i just looked at
these on ES... if the specs are true (or even close to true), it seems like a better option. i could configure the same setup as what's in it currently (five 12v packs wired in series) and have 36Ah instead of ping's 30Ah. plus the heavy protective casing (i hit some pretty big bumps along the way to work. still trying to find the least-bumpy line).
2 problems i can see:
-it almost seems too good to be true (and you know what they say about that). with all 5 cases plus the cells, i suspect the weight is way off
-i wouldn't be able to take the cells in at night when it's cold.
anyhow, more options than just ping and cell man. (i got an email back from cell man giving a quote. 16S 2P A123 20Ah Pack 1 50V 40Ah 40A BMS $1490)