Re: {SPAM?} Home made Hybrid

["Jim Blair" <carnuck@xxxxxxxxxxx>]

A: This is getting into the area of my own slow to assemble design. I am 
adding an electric motor to my transfercase's front output shaft so that 
when highway cruising I can disengage the gas motor and run straight 
electric. The gas motor will be shut off for short trips (50 miles or so) or 
run to keep the batteries up. Still trying to decide what voltage system to 
run. Newer ones are closer to 110VDC, but require more bateries. I got a 
screaming deal on 4D batteries that will fit between my frame and 
driveshaft. Extra weight (even though it already weighs 5,000lbs) will be an 
issue.


From: farna@xxxxxxx
Subject: Re: {SPAM?} Home made Hybrid
To: mail@xxxxxxxxxxxx
Message-ID: <ADVANCES62NXRPmcarc00000145@xxxxxxxxxxxxxxxxxxxxxxx>

There are several electric conversion sites. That's what you want to look at 
first. The simple hybrid idea is to use a small generator, something quiet 
like a Honda, to supplement range. Th batteries are still the primary power 
source. The generator doesn't have to provide total power, just a bit more 
than enough to pull the car at a steady cruising speed. Then you need to 
start the generator when the batteries are 40-60% depleted. The generator 
would be connected through a charging controller or large diodes that would 
prevent current drain when the gen isn't running. Diodes are all that's used 
on solar cells when overcharging the battery isn't an issue (like on the 
little "battery saver" types). Of course you'd have to have some type of 
on-board charger. That itself will limit how much you can charge the 
batteries while driving. But when you're stopped, the gen is still running. 
So you're charging at stop lights. If you get on the interstate and cruise 
at 55-60, the genera!
 tor could be run and ideally would put out a little more power than the 
electric motor is using, at least on level ground. You'd only be pulling the 
batteries down when accelerating, passing, or pulling up hills. It takes 
very little power to keep a car cruising, remember.

Of course that would be ideal. In a practical situation if you built a car 
with a strictly battery range of say 60 miles, I think you'd extend the 
range with the small generator to 90-100 miles in town, maybe 120-150 if you 
have a long level cruise area. I think batteries to run that extra 30-80 
miles would weigh and cost a lot more than the generator setup. Another plus 
on the gen setup is that if you did run the batteries down a good bit you 
could leave the generator running while you stopped for a rest. An hour 
probably wouldn't get you more than another 20 miles or so, but if you 
couldn't plug up the generator only uses a few gallons over 5-8 hours -- it 
wouldn't be cost prohibitive to charge batteries while at work, overnight at 
a motel, etc. Might not be saving much, but you wouldn't be stranded. A 
Honda EN2500 uses a 5hp motor and produces 2300 watts (2500W is peak output, 
2300W sustained), and will run 7 hours on just under 3 gallons (2.9) or gas. 
Should be enough to!
  replenish the battery pack at least by 50% over that amount of time.

If you had a generator that would keep up with total electric use you'd use 
as much or more gas than the gas engined car. You'd have to keep up with 
peak demand, not lowest demand. Though you could keep a few batteries on 
board for dead stop take-offs, you'd be adding lots of weight with little 
gain in efficiency. You'd have hybrid drive, sort of like a diesel 
locomotive. that doesn't save fuel directly, it's a bit more efficient 
because the electric motors can be made in such a way to provide lots of 
traction without a lot of gearing like the diesel engines would need if 
driving directly. For a car the weight of the generator in combination with 
the driving engine would make it less efficient. I'm not so sure the combo 
wouldn't work with something like a heavy load 18 wheeler though. I doubt 
there would be enough efficiency gain to make it worth while. With a train 
there obviously is.

On a home built hybrid the generator could easily be manually started. I 
don't necessarily mean with a pull cord under the dash, though using a long 
rope and pulleys it certainly could be done that way and not be obvious. An 
electric start would be better, but I've not seen a small enough generators 
with electric start. Anyway, what I meant was you could watch your charge 
level gauge and start the gen when needed. For short commutes you wouldn't 
need it at all. If I had 70% charge left and was only a few miles from home, 
I wouldn't use it.

I'm serious about the pull cord start though. I wouldn't think much at all 
about putting a generator under the hood and using pulleys to route a cord 
to an inconspicuous handle under the dash on a home built hybrid. As long as 
it only takes 10-12" to pull, and was carefully placed relatively close to 
the firewall, it would work fine. An electric door lock solenoid and/or 
vac/electric heater control could even be rigged for the choke/gas (solenoid 
would only work for choke) if cables weren't convenient.

Running the generator off a wheel is kind of like perpetual motion! It takes 
as much power to turn the gen as you get back. Regnerative braking sort of 
works that way, but you're getting back power that you used to accelerate. 
Instead of throwing the power away as heat energy you use the electric motor 
to slow the car (engine braking), and the motor is turned into a generator 
while slowing to put that power back into the batteries. There's a rather 
expensive control circuit for that. Worth it for a mass produced hybrid, for 
a home built it complicates things and adds a lot to cost. Running the AC 
compressor off a wheel instead of hte motor may have some merit, but you'd 
be out of AC when stopped. If you're not in a lot of traffic that would 
work. But I hate the fact that my wife's Volvo has an AC cut-off during 
acceleration. On a hot day you just don't really want to go anywhere fast, 
not until you get the car cooled down anyway! You could extend battery range 
by having the !
 generator tied to the AC -- it would charge some while running the AC also. 
That would cut down efficiency a little, but would increase battery range. 
May as well have an electric motor driving the AC though -- won't take any 
more energy than running the generator, and the gen would be putting juice 
back into the batteries when the compressor wasn't running.

Yeah, I've thought about it ;>  My problem is the cost. It would cost a bit 
more to build than a nicely equipped four cylinder car, and would take a lot 
more careful thought and planning. I've got the concept down, would just 
need to start shopping for parts. You could even make a LPG powered car 
cheaper. I'm just reluctant to spend $2500-$5000 over what it would cost me 
to build a mild hot rod. I paid $250 for a turbo four and five speed from a 
Mercur XR4ti for what will likely be my next project. An electric motor and 
accoutrements would have cost $1000+ for used items.