netgeart m1 battery problem

Yesterday I bought a Nighthawk M1 MR1100-100EUS from Amazon Germany and have been stress-testing it since then — I got a 200GB LTE data plan and I am running my whole Internet connectivity through it to see how it performs. So far no stability problems, but...

The device just won't charge while being operated because a device and battery temperature of 43°C is already considered too high! This is outrageous. The manual states that the battery won't be charged at all when over 60°C anymore, which is sane, but already at 43°C no charge is being taken from the charger anymore and the battery percentage declines.

To prove that it's in fact the battery I put the device on a solid block of ice taken from the freezer. Within a few minutes the device and battery temperatures (which can be viewed at http://192.168.1.1/index.html#settings/status) drop to 40°C and below and the charging current raises to 5V 1.8A or — if a QuickCharge 2 power source is connected — about to 9V 1A. (I got a USB-C power meter so can see how much power is being drawn.) This makes the battery percentage slowly rise again.

If I put the ice block back into the freezer the charging process stalls again after some minutes.

Netgear, already stopping the charge at such a low temperature sucks!

I understand that everybody is afraid of exploding Li-Ion cells, but 50°C should still not constitute a problem.

BTW, it does not help buying more powerful chargers, my M1 does never draw more than 10 Watts.