MR1100-100EUS Overheating not charging battery

Hello,

I have purchased the MR1100-100EUS last week.

I have been using it as a mobile 4G router for the week end, and it worked great.

Now, I am back at home and I am using it as a stationary 4G router, and I was leaving it plugged in to a wall socket while the battery was still in it.

The morning, I have noticed the battery was completely empty (still plugged in) and I saw the overheating symbol on the screen. It might have been overheating during the night and get the battery empty. So I turned off the device for a couple of hours to let it cool down. When I plug in the device to charge the battery, the temperature goes to 45°C very quickly, and I understand it seems to be the safety limit from which the battery wont charge.

So I have a battery at 0%, but unable to charge it because of overheating problem.

I can still use the router without the battery, but I still want to be able to use it as a mobile router.

What can I do the solve this overheating problem ? Is a common problem. My room temperature is adequate around 20°C, so that is not a problem. If I get a new battery will it solve the problem ?

Also, I have notice that my firmware version is NTG9X50C_12.06.12.00, while the last one available is NTG9X50C_12.06.11.00. Should I downgrade the firmware ?

Thank you for your help.