Beware of Huawei 4G LTE modem battery - continuous USB connection (explosion)

This is just for a record of Huawei E5577 4G LTE modem - if the connection between the modem and the computer is using USB it is not only transferred internet connection but confined to continuous charging.

It happens to my Huawei modem which using USB to connect the modem to the desktop computers for internet since the PC does not have wireless capability to receive the signal. Apart from that, the USB connection is much stable and faster compare to wireless.

However after long years of connected continuously which means it also charges the battery constantly - finally the battery pop-out of the modem casing. I thought what was happening until it was opened and take a look at the picture below. You can see the bulge due to the expanded size of the battery because of constant overheating. This is Lithium Ion polymer  battery which is also use by most of smart phone.

It could have exploded but fortunately it didn't and save the day. Huawei should have thought how to limit the charging process when the battery is full but there is no such circuit mechanism provided by the modem. In order to completely be safe with this is to avoid using USB cable to connect the modem to computers and using wireless only which is not very convenient if you are using desktop computers where there is no Wi-Fi capability.

Be safe always!! this could hurt somebody if the battery exploded.