Jerry:

I use a Magnum geared starter (very similar to the Kavan) with two 7-cell 3800mah NiMH car packs in series. Spins my Saito R-350, Fugi BT32 and DA-50 with power to spare. Extremely light weight and totally portable. I wired the packs so that I can fast charge them as a unit (14 cells) with my Astroflight 110D or separate them and charge as 7-cell packs with either my Ace Digipulse or Ace DDVC at overnight rates. I have been using this starter setup for a number of years only upgrading the mah rating of the packs.

Works for me.

Dan