Our Viper Alarm/Keyless Entry/Remote start key fob started to have a very short lifespan between charges. The key fob charges via a usb type-b cable and when new offers quite a bit of lifespan between charges.
This specific one is about 8 years old though so the battery is well past its best part of its life.
It is very easy to find a replacement battery and it only takes one small phillips screw to expose where the battery is inside, and then all you have to do is unplug the battery cable from the circuit board and carefully remove the battery from the case.
Here is the Amazon link for the correct battery for a Viper 7752V Key fob: LINK HERE
At the time of writing, this battery was $9.49 on Amazon