Electric vehicle batteries and chargers

Pack: 16s15p comprised by (240) 2.2ah lithium 18650s from all-battery.
Controller: 35amp 72 volt crystalyte

Problem: The ammeter on my handlebars, verified by my sense of normal torque, says when just starting out the controller is getting/pulling a max 32 amps instead of the usual 35. After riding for 15 minutes or so, when I crank the throttle, amps go back up to 34-35.
By later in the ride, when the cells are down to ~50% capacity at 3.85 volts, max amps drops to 30 under load. During all these times, the voltage sag remains in it's normal range of 4-5 volts on a fresh charge to ~7 volts at 50% charge.

I went to the SF auto show, and learned two things that made it worthwhile (forget the Ferraris, been there, done that).

First was Phoenix Motorcars. Nice Truck! 95 mph (controller limited), >100 mile range, $45K. Right now only fleet sales.

Second was Altair NanoSafe batteries - they power the Phoenix. Holy $#!+. Yes, it's going to require a sophisticated BMS. And they won't be cheap. But no matter, and here's why (ok, not proven, but it's on the datasheet I have):

Currently shipping to OEMs. Won't be too long before they find their way into other applications.
Recharge the pack in <10 minutes! Can discharge at 100C. Can charge at 50C. (you may need a 200 amp socket!)

Hey all, maybe someone has seen something that i have over looked on this. I'm making plans to build an electric drag pocket bike, the mid bikes to be exact. The bike only has to go a 1/4 mile length, but more range would be nice. I have most of the components picked out that i want to use like the 6.7" motor that i'm having re-done, and a 72 volt 1000 amp controller. Which battery would offer the best performance though under these high amp draws?

I've already considered svr, hawkers, flooded nicads from sg photo, sub c surplus nicads, and some others. The main thing i am concerned with though is price as you can tell, a123 and e-moli cells are too costly for this project.

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3071

"Li-Fe-PO4 Rechargeable: 18650 Cylindrical Cell 3.2V 1300 mAh, High Discharge (10C) Rate and safer than regular Li-Ion battery"
$6.75 USD for one battery.

Lithium Polymer Battery Explosion's (liposack): Does anybody know about this product? This video seems to show a bag, the LipoSack, which will safely contain a Li-POLY explosion.

I've been struggling to find a charger to charge my nimh packs. I have the 24 volt 13AH packs. I'm only using 2 at the moment. I had a 'Highpower' type charger but it broke and now only trickle charges. I was a bit reluctant to buy another one as the only person who sells them here ( UK )is pretty pricey. So i thought I might try some experiments with 24 volt nimh/nicd drill chargers. They seem to be around pretty cheap. I'm going to try disassembled my friends drill charger (he's reluctantly agreed : )) and go from there. I'm guessing they're Vdelta plus overtemp cutoff. I'll post back when I get a look.