The battery cost per kwhr/cycle ( cycle in as number uses you get before having to replace batteries)
is still very high. For most users the cost for the battery replacement is far morethan the cost of the electricity used to recharge the batteries. I am trying to develop a network batttery exchange stations where you just drop of your old battery and grab aftreshly charged one. To do that we need a standard battery module . Although I did have ecars in mind when I started this project ebikes are probably a more significant user group, since ebikes are already trying to minimize their carbon footprint. Here's the initial spec. If you are interested her's the uRL to my original article:
http://www.members.cox.net/rdoctors/evs.html
I'd like comments:
BATCHANGE
Battery Pack Specification
BPS- RACH-1007-REV A
Application:
Module for EV use. Modular packaging for easy removal for off vehicle low rate charging/conditioning.
Electrical:
Voltage 45-55 , nominal 50 volts.
Discharge current Max current 100 A 5 seconds, 50 A 20 seconds, 30 A continuous, 20 A 1 hour.
Charge acceptance as high as possible for regenerative braking.
Series and/or parallel connections to provide 400 volt systems
BMS required for each pack.
Connector: Andersen style or equal
Dimensions:17" x 7.5" x 4" 430mm x 190mm x 100mm
Weight:Less than 20 Kgs, 22 #
Life :LIfe is dependent on cost.
Goal under $US0.10 /kwHR/cycle.
Examples: lead-acid battery cost $50 for 20AH 48 V pack Life 250 cycles:
Cost /kwhr/cycle= 50/250 = $0.20 ( note that this is 100% greater than goal )