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Discussion Starter · #1 ·
Dumb question --

I'm planning a 140 mile trip, 70 mi our and 70 miles back. I'll be fully charged before I leave and I'll have about 9 hrs to charge before I turn around and come home. I'll bring the charger with me and I'll have access to an outlet with enough juice for 12 amps (I think), but I will need an extension cord.

So ...
I could use up the battery and then run on gas on the return trip.
or
Charge at 8 amps with the extension cord & charger
or
Do it at 12 amps.

None of this really matters, gas will not be a problem, but I'll be making the trip a few times so might as well try to do it in a reasonable way.

Will using that extension cord mean that I should go with 8 amps?
Will charging the car from a fully dead battery at 12 amps hurt long term battery life?

Thanks for your thoughts, folks,
Steve
 

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12 amps at 120V is a very low charging rate for the battery. You should not hurt the battery at that rate. When you use a 240V charger, the max is 240V at 16 amps, almost 3 times the energy.

I'm more concerned about you using an extension cord on your charger The owner's manual specifically says not to. But if you have to, make sure you use an extension cord that's rated for the amperage you're sending through it.
 

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As the others have said, the battery will be fine, the arrangement with the extension cord is a bother and possibly prone to failing, and (adding on) it's five bucks (maybe eight in California) for the gas if you skip the charging. You'll be spending three times as much on an extension cord if you don't have a 12/3 or 10/3 cord already. Just go, don't think about it, be joyful about NOT having to think about it.
 

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I use an extension cord when I charge my 2012 (at 12 amps) at my in-laws, once every couple of months. Make sure it is a heavy duty cord, and pay attention to the ends, that's where the problems will be if you don't have quality good fitting plugs or a cheap outlet. The ends can start to get very warm and melt things, which can turn into a serious problem. I would check the ends after an hour or two the first few times charging. The first cord I used got very warm at the end the charge adapter plugged into, so I got another which I have been using for 3-4 years now.
 

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I charge at 12 amps every day, this isn't an issue. The bigger issue would be the condition of the outlet, the length of the run required on an extension cord, and whether or not the outlet is on a dedicated circuit. Frankly, I'd just use gas and not worry about it. The juice isn't worth the squeeze.
 

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Discussion Starter · #8 ·
Excellent advice. I will probably go with gas. I'll see what's what when I get to the destination. Might not need the extension cord. And we need to check the wiring, too. I wouldn't worry about it except that I'll be making this trip many times. But I understand the point about "you've got a gas engine, might as well use it."
 

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I wouldn't worry about it except that I'll be making this trip many times.
If you have a 12/3 extension cord (it should say 12 gauge on the insulation jacket), go ahead and use the higher charging rate. Make sure the plug is resting in a location where it can't start a fire (concrete, gravel, bare dirt, etc.).

If you don't have a quality extension cord, it probably isn't worth saving 1-4$ each trip for the risk. Most are 16 gauge and not really made for unattended high power draw (even the orange ones that should be 14 gauge are normally not).

One thing to think about with that length trip - if you CAN make it fully on battery, go ahead. If you CAN'T (winter...) use Hold mode for a bit at the start to get 'free' cabin heat for better electric range.

-Charlie
 
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I have an all weather 40 ft 10 gage x 3 strand extension cord. It works just fine at 12 amps, including not getting warm. I have had exactly one outlet not be able to charge my Volt through this cord. I didn't use that outlet. The warning in the owners manual is to keep people from using those 13 amp el-cheapo extension cords.
 

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I also use a 10 gauge extension full-time for my home set-up, and have no issues. If one is going to use an extension cord, you really need to spend the extra money on a good one, and keep the run as short as needed.

However, I only use it on the dedicated circuit I had properly installed, and the outlet is a heavy duty commercial grade outlet. The problem with using other outlets are the unknowns.
 

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Discussion Starter · #12 ·
Thanks, folks. I did bring my charger on the trip, but didn't need an extension cord after all. Got about 85% charge in 10 hours at 12 amps. No problems, everything stayed pretty cool.

I did not get the electric MPGe that I was expecting though. Most long trips in the past have been about 110 or so. This time, with minimal AC (no heat) and running more or less steady at about 70 or 75 mph, I got 88. Seems low to me. I consistently get 125-130 in the city. Maybe there was a headwind or something, but gas mileage was what I usually see -- roughly 45. Car seems fine otherwise, so I'm not too worried, but it seems strange.
 

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75 MPH is not an efficient speed under any conditions below "gale force tailwind". :) And the longer the trip is, the harder doing that will hit the efficiency because that usually means "more time at 75" instead of less. Even factoring in "burning some gasoline" doesn't help much because Volts drink about a quart of fuel in the first five miles switching over at highway speeds and don't really reach their peak efficiency for whatever conditions are being driven under until their second half-gallon.
 

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Discussion Starter · #14 ·
Thanks -- and yes, I understand, the faster you go the less efficient you are. This is mostly a city car and I've got a record of every long trip I've taken. They're all mostly freeway and typically show about 110. This time it was more like 90. The only explanation is that all the other trips were in heavy traffic, which slowed me down. Seems a bit strange to me, but maybe so. No way to know anymore.
 

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In EV mode the difference is pretty staggering. In clement temperatures (so climate control isn't a factor) I get 60-65% more range traveling 50 MPH on frontage roads, even with the occasional stop sign, instead of 75 MPH.
 

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It does. You just need to decide that losing 15-20% of your fuel economy for the getting there 20% faster is worth it.
 

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...I did not get the electric MPGe that I was expecting though. Most long trips in the past have been about 110 or so. This time, with minimal AC (no heat) and running more or less steady at about 70 or 75 mph, I got 88. Seems low to me. I consistently get 125-130 in the city. Maybe there was a headwind or something, but gas mileage was what I usually see -- roughly 45. Car seems fine otherwise, so I'm not too worried, but it seems strange.
Keep in mind you are extrapolating your mileage estimates from the consumption of a fraction of a unit of fuel. The Gen 2 Volt fuel tank holds only a half-gallon of fuel (0.5 Ge), so you can’t really drive 125-130 ev miles in the city without stopping to refuel once or twice. And when you are on the road, you can only drive as many electric miles as you can squeeze out of that fraction of a unit of fuel... certainly not 110 or even 88 without stopping to refuel... so on this trip, was most of that half-gallon used for driving at highway speeds, whereas on other road trips, some was used for lower speeds, some for higher speeds (as you say in post #14, "all the other trips were in heavy traffic, which slowed me down")?

When the energy usage display calculates your "fuel mileage" in gallon-equivalent terms, it doubles the distance you drove on that half-unit of fuel in the tank to create the "mileage" number for the use of a whole unit of fuel. This, in effect, "magnifies" the distance per one unit of fuel difference, so the "mileage" you get from using the fuel in town appears that much higher than the "mileage" you get when using the fuel for high-speed driving...
 

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Discussion Starter · #20 ·
Interesting, thanks. Makes sense. But can you explain how doubling the distance magnifies the difference? I drive 60 miles (or more) on a charge around town. Equivalent to 120 miles on two charges. On the freeway, I'm going 40 miles on one charge. The difference is just 60 vs 40, no? Little regen, lots of wind resistance, lots of energy to maintain high speed. 60 vs 40 miles per charge or 120 vs 80 mpge. Or is it more complicated than that?

Also, my intuition has always been that driving in L wouldn't make much sense on the freeway, and might actually hurt mileage. Any thoughts about that? I rarely use L anymore and just use the paddle regen on the steering wheel to slow the car.
 
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