[Question_Assumptions]

I'm basing that assumption on the fact that several episodes last more than the few days that a cell phone battery would last and their communicators still worked.

[ArrogantBustard]

My first cell phone, an analog (IS54) device, used a NiCd battery which would hold charge for a few hours if left on and intermittently used. This was in the mid-1990s.

My second cell phone, a CDMA/IS54 device, used a large NiMH battery, and would hold charge for two days or so, if left on and intermittently used. I purchased it in 1999.

My current cell phone, a "tri-mode" device, uses a small NiMH battery, and will hold charge for almost five days if left on and intermittently used. I purchased it in 2002.

If Starfleet can't come up with a better battery than Nokia, it need to hire better engineers.