2009 Mini E: Does Charging My iPhone Shorten My Driving Range?

Seriously...it's one thing if you were trying to make a joke about electric cars and the poor range of the Mini E. But to seriously ask this question as the Editor in Chief of a car publication? Not good...

I'm wondering about the comment..

"I'm assuming the answer is "No" because for hybrid vehicles the on-board electronics are totally separate from the drivetrain electronics. It's probably the same on the all-electric Mini E."

On a hybrid normal electrics are run off the normal battery/ altenator that is powered by the gas engine.

The MiniE has no gas engine and thus no altenator.

The only power source is in the car is the main battery. Of course it powers everything even the tiny amount of power the iphone uses.

Where did you think the power comes from?

BTW, if your eyes glossed over at my mention of kilowatts, perhaps this will put things in terms that a gearhead brain can understand:

Pretend the Mini E ran on gasoline stored in the humongous battery bay that ate the backseat. Use up all the fuel and you'll have gone about the same 100 miles as in real life (about 5MPG, is it?). Also pretend that the iPhone ran on gasoline. Take enough gasoline out of the Mini E's huge battery bay to fill up the iPhone's dinky little battery bay. Now can you visualize how much range you've lost by recharging/refuelling the iPhone?

Guys, I think this staement is tongue-in-cheek...aka he's joking.

...Probably :-)

@7driver

Did YOU ever take a high school electronics class? NOTHING in this world is 100% efficient. If you really think any electronic device is transferring current from the wall/socket to the device, I highly recommend you develop a perpetual motion drive as well.

Karl's concern is indicative of a bigger one- if I was to use, say, an inverter for my laptop, that'd be a pretty significant draw on the car's battery (considering my inverter puts out in the neighborhood of 120W aka .12kw) and is certainly not 100% efficient.

@dragonflight

120W is 0.12kW. 12kW would be 12,000W. Your 120W inverter, run for an hour, would only consume 0.12kWh of energy (or slightly more, accounting for inefficiency).

While the MINI E's charging circuit is without doubt less than 100% efficient, the amount of power the iPhone draws is negligible.

Digital consumer electronics in general have comparably little power consumption compared to mechanical electronics. Even a laptop would have little effect on the MINI E's battery. Back-up power supplies for PCs have a fraction of the MINI E's battery power, but will run those PCs for hours.

dragonflight,

If kilowatts was over his head, surely efficiency would have blown his mind. I was trying to keep things simple. The reason I could do that is that conversion losses are negligible at those dinky little current draws compared to the Mini E's motor.

But if you want to pick nits, your laptop inverter is probably in the neighborhood of 170W going in since you'd otherwise blow the 15 amp fuse typically found on a cigarette lighter circuit. In my book, that's not *that* inefficient. Not enough to start worrying about making 10 miles against a 30 mile range, anyway.

@7driver and mjp16

No way that this would cut 10 miles off his commute (I think even he realized that, cause he still used it anyway) but if we're ever looking at real-world electric cars, it becomes a factor. When you take a minivan with rear seat entertainment, navigation, an inverter, maybe a cooler like the Flex, those are significant draws from the battery that could reduce range if you're REALLY pushing the edge (as Edmunds editors seem to always be doing).

PC power backups typically can only run the computer for 15-30 minutes, long enough to ensure a proper shut down of the equipment. Only high end ones will run it longer than that, and they are also considerably bigger. I work with these all the time, as I work IT.

ps just a trend I'm noticing: what gives with everyone coming out of the woodwork and criticizing Karl every time he posts one of these? Just because he's EIC doesn't make him all-knowing, and more than likely prevents him from doing more research on the topics he posts, not to mention rarely posting stuff like Jriz (who must not have a real job, judging by the time he probably took to set up some of his previous posts).

Just kidding, we still want our resident canadian blogger.

dragonflight,

Those PC power backups are lead-acid batteries, which are considerably larger and heavier than the li-ion units in the Mini E.

Anyway, the Mini E has a rated range of 150 miles, but people seem think it's only ~100 in practice. The battery is 35kWh, but it probably doesn't drain all the way to 0. I don't remember what it's useful states of charges are allowed so let's just call it 80%. That would give 28kWh = 100 miles or 1 mile = 0.28Kwh.

Most laptops draw less than 70 watts at full bore, although some newer ones are 90 watts. Note that "full bore" means the laptop battery is dead and being recharged, the CPU is busy computing prime numbers, the graphics chip is rendering trillions of textured polygons, the LCD is at full brightness, the HDD is running a SQL search, etc.

But even then, let's say your laptop's power brick isn't very efficient and you are running your laptop full bore for an hour, thus putting that 15 amp fuse on the cig lighter circuit right on the ragged edge. You'd still only shave off less than a mile off your range. Maybe there's another conversion stage between the Mini E's battery and the cig lighter circuit, so let's call it a mile and a half. After an hour, the laptop battery would be back up to 100%, the hard drive will be full of primes and the SQL search would have finished so you wouldn't be at full bore any more anyway.

P.S. I don't think I'm "coming out of the woodwork". If Karl's bang on, I'll try to let him know. If he's out in left field, well, ditto. :-)

In a humorous vein, what would happen if the Mini E was low on power, and you plugged in a fully-charged iPhone or iPod?

Imagine using an iPod to recharge the car. :D

I'll admit I was curious about this too but I'm glad to see that there are so many brilliant InsideLine readers...

Charing the iPod/iPhone won't have a noticable impact on the Mini E's battery.

Having the A/C or heater on full blast while cranking up the stereo's volume to max will.