View Single Post
Old 10-21-2008, 11:51 AM   #730 (permalink)
MetroMPG
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,055

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 54.01 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)
Thanks: 2,842
Thanked 5,702 Times in 2,946 Posts
State of the (battery) Union

How worn out is the "good" ForkenSwift battery pack (currently in the car)?

Some simple calculations to get an estimate:
  • It's a 10.56 kWh nominal pack (8 batteries * 6V * 220 Amp hours rated per battery) (V * Ah = kWh).
    .
  • 80% of the new pack capacity is 8.45 kWh (10.56 * .8).
    .
  • Looking @ an average of 5 similar drive cycles on the existing pack to an estimated 80% depth of discharge (W.A.G. - impossible to say without a hydrometer), it could travel 28.1 km, in warm weather (>20 C / 68F).
    .
  • The average energy from the wall to recharge was 4.36 kWh.
    .
  • Assuming 85% charging efficiency (another W.A.G.), then the capacity to 80% DOD of the current pack is 3.7 kWh (4.36 * .85).
    .
  • The car's efficiency based on these figures is 132 Wh/km (3.7 kWh/28.1km), or 212.4 Wh/mile, or 158 mpg(US) equivalent energy consumption.
So, the current pack has 43.8% of the capacity compared to "new", to 80% DOD (3.7 kWh / 8.45 kWh).

So what would the car's range be on a new set of batteries?

64 km (8.45 kWh / 132 Wh/km) or about 39.8 miles. In warm weather.
__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote