I put one of these in my SCAR
http://www.airsoftparts.ca/store2/in...oducts_id=1807
One of these in my AK
http://www.airsoftparts.ca/store2/in...oducts_id=1806 it's a tight fit though.
And got this to charge them
http://www.airsoftparts.ca/store2/in...oducts_id=1302
I've only gamed the SCAR so far but it ran all day with a charge and it was always an issue running on a mini. You'd get maybe an hour of life.
Next weekend I'll try the AK, and maybe slip that tri-panel into the 249 to see how it runs under pressure.