As long as your controller can handle the voltage, the small difference between
72 volts and 80 volts probably isn't causing the problem.  I'd leave the pack as
it is (I'm jealous, BTW... still on lead here!)

As far as the controller goes, it is unlikely to be the problem as well.  Stock
controllers put out about 350 to 400 amps for a short time (starting from a
stop, floored) but motors this size generally taper off how much power they can
use as they accelerate.  At top speed, it is likely you are using less than 130
to 150 amps.  Hot, but probably not enough to cause problems.

The more likely problem is that the motor is overspeeding.  The GEM transaxle
has an overall ratio of about 8.9:1, so at 35 MPH indicated the motor is turning
about 4,500 RPM - about the fastest I'd recommend turning these motors for long
durations of time.  For reference, at 45 MPH, the motor is turning about 5,800
RPM - Way too fast for these small stock brushed motors.

Many GEMs have been modified to operate over 35 MPH indicated (they came from
the factory with a 25 MPH limit).  At higher speeds, the brushes in DC motors
tend to 'float' which causes an arc to form between the brush and the
commutator.  This arcing causes a tremendous amount of heat, and is likely the
cause of your motor(s) burning out.

One possible way to help with the brushes arcing too much at high speed is to
increase spring tension.  The other is to reduce the speed of the motor - keep
it under 35 or so.

Most of these motors are somewhat under-sprung for traction applications at
about 2 or 3 PSI tension.  Brush pressure should be 6 to 9 PSI for EV
applications.  It seems counter intuitive that higher spring pressure would help
things last longer, but one of the main killers of brushes and commutators is
arcing, not excessive tension.

Hope this helps!

Tom Keenan

--- On Fri, 9/30/11, art maurice <amaurice@...> wrote:

From: art maurice <amaurice@...>
Subject: [eaasv] New motor
To: "eaasv"
  <eaasv@yahoogroups.com>
Date: Friday, September 30, 2011, 3:19 PM
















 









       Hi EAASV,
 
I bought a GEM EV and then went online to get an upgrade kit.  I also had
Richard Hatfield's company install Li batteries up to 80 volts.  I burnt out the
original 5 HP motor but a 7.5 HP motor came witht he upgrade kit.  After about 6
months I burnt out the 7.5 HP motor.  The GEM service guy said my batteries were
too powerful for the motor and suggested I shrink the battery pack. 
 
Then I was telling this story to a friend who electrically inclined and he said
a 10 HP motor should be able to handle that battery pack.  He qualified it by
saying not to "punch it" when I start the car because I could damage the
transmission.
 
My question to you all is:  Will a 10 HP motor solve my problem or should I
shrink the battery pack?
 
Thanks in advance,
Art Maurice

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Howdy,

I am planning to have Electric Motor Werks as our guest speaker on October 15th.
They brought their orange BMW 3-series conversion to our car show last weekend
More details about our meeting will be sent later.

In the meanwhile, we have been invited to participate in the National Plug in Day on Sunday, October 16th.
This is scheduled to take place in 16 cities across the US - the nearest one is in Santa Cruz.
Below is the invitation with a PDF attachment.
For a list of the other cities that are scheduled, you can see them here:
http://www.pluginamerica.org/pluginday

I suppose that some people will want to carpool.
If you can take a passenger or need a ride, feel free to reply to this email.
If we get too many emails, we can come up with some other method of handling the logistics.

There is a charging station in Santa Cruz in the Front Street Garage - free EV parking for up to 4 hours.
Take a ticket from the machine and then tell the attendant you have an electric car just prior to leaving.
Details are here:   http://www.evchargernews.com/regions/95060_1.htm

Lots to do in the area while you are charging.

Adios,

Jerry Pohorsky
EAASV chapter president
408-464-0711

---

---------- Forwarded message ----------
From: Beverly DesChaux <bdchaux@...>
Date: Sun, Oct 2, 2011 at 1:02 PM
Subject: Meeting/Event for this month, Sun, Oct 16 10-4 @ Whole Foods
To: EAACC driver list <drivers@...>
Cc: jerry pohorsky <jerry@...>

Hi Folks,   See the attached flyer for details of our October Meeting/Event. We'll be celebrating National Plug-In Day at Whole Foods in Santa Cruz along with 15 other cities around the country  (& growing), and seems like we may have the priviledge of EAASV joining us here in town.   We will be doing a press conference & inviting elected officials and invite everyone to bring their EV's and/or just come along to support the event. Notice that we will have the brand new Mitsubishi iMiEV available for test drives as part of their launching campaign.   Definitely see you there, Beverly DesChaux

<National Plug In Day SC flyer draft sls.pdf>

I need to get some advice with a home-brew conversion in Palo Alto,
mostly looking for saving the body and putting in different battery,
maybe motor and controller.

And I'm not the guy to do the labor. So I'm really looking for a local
conversion shop.

And for those who might know, this is the 1967 Sunbeam Alpine Bob
Murray converted years ago.
  -Barry

--
bhayes yat cs dot stanford dot edu is what you should put in your
contact files -- it'll forward to me no matter where I move

As discussed in today's EAASV meeting, PG&E is proposing changes to
the E-9 rate schedule for EV customers that will significantly
increase costs for those EV drivers who have also invested in a solar
PV system to keep their usage in the low tiers.  The public has an
opportunity to file protests against this proposed change, but the
deadline for doing so is this coming Monday, October 17.  This can be
done via email.  Links to documents with the details are below.

PG&E has filed Advice 3910-E with the California Public Utilities
Commission in accordance with CPUC Decision D.11-07-029 proposing to
revise the E-9 rate schedule that is optional for customers who charge
an EV.  This proposal eliminates surcharge tiers so that customers who
already use a lot of electricity and then add an EV won't be hit hard
by going into the high tiers as a consequence of using more
electricity than before.  That might seem like a good thing, and would
be for those customers who are already consuming enough power to be
charged in the hier tiers.

However, this single-tier rate is set at a level that is roughly
double the part-peak and off-peak rates from the lowest tier of the
current E-9 rate schedule (going from 5.5 cents to 11 cents per kWh
for the off-peak when we do all our EV charging) .  For those of us
who have invested in solar power and/or who are very conservative in
their power use to keep their consumption in the lowest tier, this is
a big increase.  The proposed change also institutes year-round 3pm -
9pm peak rates, rather than only in the summer, which can put a real
crimp in one's lifestyle.

PG&E is also proposing to translate the current $8.00 per month meter
fee (that we are currently paying and that was to be eliminated with
the installation of SmartMeters) into a fixed "customer charge".  That
seems unfair given that the average E-1 customer does not pay such a
charge.

PG&E's advice letter states that 3/4 of the customers currently taking
service on the E-9A rate schedule will be negatively impacted, with
the worst quartile seeing an average increase of 80%.  I can only
assume that they expect those of us in that categorey to switch to
some other rate schedule.  But the only choices are non-TOU E-1 at 12
cents or the E-6 TOU rate schedule with 9.3/16/27 cents per kWh for
off/part/peak periods.  To me, the proposed change clearly decreases
the incentive to charge between midnight and 7am that the current E-9
rate schedule favors.

I plan to file a protest by the deadline of October 17.  I have filed
protests in the past, and have learned that in some cases the PG&E
Advice letter is simply responding to specific orders contained in the
CPUC Decision document.  In that case, PG&E's response to the protest
is that they are simply implementing what the CPUC directed them to
do.  For this particular Advice 3910-E, there is some wiggle-room room
because the CPUC only ordered that the E-9B separate-meter rate be
changed.  The CPUC did not order that the E-9A single-meter (whole
house) rate be changed, although they did support doing so.  I plan to
argue that the E-9A rate should not be changed, or alternatively that
it should be kept and that a new single-meter rate be established.

The main counter-argument that PG&E will wage is that the E-9 rate for
tiers 1 and 2 is below the true cost.  This is stated in their Advice
letter.  However, that is as it should be: if tier 1 was the true
cost, then the full increment for tiers above that would be extra
profit.

The CPUC decision was issued in July.  Such decisions follow hearings
in which the stakeholders can make comments, but it is very hard for
individuals to play in that game.  I have not investigated yet whether
there have been any positions stated by TURN or proponents of EV
and/or solar technologies.  However, the list of stakeholders did not
include the main solar players, and I think that is part of the
problem.

Here is a link to the Advice 3910-E letter:

http://www.pge.com/nots/rates/tariffs/tm2/pdf/ELEC_3910-E.pdf

Advice letters are the routine mechanism by which PG&E tells the CPUC
about changes they propose for their regulated business.  The letter
includes instructions for filing a protest, including the email
addresses and the postal address for a hardcopy to follow.

The PG&E proposals are often filed in response to orders from the CPUC
contained in a Decision document.  The relevant document for this case
is CPUC Decision D.11-07-29, found here:

http://docs.cpuc.ca.gov/word_pdf/FINAL_DECISION/139969.pdf

The current tariffs (rate schedules) are available from the PG&E web
site.  These rates schedules are:

E-1: http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-1.pdf

This is the common residential rate with the same rate for all hours
of the day.

E-6: http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-6.pdf

This is a time-of-use (TOU) rate with a higher price during peak
periods of the day and a lower price at night.  That is good for those
with solar PV systems because power is fed back during the peak
periods and consumed during the off-peak periods.

E-7: http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-7.pdf

This is an older TOU rate that is even better, but is now closed to
new customers.

E-9: http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-9.pdf

This is the TOU rate that is voluntary for customers who will charge
an EV at home.  (Until a couple of years ago, it was mandatory but not
always enforced.)  This is the topic of the proposal.  The contents of
this rate schedule are also included in the Advice 3910-E with changes
marked.

NEM: http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_NEM.pdf

This is the Net Metering tariff that does not set rates, but works in
conjunction with one of the rate schedules above for customers with
solar PV systems.  It tells how credits for excess power generated by
the customer during the day will be balanced with charges for power
consumed at night.

                                                         -- Steve

Hello everyone,

My name is Venky. I have moved to the Bay Area since six months, and am in the
market for a used EV. As I was researching, I came across this posting on
evtradingpost for a Ford Escort 1981 factory-converted by Jet Electrica of
Austin, TX.

Does anyone in the Bay Area own this particular make? Can someone share his/her
experience(s) with the Jet Electrica Ford Escort? How easy are parts available,
particularly items like headlight covers, brackets, upholstery, screws, etc? I
ask because I don't want to end up buying a car that became out-of-date (this
one's 30 years old) and finding parts to be either unavailable or phenomenally
expensive.

I live in Milpitas.

Regards,

Venky