My fellow EV friend Steve and I did a trial run with his Honda Civic EV from my house to my work to see if his DC design would work for my commute. My commute is 22miles one way, mostly freeway at 65mph, and has a monster 9% grade hill for 1/2 mile at the end of my commute. Here are the specs for his Honda Civic EV:
- 15 8V flooded lead acid (US Battery 8VGC XC)= 120V
- Curb weight: 2700 lbs
- 8″ Advance DC motor
- Webpage: http://www.evalbum.com/853
The 8VGC has 170 amp-hours of capacity each, which comes out to 20400 watt-hours (170 amp-hours * 8V * 15 batteries). A rough estimate I got from online EV conversion resources is that it takes about 200-250 watt-hours to go a mile, depending on terrain, speed, weight of car, aerodynamics, tire resistance, etc. Since the commute will be mostly freeway at 65mph, I used the 250 wh/mile as a conservative estimate. So if we completely drain Steve’s batteries, we could theoretically go 81.6 miles. However, draining a battery too much will adversely affect the life of the battery, the performance also suffers when they are drained. Most EV resources recommend that one does not drain lead acid batteries below 50% depth of charge on a regular basis. Therefore, Steve’s car can practically go around 40 miles or so at freeway speeds. We knew it was going to be a challenging test run to go 44 miles but wanted to try anyway. I rented a small generator just in case we needed to charge mid-way.
We made it to work with no problems and started on our return trip, with about 10miles left, we noticed that the battery was starting to tire and decided to stop and get some coffee and charge the batteries a bit. Well, the coffee was good, but the charging didn’t turn out too well since the small generator I rented was too weak to drive amps into the battery. Nervously, we started our last 10 miles back to Castro Valley. Instead of taking the freeway, we opted to take the back roads at slower speeds for obvious reasons. Though we made it back to Castro Valley, it was really close and we almost didn’t make it, we didn’t even bother going up the 9% grade hilll back to my house since towards the end, the car struggled on take off and small hills. I felt really bad that the small generator I rented didn’t work and that the test run might have damaged Steve’s batteries but am glad we made it back to Castro Valley at least. When Steve got back to his house, he had about 40% left on his batteries.
