# [EVDL] Cheap inverter



## EVDL List (Jul 27, 2007)

Some folks in the past have indicated interest in using their EVs for 
household backup power, or for running 120vac electrical gear on the road. 

Here's an Ebay seller offering a few 48v input Exeltech 1100 watt true sine 
wave inverters. One of these could be used with a C-car or 48v NEV; two 
could be used with a 96v conversion (if you split the 120v load equally 
between them). These inverters are not designed to be strapped for 240v 
operation.

Exeltech inverters have an excellent reputation. They are of Texas 
manufacture, and carry a Texas-sized price tag, but these are used and the 
asking price is less than half the new price. 

David Roden - Akron, Ohio, USA
EVDL Administrator

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## EVDL List (Jul 27, 2007)

Or three on a 144V system. Do they have a parallel stacking feature so that their outputs be wired in parallel to increase the power output? If so, and if they have an isolated output, it could put a fairly equal load on all the batteries.
-Randy


> 
> Some folks in the past have indicated interest in using their EVs for 
> household backup power, or for running 120vac electrical gear on the road. 
> 
> Here's an Ebay seller offering a few 48v input Exeltech 1100 watt true sine 
> wave inverters. One of these could be used with a C-car or 48v NEV; two 
> could be used with a 96v conversion (if you split the 120v load equally 
> between them). These inverters are not designed to be strapped for 240v 
> operation.
> 
> Exeltech inverters have an excellent reputation. They are of Texas 
> manufacture, and carry a Texas-sized price tag, but these are used and the 
> asking price is less than half the new price. 
> 
> David Roden - Akron, Ohio, USA
> EVDL Administrator

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## EVDL List (Jul 27, 2007)

> On 22 May 2012 at 11:04, RightHand Engineering wrote:
> 
> > Do they have a parallel stacking feature so that their outputs be wired
> > in parallel to increase the power output?
> ...


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## EVDL List (Jul 27, 2007)

> EVDL Administrator wrote:
> > Some folks in the past have indicated interest in using their EVs for
> > household backup power, or for running 120vac electrical gear on the road.
> 
> ...


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## EVDL List (Jul 27, 2007)

In the last power outage I was running off my shed's 4,800 watts of 
batteries. When they needed a recharge, I did it by running a charger 
off a 1,500 watt Cobra inverter attached to my Sienna's 12 volt battery. 
No problem running the charger and even a microwave oven as needed.

Chris


On 5/22/2012 2:29 PM, Willie McKemie wrote:
>


> EVDL Administrator wrote:
> >> Some folks in the past have indicated interest in using their EVs for
> >> household backup power, or for running 120vac electrical gear on the road.
> >
> ...


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## EVDL List (Jul 27, 2007)

> On 22 May 2012 at 16:43, Christopher Zach wrote:
> 
> > In the last power outage I was running off my shed's 4,800 watts of
> > batteries.
> ...


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## EVDL List (Jul 27, 2007)

On 5/22/2012 1:29 PM, Willie McKemie wrote:
>


> EVDL Administrator wrote:
> >> Some folks in the past have indicated interest in using their EVs for
> >> household backup power, or for running 120vac electrical gear on the road.
> >
> ...


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## EVDL List (Jul 27, 2007)

Lee,

Since the motor controller has to PWM to reduce pack voltage and
regulate the motor speed to 1800 RPM, wouldn't the peak AC voltage
equal the motor voltage for that particular load current and RPMs?

If so, it seems like regulating the voltage would be a challenge.

Also, would the slip rings just connect to two armature windings the
right distance apart? (I would guess 90 or 180 electrical degrees.)

-Morgan LaMoore



> Lee Hart <[email protected]> wrote:
> > ...
> > One clever way to do this is to modify the series traction motor so it
> > has a direct AC output. This is called a rotary converter. Basically,
> ...


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## EVDL List (Jul 27, 2007)

Morgan LaMoore wrote
> Since the motor controller has to PWM to reduce pack voltage and
> regulate the motor speed to 1800 RPM, wouldn't the peak AC voltage
> equal the motor voltage for that particular load current and RPMs?

Yeah, it gets complicated. With a series motor, the PWM speed controller 
can adjust speed, or voltage, but not both of them independently. The 
best you can do is pick one (AC voltage or frequency), and let the other 
one vary.

A rotary converter works better with a PM or shunt field. In that case 
you can adjust the armature voltage to get the RPM you want, and then 
trim the output voltage with the field. They interact, but you can 
regulate both voltage and frequency independently.

> If so, it seems like regulating the voltage would be a challenge.

Yes. The simple case is to have a 170vac pack, so you can connect the 
armature directly to the pack. This makes the peak AC voltage match the 
pack, i.e. 170vac peak = 120vac RMS.

Then use the PWM controller to control the field current, as a way to 
adjust RPM to get 60 Hz.

> Also, would the slip rings just connect to two armature windings the
> right distance apart? (I would guess 90 or 180 electrical degrees.)

The slip rings connect to two commutator bars for a 2-pole motor, or 
four bars for a 4-pole motor. Which bars? Look at the motor when it's 
not running. Connect the slip rings to the bars that are sitting under 
the brushes at the moment. A 4-pole motor has two + brushes; the bars 
under them are connected to one slip ring, and the bars under the two - 
brushes to the other slip ring.

As a practical matter, it was usually easier to put the slip rings at 
the other end of the armature. In that case, you're connecting the slip 
rings to the center tap of the winding between two adjacent bars.

Note that you can get 2-phase or 3-phase AC the same way; just add slip 
rings that bring out taps every 90 or 120 electrical degrees apart 
instead of 180 degrees.

-- 
Ingenuity gets you through times of no money better than money
will get you through times of no ingenuity. -- Terry Pratchett
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart at earthlink.net

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## EVDL List (Jul 27, 2007)

> On 22 May 2012 at 20:22, Chris Zach wrote:
> 
> > Yeah, I know. 4.8kw/hr based on a 10 hour draw time with c/10 discharge
> > tables. Can't forget that.
> ...


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## EVDL List (Jul 27, 2007)

> On 22 May 2012 at 13:29, Willie McKemie wrote:
> 
> > I do have visions of being able to plug an inverter in a charging port
> > of my 120/144/156vdc vehicles and running the ac into the (main breaker
> ...


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