I thought I'd post this because it was information I had to find by myself and might be of use to others.
I built a battery powered AP for use as a standalone survey AP.
I used an AP 105:
1. It needed a 1.7mm/4.0mm DC power connector (from Maplins).
2. I used a 1000mAh 3S (11.1V) LiPo battery and it powered the AP for just under 200 minutes continuously.
I hope this helps.
Mike