David's 2001 Civic EV (80-100 mile range; 65+ MPH; 8 second 0-60) - Page 24 - Fuel Economy, Hypermiling, EcoModding News and Forum

TheSGC · 03-24-2013, 10:33 PM

This past Thursday I took my EV on a whooping round trip of 39.6 miles for a job interview! I used heat for 22.6 of those miles and it was some of the hilliest roads I've ever been on!

I ended up putting 15.41 KWh back into the pack. Assuming my charger is 92% efficient, I had an overall efficiency of 358 Wh/Mi from the batteries. That gives me a 58 mile range in the winter when driving 45 MPH and under with hills.

I really want to improve that. I know my heater is knocking off some range, but I also think my tire pressure is too low and I am really wondering if my back being lower than the front is having a massive effect on it. I wasn't also to install my Skunk2 lowering springs on the cheap struts so I think some compatible struts in the front will be in order.

Blue Angel · 03-25-2013, 10:39 AM

You should weigh the car front and rear to get a weight distribution measurement before modding the suspension. If possible, get the current spring rates and the original f/r distribution and then try to keep the spring rate matched to the weight at each end (based on how the stock car was set up). Failing to do something along these lines could result in a car with pretty strange, and maybe unsafe, at the limit handling.

Daox · 03-25-2013, 10:44 AM

358 is fairly reasonable. The warp engines are efficient, but not as much as AC induction motors, so you'll not likely see the 250 Wh/mile that most OEMs seem to go by. Even that I think is more of a 'summer rating'. I haven't heard of what kind of wh/mile Leafs and Volts are getting in winter.

TheSGC · 03-25-2013, 03:11 PM

Quote:

Originally Posted by Daox

358 is fairly reasonable. The warp engines are efficient, but not as much as AC induction motors, so you'll not likely see the 250 Wh/mile that most OEMs seem to go by. Even that I think is more of a 'summer rating'. I haven't heard of what kind of wh/mile Leafs and Volts are getting in winter.

This past fall I was doing 295 WH/Mi from the wall, and once I did 271 WH/Mi so I know there is some room for improvement. I think what I really need to do is get my volt/current meter installed so I can actually see where I can do better.

TheSGC · 03-30-2013, 08:32 AM

Yesterday I pumped up my tires before going on a 31.4 mile run for the day. I had about 40% 45 MPH highway and the rest 30-35 MPH stop on go traffic. I even had a bit of heat at the end of the day and my final WH/Mi from my Kilowatt meter was 327 WH/Mi!

That gives me a 63.6 mile range to 80% DoD. I'm going to check my tire pressure for real today as I didn't have a gauge so I just eyeballed it. I'm aiming for 40 PSI at the tires.

RedDevil · 03-30-2013, 09:30 AM

You got the batteries in the back, right?
If those behave anything like the NiMH batteries in my hybrid (which vents the battery with air from the passenger compartment) they would benefit from being in the passenger compartment; as they seem to function best under temperatures that we find agreeable ourselves.
When they start to give off some heat after long use you'd need the heater less.
And you get better weight distribution and more boot space.
You do need some shielding though to be safe in case of a blowout.

Just a thought...

Daox · 03-30-2013, 09:54 AM

Good point reddevil. Do you have any battery warming setup? Voltage sag under load is MUCH more pronounced when batteries are cold, thus you need more current for the same acceleration which is harder on the batteries, etc. etc.

TheSGC · 03-30-2013, 10:38 AM

I don't have any heating setup for the batteries, or any insulation. As it warms up I'm getting I will see a huge increase in efficiency. Next year I will have insulation for my battery pack, but we are having much better weather these days and my current commute is only 33 miles round trip with charging at my destination.

RedDevil · 03-30-2013, 02:52 PM

It works the other way tound too; when it gets hot Honda advises to use the airco to prevent the batteries from overheating, not just yourself. A/C off under desert conditions might hurt the pack...!

TheSGC · 03-30-2013, 04:33 PM

Quote:

Originally Posted by RedDevil

It works the other way tound too; when it gets hot Honda advises to use the airco to prevent the batteries from overheating, not just yourself. A/C off under desert conditions might hurt the pack...!

I don't stress my LiFePO4's enough to make them heat up, and on the hot days my sunroof is open keeping things cool, but I've never had the car past 100 F in the sun in the battery bank.