conditions, you can replace it with a new one.

I tried it with a hair dryer, and I was planning to buy a suitable battery on AliExpress. Thank you for your help