What would it take to make a range-extended series hybrid? - Fuel Economy, Hypermiling, EcoModding News and Forum

chuckm · 03-25-2010, 01:19 PM

I've toyed around with the idea of a DIY series hybrid numerous times, and mentioned it here once or twice. Anyway, what all would a person need to build a range extending plug-in series hybrid? (Not a charge maintaining hybrid like the Volt.)

Use a Metro sized car for the donor car. I'm thinking of a power takeoff generator like this one, mated to a 30 hp or so diesel (or even gasoline tuned for lean-burn) engine through a reduction gearbox. Set and optimize the engine for single speed operation. Couple that gen-set, set at 220V, through a on-board charger. Use a two string 120V battery pack and an ultracapacitor, routed to DC motor/controller. At home charge via 220V single phase. Daily driving ~110 miles/day.

Could such a setup provide decent power and range?

Daox · 03-25-2010, 01:39 PM

How is that different from the Volt?

chuckm · 03-25-2010, 03:09 PM

The Volt's genset is sized to be a charge-maintaining system. I'm talking about a using genset that is unable to provide average driving load amps.

I don't think charge-maintaining is necessary unless you plan on driving 300+ miles in one shot. I think the better way to go, for most people, is to charge your battery pack from the grid, but decrease the load on the pack with the genset. By providing only some of the required power from a genset, you extend the range of your pack (hence range extending). The Volt will go as long as you have gas in the tank because it will *maintain the charge*.

Piwoslaw · 03-25-2010, 03:55 PM

VW wagon EV with charging trailer...thoughts?

DonR · 03-26-2010, 12:18 PM

Use a heavy duty A-B switch to isolate batteries from controller & to engage the generator to the controller. You can switch over to the generator whenever your heart desires.

Daox · 03-26-2010, 12:30 PM

I still don't understand. You basically have a volt, but now your engine isn't big enough to recharge the batteries to keep you going at highway speeds?

DonR · 03-26-2010, 12:41 PM

I believe he sees recharging the batteries with the generator as a poor use of fuel. To maintain highway speeds he would need to make sure that the generator can provide enough electricity.

sprkthead2 · 03-28-2010, 11:00 AM

You mean a series hybrid. GM coined the phrase range extender, which is a series hybrid.

Piwoslaw · 03-28-2010, 01:28 PM

Quote:

Originally Posted by sprkthead2

You mean a series hybrid. GM coined the phrase range extender, which is a series hybrid.

I think there is a difference between those two. A series hybrid is an electric car with a generator engine large enough keep a charge for as long as it has fuel, no matter how you drive. A range extender is an electric car with a small engine which adds some juice to the batteries (or actually slows down their rate of discharge), but not enough to allow any type of drive for an indefinite time. At a slow speed the small genny may barely charge the batts, but the generator will supply only, say, 80% of the power needed to sustain highway speed. The car will have to slow down when the batteries discharge, though this will happen after a distance 5 times greater than without the engine.

I think the undersized genny is better, since it will work great in a typical driving scenerio: drive some, stop, drive some more. The batteries recharge during the stop. Even on the highway you could go 12-15h, with stops every 3-5h for lunch+pee, then sleep while the genny recharges. But a series hybrid isn't the most efficient set-up for highway driving.

sprkthead2 · 03-28-2010, 03:57 PM

Quote:

Originally Posted by Piwoslaw

I think there is a difference between those two. A series hybrid is an electric car with a generator engine large enough keep a charge for as long as it has fuel, no matter how you drive. A range extender is an electric car with a small engine which adds some juice to the batteries (or actually slows down their rate of discharge), but not enough to allow any type of drive for an indefinite time. At a slow speed the small genny may barely charge the batts, but the generator will supply only, say, 80% of the power needed to sustain highway speed. The car will have to slow down when the batteries discharge, though this will happen after a distance 5 times greater than without the engine.

No difference, don't fall for the GM marketing scheme. Its a hybrid not electric car. Since it carries an ICE and fuel for the ICE it is a hybrid, a series hybrid at that. An electric car only carries batteries, no ICE.

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