I have recently updated the specs for the 301 version 3 (Alfa fans) at
http://www.edfmodel.com/content.asp?PageID=12433.
The battery recommendation remain the same for version 2 or 3 (Graupner or Alfa).
They are
Batteries for the Hacker option - two 2s Lithium Polymer Poly-Quest 2100-3300mAh batteries wired in series.
What capacity battery?
This depends on your 301 model setup preference. Using a 3300 mAh battery will produce a flight time of around 15 minutes (with the model flown slow and scale like). However, this also produces a heavier model required to fly faster. A 2200 mAh size battery will provide a lighter model with flight times of around 10 minutes.
What brand of battery?
New generation of batteries are always appearing and it depends on whether you want the latest. There are two Polyquest selections and a Hyperion choice.
From the below options two 2s batteries are required to be joined in series.
Option #1 - Poly-Quest -latest development in batteries
Poly-Quest PQ-2100XP 20-30C Packs - 2100mAh, 42.0A Continuous
Poly-Quest PQ-2500XP 20-30C Packs - 2500mAh, 50.0A Continuous
Poly-Quest PQ-3300XP 20-30C Packs - 3300mAh, 66.0A Continuous
Option #2 - Poly-Quest -old design and still around (slightly cheaper)
Poly-Quest 2200mAh SLIM 12C-16C Lithium-Polymer
Poly-Quest 2200mAh SLIM 12C-16C Lithium-Polymer
Poly-Quest 3100mAh SLIM 12C-16C Lithium-Polymer
Option #3 - Hyperion -slightly higher discharge rates
HP-LVX2100 20-30C Packs - 2100mAh, 42.0A Continuous
HP-LVX2500 20-30C Packs - 2500mAh, 50.0A Continuous
HP-LVX3300 20-30C Packs - 3300mAh, 66.0A Continuous
Ian.