# Re: [EVDL] Accessory 12v generator / regen capability



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

The issue I see with this is that the current's available at 12 volts are
not very much compared to those needed to slow the car down -- even if you
are generating 100 amps at 12 volts, that is only 1200 watts -- or maybe
about 2 to 3 mechanical horsepower depending on efficiency. The regen needs
to be a significant percentage of the drive horsepower to have much of an
effect on steeper hills, or for actually slowing the car. Many of the regen
systems that operate through the drive motor are more like 200 or 500 amps,
at the main pack voltage. The small load of the alternator would be better
than nothing... and Roland seems to use it with good effect (he has alot
more than just a 100A alternator, IIRC), but it doesn't seem to me like it
would generally be significant enough to slow the car down much.

Z



> lumberjack_jeff <[email protected]>wrote:
> 
> >
> > I've searched the archives on a question I have, yet it remains unanswered.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

In my application, my main motor pilot shaft is not only turning a 
alternator, but a power steering pump, vacuum pump, air conditioning pump, 
and water pump for the heating.

There are two electric clutches that can disengage the units or one electric 
clutch that can disengage the whole drive unit. There are seven drive belts 
and eight pulleys.

If I disengage the accessory drive system while going down a long 2 mile 
hill, the EV will actually increase in speed from 60 mph to 80 mph and can 
do a 2 mile roll out on the flats.

Now if I engage the accessory drive units, the EV will maintain or even 
reduce in speed and will only have about a 1/2 mile roll out on the flats.

On snow back and icy streets, the main motor is connected to the accessory 
drive every time I let up on the accelerator and the EV slows down just like 
the same feel as the compression on a engine.

You have to remember there is a ratio difference between pulley sizes and 
the added resistance of the belt drives.

Roland




----- Original Message ----- 
From: "Zeke Yewdall" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Saturday, January 03, 2009 8:05 AM
Subject: Re: [EVDL] Accessory 12v generator / regen capability


> The issue I see with this is that the current's available at 12 volts are
> not very much compared to those needed to slow the car down -- even if you
> are generating 100 amps at 12 volts, that is only 1200 watts -- or maybe
> about 2 to 3 mechanical horsepower depending on efficiency. The regen 
> needs
> to be a significant percentage of the drive horsepower to have much of an
> effect on steeper hills, or for actually slowing the car. Many of the 
> regen
> systems that operate through the drive motor are more like 200 or 500 
> amps,
> at the main pack voltage. The small load of the alternator would be 
> better
> than nothing... and Roland seems to use it with good effect (he has alot
> more than just a 100A alternator, IIRC), but it doesn't seem to me like it
> would generally be significant enough to slow the car down much.
>
> Z
>
> On Fri, Jan 2, 2009 at 11:57 PM, lumberjack_jeff 


> > <[email protected]>wrote:
> >
> > >
> > > I've searched the archives on a question I have, yet it remains
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

In a message dated 1/3/2009 2:42:11 A.M. Eastern Standard Time, 
[email protected] writes:



> On 2 Jan 2009 at 22:57, lumberjack_jeff wrote:
> 
> > It is apparently common to use an alternator (or a generator) coupled or
> > belt driven from the main propulsion motor to charge the 12v battery system
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> lumberjack_jeff wrote:
> >
> > I've searched the archives on a question I have, yet it remains
> > unanswered.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> Charlie P wrote:
> > I have a 12v alternator off a transit bus It is about 12in in dia. and
> > 12in long without drive assy weighs about 100lbs what would be amp output
> > ? could this be converted to motor or regen braking?
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> lumberjack_jeff wrote:
> >> It is apparently common to use an alternator (or a generator) coupled or
> >> belt driven from the main propulsion motor to charge the 12v battery
> >> system in lieu of a dc-dc convertor.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

Hello Charlie,

You will not over charge a battery with the alternator, because the 
alternator has a regulator that maintain the proper charge voltage. Anyway, 
you do not relied on just the battery to provide the load all the time.

I use a large 12 volt deep cycle battery and a very large 
inverter-alternator which is the type that is use on cabin cruisers and some 
large trucks which provides both 13.5 to 16 volts DC and 110 VDC at 7kw 
which is inverted to 120 VAC 60 hz at 6kw.

In the summer driving during the day time, the load is very light, which is 
between and 40 to 60 amps with this unit. During the winter and if I know 
that I am going up some very steep hard pack roads, then I will turn off the 
alternator regulator circuit which can easily done with a 3 wire alternator. 
You install a switch in the small wire that plugs into the alternator. This 
wire is call the R-wire.

I then turn off the R Circuit and let the deep cycle battery discharge until 
I have to go down these hills in the winter time. Also I can switch on 
three heater units, two pumps, four fans, and all the lights that will put 
on about a 5 kw load.

As I proceed down the hills generating this power, the motor amps and main 
battery pack amps is now at 0 amps while the DC-AC unit could generated up 
to 100 amps.

On level dry surfaces, I can disconnected the drive unit from the pilot 
shaft of the motor by use of a electric coupler that is made by Dodge Power 
Transmission Systems. Then at this time, a pack of DC-DC converters that 
come off the main battery pack will now supplied the power to these 
accessory units by use of a transfer switch.

The advantage here for me driving in these roller coaster roads, is that in 
the winter, this system holds back or can even slow the EV on down hill icy 
roads. When the roads are dry, I can turn off the load which allows me to 
roller coast the hills. On some roads I can have over 5 miles of run out 
with no additional main battery power.

Roland




----- Original Message ----- 
From: "Charlie P" <[email protected]>
To: <[email protected]>
Sent: Sunday, February 22, 2009 10:25 PM
Subject: Re: [EVDL] Accessory 12v generator / regen capability


>
>
>


> > lumberjack_jeff wrote:
> > >
> > > I've searched the archives on a question I have, yet it remains
> > > unanswered.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

So i've been wondering for a while now, what would happen if you 
tried to use an alternator for regen and put the energy into the 
Traction Pack (144 volts as an example)?



> Lee Hart wrote:
> 
> > lumberjack_jeff wrote:
> >>> It is apparently common to use an alternator (or a generator)
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> John in Ma <[email protected]> wrote:
> > So i've been wondering for a while now, what would happen if you
> > tried to use an alternator for regen and put the energy into the
> > Traction Pack (144 volts as an example)?
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

Hello John,

Yes, this can be done. I have all the equipment on board to do this, but I 
did not test this out yet.

The method I thought might work, is to have my 7kw inverter part of the 
alternator which has to supply a pure 60 Hz sine wave back to the on board 
PFC-50 charger which the current would have to be preset.

The theory of operation would be:

1. As the accelerator pedal is let up, a micro switch turns off the
two safety contactors that are between the battery pack and the
main contactor and Zilla controller.

a. Problem one is, if the battery power is off for a long time to
the controller, that capacitors may loss it charge and may have
to be pre-charge again.

2. Then another contactor is activated to turn on the battery box
exhaust ventilation system and a blower fan to blow in fresh air
into the charger compartment for cooling.

a. When the blower fans are up to pressure, then it activates a
vacuum/pressure switch which then turns on a 2 pole contactor
that connects the output of the charger to the batteries.

b. This contactor has a added power pole that turns on another
2-pole contactor that turns on the power from the inverter to
the on board charger.

c. The inverter control unit has a phase control and low voltage
control modules. If the 60 hz is not in with +/- .1% or the
voltage is not at the proper level, then the inverter unit will
not provide any output.

d. The alternator-inverter unit must be turning at least 1100 rpm
to excited the fields for any output.

There is on dash controls and indicators that monitors the
inverter-alternator 110 VDC @ 60 A input and 120 VAC @ 50 A output
and the battery charger voltage and ampere data.

So you see, it could be done if you were driving down long hills driving 
long distances where this equipment would cycle once during the down hill 
run. Doing short city stop and go you loss the regen energy when the rpm is 
too low. It is much better to regen the power directly into the accessory 
units.

Anyway if a person takes on short trips, then there is not enough discharge 
time on the main battery pack. You do want to charge the batteries at 50 
amps if your batteries are still 98% SOC.

Roland






----- Original Message ----- 
From: "John in Ma" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Monday, February 23, 2009 8:09 PM
Subject: Re: [EVDL] Accessory 12v generator / regen capability


> So i've been wondering for a while now, what would happen if you
> tried to use an alternator for regen and put the energy into the
> Traction Pack (144 volts as an example)?
>


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> John in Ma wrote:
> > So i've been wondering for a while now, what would happen if you
> > tried to use an alternator for regen and put the energy into the
> > Traction Pack (144 volts as an example)?
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> Grant Stockly wrote:
> > I have modified alternators... to get ~110vDC under full load
> > and ~300vDC open circuit.
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> Lee Hart wrote:
> > John in Ma wrote:
> >
> >> So i've been wondering for a while now, what would happen if you
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

It was real hard to understand what the movie was trying to show. You
made a connection to something and an arc was struck.



> Grant Stockly <[email protected]> wrote:
> > At 08:36 PM 2/23/2009, you wrote:
> >>
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

They were quite common back in the early 80's -- if you look at JcWhitney
catalogs from back then, they're in there. However, they have been mostly
supplanted by solid state inverters now (for most purposes....for purposes
of high capacity regen... I think they'd be alot better than a cheapo
inverter).

Z



> Grant Stockly <[email protected]> wrote:
> 
> > At 06:41 AM 2/24/2009, you wrote:
> > >Hello Grant,
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> Stefan wrote:
> > Lee Hart wrote:
> >> John in Ma wrote:
> >>
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> On 23 Feb 2009 at 22:49, Grant Stockly wrote:
> 
> > What I describe below will put a good
> > constant 5HP draw on the engine and would only involve a switch
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> David Roden wrote:
> >> I think I must have missed the point here. Can you explain what
> >> all this has to do with EVs?
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> Grant Stockly wrote:
> > In my opinion less work... I got half way through removing the
> > windings from an alternator stator. It was a nightmare. : ) I
> > ended up buying a replacement stator.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

>> I'm not familiar with this dynamote. Is it discontinued? Does it
>> use power from the battery to make AC too? 6kw from an alternator is
>> a pretty beefy alternator!

Zeke Yewdall wrote:
> They were quite common back in the early 80's -- if you look at JcWhitney
> catalogs from back then, they're in there. However, they have been mostly
> supplanted by solid state inverters now (for most purposes....for purposes
> of high capacity regen... I think they'd be alot better than a cheapo
> inverter).

"Dynamote" was a trade name that covered a range of models. Some were 
motor-generators -- the motor ran on 12vdc, and the generator output 
120vac. Others were belt-driven units that your ICE could drive to 
produce 12vdc, 120vac, or both.

Other companies made similar motor-generator units. I still have a 36vdc 
input 120vac output unit from Pacific Electric. While bigger and heavier 
than a modern inverter, these units were very rugged and could easily 
drive difficult AC loads.
> 
> Z
> 
>


> Grant Stockly <[email protected]> wrote:
> >
> >> At 06:41 AM 2/24/2009, you wrote:
> >>> Hello Grant,
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

All,
>From the archives below, what was once available!:
http://www.evalbum.com/tech/regen.jpg
Suck Amps,
BB

http://tech.groups.yahoo.com/group/evdl_post_archive/message/44276
>Mon Nov 10, 2008 11:21 pm 
>"Douglas A. Stansfield" 
>Re: [EVDL] Re generative Braking
>
>A Google search for Solar Car Corporation revealed the company is out of
>business. That is a shame because that part looks really interesting and
>would be perfect for my conversion. Any idea if any other manufacturers
>exist that bought this product from Solar Car Corporation? Maybe GM has it
>now.
>
>
>Sincerely,
>Douglas A. Stansfield
>
>>-----Original Message-----
>>From: Dave (Battery Boy) Hawkins
>>Sent: Monday, November 10, 2008 5:35 PM
>>
>>Doug and All,
>>My RX-7 came with this Solar Car Corporation alternator system from a
>>previous converter:
>>http://www.evalbum.com/tech/regen.jpg
>>
>>I found the above link in the archives at:
>>http://www.mail-archive.com/[email protected]/msg07960.html
>>
>>I'm thinking that Roderick Wilde at EV Parts built one of these for their
>>Land Rover, but I don't think they made them available.
>>Suck Amps,
>>BB

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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

You guys may be interested in this. 
http://islandcastaway.com/stuff/windpower/Alternator%20Secrets.htm

Stub

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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

I'm still largely electrically ignorant so I have to ask; why would 
you have to transform to a higher voltage.

Isn't the objective to put energy into the traction pack?

Is it a matter of the high voltage traction pack destroying the 12v 
alternator?



> Lee Hart wrote:
> 
> > John in Ma wrote:
> >> So i've been wondering for a while now, what would happen if you
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

Think of it like this...

Consider electricity as water. Voltage represents how high a body of water
is, as in a bucket of water on the table vs a bucket of water on the floor. 
The bucket of water on the table has a "higher potential" or "higher
voltage". Potential == Voltage.

Then you have current. If you put a small straw between the two buckets
(one on the table, one on the floor) you would have current flow, just like
water in a river. The smaller the "pipe", the less current can flow. The
bigger the pipe, the more current can flow.

The Traction Pack is like a bucket of water on your roof, vs your alternator
which is like a bucket of water on the table. In order for the alternator
to "push" current into the traction pack, it has to have a higher potential,
or higher voltage... otherwise current doesn't flow.

That explanation is like so totally wrong on many levels, but it gives you
the basic idea of electricity and how it behaves.





> John in Ma wrote:
> >
> > I'm still largely electrically ignorant so I have to ask; why would
> > you have to transform to a higher voltage.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*



> John in Ma wrote:
> > I'm still largely electrically ignorant so I have to ask; why would
> > you have to transform to a higher voltage?
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] Accessory 12v generator / regen capability*

Sorry, it's late and I'm very tired, so don't read too much into that
extremely simplistic explanation. Just think of electricity like water, and
pipes like wires, check valves like diodes, "tanks" like capacitors, valves
like transistors and you'll be well along the way to understanding basic
electronics.




> mark at evie-systems wrote:
> >
> > The Traction Pack is like a bucket of water on your roof, vs your
> > alternator which is like a bucket of water on the table. In order for the
> ...


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