Are you able to drive an EV while its being charged?

[euromodder]

Originally Posted by ShadeTreeMech

If you had a portable genset capable of recharging the batteries after they've been discharged plus driving the electric motor, it would be so heavy and consume so much fuel you'd be better off attaching the engine to a transmission and losing the electric drive altogether.

A dedicated ICE-generator that would only need to supply the average power drawn during a ride, would be a fraction of the displacement,size and weight of an ICE that must cope with peak performance because it's driving the wheels directly.

[ShadeTreeMech]

David Cloud's long distance EV used 170 watt hours per mile. I've heard of that figure being easily twice that (I'm hoping a couple EVers chime in pretty soon!) So if he went 30 miles per hour, that would be 5100 watt hours total usage.

This Honda generator can produce 4,810 watt hours on 1 gallon of gas. I calculated it according to 50% capacity producing 1500 watts *9.3 hours/2.9 gallons used. For David Cloud's highly efficient EV to burn through 4,810 watt hours (one gallon of gas) he would be able to travel up to 28.3 mph, and burn 1 gallon of fuel in the process.

This larger generator produces 5220 watt hours per gallon at full throttle. This would surely boost his speed, and it does, to 31 mph.

I've owned an old Nissan that could trump 31 mpg if I drove it hard and fast with the AC blasting!

The point of an EV is to take advantage of VERY cheap electricity available at the tap anyplace there is an electric grid.

There must be some flaw to my math because this doesn't make any sense!

[alohaspirit]

Originally Posted by alohaspirit

the original topic wasnt about adding a gen to an EV permanantly


more like a just-in-case

and i steer everyone back on track again



this isnt a "hey im going on a 500 mile road trip so lets attach a gen" scenario


more like
"this hill expectedly drained my battery and im 15 miles from the house,
can someone drop off my generator so i can drive home"

[MPaulHolmes]

I think the Volt is going to get around 35 mpg in non-ev mode. Thank you for finding that link! I get a little over 30 mpg in my figgerin'. 1500w*9.3hr/2.7gal = 5166.67 w*hr/gal. Then 170 w*hr/mi means 30.4 miles/gal. It really depends on speed though. Watt*hrs/mile is a measurement of force. So the slower you go, the less force the wind pushes on you, and the further your generator will get you. I think regular cars have an optimal mpg speed of around 50 mph, assuming flat road etc. But as range anxiety insurance, 20 mpg or whatever it would turn out to be in real life isn't so horrible?! If it was once in a blue moon, and you were in EV mode 95% of the time?

[ShadeTreeMech]

sorry for going off topic, mate. I suppose you may have possibly accidentally set off a lively discussion?

Assuming you're in such a scenario, and you drive an EV within the confines of civilization, I'd suggest a pocket with cash for the homeowners you want to plug your extension cord into (assuming the charger is onboard.....)

[alohaspirit]

Originally Posted by ShadeTreeMech

sorry for going off topic, mate. I suppose you may have possibly accidentally set off a lively discussion?

Assuming you're in such a scenario, and you drive an EV within the confines of civilization, I'd suggest a pocket with cash for the homeowners you want to plug your extension cord into (assuming the charger is onboard.....)

nah its all good
chat away. evolution is good
(sometimes )



just sayin that
i dont, like a lot of people, believe that an EV should be driven attached to a gen.
(kinda defeats the purpose)
but if you must you must

[ShadeTreeMech]

Well, I would have thought it to be a good idea to tote a generator around, but after crunching the numbers, it sounds like a bad one!

[todayican]

I, as one of the "full time hybrid interlopers" was having a merry old time talking about full time gens and "engine more on then off"

Does this call for a separate thread?

Tom

[ShadeTreeMech]

This thread is opening up so many rabbit trails we may have to start a new forum on EM to allow it to evolve fully

[todayican]

I have to say, im excited! for a purpose built vehicle like mine, I can get the acceleration using what electric motors are great at (takeoff torque) and range using what ICE's are good at, particularly diesels (droning on for hours on end right smack dab in the middle of their efficiency curve)

and wind up with something nice, possibly even in the 200mpg range.

Using the EcoModder tool, feeding in all the "knowns" and making educated guesses at the rest, it puts the 70mph requirement for my vehicle at about 3500 watts.

Take a 10hp diesel with a 200 gram per kw per hour (got the info here: NEW 10HP Diesel Engine Electric Start Tractor 10 HP - eBay (item 180588653876 end time Dec-16-10 16:21:41 PST) )

using 5.5hp (fudge factor) thats 200 grams x 5 = 1000 grams. there are 3213 grams in a gallon of diesel so 3.2 hours of running time to the gallon.

3.2 x 70 = 224 miles to the gallon

but...

going serial hybrid and using the electic motor as the drive engine, (and using high efficiency and not too expensive etek style motors) your losing say 10% at the gen and 12% at the pack, controller, and drive motor

so 10hp - 10% = 9hp 9hp- 12%= 7.92 so your losing 20.8% to the serial system.

Brings you down to *Only* 177mpg at 70mph

I could live with that, not to mention the 40 or 50 miles of electric only driving youd get from a wall charge)

The thing that I dig is using the next best thing, a transmission equipped motorcycle engine to drive the trike (without an e-motor as the primary motor, you'd need that tranny) your burning 354 grams per kw per hour. damn near twice the fuel...

Makes the 20.8% losses to the serial drive train not look so bad :-)