What radio do you use?I use a 2800mah 3S pack that came from CommonSenseRC in my 3PMFASST. AWESOMEpack.. go 6-7 months without having to recharge, and even then voltage is usually only down to 10.4-10.5 when i finally stick it on the charger. I see now they only show a 2500mah square pack that is for most of the JR radios, and maybe the 3PK/M11's.
Brian @RocketCityRacing shows he has both the 2500mah square and 2800mah flat packs in stock.
2500mah square
http://www.rocketcityracing.com/prod...2&item_id=1586
2800mah flat
http://www.rocketcityracing.com/prod...2&item_id=1587