TDS 480 (for the 48sx) RS-232 powering question

[carolinahomes]

This unit comes with a rechargeable battery so I assume it can be charged through the RS-232. It uses the first seven pins. Pin 5 is the ground, of course. Pin 6 is a red wire, does that mean this DSR pin is where it receives the charging voltage?
The wire colors are as follows 1 through 7, pins 8 & 9 are not used: White, Yellow, Green, Purple, Black, Red, Brown.

My solution so far is to splice the cut plug from the old battery onto the new plug, connect the original plug to the board while leaving the end of the new plug dangling on the inside with enough slack to plug in a charger as needed in the future. Are there any issues with charging a battery like this while one spliced end is still plugged into the board?

So far so good, the SX works well when hooked up to this rechargeable case. GX's do not seem to like it at all though.