Are you able to drive an EV while its being charged? - Fuel Economy, Hypermiling, EcoModding News and Forum

alohaspirit · 11-22-2010, 11:19 PM

I was having a good conversation with friends.
(naturally about eco-driving

)
And it brought up some good questions.

Is it possible to drive an electric vehicle while it is being charged by a generator?

(Not that you need too. More like a "what if" question.)

I know the newer cars (Tesla/Leaf/Volt) would be a little difficult
but what of the older smaller (home-made?) models?

04_Sentra · 11-22-2010, 11:55 PM

Sure just put alternators on the wheels and charge as you drive. Kidding. I can't help myself sometimes.

AC propulsion had a generator trailer at one time called "Long Ranger" so it is possible. You could also have a pusher trailer. Neither are really good options.

Angelus359 · 11-23-2010, 01:18 AM

If somehow you had an extra battery pack that you used to charge the original battery pack, sure.

alohaspirit · 11-23-2010, 01:28 AM

ok... ill make it simpler

can i start a generator in the backseat of an EV.
connect the two via an extension cord.
then drive around.

MPaulHolmes · 11-23-2010, 01:37 AM

I think you can. At least it better work, because I'm working on something like that right now. A 6kW generator charges a battery pack, and at the same time, the battery pack is being used by the controller. I don't have the generator yet, so it's only been tested as the charger and the controller separately.

alohaspirit · 11-23-2010, 02:23 AM

the only reason i ask is because these topics were brought up

1. What if i run out of power in an EV?
(can i plug in and continue driving?)

2. What if i want to drive father than the range will allow?
(again, can i plug in and continue driving?)

Tweety · 11-23-2010, 05:00 AM

Besides the obvious downsides like the noise and the fact that you would be deaf afterwards, yeah... Why wouldn't you?

Most commercial built cars have a feature that prevents them from driving off while plugged in to an outlet, but disabling that should be easier than dealing with the generator...

sawickm · 11-23-2010, 10:45 AM

Quote:

Originally Posted by MPaulHolmes

I'm working on something like that right now. A 6kW generator charges a battery pack, and at the same time, the battery pack is being used by the controller.

Hi Paul,

I think that would be so cool if you could get that to work !!! A DIY extended range EV would be radical !!!

Does your dsPIC controller have the intelligences to start and stop the generator during the battery charging ? Is the dsPIC controller you are using DC or AC ?

I hope that you continue to tell us about your success with that project.

-Mark

alohaspirit · 11-23-2010, 11:27 AM

Quote:

Originally Posted by Tweety

Most commercial built cars have a feature that prevents them from driving off while plugged in to an outlet, but disabling that should be easier than dealing with the generator...

this is what i was referring to

sometimes that failsafe is difficult to bypass

MetroMPG · 11-23-2010, 11:37 AM

I figured by now, someone would have posted a YouTube clip of just what you're talking about, aloha. But I searched high and low and came up mostly empty.

I do recall seeing a clip on Britain's "Fifth Gear" tv show where the presenter, after driving the snot out of an OEM electric Smart car, raised the issue of getting stranded, and then loaded a generator into the hatchback, plugged it into the car, fired it up and drove off. But you can never tell if it's for real on TV.

A member of the Ottawa EV club tried this with his electric pickup (more practical, since the noisy, stinky, hot generator is on the back of the truck, not in the passenger compartment. He tried driving with it running, but I seem to recall it kept tripping the breaker. Maybe a case of not adequately sized generator for the job.

Your post caused me to hit the local classifieds looking for a 2kW generator. I'd need at least that to try this on the ForkenSwift, since its charger consumes ~1200 Watts at its max charge rate.

Found 1 video for you. Not exactly what you're asking, but close. The generator is apparently running the e-motor directly in this clip. The batt pack isn't installed yet. Pretty ghetto.

http://www.youtube.com/watch?v=0QIaUl7XcrU

Keep in mind though: most EV chargers only output a fraction as much power as the car consumes while driving. A simple way to look at it: I could easily drain the ForkenSwift's (half worn out) pack by driving it non-stop at about 30 mph for 45 minutes. But then it would take ~8 hours on the charger to bring it back to 100%.

So even if I had a generator powering the battery charger while driving, it would only extend my range a little bit. It wouldn't permit me to drive until its gas tank ran dry. It would extend stop & go driving proportionately more than non-stop driving though.