EV Digest 6494
Topics covered in this issue include:
1) Re: PFC 20 thermal compensation
by "Rich Rudman" <[EMAIL PROTECTED]>
2) Re: Electric Bike as Cordless Tool
by "martin emde" <[EMAIL PROTECTED]>
3) Re: Connector choices
by <[EMAIL PROTECTED]>
4) Re: Electric Bike as Cordless Tool
by "damon henry" <[EMAIL PROTECTED]>
5) RE: Connector choices
by Don Cameron <[EMAIL PROTECTED]>
6) Re: Nicad update and PFC charger
by Lee Hart <[EMAIL PROTECTED]>
7) Re: EVLN(New ratings reduce MPG numbers)
by Lee Hart <[EMAIL PROTECTED]>
8) Re: EV bashing, RE: T-105 Sitcker Shock
by Lee Hart <[EMAIL PROTECTED]>
9) Re: Zilla for the newbie
by Lee Hart <[EMAIL PROTECTED]>
10) Re: Electric Bike as Cordless Tool
by Tony Hwang <[EMAIL PROTECTED]>
11) Re: EV competition classification question
by Victor Tikhonov <[EMAIL PROTECTED]>
12) Re: Zilla for the newbie
by xx xx <[EMAIL PROTECTED]>
13) Re: Nicad update and PFC charger
by "Mike Phillips" <[EMAIL PROTECTED]>
14) Re: EV competition classification question
by Victor Tikhonov <[EMAIL PROTECTED]>
15) Re: Nicad update
by "Mike Phillips" <[EMAIL PROTECTED]>
16) Toyota pedal /plug in
by "jmygann" <[EMAIL PROTECTED]>
17) Re: Electric Bike as Cordless Tool
by "damon henry" <[EMAIL PROTECTED]>
18) Re: EV competition classification question
by Bill Dube <[EMAIL PROTECTED]>
--- Begin Message ---
Yes the peak voltage setpoint drifts according to the AIR temp on the PCB of
the Regulator.
NOT the heatsink temp.
All MK2 Regs have this feature. Most have no clue it's there.
That is the reason why you want the PFC charger's volt setting to be about 2
to 3 volts above the Sum of the Reg's trip point at 68 Deg F. So the regs
can drift up and down and the Charger's Peak voltage setpoint should stay
very solid over temp and time.
I have my PFC30 set to the exact point the Regs cycle. This can run the
charger for hours on a cold day since the V peak on the regs rises, and they
stop cycling when it's cold out. But this gives a long hold time, that the
charger times out on.
So yes the Regs have temp comp. And it works with the Regbuss also.
I am glad to see somebody besides me uses the Regbuss feature to trap other
potential charge problems. You only get 1/3 the safety protection when using
Regs alone. With the Regbuss hooked up.. Even if you have the voltage
setpoint on the charger really messed up and out of tolerance, No damage
occurs.
With a 120 Deg temp switch across the RT2 port, And properly placed in the
pack, you also have Thermal Runaway protection. For those of you who need
this function.. It's there and has been there for years. It doesn't work
without the Regbuss. Another reason to finish the job of installing Regs on
a pack with PFC charger. You can have a temp cut out sensor on every Reg. I
cut out the charger if any Reg over heats during Equalize and when ever the
RT2 port is pulled above 4.4 volts.
I don't even use this on my Street EVs, but I know I can use it. It will be
part of the BMS of any PHEV system.
How much protection do you Need? For most of you, it's entirely up to you.
I just have the solutions, Should you want to pay for them.
Making a Bullet proof BMS is not cheap or easy to implement. There are many
places that the install can be compromised. Having back up in depth helps.
I have analog and Digital Res, The analog Regs are easier to keep working.
The Digi Regs Mk3s have a LOT more data points, But you need a PC and
software and skills to use them at their fullest extent.
keep in mind that all the advanced CAN buss and local area networked Regs
for the Lion efforts... can fail just as easy as a stack of Old Mark2 regs
if wire gets broken or is compromised. All this stuff has to work and be
checked, or else you have a false sense of security.
Rich Rudman
[EMAIL PROTECTED]
Manzanita Micro
360-297-7383,
Cell 360-620-6266
Production shop 360-297-1660
----- Original Message -----
From: "Jeff Shanab" <[EMAIL PROTECTED]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Thursday, March 01, 2007 5:32 AM
Subject: Re: PFC 20 thermal compensation
> Ralph : Rudmen regs. Of course I have a regbus and of course it is
> connected, It is a fire hazard not to! regs are useless without the
> regbus connected to the charger.
>
> I don't know what you mean by "charger set to taper", It doesn't do
> that, it never has. It sharply cuts back on the amps. When all the regs
> are flashing I go turn down the current knob so they flash slowly and I
> get some equilizing amps without flickering the lights in the house. I
> understand this is "normal" for the series regs I have with the series
> charger I have.
>
> with "tell the charger to back off as each battery comes up to voltage
for their present temperature"
>
>
> It sounds like you are saying the regs have thermal compensation. As
> long as you are not talking about the temp sensing of the heatsink. What
> I want to know is if the AIR temp is 50degrees does the regulator change
> the voltage at which point it begins to bypass? (what are these values
> anyway)
>
>
>
> (I apologize to all if I am asking or answering questions already done,
> We had a nasty power outage and I am behind on my email)
>
--- End Message ---
--- Begin Message ---
Mick,
I too am looking to supe-up my EV Bike (http://www.austinev.org/evalbum/948).
I'm currently lugging 2 12V AGM @ 27 lbs each. The batteries are rated at
roughly 30 Ahr (C20 I believe). The total weight of the bike is 105 lbs,
half of that due to the heavy lead-acid batteries. I like the power density
of the power tool lithiums and am considering an upgrade in the future.
Perhaps 6 DeWalt DC9360 36V packs in parallel. I'd like not to have to
remove the batteries for charging. So, I'm wondering if I could use the
dewalt charger to charge more than one pack at a time. I'd like to take
advantage of the BMS features of the battery-charger combo. Of course I
would not modify the batteries in any way as to void the warranty (somehow
integrate plug-in receptacles on the bike). If I were to simply connect the
charger to two packs in parallel what would the charger do? What about
trying to charge 6 packs with a single charger? Anyone ever done anything
like this before? Thanks.
Martin
On 3/1/07, Mick Abraham <[EMAIL PROTECTED]> wrote:
My electric assist bike (Charger brand) has over 2,000 miles on
it.
I've been through lead-acid, nickel-zinc, and nickel metal hydride
batteries: all unbalanced and all less than ideal. Just the cost of
batteries and chargers so far amortizes out to about 25 cents per mile of
travel.
I empathize with the "battery woes" expressed on the EVDL, but my
experiments have only cost hundred$ instead of thousand$. (Why do I
persist
with this hobby? My wife would like the answer to that same question. On
early season rides when I'm out of shape, the EV <Grin> is more of an EV
<Grimace>. But I digress.)
To my mind, the electric assist bike is like a cordless power tool
which doesn't replace work but extends my own work effort. Now I'm ready
to
fully embrace that concept. For 2007, I'm using Milwaukee lithium ion
packs
from the V28 cordless tool line.
At last the batteries and the charger come from the same company,
with single source accountability. The V28 packs record the date of first
charge and they also count the number of recharges. Service centers can
read
that data for warranty purposes. There actually is a warranty, too: full
for
2 years or 1,000 charges, then pro-rated for another 3 years/1,000
charges.
The V28 batteries have a built in "performance optimizing circuit
which maintains cell balance". Now we're talking! I'm determined to not
butcher up the battery packs but leave them stock so I won't destroy my
warranty chances and so I can clip the same batteries onto some amped up
cordless tools someday.
I've had to modify the bike of course, mainly to allow the
batteries
to be removed for charging. Putting batteries in a part of the bike where
they can't be quickly removed is a questionable decision in any case,
because most unbalanced batteries behave so badly that they must be
accessed
often. I hope I never have to unscrew the cover for my main Charger
control
box ever again because of battery hassles. The screws are all worn out.
From lurking on the EVDL I learned how to build a pre-charge
resistor circuit so I won't have a spark every time I connect a battery to
the discharged capacitors in the bike controller. (Thanks, EVDL crew.)
I've only got one battery at present, but two more on the way. The
bike actually runs fine off a single 3 amp hour V-28 pack. That's pretty
amazing, but only for about 15 minutes. I'll parallel the three packs for
a
total of 9 amp-hours. I plan to use Schottky diodes so one pack can't
backfeed energy into another pack of slightly lower voltage. The diodes
may
be overkill, but I'd like to not mess anything up...not this time.
The easy access battery box I built resides on the rack behind the
seat, so this put the battery weight higher than I would like. Battery
weight is fairly low, however.
With the money I've now spent on the Milwaukee parts, I'll need to
crank for another 1,400 miles to maintain my 25 cent per mile cost for
batteries etc. I'd better get pedaling or (as my wife suggests) I'd better
stop thinking that way. When the bike is dormant (such as winter/mud
season)
I can still use my batteries on the new Milwaukee tools that I now am
required to buy in order to use the batteries that way. That helps me
justify the cost, doesn't it? Ah, America!
Seriously, though the experience of riding on a bionic bike is
very
satisfying to me, a good way to get exercise, and a handy way to make
short
errand runs. I've saved a few gallons of gasoline, and this hobby is also
educational for me. My Charger & I are longtime friends. Since it's a 24
volt bike that's part of why I went with the Milwaukee packs. Those with
hotter bikes that run on 36 volts might prefer the DeWalt or Bosch system.
If I can EVer get past battery problems with my bike there are
other
things I need to work on such as performance enhancements. Hmm...I wonder
if
one of those Milwaukee 28 volt saw motors might fit?
Mick Abraham
www.abrahamsolar.com
--- End Message ---
--- Begin Message ---
I see lots of types of connectors for use in various EV applications like
Molex, Anderson, Deutsch etc for high and low voltage connectors and
harnesses etc. Is there a streamlined way to figure out the best for each
application?
Those with experience with these connectors, can you please share your
wisdom, thanks
JJ
--- End Message ---
--- Begin Message ---
I think the best solution is to buy a second charger. I don't believe you
will be happy with the results of trying to charge two packs in parallel.
As I recall the chargers are supposed to be 1 hour chargers, so 2 chargers
could charge your 6 batteries in 3 hours, provided you are there to change
out the full ones.
damon
From: "martin emde" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: Electric Bike as Cordless Tool
Date: Thu, 1 Mar 2007 10:34:36 -1000
Mick,
I too am looking to supe-up my EV Bike
(http://www.austinev.org/evalbum/948).
I'm currently lugging 2 12V AGM @ 27 lbs each. The batteries are rated at
roughly 30 Ahr (C20 I believe). The total weight of the bike is 105 lbs,
half of that due to the heavy lead-acid batteries. I like the power
density
of the power tool lithiums and am considering an upgrade in the future.
Perhaps 6 DeWalt DC9360 36V packs in parallel. I'd like not to have to
remove the batteries for charging. So, I'm wondering if I could use the
dewalt charger to charge more than one pack at a time. I'd like to take
advantage of the BMS features of the battery-charger combo. Of course I
would not modify the batteries in any way as to void the warranty (somehow
integrate plug-in receptacles on the bike). If I were to simply connect the
charger to two packs in parallel what would the charger do? What about
trying to charge 6 packs with a single charger? Anyone ever done anything
like this before? Thanks.
Martin
On 3/1/07, Mick Abraham <[EMAIL PROTECTED]> wrote:
My electric assist bike (Charger brand) has over 2,000 miles on
it.
I've been through lead-acid, nickel-zinc, and nickel metal hydride
batteries: all unbalanced and all less than ideal. Just the cost of
batteries and chargers so far amortizes out to about 25 cents per mile of
travel.
I empathize with the "battery woes" expressed on the EVDL, but my
experiments have only cost hundred$ instead of thousand$. (Why do I
persist
with this hobby? My wife would like the answer to that same question. On
early season rides when I'm out of shape, the EV <Grin> is more of an EV
<Grimace>. But I digress.)
To my mind, the electric assist bike is like a cordless power
tool
which doesn't replace work but extends my own work effort. Now I'm ready
to
fully embrace that concept. For 2007, I'm using Milwaukee lithium ion
packs
from the V28 cordless tool line.
At last the batteries and the charger come from the same company,
with single source accountability. The V28 packs record the date of first
charge and they also count the number of recharges. Service centers can
read
that data for warranty purposes. There actually is a warranty, too: full
for
2 years or 1,000 charges, then pro-rated for another 3 years/1,000
charges.
The V28 batteries have a built in "performance optimizing circuit
which maintains cell balance". Now we're talking! I'm determined to not
butcher up the battery packs but leave them stock so I won't destroy my
warranty chances and so I can clip the same batteries onto some amped up
cordless tools someday.
I've had to modify the bike of course, mainly to allow the
batteries
to be removed for charging. Putting batteries in a part of the bike where
they can't be quickly removed is a questionable decision in any case,
because most unbalanced batteries behave so badly that they must be
accessed
often. I hope I never have to unscrew the cover for my main Charger
control
box ever again because of battery hassles. The screws are all worn out.
From lurking on the EVDL I learned how to build a pre-charge
resistor circuit so I won't have a spark every time I connect a battery to
the discharged capacitors in the bike controller. (Thanks, EVDL crew.)
I've only got one battery at present, but two more on the way.
The
bike actually runs fine off a single 3 amp hour V-28 pack. That's pretty
amazing, but only for about 15 minutes. I'll parallel the three packs for
a
total of 9 amp-hours. I plan to use Schottky diodes so one pack can't
backfeed energy into another pack of slightly lower voltage. The diodes
may
be overkill, but I'd like to not mess anything up...not this time.
The easy access battery box I built resides on the rack behind
the
seat, so this put the battery weight higher than I would like. Battery
weight is fairly low, however.
With the money I've now spent on the Milwaukee parts, I'll need
to
crank for another 1,400 miles to maintain my 25 cent per mile cost for
batteries etc. I'd better get pedaling or (as my wife suggests) I'd better
stop thinking that way. When the bike is dormant (such as winter/mud
season)
I can still use my batteries on the new Milwaukee tools that I now am
required to buy in order to use the batteries that way. That helps me
justify the cost, doesn't it? Ah, America!
Seriously, though the experience of riding on a bionic bike is
very
satisfying to me, a good way to get exercise, and a handy way to make
short
errand runs. I've saved a few gallons of gasoline, and this hobby is also
educational for me. My Charger & I are longtime friends. Since it's a 24
volt bike that's part of why I went with the Milwaukee packs. Those with
hotter bikes that run on 36 volts might prefer the DeWalt or Bosch system.
If I can EVer get past battery problems with my bike there are
other
things I need to work on such as performance enhancements. Hmm...I wonder
if
one of those Milwaukee 28 volt saw motors might fit?
Mick Abraham
www.abrahamsolar.com
_________________________________________________________________
Find a local pizza place, movie theater, and more
.then map the best route!
http://maps.live.com/?icid=hmtag1&FORM=MGAC01
--- End Message ---
--- Begin Message ---
Of course, it depends...
- voltage rating
- current rating
- weatherproof requirements
People use Anderson for the high voltage/high amperage connections.
For me, I like the low voltage connectors from waytek wire. OEM quality and
weather proof. Reasonable price.
Don Cameron, Victoria, BC, Canada
---------------------------------------------------
See the New Beetle EV project www.cameronsoftware.com/ev
Check the EVDL Archives: http://autos.groups.yahoo.com/group/ev-list-archive
Check out the EV FAQ: www.evparts.com/faq
Check out the EV Photo Album: www.evalbum.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of [EMAIL PROTECTED]
Sent: March 1, 2007 12:46 PM
To: [email protected]
Subject: Re: Connector choices
I see lots of types of connectors for use in various EV applications like
Molex, Anderson, Deutsch etc for high and low voltage connectors and
harnesses etc. Is there a streamlined way to figure out the best for each
application?
Those with experience with these connectors, can you please share your
wisdom, thanks JJ
--- End Message ---
--- Begin Message ---
I'm not sure why you say that voltage is a bad indicator. Nicads have
a very pronounced knee. Many nicad chargers depend on that knee.
Peter VanDerWal wrote:
When you have 200+ cells in series, that don't ALL hit the knee at the
same time, it might get a bit obscured. I.e how do you see one cell knee
over when 199+ other cells are still climbing?
You're correct. The knee gets less visible as the number of cells
increases. It isn't very reliable for over 20 or so cells.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Martin Klingensmith wrote:
If only this were realistic - how many people in your family would
you trust to convert - or even drive properly - an electric vehicle
conversion like most people here have? They have to be fool proof.
Well, my 10 year old BEST kids build and convert and drive their own
EVs. I trust them with EVs *more* than I would with ICEs!
Everyone's standards are different. Teenagers put up with horrible
pieces of s**t for their first cars, because it's all they know, and
it's preferable to walking, bicycling, or bumming rides with friends or
(gasp!) mom or dad.
So EVs don't have to be foolproof; they just have to up to the
particular driver's standards.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Lee Hart replied:
Scratch built cars can be as safe, or even safer than
conventional cars.
Mark Brueggemann wrote:
Agreed. But, my comparison was to the EWoody, not a
race car with a roll cage.
Well, Jerry's EWoody is a special case. It's not a car; it's a
3-wheeler. He only built it as experimental prototype; not something to
sell.
> When the EWoody passes a crash test, I'll be a believer.
He did do some informal crash-testing on it. Another driver hit him from
the rear, probably totalling his car in the process. Jerry was
uninjured, and the EWoody only sustained minor damage; he drove it home.
I've seen his Freedom EV, and must say it is pretty strongly made. I
don't know if it would pass official DOT/NHTSA crash tests or not, but
it has a pretty good chance.
Think about how you would sell that idea to the general public.
"You'll save hundreds of dollars on gas every year, but your odds
of getting injured or killed in it are pretty high".
That would not be an accurate statement. You would say "has not been
crash tested", but then describe whatever safety features have been
provided. If it hasn't been crash tested, you can't predict the odds of
injury.
You're not going to get the majority of people interested in EV's
until they are nearly form, fit and function to ICE.
True; but that doesn't matter, because we are *decades* away from having
enough EVs to even offer them to a "majority" of drivers. EV
manufacturers today only have to make them appeal to a small percentage
of the market; that's still millions of potential customers.
And, sorry to say, a very large part of the market just doesn't care
about safety. They are perfectly happy riding motorcycles, old cars, and
other vehicles that are far less safe.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Roland Wiench wrote:
Transformers and some capacitors use oil, but most of these are
formulated as a dielectric as well some cooling in the transformer.
The oils in a vehicle that may be rated for higher temperature
than a at 46/54% water to antifreeze ratio, but has a lower heat
transfer than antifreeze, even its mix at 30/70% for 270 degree
rating.
Also you would have to add a double oil filter system, to remove
the metal particles and some carbon.
Roland, your comments are correct if the electrical parts are *directly*
immersed in the oil. But in the Zilla, the coolant never touches the
electrical parts; it merely circulates through passages in the
heatsinks. That's why even water (which is conductive) can be used as
the coolant.
Since oil moves less heat than water, we need a higher flow rate to move
an equivalent amount of heat. But, the flow rate is still low enough not
to present problems.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Would it be possible to use two chargers in parallel to charge two batteries in
parallel? Just something I'm wondering, I know if you had two chargers, and two
batteries, you'd want to use one charger per battery, of course. :)
- Tony
----- Original Message ----
From: damon henry <[EMAIL PROTECTED]>
To: [email protected]
Sent: Thursday, March 1, 2007 1:33:56 PM
Subject: Re: Electric Bike as Cordless Tool
I think the best solution is to buy a second charger. I don't believe you
will be happy with the results of trying to charge two packs in parallel.
As I recall the chargers are supposed to be 1 hour chargers, so 2 chargers
could charge your 6 batteries in 3 hours, provided you are there to change
out the full ones.
damon
>From: "martin emde" <[EMAIL PROTECTED]>
>Reply-To: [email protected]
>To: [email protected]
>Subject: Re: Electric Bike as Cordless Tool
>Date: Thu, 1 Mar 2007 10:34:36 -1000
>
>Mick,
>
>I too am looking to supe-up my EV Bike
>(http://www.austinev.org/evalbum/948).
>I'm currently lugging 2 12V AGM @ 27 lbs each. The batteries are rated at
>roughly 30 Ahr (C20 I believe). The total weight of the bike is 105 lbs,
>half of that due to the heavy lead-acid batteries. I like the power
>density
>of the power tool lithiums and am considering an upgrade in the future.
>Perhaps 6 DeWalt DC9360 36V packs in parallel. I'd like not to have to
>remove the batteries for charging. So, I'm wondering if I could use the
>dewalt charger to charge more than one pack at a time. I'd like to take
>advantage of the BMS features of the battery-charger combo. Of course I
>would not modify the batteries in any way as to void the warranty (somehow
>integrate plug-in receptacles on the bike). If I were to simply connect the
>charger to two packs in parallel what would the charger do? What about
>trying to charge 6 packs with a single charger? Anyone ever done anything
>like this before? Thanks.
>
>Martin
>
>On 3/1/07, Mick Abraham <[EMAIL PROTECTED]> wrote:
>>
>> My electric assist bike (Charger brand) has over 2,000 miles on
>>it.
>>I've been through lead-acid, nickel-zinc, and nickel metal hydride
>>batteries: all unbalanced and all less than ideal. Just the cost of
>>batteries and chargers so far amortizes out to about 25 cents per mile of
>>travel.
>>
>> I empathize with the "battery woes" expressed on the EVDL, but my
>>experiments have only cost hundred$ instead of thousand$. (Why do I
>>persist
>>with this hobby? My wife would like the answer to that same question. On
>>early season rides when I'm out of shape, the EV <Grin> is more of an EV
>><Grimace>. But I digress.)
>>
>> To my mind, the electric assist bike is like a cordless power
>>tool
>>which doesn't replace work but extends my own work effort. Now I'm ready
>>to
>>fully embrace that concept. For 2007, I'm using Milwaukee lithium ion
>>packs
>>from the V28 cordless tool line.
>>
>> At last the batteries and the charger come from the same company,
>>with single source accountability. The V28 packs record the date of first
>>charge and they also count the number of recharges. Service centers can
>>read
>>that data for warranty purposes. There actually is a warranty, too: full
>>for
>>2 years or 1,000 charges, then pro-rated for another 3 years/1,000
>>charges.
>>
>> The V28 batteries have a built in "performance optimizing circuit
>>which maintains cell balance". Now we're talking! I'm determined to not
>>butcher up the battery packs but leave them stock so I won't destroy my
>>warranty chances and so I can clip the same batteries onto some amped up
>>cordless tools someday.
>>
>> I've had to modify the bike of course, mainly to allow the
>>batteries
>>to be removed for charging. Putting batteries in a part of the bike where
>>they can't be quickly removed is a questionable decision in any case,
>>because most unbalanced batteries behave so badly that they must be
>>accessed
>>often. I hope I never have to unscrew the cover for my main Charger
>>control
>>box ever again because of battery hassles. The screws are all worn out.
>>
>> From lurking on the EVDL I learned how to build a pre-charge
>>resistor circuit so I won't have a spark every time I connect a battery to
>>the discharged capacitors in the bike controller. (Thanks, EVDL crew.)
>>
>> I've only got one battery at present, but two more on the way.
>>The
>>bike actually runs fine off a single 3 amp hour V-28 pack. That's pretty
>>amazing, but only for about 15 minutes. I'll parallel the three packs for
>>a
>>total of 9 amp-hours. I plan to use Schottky diodes so one pack can't
>>backfeed energy into another pack of slightly lower voltage. The diodes
>>may
>>be overkill, but I'd like to not mess anything up...not this time.
>>
>> The easy access battery box I built resides on the rack behind
>>the
>>seat, so this put the battery weight higher than I would like. Battery
>>weight is fairly low, however.
>>
>> With the money I've now spent on the Milwaukee parts, I'll need
>>to
>>crank for another 1,400 miles to maintain my 25 cent per mile cost for
>>batteries etc. I'd better get pedaling or (as my wife suggests) I'd better
>>stop thinking that way. When the bike is dormant (such as winter/mud
>>season)
>>I can still use my batteries on the new Milwaukee tools that I now am
>>required to buy in order to use the batteries that way. That helps me
>>justify the cost, doesn't it? Ah, America!
>>
>> Seriously, though the experience of riding on a bionic bike is
>>very
>>satisfying to me, a good way to get exercise, and a handy way to make
>>short
>>errand runs. I've saved a few gallons of gasoline, and this hobby is also
>>educational for me. My Charger & I are longtime friends. Since it's a 24
>>volt bike that's part of why I went with the Milwaukee packs. Those with
>>hotter bikes that run on 36 volts might prefer the DeWalt or Bosch system.
>>
>> If I can EVer get past battery problems with my bike there are
>>other
>>things I need to work on such as performance enhancements. Hmm...I wonder
>>if
>>one of those Milwaukee 28 volt saw motors might fit?
>>
>>Mick Abraham
>>www.abrahamsolar.com
>>
>>
>>
>>
>
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Bill Dube wrote:
I can comment on the "historical" perspective on voltage divisions, but
the present NEDRA tech director, Ken Koch, would be the person that
would have to make any official ruling.
Thanks, I'll ask Ken then.
Also, Victor never actually races anything, so this is just an
intellectual exercise. :-)
I haven't, this doesn't mean I won't, does it?.
Actually I attempted once on PIR but was disqualified
because my battery box had detached cover, not attached one.
It is an interesting approach.
You would have to have some way to show that the caps are really at zero
volts before you go on the track, I would think. (See below, "Why folks
don't do this")
The way to do it is to connect a voltmeter to the cap. pack :-)
>>> Why the rules are set up like this <<<
It all becomes a matter of fair and simple inspection, if you think
about it. You can inspect the batteries (or energy storage system) with
a voltmeter (and follow the wiring with your eyes) and know how to
classify the car. Once you are inside the electronics, there is no way
for the inspector to know what the voltage will become. If you were to
attempt to regulate the peak voltage inside the electronics system,
folks would figure a way to make it appear that the voltage was less
than it really was on the track. Then only cheaters would win. It is
best to not attempt to regulate something you cannot fairly and easily
inspect.
I'm not proposing to cheat, Bill. I'm asking if the voltage applied to
the drive system counts. With proposed above configuration you inspect
the vehicle and measure discharged cap bank voltage which is at zero.
*Then* a DC-DC converter is allowed to charge the pack from existing
battery before running, and this is verifiable, demonstratable and told
ahead of time to inspectors, not being hided. My question is how this
vehicle is
classified. Sounds like after flipping DC-DC switch vehicle
transitions to a different class, since caps as "energy storage" have
some voltage on them now. Such classification would make little sense
while it is easily verifiable.
>>> Why folks don't do this all the time <<<
What you are forgetting is that the DC-DC converter (or creative
uncharged capacitor bank) needed to boost the voltage will have weight
and will be expensive. If you do the engineering analysis, you will
likely discover that it will be cheaper to take the high-voltage record
with a high-voltage battery pack than it will be to take the low-voltage
record with the DC-DC converter. The weight and efficiency penalty of
the DC-DC converter will likely make it more difficult to take a record
from a well-designed low-voltage car.
Are you guessing or you have done this engineering analysis?
I haven't done it so I'm not as sure about outcome.
You might be right.
You will be going a lot faster if you spend the money taking the
high-voltage record instead of spending it to take the low-voltage
record. It is more fun to go faster. :-)
Sure, but don't forget, you will be running just as fast with, say,
pure 300V as at 30V DC-DC'ed 10x up. I do realize with 300V pack
it's just a pack weight and cost and with 30V one other than the same
amount of batteries you add expensive DC-DC but my question was not
if it worth doing. My only question was such vehicle would be
classified.
A transmission serves much the same function as the DC-DC converter you
are proposing, by the way.
In theory, but not quite in practice. This is another broad
topic though.
Thanks Bill for your opinion!
Victor
--
'91 ACRX - something different
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A thought I had on cooling: You can use a large
enough heat exchanger that you would not need a fan,
saving power and weight, but then you'd need to pump
more fluid, which would require more energy as well as
carry around that extra fluid. In the end, would it
all equal out energy wise? Smaller heat exchanger
with fan = larger heat exchanger and no fan?
John
____________________________________________________________________________________
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--- Begin Message ---
Jerry,
Have you have problems with liquid nicad cells not peaking at the same
time?
Mike
>
> It might work as long as they all knee together but
> if the don't, the charger might never turn off or detect the
> knee.
>
> >
> >>
> >> That's probably not a good idea. While it may work
> >> as long as the batts are in balance, if they get out it
> >> will get nasty and never shut off.
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Clear and concise. Thank you.
Victor
[EMAIL PROTECTED] wrote:
HI-
After I reread my reply to Victor's message I realized that I had not
answered
his question.The voltage is measured as it leaves the battery pack. Usually
the
rough rule of thumb for lead acid is nominal pack V. 13/12=~ measured V.
The nominal voltage is used to determine voltage class.FT.
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These cells at least have held a tight bandwidth. I have checked them
several times at full charge and other states of charge. They hang
very close to each other. There is a difference between the redtops
and the greentops however. But above say 40% soc or higher the redtops
don't seem to get too low on voltage.
Besides, isn't looking for a knee with cells in parallel alot harder
than cells in series? Series would tend to multiply the effect of the
knee.
Mike
--- In [EMAIL PROTECTED], Lee Hart <[EMAIL PROTECTED]> wrote:
>
> >> I'm not sure why you say that voltage is a bad indicator. Nicads have
> >> a very pronounced knee. Many nicad chargers depend on that knee.
>
> Peter VanDerWal wrote:
> > When you have 200+ cells in series, that don't ALL hit the knee at the
> > same time, it might get a bit obscured. I.e how do you see one
cell knee
> > over when 199+ other cells are still climbing?
>
> You're correct. The knee gets less visible as the number of cells
> increases. It isn't very reliable for over 20 or so cells.
> --
> Ring the bells that still can ring
> Forget the perfect offering
> There is a crack in everything
> That's how the light gets in -- Leonard Cohen
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
>
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http://tinyurl.com/23xenu
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If you are dealing with any kind of smart charger, no you can not leave
things in parallel as you will most likely confuse the smarts.
With these newer tool packs were they seem to have built in a lot of
features to keep the batteries healthy I would have a tough time convincing
myself to use anything but the OEM charger, particularly when there is a
warranty involved. Then again I would have a hard time spending $1000 for a
13 ahr battery pack for an electric bike, but I suppose if you are using the
bike as a primary source of transportation it is much easier to swallow.
Also since one of these packs can supply enough current for an ebike, there
really is no reason to wire them in parallel. A system that easily lets you
switch from a dying battery to a fresh one achieves the same result.
damon
From: Tony Hwang <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: Electric Bike as Cordless Tool
Date: Thu, 1 Mar 2007 14:10:51 -0800 (PST)
Would it be possible to use two chargers in parallel to charge two
batteries in parallel? Just something I'm wondering, I know if you had two
chargers, and two batteries, you'd want to use one charger per battery, of
course. :)
- Tony
----- Original Message ----
From: damon henry <[EMAIL PROTECTED]>
To: [email protected]
Sent: Thursday, March 1, 2007 1:33:56 PM
Subject: Re: Electric Bike as Cordless Tool
I think the best solution is to buy a second charger. I don't believe you
will be happy with the results of trying to charge two packs in parallel.
As I recall the chargers are supposed to be 1 hour chargers, so 2 chargers
could charge your 6 batteries in 3 hours, provided you are there to change
out the full ones.
damon
>From: "martin emde" <[EMAIL PROTECTED]>
>Reply-To: [email protected]
>To: [email protected]
>Subject: Re: Electric Bike as Cordless Tool
>Date: Thu, 1 Mar 2007 10:34:36 -1000
>
>Mick,
>
>I too am looking to supe-up my EV Bike
>(http://www.austinev.org/evalbum/948).
>I'm currently lugging 2 12V AGM @ 27 lbs each. The batteries are rated
at
>roughly 30 Ahr (C20 I believe). The total weight of the bike is 105 lbs,
>half of that due to the heavy lead-acid batteries. I like the power
>density
>of the power tool lithiums and am considering an upgrade in the future.
>Perhaps 6 DeWalt DC9360 36V packs in parallel. I'd like not to have to
>remove the batteries for charging. So, I'm wondering if I could use the
>dewalt charger to charge more than one pack at a time. I'd like to take
>advantage of the BMS features of the battery-charger combo. Of course I
>would not modify the batteries in any way as to void the warranty
(somehow
>integrate plug-in receptacles on the bike). If I were to simply connect
the
>charger to two packs in parallel what would the charger do? What about
>trying to charge 6 packs with a single charger? Anyone ever done
anything
>like this before? Thanks.
>
>Martin
>
>On 3/1/07, Mick Abraham <[EMAIL PROTECTED]> wrote:
>>
>> My electric assist bike (Charger brand) has over 2,000 miles on
>>it.
>>I've been through lead-acid, nickel-zinc, and nickel metal hydride
>>batteries: all unbalanced and all less than ideal. Just the cost of
>>batteries and chargers so far amortizes out to about 25 cents per mile
of
>>travel.
>>
>> I empathize with the "battery woes" expressed on the EVDL, but
my
>>experiments have only cost hundred$ instead of thousand$. (Why do I
>>persist
>>with this hobby? My wife would like the answer to that same question. On
>>early season rides when I'm out of shape, the EV <Grin> is more of an EV
>><Grimace>. But I digress.)
>>
>> To my mind, the electric assist bike is like a cordless power
>>tool
>>which doesn't replace work but extends my own work effort. Now I'm ready
>>to
>>fully embrace that concept. For 2007, I'm using Milwaukee lithium ion
>>packs
>>from the V28 cordless tool line.
>>
>> At last the batteries and the charger come from the same
company,
>>with single source accountability. The V28 packs record the date of
first
>>charge and they also count the number of recharges. Service centers can
>>read
>>that data for warranty purposes. There actually is a warranty, too: full
>>for
>>2 years or 1,000 charges, then pro-rated for another 3 years/1,000
>>charges.
>>
>> The V28 batteries have a built in "performance optimizing
circuit
>>which maintains cell balance". Now we're talking! I'm determined to not
>>butcher up the battery packs but leave them stock so I won't destroy my
>>warranty chances and so I can clip the same batteries onto some amped up
>>cordless tools someday.
>>
>> I've had to modify the bike of course, mainly to allow the
>>batteries
>>to be removed for charging. Putting batteries in a part of the bike
where
>>they can't be quickly removed is a questionable decision in any case,
>>because most unbalanced batteries behave so badly that they must be
>>accessed
>>often. I hope I never have to unscrew the cover for my main Charger
>>control
>>box ever again because of battery hassles. The screws are all worn out.
>>
>> From lurking on the EVDL I learned how to build a pre-charge
>>resistor circuit so I won't have a spark every time I connect a battery
to
>>the discharged capacitors in the bike controller. (Thanks, EVDL crew.)
>>
>> I've only got one battery at present, but two more on the way.
>>The
>>bike actually runs fine off a single 3 amp hour V-28 pack. That's pretty
>>amazing, but only for about 15 minutes. I'll parallel the three packs
for
>>a
>>total of 9 amp-hours. I plan to use Schottky diodes so one pack can't
>>backfeed energy into another pack of slightly lower voltage. The diodes
>>may
>>be overkill, but I'd like to not mess anything up...not this time.
>>
>> The easy access battery box I built resides on the rack behind
>>the
>>seat, so this put the battery weight higher than I would like. Battery
>>weight is fairly low, however.
>>
>> With the money I've now spent on the Milwaukee parts, I'll need
>>to
>>crank for another 1,400 miles to maintain my 25 cent per mile cost for
>>batteries etc. I'd better get pedaling or (as my wife suggests) I'd
better
>>stop thinking that way. When the bike is dormant (such as winter/mud
>>season)
>>I can still use my batteries on the new Milwaukee tools that I now am
>>required to buy in order to use the batteries that way. That helps me
>>justify the cost, doesn't it? Ah, America!
>>
>> Seriously, though the experience of riding on a bionic bike is
>>very
>>satisfying to me, a good way to get exercise, and a handy way to make
>>short
>>errand runs. I've saved a few gallons of gasoline, and this hobby is
also
>>educational for me. My Charger & I are longtime friends. Since it's a 24
>>volt bike that's part of why I went with the Milwaukee packs. Those with
>>hotter bikes that run on 36 volts might prefer the DeWalt or Bosch
system.
>>
>> If I can EVer get past battery problems with my bike there are
>>other
>>things I need to work on such as performance enhancements. Hmm...I
wonder
>>if
>>one of those Milwaukee 28 volt saw motors might fit?
>>
>>Mick Abraham
>>www.abrahamsolar.com
>>
>>
>>
>>
>
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--- Begin Message ---
The real question is - What would you have accomplished by doing this?
It would take some serious money to do it. What would you be getting
for your money?
Spend the same time and money building a car that fits the rules
without clever interpretation and it will very likely take the record.
Bill Dube'
Sure, but don't forget, you will be running just as fast with, say,
pure 300V as at 30V DC-DC'ed 10x up. I do realize with 300V pack
it's just a pack weight and cost and with 30V one other than the
same amount of batteries you add expensive DC-DC but my question was not
if it worth doing. My only question was such vehicle would be
classified.
A transmission serves much the same function as the DC-DC converter
you are proposing, by the way.
In theory, but not quite in practice. This is another broad
topic though.
--- End Message ---
