MIEV and Use of Air Conditioner

Hello to all. This is my second post. As previously stated I take delivery on 31 Jul 12 from a dealer here in San Antonio. Hey, it's hot here, and my question regards the use of the A/C here with the MIEV. Best way I can think to ask the question is this way. Assume full charge of 16 bars. Take a trip of 40 miles without A/C and bars remaining are 6 bars. If I take the same trip and A/C is on for the entire trip, how many bars left at end of the trip? There may be a better way to ask the question, but I am trying to figure out the "degradation effect" of using A/C. One can't travel around here without it. Thank you in advance for any comments. Still the new guy. Bill Thompson.

http://www.sae.org/events/aars/presentations/2010/W2.pdf

Took me forever to find this excellent very recent link (because it was in an off-topic discussion... :roll: ). Maybe someone wants to take a stab at the math?

7/21 evening.Coincidentally, just arrived home after a day of leadfoot driving around town with the a/c ON all the time. Started the day with 14 bars and RR=57. Covered 40.1 miles today (I zero my GPS tripmeter every morning) and have 4 bars left and RR = 14 (reading with a/c OFF). Turning ON the a/c drops the RR to eleven, but at other times I've seen six miles subtracted from RR when turning on the a/c (never paid much attention to this, and rarely use a/c with today being an exception).

Update 7/22/12 morning. Been thinking about the mileage hit due to using air conditioning. It is NOT a fixed number, and logically should be a percentage of Range Remaining. Using my numbers (above) the hit is 3/14 = a little over 20%. Looking at the graphs in the above link, it depends on whether MAX is enabled or not, but the hit appears to be around 25%. So BillThompsonMIEV, I'd be conservative and use 25% as the mileage hit resulting from air conditioning. As you'll find out once you start driving, you have enormous control over the mileage and you'll soon adjust your charge level, driving distances, and driving habits to keep yourself comfortable (both physically and mentally) and the car happy.

Bill,

It's HOT here too and we use the A/C almost all of the time, every day

As I mentioned when answering another one of your questions (about the RR meter) you can actually SEE what various scenarios 'cost' you by looking at the meter. You'll discover that it will approximate very well how big a range hit you can expect by using the A/c in the car. From my experience it's around 10 to 15% - Of course it depends on how you have the A/C set, how hot it is outside and how much solar gain you're experiencing through that big radiator that our windshield imitates. If you have the A/C blasting MAX all the time and never cycling off, the hit will be larger . . . . probably nearer Joe's 25% guesstimate, but for us in actual practice, it's not that big. Using those solar shades in the windshield whenever you must park in the sun REALLY helps! - I suspect some window tint would help a bunch too

If you back out of your garage and see 80 miles remaining, it will probably drop to the upper 60's to low '70's as soon as you switch on the A/C. When you get back after a day of driving and add up the distance you've gone and the RR left, you'll see about that same number

From my experience after about 2500 miles, the A/C actually costs us less than driving fast does - If we take the freeway to our destination without using the A/C, we usually have fewer miles left than if we had taken the back road at 35 to 45 mph using the A/C . . . . so, we usually leave a bit earlier and take the back roads and drive in comfort

Don

I agree that driving fast, over 45 mph wastes more battery per mile than the A/C on almost any setting other than Max.

Sometimes you can't help driving 'fast'. My commute is 40km (27 miles) down the QEW (Queen Elizabeth Way) which is rated at 100kmh (62mph), but that is only a suggestion as most cars are going at least a buck-ten to a buck-twenty. I keep it at 90kmh(55mph) to keep within the legal minimum speed. I don't use A/C, use Eco mode, keep the windows up and the fan on high. It takes me about 40 minutes to get to work, which isn't much longer than if I was doing 120 in my I.C.E. I use about 6 bars at 1 bar = 6.64 km (apr.) which should be 39.84 kilometers, with my actual distance being 43 kilometers. I have done this commute with as few as 5 bars, haven't repeated that again and not sure how I did it either.

Keeping with the topic at hand, I do notice the A/C does use quite a bit of energy. Like others have said, it does drop the guess-o-meter down a bit when it goes on. On weekends, I get sloppy and drive in D with the A/C and I can easilly go through 3/4 of the bars on the fuel meter on a Saturday afternoon of running errands and taking my son places.

Bill ... congrats on your purchase!

You can pre-heat or pre-cool the i while it's still on the charger. On hot days here in Taos (we had a spate in the mid 90s last month), I tried pre-cooling for 20 minutes or so prior to departure. I was able to keep the car quite comfortable without using the MAX setting on the a/c, and the impact on range was marginal.

And mandatory sun shades in that big windshield when you park in the sun!

Thank you all for your comments. The pre-cool idea is interesting. I think I will plan a 20% "hit" for the A/C use. However, it will be difficult to come up with a baseline, as I am taking delivery on 31 Jul 12. Needless to say this is the hottest time of the year here in San Antonio. Again, thanks to all for comments.

My GF uses this car as her DD and commutes 27 miles each way here in Phoenix where it is quite hot. She has had the range meter show as much as 20 miles left upon her return to as little as 3 depending on her driving. Her commute is about 90% freeway.