EV Digest 5383
Topics covered in this issue include:
1) Re: Otmar's motor speed sensor
by Ryan Bohm <[EMAIL PROTECTED]>
2) RE: Some problems to solve
by "Matthew D. Graham" <[EMAIL PROTECTED]>
3) RE: Some problems to solve
by "Roger Stockton" <[EMAIL PROTECTED]>
4) Re: longest range?
by =?ISO-8859-1?Q?Jukka_J=E4rvinen?= <[EMAIL PROTECTED]>
5) RE: Some problems to solve
by Ryan Bohm <[EMAIL PROTECTED]>
6) RE: Otmar's motor speed sensor - where to buy?
by "Mark Fowler" <[EMAIL PROTECTED]>
7) Re: Switched Capacitor Equalization of Long Strings WAS: Some problems to
solve
by "Mike Phillips" <[EMAIL PROTECTED]>
8) RE: Some problems to solve
by Cor van de Water <[EMAIL PROTECTED]>
9) Re: longest range?
by "Alan Smith" <[EMAIL PROTECTED]>
10) VW Beetle
by "Alan Smith" <[EMAIL PROTECTED]>
11) RE: Some problems to solve
by "Roger Stockton" <[EMAIL PROTECTED]>
12) Re: longest range?
by "Robert Chew" <[EMAIL PROTECTED]>
13) RE: Switched Capacitor Equalization of Long Strings WAS: Some pro
blems to solve
by Cor van de Water <[EMAIL PROTECTED]>
14) RE: longest range?
by "Mark Fowler" <[EMAIL PROTECTED]>
15) sheilding for zilla wiring
by David Brandt <[EMAIL PROTECTED]>
--- Begin Message ---
Hi Dave and all,
I have the long shaft motor and I just got my speed sensor. (Thanks Ryan!)
You're welcome. I responded to Dave privately, but thought I'd share
some of my thoughts on the to the list too.
First, the end of the sensor housing would have to be opened up, but it doesn't
LOOK like it would
be a problem. It's look like it's just a thin cap that can be easily drilled.
The sensor is in the side, so this would technically be feasible.
However, read below.
Second, you'd have to replace the magnet ring with one that fits between the
shaft and the sensor
housing. If there was a way to attach some small neodynium (sp?) magnets to the
shaft, wouldn't
they work? Maybe drill some small indents into the shaft and epoxy the magnets in?
The clearance from the inside of the speed sensor to the motor shaft is
pretty small. The magnetic ring is about 1". The inside of the speed
sensor is about 1/8" larger in diameter (I'm not measuring...just going
off of memory. If anyone wants exact numbers, let me know). So that
leaves you only about 1/16" to play with for magnets...not much.
It might work better to create a bracket that mounts to the motor, and
loops around leaving clearance for a pulley, e.g.
Motor ---------------
____| | |
| | |
---------X
I'm not much of an ASCII art pro, but the motor face is right next to
"Motor", the shaft extends downwards to the speed sensor, "X". (Lee -
how in the world do you do your ASCII art?? You must spend hours...:)
). The trouble would be making the bracket sturdy enough that it kept
the speed sensor at the right position relative to the magnetic ring.
BTW, I think Mike Willmon was going to do his this way. Mike, are you
listening? Maybe you could share how you did it.
I'm hoping this summer to have bracket options for WarP customers that
are using the Zolox speed sensor kit.
-Ryan
--
- EV Source <http://www.evsource.com> -
Selling names like Zilla, PFC Chargers, and WarP Motors
E-mail: mailto:[EMAIL PROTECTED]
Toll-free: 1-877-215-6781
--- End Message ---
--- Begin Message ---
Dear Rich and Lee:
You are killing me. ;-)
Apparently, I am one of the poor, unfortunate souls with 25 Orbitals that
just can't seem to agree on a common voltage. I have Mk2/2b regs on each
one, which I feel have been very useful from the standpoint of communicating
with the charger and not allowing me to overcharge my batteries. However, I
have quite a few that hit the 14.8 V mark and start blinking while others
want to hang out around 13 and small change. Could it be that I've abused
them with 1400+ Amp discharges at the track? Absolutely. ;-)
Still, I'd like them to play together more nicely. Maybe I'm just not
allowing them to finish charge long enough, and need to increase the
timeout. Right now, it's an hour, but maybe it needs to be more like two
hours at 1-2 amps while held at the 14.8 V limit.
Anyway, all this talk of equalization finally got me inspired to put it to
the test last night. I thought, "maybe I should take better care of my poor
batteries and treat them to a nice equalization charge!" (their first ever).
After topping up the pack with a normal charge cycle to about 345 V, I
followed the equalization procedure, but chickened out after about 40
minutes. Some of the batteries got up around 15.5 V, while half of the
pack's batteries were still wallowing around 13.2 V. This was at a charge
current of 1 amp and pack voltage got to about 360 V. Ten minutes of me
nervously pacing around the car, sticking my face over each battery and
sniffing for any hint of venting gas got old very quickly.
Needless to say, hearing today that I should NEVER equalize my pack of
Orbitals kinda bummed me out, even if there is some disagreement on the
subject. If I can avoid the equalization stage in the future, that's great.
But in the meantime, what's the best way to get all the batteries in line?
I'm not a fan of charging individually since I've done it before with only
short term satisfaction. The batteries soon get out of whack again.
Am I the only one experiencing this? How are others' Orbitals/AGMs doing,
and what charging regimen do you use?
Matt Graham
300V "Joule Injected" Nissan
http://www.jouleinjected.com
Hobe Sound, FL
-----Original Message-----
From: Rich Rudman [mailto:[EMAIL PROTECTED]
Sent: Tuesday, April 18, 2006 1:21 PM
To: [email protected]
Subject: Re: Some problems to solve
For the ground rules Sake...
Lets assume the brute force method is out of the question.
And you don't want to just force 2 amp into a full battery. The result will
cause venting.
So.. What else do you have?? Voltage? and Amps...These are the only two
tools to read and to vary.
Unless you are also tracking past demand and charge cycles.
So.. You pick a voltage that will fill the battery on time and not vent it.
AGM and specifically Optimas recommend 14.8 volts. Seams to work for most
AGM batteries.
That old Bucket of water concept is very valid. but you want them all full,
no matter if the buckets are slightly different sizes. Full and barley
dribbling over is a Known state.
Locking the peak voltage with any kind of regulator.. is a very good first
step. The second is to back off the main charger If you can't dribble the
extra power fast enough to keep the voltage below the level you want them
at.
Or adding power to the ones that just take a little longer to
dribble...Good idea helps get to that nice all full state faster. Without
having to abuse any single battery with high volts like the Bulk 2amp for
ever stage that some Battery vendors and Charger designers favor. Heck Lee
if these old concepts actually worked like folks say they do...we wouldn't
be making Chargers and BMS improvements now would we?
14.8 is going to "Gas" the internal chemistry.. But not such that venting
will occur. Well to any great degree. I have vented at 14.8 after a 150 amp
cycle.. there are limits...
But to most EVers that are coming over from Flooded PbLa.. You don't want to
push a AGM through the "classic" equalization cycle. We have to do it by
other means.
The other means for AGM is a voltage hold While the amps taper back to less
than 2 amps. You NEVER drive the AGM over 15 if you can help it. Doing so
with a long series string just about guarantees you will vent one of the
batteries. There are clear exceptions to this rule.. But if you do just
what the procedure says, you will get rated cycle life if not a couple times
more that the posted cycle life.
Since the advertised cycles assumes you will have some... "Events".
Knowing the Actual requirements of a single Battery's State of charge...
Well Lee that's just about impossible. You need a LOT of solid lab grade
data, as well as the history of the last charge cycle and depth of
discharge, Age of battery and the number and depth of all cycles. And then
with some math and a Good WAG... you can kinda predict the Watts needed to
solve the equation. Yup you can get close with a good data cruncher and
"Best practice" methods. Been there done that.. by hand many times.
Or you can hold all the regs at blink levels for 30 minutes.. and yer
done...
I am not sure..which one gives a better charge... But.. I really do know
which one is more cost effective....
And which one is easier to implement.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, April 18, 2006 9:11 AM
Subject: Re: Some problems to solve
> Rich Rudman wrote:
> > Forget forced equalization. That's for floodeds. AGM guys use the Regs.
> > And Never drive the Lead over 15 volts if we can help it.
> > Never Equalize, The regs do that as they blink.
>
> Rich, I disagree.
>
> "Equalization" is the process of somehow getting different numbers of
> amphours into batteries, to compensate for them being at different
> states of charge. There are lots of ways to do it; your regulators are
> only one.
>
> Ye Olde Brute Force method, used for floodeds, is to just blindly charge
> excessively. Like filling buckets with a hose. They all fill up all
> right; but the excess spills on the ground and makes a mess. With
> batteries, the "mess" is gassing, fizzing, water loss, higher battery
> temperature, and somewhat shorter life.
>
> You're right; you don't want to use this method for sealed batteries.
> The top is "sealed", so attempting to overfill it causes the pressure
> inside to increase. It can blow the safety vents, lose water (which
> can't be replaced), make them get hot, and seriously shorten their life.
>
> But, I disagree that you *never* take AGMs up over 15v. Let's assume you
> are doing your equalization via extra charging. If one battery is 1
> amphour lower than the rest, you have to put one extra amphour into it.
> There are lots of ways you can do this.
>
> You could apply a lower voltage for a longer time. My simple zener-lamp
> regulators start shunting current at 13.5v, and gradually increase to
> 0.5 amps at 15v. Let's say the average is 0.25 amps. It takes 4 hours to
> get from 13.5v to 15v; so they are providing 0.25a x 4h = 1 amphour of
> equalization without ever reaching 15v.
>
> Or, you can charge to a higher voltage but limit the time. 15.5v at 2
> amps for 30 minutes is also 1 amphour. In fact, there is evidence that
> higher currents do a better job of equalzation. Hawker suggests
> equalizing at 2 amps with *no voltage limit*, for example. The key here
> is that you need to *know* that there is room for that extra 1 amhour.
> You don't blindly charge at 15.5v and 2 amps into an already-full
> battery; that will only force it to gas; the internal pressure goes up;
> it gets hot, vents, loses water, and is damaged.
>
> The key for AGMs is not to blindly hold some voltage limit; but to
> *know* the state of charge, and put in the *right* amount of overcharge
> to bring it to full. The actual voltage and current you apply to do this
> has rather wide limits.
> --
> 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 ---
Rich Rudman [mailto:[EMAIL PROTECTED] wrote:
> So.. You pick a voltage that will fill the battery on time
> and not vent it. AGM and specifically Optimas recommend 14.8
> volts. Seams to work for most AGM batteries.
But Optima also specifically recommends a constant current finish with
no voltage limit. Picking the parts you like from their recommendations
and ignoring the others is somewhat questionable.
> 14.8 is going to "Gas" the internal chemistry.. But not such
> that venting will occur. Well to any great degree. I have
> vented at 14.8 after a 150 amp cycle.. there are limits...
14.8V can gas an Optima even at less than 2A charge current; I've seen
it happen. My belief is that if the battery sits long enough the cells
self-discharge unequally enough that you can have one or two of the 6
cells gassing vigorously even though the module voltage is "safe".
> The other means for AGM is a voltage hold While the amps
> taper back to less than 2 amps.
This isn't equalising an AGM, this is just getting it fully charged (ie.
it is the normal absorption phase).
> You NEVER drive the AGM over 15 if you can help it.
Maybe you don't, but taking the AGM to high voltages is not a problem,
in my experience, provided you carefully limit the time it is there.
> Or you can hold all the regs at blink levels for 30
> minutes.. and yer done...
This is where the reg's equalise the AGMs. You're basically doing the X
amps for Y minutes constant current finish, but with a voltage cap
instead of the unlimited voltage Optima recommends. Since the regs are
pulsing the finish current at different rates for each battery, you
don't actually know if each battery has gotten enough finish Ah or not
since the average current through each battery depends on the exact
blink rate and bypass current and voltage setpoint, etc. of its
associated reg.
A big problem with this approach is, I think, that the finish voltage of
the batteries is not a reliable indicator of SOC because it is so
strongly influenced by the recombination efficiency and internal
impedance, etc. I suspect that the benefit of regs is almost entirely
that they prevent any module from being held at excessively high
voltages for longish (indeterminate, really) times during the absorption
phase while the current is still high and venting is likely. Once the
current has tapered to the finish level, I suspect that disabling the
regs and allowing the voltage to go where it needs to for the finish
phase might well result in even better performance. Of course, the
amount of finish/overcharge Ah should ideally be controlled to be
proportional to the DOD so that one doesn't blindly put a fixed
overcharge into a battery that was only shallowly cycled.
Have you done any testing to compare the performance of AGMs when the
regs are disabled for the finish vs leaving the regs active right to the
end of charge?
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
A bit over 150 miles with Citroen Berligo Lithium.
http://www.austinev.org/evalbum/641.html
-Jukka
Alan Smith kirjoitti:
What is the longest range everyone has gotten on their ev? If you've gotten
over 60, definitely let me know.
Thanks, Alan
--
// Quotes from yours truly -------------------------
"You don't forget, you just don't remember."
"Maturity resides in the mind."
--
Jukka Järvinen
R&D Director
Oy Finnish Electric Vehicle Technologies Ltd
Teollisuuskatu 24
11100 RIHIMÄKI
FINLAND
VAT ID: FI18534078
jukka.jarvinen(a_t)fevt.com
mobile. +358-440-735705
fax. +358-19-735705
--- End Message ---
--- Begin Message ---
Matt,
Maybe it's just Nissans that exhibit this behavior :)
I have 12 Orbitals, and see exactly what you describe. Mine have been abused
with frequent 1000 amp runs. Also, I have MK2B's right now (soon to have MK3's
for beta testing!).
When the first green LED fires, there are usually other batteries hanging
around 14.0-14.2V. I've found that the red LED sometimes won't clear on the
weaker batts unless I have the voltage on the charger up high enough. Also, my
timer is set for about 45 minutes. Even then, sometimes I have to reset the
charger and give it another 45 minutes. The regs on the stronger batts have to
get a really good workout to keep things in line. Makes me wonder how anyone
with AGMs could go without some sort of regulator.
And finally, I think Rich's latest 'sploding experience should teach us
something. If a battery is always first to light the red LED, and last to
clear it - better to pull it out of the string before there's action on one of
those high-amp runs :)
-Ryan
Original Message -----------------------
Dear Rich and Lee:
You are killing me. ;-)
Apparently, I am one of the poor, unfortunate souls with 25 Orbitals that
just can't seem to agree on a common voltage. I have Mk2/2b regs on each
one, which I feel have been very useful from the standpoint of communicating
with the charger and not allowing me to overcharge my batteries. However, I
have quite a few that hit the 14.8 V mark and start blinking while others
want to hang out around 13 and small change. Could it be that I've abused
them with 1400+ Amp discharges at the track? Ab
solutely. ;-)
Still, I'd like them to play together more nicely. Maybe I'm just not
allowing them to finish charge long enough, and need to increase the
timeout. Right now, it's an hour, but maybe it needs to be more like two
hours at 1-2 amps while held at the 14.8 V limit.
Anyway, all this talk of equalization finally got me inspired to put it to
the test last night. I thought, "maybe I should take better care of my poor
batteries and treat them to a nice equalization charge!" (their first ever).
After topping up the pack with a normal charge cycle to about 345 V, I
followed the equalization procedure, but chickened out after about 40
minutes. Some of the batteries got up around 15.5 V, while half of the
pack's batteries were still wallowing around 13.2 V. This was at a charge
current of 1 amp and pack voltage got to about 360 V. Ten minutes of me
nervously pacing around the car, sticking my face over each battery and
sniffing for any hint of venting gas got old very quickly.
Needless to say, hearing today that I should NEVER equalize my pack of
Orbitals kinda bummed me out, even if there is some disagreement on the
subject. If I can avoid the equalization stage in the future, that's great.
But in the meantime, what's the best way to get all the batteries in line?
I'm not a fan of charging individually since I've done it before with only
short term satisfaction. The batteries soon get out of whack again.
Am I the only one experiencing this? How are others' Orbitals/AGMs doing,
and what charging regimen do you use?
Matt Graham
300V "Joule Injected" Nissan
http://www.jouleinjected.com
Hobe Sound, FL
--- End Message ---
--- Begin Message ---
You can, however, make them work for a Zilla. I did.
The Zilla expects four pulses pre rev, but the collar has only two
magnets.
However, the sensor comes with two magnets of its own.
The collar comes in two U shaped parts, with the magnet embedded in the
bottom of the U.
Imagine you are looking down onto the top of the U - it is a square
cross-section, with the attaching bolt running through the center.
Half way between this center hole and the outer edge I cut a
semicircular hole to fit half of a sensor magnet.
Same procedure on the matching face of the other collar, so that the
sensor magnet is held securely in place when the collar is clamped on
the shaft.
Make sure that the polarity of the magnet is the same as the embedded
magnets.
Repeat on the other side of the U with the second sensor magnet.
Of course there are no guarantees about how well this will hold together
at ultra-high revs, but it has worked just fine for me with a standard
ADC 9" that never goes over 5000 rpm.
Mark
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of Roland Wiench
> Sent: Tuesday, 18 April 2006 7:25 AM
> To: [email protected]
> Subject: Re: Otmar's motor speed sensor - where to buy?
>
>
> If you are using a Zilla, Otmar said these will not work.
> The Zilla needs 4
> magnets for a 4 pulse input. The sensor is a normally
> closed, and when
> passes over a magnet it switches off the signal. The on
> pulse must be at
> least on three times longer than the off pulse, so the magnet
> length and
> spacing is critical.
>
> The sensor Otmar sent me is a Hamlin No 55110 which is a non-latching
> normally closed type activated by the south pole of the magnets.
>
> Roland
>
>
> ----- Original Message -----
> From: "Ryan Stotts" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Monday, April 17, 2006 2:39 PM
> Subject: Re: Otmar's motor speed sensor - where to buy?
>
>
> > Mark Ward wrote:
> >
> > > Does anyone make one that lets you keep using the shaft for other
> > > accessories?
> >
> > How about this?
> >
> >
> http://www.evparts.com/shopping/product_details.php?id=444&pro
duct_id=1568
>
>
http://www.evparts.com/shopping/product_details.php?id=444&product_id=15
65
>
>
--- End Message ---
--- Begin Message ---
Now that is a link! What great set of papers that were furnished at
the bottom of the page! Got my brain turning in a big way.
Thank You!
Mike
--- In [EMAIL PROTECTED], Meta Bus <[EMAIL PROTECTED]> wrote:
>
> Lee, Rich, may I divert this subject a little, something related--
>
> What do you think of using switched-capacitance to equalize large
> strings? (A la http://www.smartsparkenergy.com/batteq.htm)
>
> Regards and TIA,
> Jim
>
> Lee Hart wrote:
> > Rich Rudman wrote:
> >
> >>Forget forced equalization. That's for floodeds. AGM guys use the
Regs.
> >>And Never drive the Lead over 15 volts if we can help it.
> >>Never Equalize, The regs do that as they blink.
> >
> >
> > Rich, I disagree.
> >
> > "Equalization" is the process of somehow getting different numbers of
> > amphours into batteries, to compensate for them being at different
> > states of charge. There are lots of ways to do it; your regulators are
> > only one.
> >
> > Ye Olde Brute Force method, used for floodeds, is to just blindly
charge
> > excessively. Like filling buckets with a hose. They all fill up all
> > right; but the excess spills on the ground and makes a mess. With
> > batteries, the "mess" is gassing, fizzing, water loss, higher battery
> > temperature, and somewhat shorter life.
> >
> > You're right; you don't want to use this method for sealed batteries.
> > The top is "sealed", so attempting to overfill it causes the pressure
> > inside to increase. It can blow the safety vents, lose water (which
> > can't be replaced), make them get hot, and seriously shorten their
life.
> >
> > But, I disagree that you *never* take AGMs up over 15v. Let's
assume you
> > are doing your equalization via extra charging. If one battery is 1
> > amphour lower than the rest, you have to put one extra amphour
into it.
> > There are lots of ways you can do this.
> >
> > You could apply a lower voltage for a longer time. My simple
zener-lamp
> > regulators start shunting current at 13.5v, and gradually increase to
> > 0.5 amps at 15v. Let's say the average is 0.25 amps. It takes 4
hours to
> > get from 13.5v to 15v; so they are providing 0.25a x 4h = 1 amphour of
> > equalization without ever reaching 15v.
> >
> > Or, you can charge to a higher voltage but limit the time. 15.5v at 2
> > amps for 30 minutes is also 1 amphour. In fact, there is evidence that
> > higher currents do a better job of equalzation. Hawker suggests
> > equalizing at 2 amps with *no voltage limit*, for example. The key
here
> > is that you need to *know* that there is room for that extra 1 amhour.
> > You don't blindly charge at 15.5v and 2 amps into an already-full
> > battery; that will only force it to gas; the internal pressure
goes up;
> > it gets hot, vents, loses water, and is damaged.
> >
> > The key for AGMs is not to blindly hold some voltage limit; but to
> > *know* the state of charge, and put in the *right* amount of
overcharge
> > to bring it to full. The actual voltage and current you apply to
do this
> > has rather wide limits.
>
--- End Message ---
--- Begin Message ---
OK, I have AGM's and I >do< equalize them, though some on this list
disagree that this is truly an equalization, but the question is
always: what is lore and what is data, so I'll present the data
that supports my story...
My pack is 26 AGMs in 1 string (312V) of 110 Ah.
I charge them every night except when they still are over 80%
(standard commute is 23 miles round trip which brings them to
60% but sometimes I work from home or only make a 3 miles trip
to church or supermarket)
This charge is a fixed 7 hours to 356V (13.7 per battery) at
maximum 10A and tapering off to 0.5A after 7h.
This is the factory recommendation for float charge.
Once a month or so I will cranck the voltage up to 385V
(14.8V per battery) at the end of the float charge, with a
current limit of 3A to allow the batteries to recombine all
gas that might be produced.
I see that for a while the voltage is rising slowly from
356 to about 365V, then quickly shoot from 365V to 385V after
which the current starts falling.
When I perform this procedure at the end of the float charge
(batteries sitting at 356V 0.5A for hours) then the voltage
immediately goes to 385V while the current limit never engages
for more than a short moment.
This tells me that my batteries are pretty well equalized with
the long float charge.
To validate this idea, I measured all batteries I cound reach
and found them all within 20mV from each other in charged state
(13.25 - 13.27V)
Any opinions on this way of "equalizing once a month"?
BTW - I have no regs, batteries are 3 months in service, 2000 miles
and arrived with approx 200 mV difference between them.
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Rich Rudman
Sent: Tuesday, April 18, 2006 10:21 AM
To: [email protected]
Subject: Re: Some problems to solve
For the ground rules Sake...
Lets assume the brute force method is out of the question.
And you don't want to just force 2 amp into a full battery. The result will
cause venting.
So.. What else do you have?? Voltage? and Amps...These are the only two
tools to read and to vary.
Unless you are also tracking past demand and charge cycles.
So.. You pick a voltage that will fill the battery on time and not vent it.
AGM and specifically Optimas recommend 14.8 volts. Seams to work for most
AGM batteries.
That old Bucket of water concept is very valid. but you want them all full,
no matter if the buckets are slightly different sizes. Full and barley
dribbling over is a Known state.
Locking the peak voltage with any kind of regulator.. is a very good first
step. The second is to back off the main charger If you can't dribble the
extra power fast enough to keep the voltage
below the level you want them at.
Or adding power to the ones that just take a little longer to
dribble...Good idea helps get to that nice all full state faster. Without
having to abuse any single battery with high volts like the Bulk 2amp for
ever stage that some Battery vendors and Charger designers favor. Heck Lee
if these old concepts actually worked like folks say they do...we wouldn't
be making Chargers and BMS improvements now would we?
14.8 is going to "Gas" the internal chemistry.. But not such that venting
will occur. Well to any great degree. I have vented at 14.8 after a 150 amp
cycle.. there are limits...
But to most EVers that are coming over from Flooded PbLa.. You don't want to
push a AGM through the "classic" equalization cycle. We have to do it by
other means.
The other means for AGM is a voltage hold While the amps taper back to less
than 2 amps. You NEVER drive the AGM over 15 if you can help it. Doing so
with a long series string just about guarantees you will vent one of the
batteries. There are clear exceptions to this rule.. But if you do just
what the procedure says, you will get rated cycle life if not a couple times
more that the posted cycle life.
Since the advertised cycles assumes you will have some... "Events".
Knowing the Actual requirements of a single Battery's State of charge...
Well Lee that's just about impossible. You need a LOT of solid lab grade
data, as well as the history of the last charge cycle and depth of
discharge, Age of battery and the number and depth of all cycles. And then
with some math and a Good WAG... you can kinda predict the Watts needed to
solve the equation. Yup you can get close with a good data cruncher and
"Best practice" methods. Been there done that.. by hand many times.
Or you can hold all the regs at blink levels for 30 minutes.. and yer
done...
I am not sure..which one gives a better charge... But.. I really do know
which one is more cost effective....
And which one is easier to implement.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, April 18, 2006 9:11 AM
Subject: Re: Some problems to solve
> Rich Rudman wrote:
> > Forget forced equalization. That's for floodeds. AGM guys use the Regs.
> > And Never drive the Lead over 15 volts if we can help it.
> > Never Equalize, The regs do that as they blink.
>
> Rich, I disagree.
>
> "Equalization" is the process of somehow getting different numbers of
> amphours into batteries, to compensate for them being at different
> states of charge. There are lots of ways to do it; your regulators are
> only one.
>
> Ye Olde Brute Force method, used for floodeds, is to just blindly charge
> excessively. Like filling buckets with a hose. They all fill up all
> right; but the excess spills on the ground and makes a mess. With
> batteries, the "mess" is gassing, fizzing, water loss, higher battery
> temperature, and somewhat shorter life.
>
> You're right; you don't want to use this method for sealed batteries.
> The top is "sealed", so attempting to overfill it causes the pressure
> inside to increase. It can blow the safety vents, lose water (which
> can't be replaced), make them get hot, and seriously shorten their life.
>
> But, I disagree that you *never* take AGMs up over 15v. Let's assume you
> are doing your equalization via extra charging. If one battery is 1
> amphour lower than the rest, you have to put one extra amphour into it.
> There are lots of ways you can do this.
>
> You could apply a lower voltage for a longer time. My simple zener-lamp
> regulators start shunting current at 13.5v, and gradually increase to
> 0.5 amps at 15v. Let's say the average is 0.25 amps. It takes 4 hours to
> get from 13.5v to 15v; so they are providing 0.25a x 4h = 1 amphour of
> equalization without ever reaching 15v.
>
> Or, you can charge to a higher voltage but limit the time. 15.5v at 2
> amps for 30 minutes is also 1 amphour. In fact, there is evidence that
> higher currents do a better job of equalzation. Hawker suggests
> equalizing at 2 amps with *no voltage limit*, for example. The key here
> is that you need to *know* that there is room for that extra 1 amhour.
> You don't blindly charge at 15.5v and 2 amps into an already-full
> battery; that will only force it to gas; the internal pressure goes up;
> it gets hot, vents, loses water, and is damaged.
>
> The key for AGMs is not to blindly hold some voltage limit; but to
> *know* the state of charge, and put in the *right* amount of overcharge
> to bring it to full. The actual voltage and current you apply to do this
> has rather wide limits.
> --
> 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 ---
I have to say I'm immpressed with what people have gotten.
Now, how do you do it?
The Venturi Fetish gets some high amount and it can't be that hard to get
good range; obviously. So, looking at the results of my original question,
it shouldn't be too hard to make a 5 seater vehicle go about 100 miles.
Thanks, Alan
--
// Quotes from yours truly -------------------------
"You don't forget, you just don't remember."
"Maturity resides in the mind."
--- End Message ---
--- Begin Message ---
A friend of mine wants to convert to an ev because he only drives about
10-15 round trip for work. And occasionally takes his kids places around
town. The first question is, what car should he use as a donor? Now, I know
almost nothing about cars, but I was thinking a VW Beetle because they're
small and it shouldn't take much to power them. What do you all think?
The second question would be, what batteries to use? His, and his wife's,
only objection to an ev is the lead acid batteries. From looking at lots of
evs, the best seem to be Lithium Ion. How much per battery, or whatever, or
they? How much range do you get out of one?
Thanks, Alan
--
// Quotes from yours truly -------------------------
"You don't forget, you just don't remember."
"Maturity resides in the mind."
--- End Message ---
--- Begin Message ---
Matthew D. Graham [mailto:[EMAIL PROTECTED] wrote:
> However, I
> have quite a few that hit the 14.8 V mark and start blinking
> while others want to hang out around 13 and small change.
> Still, I'd like them to play together more nicely. Maybe I'm
> just not allowing them to finish charge long enough, and need
> to increase the timeout. Right now, it's an hour, but maybe
> it needs to be more like two hours at 1-2 amps while held at
> the 14.8 V limit.
If you have modules that are hanging out around 13V, then those modules
are not getting fully charged. You've got to let the charger keep
running in the constant voltage phase until all the regs are blinking.
Once all regs are blinking, then you let it run for some limited
additional time to put in the overcharge required to get the cells fully
and equally charged.
> Anyway, all this talk of equalization finally got me inspired
> to put it to the test last night. I thought, "maybe I should
> take better care of my poor batteries and treat them to a
> nice equalization charge!" (their first ever). After topping
> up the pack with a normal charge cycle to about 345 V, I
> followed the equalization procedure, but chickened out after
> about 40 minutes. Some of the batteries got up around 15.5 V,
> while half of the pack's batteries were still wallowing
> around 13.2 V.
You don't want to do an equalisation until the batteries are fully
charged, and the fact that you have some batteries still at 13 and
change indicates that your normal charge cycle is *not* getting your
batteries fully charged.
Leave the regs enabled and hold the voltage at about 365-370V
(14.6-14.8V x 25 modules) or so until all regs are blinking. Now you
know that all the batteries are fully charged and can safely provide
some overcharge or equalisation Ah to them.
Whether you disable the regs at this point and let the voltages go wild
while you pump in a couple of Ah at a low rate, or leave the regs
enabled and let the charger run for some arbitary time (like 30min) at
low current is your call.
> Needless to say, hearing today that I should NEVER equalize
> my pack of Orbitals kinda bummed me out, even if there is
> some disagreement on the subject. If I can avoid the
> equalization stage in the future, that's great. But in the
> meantime, what's the best way to get all the batteries in
> line? I'm not a fan of charging individually since I've done
> it before with only short term satisfaction. The batteries
> soon get out of whack again.
>
> Am I the only one experiencing this? How are others'
> Orbitals/AGMs doing, and what charging regimen do you use?
If your batteries are quickly getting out of whack, then I'd suspect
that your charge regimen is not quite where it needs to be yet. 345V
sounds awful low to me for a 25 module string: this is just
13.8V/module, which is more like a good float charge level than an
appropriate voltage for cyclic charging. Crank that voltage up to
14.7-14.8V/module (at room temp) and let the charger go until all the
regs are blinking. It may take a long time for the first cycle or few,
but once they are in balance you should find they stay in balance and
take less time to all get full.
How much overcharge you put in after this point, and whether you limit
the voltage (leave regs enabled) or not, etc. is where the holy wars are
being fought, but I think everyone agrees on one thing: the charge you
put in after all modules have been brought to 14.7V at low current is
overcharge/equalisation, and you must put this additional charge into
the pack at least occasionally.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
I am jealous....
I am only getting about 20 km's before i get into danger zone on my batts.
Something like 40 SOC. Thats with plenty of stop and start.
Not good at all, serves me right however, for using marine batts and a low
voltage.
Next batteries will be T-1275 golf 12 volt batts 150 amp hour.
Should be a little stiffer than my SCS225.
Cheers
From: Jukka Järvinen <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: longest range?
Date: Tue, 18 Apr 2006 23:17:29 +0300
A bit over 150 miles with Citroen Berligo Lithium.
http://www.austinev.org/evalbum/641.html
-Jukka
Alan Smith kirjoitti:
What is the longest range everyone has gotten on their ev? If you've
gotten
over 60, definitely let me know.
Thanks, Alan
--
// Quotes from yours truly -------------------------
"You don't forget, you just don't remember."
"Maturity resides in the mind."
--
Jukka Järvinen
R&D Director
Oy Finnish Electric Vehicle Technologies Ltd
Teollisuuskatu 24
11100 RIHIMÄKI
FINLAND
VAT ID: FI18534078
jukka.jarvinen(a_t)fevt.com
mobile. +358-440-735705
fax. +358-19-735705
_________________________________________________________________
Read, write and reply to Hotmail on your mobile. Find out more.
http://mobilecentral.ninemsn.com.au/mcmobileHotmail/home.aspx
--- End Message ---
--- Begin Message ---
Nice to see that the paper about switched capacitor
equalization confirms that passive equalization of
sealed Lead Acid batteries does work, if you have
enough time to (float) charge them and allow a
low and controlled (recombined) gas production
inside the cells.
http://www.smartsparkenergy.com/pdf/batteq2.pdf
To reduce charge time and speed up equalization
they present the non-dissipative capacitor switcher,
though from their data you can see that the dissipation
is mainly a concern for UPS standby operations, the
typical EV recharge regimen does result in pretty low
losses as the charging is a fraction of the time and
the equalization part of the charge even shorter.
It is an interesting approach though, the principle of
power shuttling between batteries, in this case it is
shuttled not in a specific direction - always from the
highest voltage battery to a lower voltage battery.
Series-switching involves "overlapping" the switchers
by 1 battery, so 2 switchers for 4 batteries can
equalize 7 batteries.
It seems that they are not protected against fault
situations, such as a low capacitance cell that gets
low and reverses during load - this will blow up the
circuit or the adjacent cells will also be reversed.
When one battery is bad and loses a cell then all
other batteries will be equalized to the voltage of
the bad battery, while the bad one will be hit with a
severe overcharge.....
These issues may be detected and should be avoided
when this principle is applied in a product.
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Mike Phillips
Sent: Tuesday, April 18, 2006 2:55 PM
To: Meta Bus
Subject: Re: Switched Capacitor Equalization of Long Strings WAS: Some
problems to solve
Now that is a link! What great set of papers that were furnished at
the bottom of the page! Got my brain turning in a big way.
Thank You!
Mike
--- In [EMAIL PROTECTED], Meta Bus <[EMAIL PROTECTED]> wrote:
>
> Lee, Rich, may I divert this subject a little, something related--
>
> What do you think of using switched-capacitance to equalize large
> strings? (A la http://www.smartsparkenergy.com/batteq.htm)
>
> Regards and TIA,
> Jim
>
> Lee Hart wrote:
> > Rich Rudman wrote:
> >
> >>Forget forced equalization. That's for floodeds. AGM guys use the
Regs.
> >>And Never drive the Lead over 15 volts if we can help it.
> >>Never Equalize, The regs do that as they blink.
> >
> >
> > Rich, I disagree.
> >
> > "Equalization" is the process of somehow getting different numbers of
> > amphours into batteries, to compensate for them being at different
> > states of charge. There are lots of ways to do it; your regulators are
> > only one.
> >
> > Ye Olde Brute Force method, used for floodeds, is to just blindly
charge
> > excessively. Like filling buckets with a hose. They all fill up all
> > right; but the excess spills on the ground and makes a mess. With
> > batteries, the "mess" is gassing, fizzing, water loss, higher battery
> > temperature, and somewhat shorter life.
> >
> > You're right; you don't want to use this method for sealed batteries.
> > The top is "sealed", so attempting to overfill it causes the pressure
> > inside to increase. It can blow the safety vents, lose water (which
> > can't be replaced), make them get hot, and seriously shorten their
life.
> >
> > But, I disagree that you *never* take AGMs up over 15v. Let's
assume you
> > are doing your equalization via extra charging. If one battery is 1
> > amphour lower than the rest, you have to put one extra amphour
into it.
> > There are lots of ways you can do this.
> >
> > You could apply a lower voltage for a longer time. My simple
zener-lamp
> > regulators start shunting current at 13.5v, and gradually increase to
> > 0.5 amps at 15v. Let's say the average is 0.25 amps. It takes 4
hours to
> > get from 13.5v to 15v; so they are providing 0.25a x 4h = 1 amphour of
> > equalization without ever reaching 15v.
> >
> > Or, you can charge to a higher voltage but limit the time. 15.5v at 2
> > amps for 30 minutes is also 1 amphour. In fact, there is evidence that
> > higher currents do a better job of equalzation. Hawker suggests
> > equalizing at 2 amps with *no voltage limit*, for example. The key
here
> > is that you need to *know* that there is room for that extra 1 amhour.
> > You don't blindly charge at 15.5v and 2 amps into an already-full
> > battery; that will only force it to gas; the internal pressure
goes up;
> > it gets hot, vents, loses water, and is damaged.
> >
> > The key for AGMs is not to blindly hold some voltage limit; but to
> > *know* the state of charge, and put in the *right* amount of
overcharge
> > to bring it to full. The actual voltage and current you apply to
do this
> > has rather wide limits.
>
--- End Message ---
--- Begin Message ---
Hi Alan,
Don't forget that the Fetish uses Lithium batteries.
Lithium batteries have about 4x the energy capacity of Lead batteries
per unit weight.
However, since Lithiums are still in their infancy, they are much more
expensive and require careful monitoring.
This will change.
The Chinese are starting to produce EVs with Lithium batteries and BMS.
(Have a look at articles like http://www.msnbc.msn.com/id/6290392/)
Mass production will bring the prices down and standardise the
monitoring technology.
They will license or independently develop the high current technology
that we are starting to see from the tool battery manufacturers, so
these batteries will be both high energy (range) and high power (speed).
Mark
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of Alan Smith
> Sent: Wednesday, 19 April 2006 8:20 AM
> To: [email protected]
> Subject: Re: longest range?
>
>
> I have to say I'm immpressed with what people have gotten.
>
> Now, how do you do it?
> The Venturi Fetish gets some high amount and it can't be that
> hard to get
> good range; obviously. So, looking at the results of my
> original question,
> it shouldn't be too hard to make a 5 seater vehicle go about
> 100 miles.
>
> Thanks, Alan
> --
> // Quotes from yours truly -------------------------
> "You don't forget, you just don't remember."
> "Maturity resides in the mind."
>
>
--- End Message ---
--- Begin Message ---
I'm not able to place the contactors and shunt more than 1 ft. away
from the hairball as recommended in the zilla manual (though I can
manage 6"). I'd like to know what my options are for shielding. What
products and what techniques are recommended? If given an option, I'd
rather shield the low voltage wires close to the area, instead of the
power wires, but I'll shield the power wires if I have to. My main
concerns are the zilla data cable and the speed sensor wiring.
Also, it's a bit early, but I'd love to have some window stickers for
some of the products I'm using. A green on white or green on clear
"powered by zilla!" with a little godzilla logo would be great!
For my last EV, I took the GIF's of supplier's logos and had a printer
print them in color on sticky backed vinyl. Worked great, and added
some needed accents to the car. Not so much as to be ostentatious, but
enough to make people ask questions.
Thanks in advance!
David Brandt
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--- End Message ---
