EV Digest 5254

Topics covered in this issue include:

1) Re: When to Charge?
by "Rich Rudman" <rmanzan@...>
2) Re: Car Transport (was: RE: Bradley GT EV kitcar available cheap in Fla on
E bay )
by "Rich Rudman" <rmanzan@...>
3) RE: Range extender on the Nissan
by "Matthew D. Graham" <MGraham@...>
4) Re: Also looking for a small motor controller?
by Christopher Zach <czach@...>
5) RE: Range extender on the Nissan
by Tim Humphrey <hump@...>
6) RE: Range extender on the Nissan
by "Matthew D. Graham" <MGraham@...>
7) Re: Cheap charger
by Juergen Weichert <juergen@...>
8) Re: Range extender on the Nissan
by Neon John <jgd@...>
9) Re: Li-poly cycle life (was Re: Better to Run Down or...)
by "ProEV" <Promo@...>
10) Re: When to Charge?
by TiM M <mr_tim34@...>
11) Re: When to Charge?
by bruce parmenter <ev_list_editor@...>
12) Re: Li-poly cycle life (was Re: Better to Run Down or...)
by "ProEV" <Promo@...>
13) Re: Different Cell Capacities
by Victor Tikhonov <ac@...>

----- Original Message -----
From: "bruce parmenter" <ev_list_editor@...>
To: "evlist" <ev@...>
Sent: Tuesday, March 14, 2006 2:32 PM
Subject: Re: When to Charge?



> while at work, and again at home, fully charging each time: the
> Battery rep's ASAP method.
>
>
>
>
> Bruce {EVangel} Parmenter
>
> ' ____

As a charger guy, I fully support the Charge ASAP method. It really seams to
work for me and my customers.
In times of haste.. the deeper the discharge event the more important it
seams to be to get some kind of charge onto the Lead as soon as possible.

light cycles say down to %10 or less, it really doesn't matter to the
battery, as long as you don't leave them like this for months on end.

I cycle and test a Lot of batteries here... This is just a good rule of
thumb. Get 'em charged then you can ignore them for a while.
On my street machines, If they are not rolling they get charged. The drive
is not finished until the E-meter is blinking Green or the PFC has a locked
on blue.

Rich Rudman
Manzanita Micro

----- Original Message -----
From: "Myles Twete" <matwete@...>
To: <ev@...>
Sent: Tuesday, March 14, 2006 5:44 PM
Subject: Car Transport (was: RE: Bradley GT EV kitcar available cheap in Fla
on E bay )



> I've read a lot of horror stories about shipping.
> Remember, there's lots of competition, and they'll say nearly anything to
> get you
> to ship with them.
> I guess I was lucky.
>
> -Myles Twete, Portland, Or.
>
This is the primary Reason I just drove a Ford Tarus from Virgina Beach Va
to Seattle.

Took 5 days, I got to see my Sister and her kids, and had a nice stay in
Racine.

But it took about $400 in Unleaded, and 5 days single handed.

So... I have no fear of coast to coast runs in the winter. And I do love
driving and seeing the sights.

The Heated rest areas in Montana... were a life saver. When it's 10 Deg out
side.. the thaught of a Sani Can is fearfull.


Madman

John,

Thanks for all that information. I suspect that the generator I saw at
Costco (Troy-Bilt or Coleman) is probably not one of the best, and I'm sure
it can't be accurately described as "quiet" mainly because it's not one of
the most expensive. It's a 5500 W continuous, 6850 W surge for $550. I had
looked at the quiet Honda EU series before, and they were very expensive and
pretty low on output power (maybe 3kW).

I saw some over/under voltage relays online, including one from K-Tech at
http://www.k-tech.com/Crompton/CromptonPDF/250SeriesTripRelayK.pdf
The AC voltage protection models start on page 3. They have over-, under-
and combo units available.

I see the benefit in providing straight DC to the pack, but I would prefer
to use the generator for providing AC power, since I'd also want to use it
for lighting, the laptop and other accessories at the track.

Matt

-----Original Message-----
From: Neon John [mailto:jgd@...]
Sent: Tuesday, March 14, 2006 4:15 PM
To: ev@...
Subject: Re: Range extender on the Nissan

On Tue, 14 Mar 2006 12:28:48 -0500, "Matthew D. Graham"
<MGraham@...> wrote:

>Hey everyone,
>
>As much as I would love to pull a White Zombie and drive to and from
>the race track, the Joule Injected 240SX just doesn't have the range.
>Moroso is a good 30 miles from me, and that's just begging for
>disaster, pushing the absolute limits of the car. Plus, I'd need to
>bring along a generator for charging between races, and that's just not
going to fit in the hatchback.
>
>I picked up a nice little utility trailer with the idea of loading a
>generator onto it and powering the PFC20 during the ride. I know the
>concept has been discussed before on the list, but searching through
>the archives, I'm afraid I'm going to miss some practical detail
>leading to expensive repairs. Steve Clunn mentioned something to me
>yesterday about a caution that had been noted regarding the generator
>surging at the end when it's running out of gas. That prompted me to
>check out the download section on the Manzanita website (thank you, Joe
>Smalley). There's a nice application note regarding this setup, and I
>see the caution about the input waveform exceeding 400 volts. I
>wouldn't have the charger connected before starting the generator, so
>this shouldn't typically be a problem, but maybe this is what happens
>in one of those "last gasp" surges. Actually, since I don't have the
generator yet, it may be a deciding factor in which one I get.

I don't have a PFC but I have lots and lots of experience designing and
using generators.

The "dying gasp" is mostly a phenomena of cheap-sh*t generators.
Quality generators, especially those designed for sensitive loads, kill the
output under various conditions including under and over speed conditions.
My Generac QuietPack is an example of that type.
The computer kills the field and thus the output upon under and over-speed
and ignition kill.

I've run into several switchmode devices with active PFC that are rather
pissy about waveform and frequency. When either deviate much from optimum
either the device shuts down or the blue smoke leaks out.
The Schumacher 30 amp 12 volt smart charger (available at Wallyworld), an
otherwise very good charger, forcefully expels its blue smoke when a
distorted sine wave from a cheap-sh*t generator is applied. I had to prove
that to myself by trying it twice :-( I don't know if the PFC fits into
this category but it is something that you need to know before proceeding.

There are some things you can do. The first thing is to verify the waveform
of the candidate generator before buying it. If the generator vendor won't
fuel one up and run it for you, you can still get an idea if you can view
the rotor. If it is a 3600 RPM generator
(2 pole) and the rotor slots are straight (parallel with the shaft) then the
waveform is likely going to be bad. A rotor with "twisted"
slots (looks like someone clamped the rotor in a vice and twisted it
axially) is usually OK. That's the purpose of the twist.

Once the waveform is taken care of (or Rich says a bad one is OK), the next
thing is to prevent the dying gasp. The simplest method is a combo
over/under voltage and frequency relay driving a contactor that opens the
circuit when either voltage or frequency deviates outside the specified
window. These devices are called "relays" for traditional reasons but
they're actually solid state devices, usually with a microprocessor. Both
functions can be had in one box. The cost is moderate. I don't have any
names on the tip of my tongue but I can find some if Google lets you down
:-)

An alternative if you're handy with tools is to supply DC power directly
from the generator without the PFC. All you need is a bridge rectifier of
the suitable rating and an external control of the generator's voltage
regulator/field excitation. This could be as simple as a pot and a
voltmeter in the cockpit or as complex as a smart charger regulator. (One
of his regulators at http://www.amplepower.com/ could be adapted with little
more than a scaling resistor to scale the pack voltage to the expected 12
volts into the regulator.)

One could even add or subtract turns on the stator to move the voltage
around to where it is needed, though for the more common EV voltages, the
standard 120/240 output, varied appropriately with field excitation, will do
the job.

A generator, particularly if the governor is locked down or disabled,
closely resembles the constant current source desired for bulk charging. Or
with the governor it is a stiff constant voltage source within the
governor's authority and the engine's capability.

Even a cheap-sh*t generator can serve this purpose. One capable of 3-phase
output (many single phase generators, particularly 4 pole 1800 rpm version
can be internally connected for 1 or 3 phase operation) would be even
better, as the rectified output is inherently low ripple.

I've built a few of these for customers. I have one for my 72 volt CitiCar
that I built from one of those $149 ChiCom cheap-sh*t 2 stroke generators
like Pep Boys is selling. It's a 1kw unit and when overloaded a little (the
engine runs out of steam before the generator overheats), will do about 15
amps at 72 volts after a minor stator rewind. For under $200 including the
diodes and other stuff, not a bad charger.

John
---
John De Armond
See my website for my current email address http://www.johngsbbq.com
Cleveland, Occupied TN A foolish consistency is the hobgoblin of little
minds.-Ralph Waldo Emerson

Speaking of the MR2 pump, I was testing the S10 truck and came to a
conclusion:

That pump is *LOUD*

Which is odd, since the Prizm has the exact same pump, same setup. Turns
out that the difference is the Prizm has the pump mounted on an
isolation mount with rubber bushings, the truck has it bloted right to
the frame.

I'm going to build an iso-mount for it, that should make it quiet.

As for this guy's post, it sounds like he wants to run the motor off
pack voltage, and not 12 volts. Which makes sense if he doesn't have a
beefy DC-DC, my pump can draw 100 amps @12 volts when cold.

Chris


Grigg. John wrote:
> Why fantasize about and just get the original motor controller, that's
> what I did. Of course I'm assuming your talking about the MR2 electric
> pump. I spent about $100 at the Toyota Junk yard acquiring the MR2 ECU,
> Driver, and wiring harnesses. Reassembled it back together and it works
> great. It was a little tough to get the MR2 steering sensor installed
> on an S10 Blazer but a little plastic mods and it works. This system
> draws very little Amps from the 12V supply when the Steering system is
> not in use or no steering is occurring. But it will Pull close to 80A
> during a hard steer. I have schematics and some pictures if any one
> needs them...

Those specs are really close to the specs on the Generac generator that I was
running at the Power of DC last year. I don't know if you heard it running or
not. But, it is noisy. As a point though, I had the chance last month to run a
similar Colemen alongside my Generac for a few days. The Coleman seemed to be
built better and was quieter, but not much. I would expect Troy-Bilt to be on
par with Coleman.

Note: My Generac is now 9 yrs old, so "new" ones might be more evenly matched
with the Coleman and Troy-Bilt.


Stay Charged!
Hump



Original Message -----------------------


-----Original Message-----
From: owner-ev@... [mailto:owner-ev@...] On
Behalf Of Matthew D. Graham
Sent: Wednesday, March 15, 2006 1:56 PM
To: 'ev@...'
Subject: RE: Range extender on the Nissan

John,

Thanks for all that information. I suspect that the generator I saw at
Costco (Troy-Bilt or Coleman) is probably not one of the best, and I'm sure
it can't be accurately described as "quiet" mainly because it's not one of
the most expensive. It's a 5500 W continuous, 6850 W surge for $550. I had
looked at the quiet Honda EU series before, and they were very expensive and
pretty low on output power (maybe 3kW).

I saw some over/under voltage relays online, including one from K-Tech at
http://www.k-tech.com/Crompton/CromptonPDF/250SeriesTripRelayK.pdf
The AC voltage protection models start on page 3. They have over-, under-
and combo units available.

I see the benefit in providing straight DC to the pack, but I would prefer
to use the generator for providing AC power, since I'd also want to use it
for lighting, the laptop and other accessories at the track.

Matt

-----Original Message-----
From: Neon John [mailto:jgd@...]
Sent: Tuesday, March 14, 2006 4:15 PM
To: ev@...
Subject: Re: Range extender on the Nissan

On Tue, 14 Mar 2006 12:28:48 -0500, "Matthew D. Graham"
<MGraham@...> wrote:

>Hey everyone,
>
>As much as I would love to pull a White Zombie and drive to and from
>the race track, the Joule Injected 240SX just doesn't have the range.
>Moroso is a good 30 miles from me, and that's just begging for
>disaster, pushing the absolute limits of the car. Plus, I'd need to
>bring along a generator for charging between races, and that's just not
going to fit in the hatchback.
>
>I picked up a nice little utility trailer with the idea of loading a
>generator onto it and powering the PFC20 during the ride. I know the
>concept has been discussed before on the list, but searching through
>the archives, I'm afraid I'm going to miss some practical detail
>leading to expensive repairs. Steve Clunn mentioned something to me
>yesterday about a caution that had been noted regarding the generator
>surging at the end when it's running out of gas. That prompted me to
>check out the download section on the Manzanita website (thank you, Joe
>Smalley). There's a nice application note regarding this setup, and I
>see the caution about the input waveform exceeding 400 volts. I
>wouldn't have the charger connected before starting the generator, so
>this shouldn't typically be a problem, but maybe this is what happens
>in one of those "last gasp" surges. Actually, since I don't have the
generator yet, it may be a deciding factor in which one I get.

I don't have a PFC but I have lots and lots of experience designing and
using generators.

The "dying gasp" is mostly a phenomena of cheap-sh*t generators.
Quality generators, especially those designed for sensitive loads, kill the
output under various conditions including under and over speed conditions.
My Generac QuietPack is an example of that type.
The computer kills the field and thus the output upon under and over-speed
and ignition kill.

I've run into several switchmode devices with active PFC that are rather
pissy about waveform and frequency. When either deviate much from optimum
either the device shuts down or the blue smoke leaks out.
The Schumacher 30 amp 12 volt smart charger (available at Wallyworld), an
otherwise very good charger, forcefully expels its blue smoke when a
distorted sine wave from a cheap-sh*t generator is applied. I had to prove
that to myself by trying it twice :-( I don't know if the PFC fits into
this category but it is something that you need to know before proceeding.

There are some things you can do. The first thing is to verify the waveform
of the candidate generator before buying it. If the generator vendor won't
fuel one up and run it for you, you can still get an idea if you can view
the rotor. If it is a 3600 RPM generator
(2 pole) and the rotor slots are straight (parallel with the shaft) then the
waveform is likely going to be bad. A rotor with "twisted"
slots (looks like someone clamped the rotor in a vice and twisted it
axially) is usually OK. That's the purpose of the twist.

Once the waveform is taken care of (or Rich says a bad one is OK), the next
thing is to prevent the dying gasp. The simplest method is a combo
over/under voltage and frequency relay driving a contactor that opens the
circuit when either voltage or frequency deviates outside the specified
window. These devices are called "relays" for traditional reasons but
they're actually solid state devices, usually with a microprocessor. Both
functions can be had in one box. The cost is moderate. I don't have any
names on the tip of my tongue but I can find some if Google lets you down
:-)

An alternative if you're handy with tools is to supply DC power directly
from the generator without the PFC. All you need is a bridge rectifier of
the suitable rating and an external control of the generator's voltage
regulator/field excitation. This could be as simple as a pot and a
voltmeter in the cockpit or as complex as a smart charger regulator. (One
of his regulators at http://www.amplepower.com/ could be adapted with little
more than a scaling resistor to scale the pack voltage to the expected 12
volts into the regulator.)

One could even add or subtract turns on the stator to move the voltage
around to where it is needed, though for the more common EV voltages, the
standard 120/240 output, varied appropriately with field excitation, will do
the job.

A generator, particularly if the governor is locked down or disabled,
closely resembles the constant current source desired for bulk charging. Or
with the governor it is a stiff constant voltage source within the
governor's authority and the engine's capability.

Even a cheap-sh*t generator can serve this purpose. One capable of 3-phase
output (many single phase generators, particularly 4 pole 1800 rpm version
can be internally connected for 1 or 3 phase operation) would be even
better, as the rectified output is inherently low ripple.

I've built a few of these for customers. I have one for my 72 volt CitiCar
that I built from one of those $149 ChiCom cheap-sh*t 2 stroke generators
like Pep Boys is selling. It's a 1kw unit and when overloaded a little (the
engine runs out of steam before the generator overheats), will do about 15
amps at 72 volts after a minor stator rewind. For under $200 including the
diodes and other stuff, not a bad charger.

John
---
John De Armond
See my website for my current email address http://www.johngsbbq.com
Cleveland, Occupied TN A foolish consistency is the hobgoblin of little
minds.-Ralph Waldo Emerson

Hi Mike,

I really like what Alain did on his range extender project and I'm sure we'd
all like to hear more about yours as the bits get put together. He's got a
very nice history of the project, including the EVDL posts that cover this
topic on his own generator page.

Aside from additional AC power at the track, a big reason why I would really
prefer to use the PFC20 is that I can rely on that system to reduce the
possibility of overcharging the pack or individual batteries. I have
regulators on every battery, so I can depend on the PFC20 to discontinue
charging if one of the regs gets too hot. If charging directly from DC, the
regs will work while they can, and then quit bypassing current when they
overheat. This scenario may be somewhat unlikely, but the protective system
is in place, so I'd like to use it.

I suppose I could rig something up to monitor the regbus and shut down the
generator if a regulator starts complaining, but I am really leaning more
towards powering the charger directly.

Thanks,
Matt Graham

-----Original Message-----
From: Mike Chancey [mailto:evtinker@...]
Sent: Wednesday, March 15, 2006 7:31 AM
To: ev@...
Subject: Re: Range extender on the Nissan

Matt, have you seen Alain St-Yves range extender projects?

He has a 5 KW unit on his truck conversion driven by an 11 HP Honda. You
can see it in the Album at http://evalbum.com/122.html

He also has a 5 KW unit in his Cavalier at http://evalbum.com/682.html

He built the truck generator using a 3 phase AC motor, based on guidance
from several members of the EVDL. He has his own page about it at:

http://www.vehiculevert.org/levehiculevert/index.php?lien=generateur

It isn't in the Album, but he built a larger one that he trailers behind his
truck. There is a page about it at:

http://vehiculevert.org/levehiculevert/index.php?lien=baie-james but it is
in French. I emailed him about it and he said:

The 10 kw one is a 15 HP baldor with some 3 x 7 x 50 uf running capacitor at
14 $ each on a 100 amp. 3 phase bridge driven by a Festiva motor at 3300
rpm. Lot of HP spare, could have put another induction generator on it.

All of his generators are based on 3 phase AC motors and output DC so the
whole charger issue is out of the picture. This is the route I would go for
a generator project. (Yes, I have to get off my but and get mine built, got
the bits just ain't done the work.)

Thanks,


Mike Chancey,
'88 Civic EV
Kansas City, Missouri
EV List Photo Album at: http://evalbum.com My Electric Car at:
http://www.geocities.com/electric_honda
Mid-America EAA chapter at: http://maeaa.org Join the EV List at:
http://www.madkatz.com/ev/evlist.html

In medio stat virtus - Virtue is in the moderate, not the extreme position.
(Horace)

Neon John wrote:
> One of the guys on the CitiCar list came up with this cheap 72 volt
> charger. A dumb charger to be sure but at $150, hard to beat.

I would use two 36V Soneil chargers.

Juergen

On Wed, 15 Mar 2006 13:55:39 -0500, "Matthew D. Graham"
<MGraham@...> wrote:

>John,
>
>Thanks for all that information. I suspect that the generator I saw at
>Costco (Troy-Bilt or Coleman) is probably not one of the best, and I'm sure
>it can't be accurately described as "quiet" mainly because it's not one of
>the most expensive. It's a 5500 W continuous, 6850 W surge for $550. I had
>looked at the quiet Honda EU series before, and they were very expensive and
>pretty low on output power (maybe 3kW).

Those are definitely cheap-sh*t generators. I bought a Coleman
several years ago after my house burned to try and save food in
several freezers located in an out-building. It went back after a
day. It was so loud that it drove me bonkers even over the sounds of
salvage operations. And it drunk gas like a wino. I bought a Yamaha
"Trades generator" with an OHV engine that used less than half the
fuel and was quite reasonable sound-wise.

If you're on a budget take a look at the ChiCom generators that PeP
Boys is selling. They're knockoffs of Hondas - Licensed copies
according to someone who talked to a manager at the import company.
The best one according to a review I read is branded something like
Kokam. Memory's fuzzy so go look. Seems like the 5KW unit was priced
under $300. Something like $245 if I recall.

If you have the budget, the Generac QuietPack is the finest small
generator I've ever seen or owned. Here is some info on my website.

http://www.johngsbbq.com/Neon_John_site/Generator/Quiet_pack_55G/Quiet_home.htm

I own one of these and use it for running my concession trailer. Maybe
public events require the use of "whisper gens" which usually involves
a rented large diesel generator on a trailer. I think that may be a
trademark. Mine is quieter. It's the quietest generator I've ever
seen. It makes no sound that resembles an engine sound until fully
loaded. Then just a little bit of intake noise is detectable.

Intended for RV use, it is fully remote controllable which would be
nice for a range extender. Electric start and equipped with a fuel
pump so it can draw from any sort of a tank. It's pricey but IMHO,
worth it.

BTW, the only difference between the three power levels in the line is
the pulley ratio and the output breaker. I can get almost 7KW out of
mine before the governor maxes out and the frequency starts to drop
even without changing the gearing. A set of pulleys and belt costs
about $100 so I can replace them at any time I need more power. The
generator is still loafing along at 7KW according to my thermocouple
gauge.

That guy at Advanced RV that I mention in my review usually has
factory refurbs at about half price. That's what I bought. I could
not tell that it had been used at all. The exhaust pipe was not
discolored and there was only 0.5 hours on the hourmeter.
>
>I saw some over/under voltage relays online, including one from K-Tech at
>http://www.k-tech.com/Crompton/CromptonPDF/250SeriesTripRelayK.pdf
>The AC voltage protection models start on page 3. They have over-, under-
>and combo units available.

That's what I was thinking about. Diversified Electronics (sorry, no
URL handy, I buy them from my local electrical wholesaler) makes a
line of protective relays in over-sized relay cans that fit in Octal
(or more) tube sockets. I really like that format because one can
change the unit by simply unplugging it. I've equipped all my HVAC
units here in the restaurant with O/U voltage, O/U frequency and phase
loss relays for the three phase devices. For things like HVAC fans
that vibrate, they supply little wire bails that hold the relays in
the sockets.

I'm on the high reliability power feed to the Maytag stove factory
across the street. When power does fail, all the motors in the plant
act like generators and back-feed power as they coast down. That
gradually dropping voltage and frequency is hard on refrigeration
compressors. After I lost the first one, I popped for full protection
on all motors. Anyway...

These are reliable little units that will save you a lot of grief from
dying gasps.

>
>I see the benefit in providing straight DC to the pack, but I would prefer
>to use the generator for providing AC power, since I'd also want to use it
>for lighting, the laptop and other accessories at the track.

I understand. Of course you could equip the generator with switches
or relays to switch from DC to AC :-) That would preclude any risk to
that pretty green PFC.

I'm thinking about buying one of those Pep Boys knockoffs and
converting it to DC. If I do I'll put the process on my web site. A
major "feature" of these cheap ChiCom generators is that they don't
dip-and-bake after winding the stator. Thus the stator can easily be
unwound, more windings added, taps added, etc. Disassembling the
thing to get at the stator is more work than actually modifying it.

I'm wanting to put something a little more powerful on my Citi so that
it can be an actual range extender instead of a stop-and-charge-er :-)
It offends my KISS engineering sensibilities to haul around a
generator AND a charger....

John

>
>Matt
>
>-----Original Message-----
>From: Neon John [mailto:jgd@...]
>Sent: Tuesday, March 14, 2006 4:15 PM
>To: ev@...
>Subject: Re: Range extender on the Nissan
>
>On Tue, 14 Mar 2006 12:28:48 -0500, "Matthew D. Graham"
><MGraham@...> wrote:
>
>>Hey everyone,
>>
>>As much as I would love to pull a White Zombie and drive to and from
>>the race track, the Joule Injected 240SX just doesn't have the range.
>>Moroso is a good 30 miles from me, and that's just begging for
>>disaster, pushing the absolute limits of the car. Plus, I'd need to
>>bring along a generator for charging between races, and that's just not
>going to fit in the hatchback.
>>
>>I picked up a nice little utility trailer with the idea of loading a
>>generator onto it and powering the PFC20 during the ride. I know the
>>concept has been discussed before on the list, but searching through
>>the archives, I'm afraid I'm going to miss some practical detail
>>leading to expensive repairs. Steve Clunn mentioned something to me
>>yesterday about a caution that had been noted regarding the generator
>>surging at the end when it's running out of gas. That prompted me to
>>check out the download section on the Manzanita website (thank you, Joe
>>Smalley). There's a nice application note regarding this setup, and I
>>see the caution about the input waveform exceeding 400 volts. I
>>wouldn't have the charger connected before starting the generator, so
>>this shouldn't typically be a problem, but maybe this is what happens
>>in one of those "last gasp" surges. Actually, since I don't have the
>generator yet, it may be a deciding factor in which one I get.
>
>I don't have a PFC but I have lots and lots of experience designing and
>using generators.
>
>The "dying gasp" is mostly a phenomena of cheap-sh*t generators.
>Quality generators, especially those designed for sensitive loads, kill the
>output under various conditions including under and over speed conditions.
>My Generac QuietPack is an example of that type.
>The computer kills the field and thus the output upon under and over-speed
>and ignition kill.
>
>I've run into several switchmode devices with active PFC that are rather
>pissy about waveform and frequency. When either deviate much from optimum
>either the device shuts down or the blue smoke leaks out.
>The Schumacher 30 amp 12 volt smart charger (available at Wallyworld), an
>otherwise very good charger, forcefully expels its blue smoke when a
>distorted sine wave from a cheap-sh*t generator is applied. I had to prove
>that to myself by trying it twice :-( I don't know if the PFC fits into
>this category but it is something that you need to know before proceeding.
>
>There are some things you can do. The first thing is to verify the waveform
>of the candidate generator before buying it. If the generator vendor won't
>fuel one up and run it for you, you can still get an idea if you can view
>the rotor. If it is a 3600 RPM generator
>(2 pole) and the rotor slots are straight (parallel with the shaft) then the
>waveform is likely going to be bad. A rotor with "twisted"
>slots (looks like someone clamped the rotor in a vice and twisted it
>axially) is usually OK. That's the purpose of the twist.
>
>Once the waveform is taken care of (or Rich says a bad one is OK), the next
>thing is to prevent the dying gasp. The simplest method is a combo
>over/under voltage and frequency relay driving a contactor that opens the
>circuit when either voltage or frequency deviates outside the specified
>window. These devices are called "relays" for traditional reasons but
>they're actually solid state devices, usually with a microprocessor. Both
>functions can be had in one box. The cost is moderate. I don't have any
>names on the tip of my tongue but I can find some if Google lets you down
>:-)
>
>An alternative if you're handy with tools is to supply DC power directly
>from the generator without the PFC. All you need is a bridge rectifier of
>the suitable rating and an external control of the generator's voltage
>regulator/field excitation. This could be as simple as a pot and a
>voltmeter in the cockpit or as complex as a smart charger regulator. (One
>of his regulators at http://www.amplepower.com/ could be adapted with little
>more than a scaling resistor to scale the pack voltage to the expected 12
>volts into the regulator.)
>
>One could even add or subtract turns on the stator to move the voltage
>around to where it is needed, though for the more common EV voltages, the
>standard 120/240 output, varied appropriately with field excitation, will do
>the job.
>
>A generator, particularly if the governor is locked down or disabled,
>closely resembles the constant current source desired for bulk charging. Or
>with the governor it is a stiff constant voltage source within the
>governor's authority and the engine's capability.
>
>Even a cheap-sh*t generator can serve this purpose. One capable of 3-phase
>output (many single phase generators, particularly 4 pole 1800 rpm version
>can be internally connected for 1 or 3 phase operation) would be even
>better, as the rectified output is inherently low ripple.
>
>I've built a few of these for customers. I have one for my 72 volt CitiCar
>that I built from one of those $149 ChiCom cheap-sh*t 2 stroke generators
>like Pep Boys is selling. It's a 1kw unit and when overloaded a little (the
>engine runs out of steam before the generator overheats), will do about 15
>amps at 72 volts after a minor stator rewind. For under $200 including the
>diodes and other stuff, not a bad charger.
>
>John
>---
>John De Armond
>See my website for my current email address http://www.johngsbbq.com
>Cleveland, Occupied TN A foolish consistency is the hobgoblin of little
>minds.-Ralph Waldo Emerson
>
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson

Hi Cor,

>I have the impression that the 20 and 80% pictures are swapped.

No, I'm pretty sure they are right.

For the 80% DOD graph, they discharge a cell 80% (for example 80 amp-hrs of
a 100 amp-hr cell). They put a dot in line with 80%. Repeat. This gives a
red horizontal line across at 80%. The 50th cycle is 100% (so the full 100
amp-hrs). They put a green dot at 100% but the connecting line up and down
from/to 80% is red. The vertical red lines between 80% and 100% make it look
like the area between 80% and 100% are the focus when really it is the area
under the red line that matters.

It is more intuitive to me if the graph is flipped over so the 0% discharge
is at the top and 100% is at the bottom.

Cliff
www.ProEV.com

I thought it sounded high also, but it's what US
Battery recomends, from their web page:

Q: How to charge USBMC deep cycle batteries.
A: There are numerous correct ways to charge the
batteries. Typically, charge at C÷10 amperes, (where C
= the 20 hour capacity of the system expressed in
Ampere Hours) until the battery voltage rises to 2.583
Volts per cell (i.e. 7.75 volts for a 6V battery).
Hold this voltage constant for 2 to 4 hours, and stop
charging. A similar method would be to charge at the
following upper limits and terminate the charge when
the time limit is reached:
* Charge Current = C÷10 Amperes
* Charge Voltage = 2.583 Volts per Cell
* Charge Time = 10 Hours Battery temperature
adjustment: reduce the voltage by 0.028 Volts per Cell
for every 10°F above 80°F, increase by the same amount
for temperatures below 80°F.

The charger tapers nicely when the finish voltage
is reached. I'm not sure I'd be able to recognize
excessive gassing. They do bubble a bit towards the
end, but don't seem to be consuming all that much
water. I add maybe 1/2 gallon every 6 to 8 weeks
across the 72 cells. Is this to much? I'm still
learning and hoping I'm not doing too much damage
while I'm at it.
I learned the hard way you don't want ot have a
leak in the panel that covers your PFC-20 during a
heavy rainstorm... that was an expensieve lesson...
Loud bangs from inside your charger when turned on is
never a good thing. So much for this years gas
savings.

TiM

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Tim,

I will assume you have a Cruising Equipment or Xantrex Link 10
Emeter that lets you see how many amp hours you are down when you
begin your charge or how many amp hours you have charged back into
the pack (i.e.: AH goes back to zero) when the charger stops. One
of
the links for this emeter is:
http://www.energyoutfitters.com/products/p_m_electronics/xantrex_link10.shtm

From: http://www.usbattery.com/pages/usbspecs.htm
Reworded for what I derive:
Increase finishing charge voltage by 0.028 Volts per Cell from
2.583VDC for every 10°F below 80°F.

40°F/10°F= 4, 4*.028= .112VDC, .112+2.583= 2.695VDC per cell

With a 144VDC pack of US145's that is 24 batteries of 3 cells each=
72 cells total, 72 cells * 2.695 per cell= 194.04VDC

Your 194VDC finishing voltage is just right for night charging a
40°F pack. But might be too high for charging at work with daytime
temperatures. I suggest you go out at lunch and 'check' your
charger to see if it has shut its self off properly.

If your emeter shows your amp hours are in the positive and it
is 'still' charging, it might be the pack is too warm to reach
194VDC and you are boiling off water unnecessarily.

If you are doing a full charge at work at lower charge currents,
you may want to set your finishing charge voltage to the
temperatures you have when at work.

I have used a PFC-20 before. I am currently using a PFC-30 on my
132VDC US125 pack, but I have experience charging with it on a
132VDC US145 pack. There is a slight difference between the two
packs both in charging and the stiffness or driving performance
(power and range).

I have found that, what current level you are charging at effects
if you reach the set finishing voltage or not. If you use too low
a charge current (ie 6amps or less) with the large capacity
US145 pack, the pack may not reach the 192VDC even if the pack is
at 40°F. If you charge at high current you may reach the finishing
voltage but the pack may not be fully charged (it reached it too
soon/fast).

If you charge with the maximum the charger will output (you
mentioned 30amps for your pack) when at work, it is likely even
though your finishing voltage is set too high for the temperature
of the pack during the day, you will reach 192VDC quickly as the
higher current raises the voltage across the internal resistance
of each battery.

I have experienced this at higher charge currents (from 30 to 150
amps) where the charger had reached its set finishing voltage, but
the pack showed on the emeter to be a few Amp Hours short of a full
charge. You have to set the finishing voltage according to the
pack temperature and the charge current you are using.

...

As a pack ages, its finishing voltage will drop. My method is to
fully charge the pack over night, and the next morning recharge it
again. The charger should charge the pack and reach its finishing
voltage fairly quickly. If the pack never reaches the finishing
voltage for the pack temperature, you know you either have an
aging pack or perhaps a cell is going out.

On a fully charged pack, let the pack rest an hour, and then take
accurate readings of each battery. If you find the voltage
drooping on one battery, you may want to replace it. If they all
read about the same surface voltage, then your pack is just
getting older. Then you have to set your finishing voltage a
little lower so that the charger will go into finishing mode
letting the pack fully recharge. Any higher finishing voltage
and the charger will not go into finishing mode and you just
boil water off.

...

When conditions change (i.e.: the weather gets warmer/colder or
during the regular six month maintenance check I do (tighten the
connections, clean the tops of the batteries, etc.) you ought to
re-check what finishing voltage to set your charger.

Again after a full charge over night, and the charger has been
shut off for a few hours by the time morning comes around, I cycle
the charger and let it charge again.

When the charger goes into finishing mode, I slightly raise the
finishing voltage setting to see if it is at the highest point the
pack wants to be fully charged.

I have found that after the first year, the finishing voltage is
a little lower that the equations on the USBattery faq page for a
new pack. And the pack progressively has a lower finishing voltage
for progressive years afterward.

If you feel you are charging correctly and you smell sulfur or
regularly use more distilled water than usual, plan to buy a new
pack, its dying.

...

In the past when I was out driving all over looking for work, I
would use my EV so much (drive 40 miles, do an opportunity charge
to 80%, then drive home) that I generally got a three year life
out of my pack. Meaning I'd use up all my cycles, getting the most
bang for the buck out of my pack purchase.

But now that I have a job with short 6 mile round trip commute
and a lighter pack (a change from US145's to US125's), it will be
interesting to see the life of this pack verses what I got before
(less driving might be a longer pack life when compared to before).




Bruce {EVangel} Parmenter

' ____
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. http://geocities.com/brucedp/
. EV List Editor, RE & AFV newswires
. (originator of the above ASCII art)
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Hi Ray,



> Does anyone have additional data on how much the cycles are reduced when
> you discharge at 2C to 5C as compared to the 1C during the bench test?
> They have warnings not to exceed 5C but what happens at 4C.

I ask Kokam if they had done any tests and they sent me a graph for a cycle
life (100% DOD) graph with discharge at 3C. It is for a 2 amp-hr cell
(SLPB8043128H) with the new cathode material. The graph only goes to 180
cycles and is showing somewhere about 97% which looks like it pretty much
matches the 1C (100% DOD) graph at that point.

But.... the graphs do not have cross hatching and the lines are fat, so I
could be about 2.5% either way on each graph.

But.... The graphs may match at this point but a lot could happen between
180 cycles and 1,400 cycles.

But.... a 2 amp-hr cell is not a 100 amp-hr cell.

But...the SLPB8043128H is rated for 20C continuous, so it is still loafing
at 3C.

So, additional data but nothing conclusive.

Cliff
www.ProEV.com

>
>
> ProEV <Promo@...> wrote:
> Hi Steve,
>
> I found another copy of the graphs at
> http://www.kokam.com/english/product/kokam_Lipo_01.html that display
> better
> on my computer. After peering at them some more, I think my first method
> of
> extrapolation which comes out with 13,200 shallow (20%) cycles before the
> lithium polymer cells drop to 80% of original capacity does a better job
> of
> matching the data we have.
>
> If you look at the 100% discharge cycle life graph, the slope is flat (the
> cell loses virtually no capacity) for the first 200 cycles and then begins
> it's slope down to 1,400 cycles. For the 80% discharge cycle life graph,
> the
> slope is flat (the cell loses virtually no capacity) for the first 1000
> cycles and then begins to slope down. For the shallow (20% discharge)
> cycle
> life graph, the graph seems to be a slight steady slope from the beginning
> but no sharper drop off.
>
> This means when you compare the number of cycles to 95% of original
> capacity
> rather than the more standard 80% of original capacity, there is less
> advantage to the shallow cycle regime
>
>>> 100% 550 cycles which gives 55,000 amp-hrs
>>> 80% 2,100 cycles which gives 168,000 amp-hrs
>>> 20% 3,300 cycles which gives 66,000 amp-hrs
>
> But if you match the graphs existing slope and extend it to 80% of
> original
> capacity, the shallow discharge is not as good as the 80% discharge but
> twice as good as the 100% discharge.
>
> 100% 1,400 cycles which gives 140,000 amp-hrs
> 80% 6,000 cycles which gives 480,000 amp-hrs
> 20% 13,200 cycles which gives 264,000 amp-hrs
>
> It looks like the 100% discharge cycle life to 1,437 cycles is the only
> complete data. The 80% discharge graph quits at 2,800 cycles and the 20%
> discharge graph quits at 3,300 cycles. It is possible that some other
> process would influence cycle life and the slope of the graph could change
> radically.
>
>> I'm wondering it the low cycle life on the 20% is because of end of
>> charge
>> being hard on the battery
>
> This might be an influence.
>
>>or becuse of just plane old age , as in many years
>
> I would guess they did these tests on a battery cycler that ran
> continuously. So 20% discharge at 1 C takes 20 minutes. Charge 1C than CV,
> probably 30 minutes. Each cycle 50 minutes. 3,300 X 5/6 of an hour = 2,750
> hours or about 115 days. Long enough test that you can see why they did
> not
> test out to 13,200 cycles but not long enough to give us any insight
> into any possible effects of old age.
>
> More info:
>
> The 100% discharge cycle life test 1,437 cycles X 2.33 hours = 3,348 hours
> or 140 days.
> the 80% discharge cycle life test 2,900 cycles X 2 hours = 5,800 hours or
> 242 days.
>
> It is clear why we never know everything about a new type of battery.
> Battery testing requires lots of time and money. Cycle life testing is
> very
> helpful but I would feel more comfortable talking about 13,200 cycles if I
> knew about calendar life. A good test would be to cycle the cell 50 times
> each month for 10 years but who wants to wait ten years? This is why big
> companies are hesitant to use new battery chemistries in their products.
> There might be a hidden 'Gotch'ya' down the line.
>
> We, at ProEV, are really excited about these reformulated Kokam's. They
> still deliver the high amps (5C/10C) and now 1,400 cycles at 100%
> discharge!
> If the cycle life data tests out, their high price is not so unreasonable.
> Time and testing will tell!
>
> Cliff
> www.ProEV.com
>
>

Issue is, 2A is below 2.7A (0.01C) current which is considered "end of
charge" criteria.
So if you drop the charging to 2A, you may never get 270Ah cell really
full, as this criteria is never met. You may not need to really have
100% SOC, this is another story...

Victor

Bill Dennis wrote:
> Super, that's what I was hoping to hear. Now I add clampers to each cell,
> including the 270Ah one. When the first cell reaches 4.25V, I lower the
> current to 2A and keep charging for a while to top off the cells. The only
> difference at this point, I think, is that the 270Ah cell should really have
> 2.7A going through it, but I hope 2A will be okay.
>
> I suppose another possibility would be, before going to the lower current,
> to hook a resistor in parallel with the first cell to burn off .7A, then put
> 2.7A through the string instead of 2A.
>
> Bill Dennis
>
> -----Original Message-----
> From: owner-ev@... [mailto:owner-ev@...] On
> Behalf Of Victor Tikhonov
> Sent: Tuesday, March 14, 2006 3:13 PM
> To: ev@...
> Subject: Re: Different Cell Capacities
>
> Bill Dennis wrote:
>
>>Thanks, Victor. Let me ask the question a second way, just to make sure I
>>understand, because I wasn't suggesting that a BMS isn't needed. I'm just
>>trying to get my thought correct on how cells discharge and charge.
>>
>>Let's say you have two batteries in series, a 200Ah cell, and a 270Ah
>>battery made of three 90Ah cells in parallel. Initially, both are fully
>>charged to 4.25V. You then run some amount of amps through them for a
>
> while
>
>>until the 200Ah cell is at 3V.
>>
>>1) Will the 270Ah cell be at around 3V, or at a higher voltage?
>
>
> At higher voltage - it's not as depleted as 200Ah one.
>
>
>>2) Now you reverse the process and charge them. Will both reach 4.25V at
>>"around" the same time (just like two 200Ah cells in series would), or
>
> will
>
>>one reach 4.25V at some longer time before the other (unlike two 200Ah
>
> cells
>
>>in series)?
>
>
> Yes, it will reach full charge (about 4.25V) at about the same time -
> for a few cycles. Repeated many times, they will diverge from each
> other, and no longer get full at the same time while amount of Ah
> flowing in and out is the same.
>
>
>>Thanks.
>>
>
> Victor
>
>
>
>

--
Best Regards,

Victor Tikhonov
President and CEO
Metric Mind Corporation
http://www.metricmind.com
10645 SE Malden Street
Portland OR 97266-8028 USA
503-680-0026 ph
503-774-4779 fx