I would not run a laptop without its battery long term though. Correct me if I'm wrong Brett, but my understanding is that the battery in a laptop serves THREE purposes:
1. Runs the laptop away from AC (duh...),
2. Filters incoming AC power better than any capacitors/coils in a PSU,
3. Pulls incoming voltage down to the proper level for the laptop; it's higher than the laptop needs, in order to charge the battery.
2 & 3 are fine if the country has a good reliable (non fluctuating) electrical supply... like in the UK , where a UPS is almost unheard of...
But if you NEED A UPS ...then battery IN can help with problems...
I see you are very busy at moment
Well done for having time to answer
All the best Brett