EV Digest 5255
Topics covered in this issue include:
1) Re: Parallel Charging
by Victor Tikhonov <[EMAIL PROTECTED]>
2) Re: Parallel Charging
by Victor Tikhonov <[EMAIL PROTECTED]>
3) RE: Different Cell Capacities
by "Bill Dennis" <[EMAIL PROTECTED]>
4) Re: Parallel Charging
by Victor Tikhonov <[EMAIL PROTECTED]>
5) RE: Parallel Charging
by "Bill Dennis" <[EMAIL PROTECTED]>
6) Soldering terminals to 2/0 welder cable ??
by "jmygann" <[EMAIL PROTECTED]>
7) Re: Controller for power steering motor
by Jacob <[EMAIL PROTECTED]>
8) Range Extending Calculations
by Jeff Shanab <[EMAIL PROTECTED]>
9) GE EV1 SCR controller info for rank novice?
by Darin <[EMAIL PROTECTED]>
10) Re: Titling EV issue
by Christopher Zach <[EMAIL PROTECTED]>
11) Re: Also looking for a small motor controller?
by [EMAIL PROTECTED] (Dana Havranek)
12) Testing Contactors
by "Don Cameron" <[EMAIL PROTECTED]>
13) Re: Cheap charger
by Mark Ward <[EMAIL PROTECTED]>
14) RE: Range extender on the Nissan in 5254
by Eric Gorodetzky <[EMAIL PROTECTED]>
15) Trike Charger Wanted
by Electro Automotive <[EMAIL PROTECTED]>
16) Re: Titling EV issue
by Ralph Merwin <[EMAIL PROTECTED]>
17) Re: Also looking for a small motor controller?
by Lee Hart <[EMAIL PROTECTED]>
18) RE: Soldering terminals to 2/0 welder cable ??
by "Robert Chew" <[EMAIL PROTECTED]>
19) Re: Li-poly cycle life (was Re: Better to Run Down or...)
by Victor Tikhonov <[EMAIL PROTECTED]>
20) Re: Different Cell Capacities
by Victor Tikhonov <[EMAIL PROTECTED]>
21) Re: Cheap charger
by Lee Hart <[EMAIL PROTECTED]>
22) Re: Range extender on the Nissan in 5254
by Neon John <[EMAIL PROTECTED]>
23) Re: Soldering terminals to 2/0 welder cable ??
by "Roland Wiench" <[EMAIL PROTECTED]>
24) Re: Soldering terminals to 2/0 welder cable ??
by "Peter VanDerWal" <[EMAIL PROTECTED]>
25) Re: Controller for power steering motor
by Lee Hart <[EMAIL PROTECTED]>
26) $21 crimpers (was: Soldering terminals to 2/0 welder cable ??)
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
27) High voltage charging
by James Massey <[EMAIL PROTECTED]>
--- Begin Message ---
What exactly these fuses are protecting?
If one battery (right on this diagram) develops really
high R_int (which is not dangerous by itself) the whole
surge current during acceleration may try to flow through the fuse
so the other buddy will supply it. It will blow.
I'd connect fuses in series with chargers if this is what you're
trying to protect.
Victor
Bill Dennis wrote:
Would it work to connect every 12th cell together, as below:
_________ _____________ pack positive
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 1 _|________| - | -
|_________| | |
_________ |---F1--|
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 2 _|________| - | -
|_________| | |
_________ |---F2--|
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 3 _|________| - | -
|_________| |_______|_____ pack negative
Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
What exactly these fuses protecting?
If one battery (right on this diagram) develops really
high R_int (which is not dangerous by itself) the whole
surge current during acceleration may try to flow through the fuse
so the other buddy will supply it. It will blow.
I'd connect fuses in series with chargers if this is what you're
trying to protect.
Victor
Bill Dennis wrote:
Would it work to connect every 12th cell together, as below:
_________ _____________ pack positive
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 1 _|________| - | -
|_________| | |
_________ |---F1--|
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 2 _|________| - | -
|_________| | |
_________ |---F2--|
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 3 _|________| - | -
|_________| |_______|_____ pack negative
Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
Thanks, Victor, that's what I was thinking. There will be extra capacity in
the 270Ah cell that I won't use anyway, since a 200Ah cell will reach bottom
first. So if the 270Ah cell has a little less capacity, it shouldn't be a
problem.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Victor Tikhonov
Sent: Wednesday, March 15, 2006 4:39 PM
To: [email protected]
Subject: Re: Different Cell Capacities
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: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Victor Tikhonov
> Sent: Tuesday, March 14, 2006 3:13 PM
> To: [email protected]
> 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
--- End Message ---
--- Begin Message ---
What exactly these fuses protect?
If one battery (right on this diagram) develops really
high R_int (which is not dangerous by itself) the whole
surge current during acceleration may try to flow through the fuse
so the other buddy will supply it. It will blow.
I'd connect fuses in series with chargers if this is what you're
trying to protect.
Victor
Bill Dennis wrote:
Would it work to connect every 12th cell together, as below:
_________ _____________ pack positive
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 1 _|________| - | -
|_________| | |
_________ |---F1--|
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 2 _|________| - | -
|_________| | |
_________ |---F2--|
| +|________| |
| | __|__+ __|__+
| charger | ___ ___
| 3 _|________| - | -
|_________| |_______|_____ pack negative
Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
Thanks, Victor, that sounds like a good idea. So I just wire the two
connection points without a fuse.
My thoughts were that I was trying to protect against the opposite: one
cell failing as an open circuit during charging, which would cause a large
rush of current into the now-lower-voltage string. This would blow the
fuse. Now the inrush of the one cell's voltage difference would be spread
over twice the amount of cells, halving the inrush. If it was still too
much and blew the second fuse, then that one would blow and the inrush would
be spread across the whole pack, so inrush would be 1/3 of original inrush.
But, maybe I'm over- (or under-) thinking it.
Thanks.
Bill
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Victor Tikhonov
Sent: Wednesday, March 15, 2006 4:45 PM
To: [email protected]
Subject: Re: Parallel Charging
What exactly these fuses are protecting?
If one battery (right on this diagram) develops really
high R_int (which is not dangerous by itself) the whole
surge current during acceleration may try to flow through the fuse
so the other buddy will supply it. It will blow.
I'd connect fuses in series with chargers if this is what you're
trying to protect.
Victor
Bill Dennis wrote:
> Would it work to connect every 12th cell together, as below:
>
> _________ _____________ pack positive
> | +|________| |
> | | __|__+ __|__+
> | charger | ___ ___
> | 1 _|________| - | -
> |_________| | |
> _________ |---F1--|
> | +|________| |
> | | __|__+ __|__+
> | charger | ___ ___
> | 2 _|________| - | -
> |_________| | |
> _________ |---F2--|
> | +|________| |
> | | __|__+ __|__+
> | charger | ___ ___
> | 3 _|________| - | -
> |_________| |_______|_____ pack negative
>
> Thanks.
>
> Bill Dennis
>
>
--- End Message ---
--- Begin Message ---
Newbie here .....
Is it best to crimp and solder or just solder ?
Special method or solder ?? Gap between insulation and ends ? Heat
shrink tubing ?
--- End Message ---
--- Begin Message ---
Lee, that sounds like this is all possible. Do you think it is made in one
component vs. 2?
Jacob
> From: Electric Vehicle Discussion List <[email protected]>
> Reply-To: <[email protected]>
> Date: Wed, 15 Mar 2006 09:45:46 PST
> To: Electric Vehicle Discussion List <[email protected]>
> Subject: EV digest 5253
>
>
> EV Digest 5253
>
> Topics covered in this issue include:
>
> 1) Re: Can some one build a small motor controller?
> by Lee Hart <[EMAIL PROTECTED]>
> 2) Re: The wreck
> by "Lawrence Rhodes" <[EMAIL PROTECTED]>
> 3) RE: Titleing EV issue
> by Jeff Shanab <[EMAIL PROTECTED]>
> 4) RE: The wreck
> by "Don Cameron" <[EMAIL PROTECTED]>
> 5) Re: Wavecrest fabrication shop up for auction
> by Ken Trough <[EMAIL PROTECTED]>
> 6) RE: Car Transport (was: RE: Bradley GT EV kitcar available cheap
> in Fla on E bay )
> by Cor van de Water <[EMAIL PROTECTED]>
> 7) RE: new low-RR tyre
> by Cor van de Water <[EMAIL PROTECTED]>
> 8) Re: When to Charge?
> by TiM M <[EMAIL PROTECTED]>
> 9) RE: battery prices
> by Cor van de Water <[EMAIL PROTECTED]>
> 10) RE: Bradley GT kitcar in CA
> by Cor van de Water <[EMAIL PROTECTED]>
> 11) Invitation to join the new US Electricar group
> by Cor van de Water <[EMAIL PROTECTED]>
> 12) Re: Bradley GT kitcar in CA
> by "Don Davidson" <[EMAIL PROTECTED]>
> 13) Re: Also looking for a small motor controller?
> by [EMAIL PROTECTED] (Dana Havranek)
> 14) Re: Range extender on the Nissan
> by Mike Chancey <[EMAIL PROTECTED]>
> 15) Re: When to Charge?
> by Lee Hart <[EMAIL PROTECTED]>
> 16) RE: Parallel Charging
> by "Bill Dennis" <[EMAIL PROTECTED]>
> 17) unsubscribe
> by [EMAIL PROTECTED]
> 18) Re: The wreck
> by [EMAIL PROTECTED]
> 19) RE: Parallel Charging
> by "Peter VanDerWal" <[EMAIL PROTECTED]>
> 20) Cheap charger
> by Neon John <[EMAIL PROTECTED]>
> 21) Re: The wreck
> by Neon John <[EMAIL PROTECTED]>
> 22) Re: The wreck
> by Andrew Letton <[EMAIL PROTECTED]>
> 23) RE: Also looking for a small motor controller?
> by "Grigg. John" <[EMAIL PROTECTED]>
> 24) Re: When to Charge?
> by "Rich Rudman" <[EMAIL PROTECTED]>
--- End Message ---
--- Begin Message ---
I would like to make a range extending trailer for the 300zx. The main
goal would be to drive to moms for xmas. Now here is the issue
It is about 110 miles from fresno to sonora AND the drive ends in a climb.
The best I could hope for would be to generate enough to still have a
full pack when I am at the bottom of the hill, at the end of the first
75 miles of 70mph freeway driving. That means I need to put out what I
use at 70mph (or slow down :-o ). Now the PFC20 wont do that so DC to
the pack sounds like the best option. Pack is 288Volts(24 Orbitals) and
75+ amps? Once the pack is sucked down, this isn't a problem, but when
the pack is near full that 75Amp max could really fry an orbital quick.
(like the regen controller issue)
I can think of a couple of ways of handling this.
1. A voltage regulator varies the field on the generator and the
govener keeps it from over reving
The voltage is chosen to be at a point where it can't really charge the
pack above 90 percent, the voltages equalize and the generator backs
off, but put your foot into it and the pack sags and the generator kicks
up, kinda like using the batteries as a capacitor bank.
2. Use the regbus (with external loads) and interface it to the generator
3. Buy a big dc-dc converter.
4. Got to a high voltage generator and buy a zilla 1K, add some
inductance, and put it between the generator and the pack and use some
trickery to the hairball.
--- End Message ---
--- Begin Message ---
hi all -
anyone have any pointers to information about the GE EV1 controller? i
recently acquired a decommissioned but working 25-year-old Baker 36v
forklift (yes, the whole thing - except the battery) and the plan is to
scavenge its parts for a low-performance, short range, small town,
shoestring budget conversion. (Joe Six-pack strikes again.)
i understand from the archives that the GE EV1 SCR controller is the
grandfather of controllers, and as such is pretty inefficient. i'm told
this forklift apparently has bypass contactors for "full throttle" -
that's indicative of something.
it's reputably robust, and it makes a neat hum/growl when you push the
accelerator. but are those its only redeeming qualities?
however, it's what i'll be starting with. and i'm just wondering if
anyone can point me to information that may be useful to a rank novice
such as myself (manual? schematics? what the trim pots do? what's
involved in going from 36v to 48v?). i'm sure i don't even know all the
right questions to ask about it yet.
EV1 guidance and/or info appreciated. thanks -
Darin
--- End Message ---
--- Begin Message ---
jmygann wrote:
Last week I titled my EV in California ...
The vehicle title was from out of state I had a form signed by a peace
officer (city policeman) to verify the vin , make , model. He also
noted that it was electric powered.
Hm. I wonder if I could have a MD police officer verify the above.
Otherwise this is going to be a real pain. I wonder at what point I have
to call in state legislators.
Chris
--- End Message ---
--- Begin Message ---
Chris -
Yes - off the pack and the motor is running the original pump.
The motor is direct coupled to the pump.
The setup is nice and quiet and isolated from the body of the car.
I jdon't need the pump running flat out all the time.
Actually, I would be looking for the sweet spot after the car is rolling.
144 VDC in, 0 to 144 VDC out, able to pass 6 or 7 amps.
It seems very difficult to find.
I was wondering if anyone has any ideas.
Dana
-------------- Original message ----------------------
From: Christopher Zach <[EMAIL PROTECTED]>
> 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...
>
--- End Message ---
--- Begin Message ---
I recently purchase brand new contactors from eBay. They are brand new, but
I got them for such a good price, I am a little concerned that they are
seconds or defective.
1) is this a valid concern?
2) how do I test them?
thanks
Don
Don Cameron, Victoria, BC, Canada
see the New Beetle EV project www.cameronsoftware.com/ev
--- End Message ---
--- Begin Message ---
Looks like it deserves a second look. Two of these could possibly do a 144
volt string as an inexpensive "opportunity" charger with a bigger one in the
garage. I plan to use Hawkers that will take more abuse than the AGM types, so
these might just work.
I like the price too!
Mark Ward
95 Saab 900SE "Saabrina"
www.saabrina.blogspot.com
---- Neon John <[EMAIL PROTECTED]> 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. 10
> amps max plus the timer isn't going to harm wet cell packs. Two of
> these would handle a 144 volt system. The below link is the best
> price we've found so far.
>
> John
>
> On Tue, 14 Mar 2006 21:22:58 -0000, "Tell you if you ask."
>
> >http://www.batteryservice.com/products_final.aspx?ModelNumber=SE-1072
> >
> >Also, thanks for the good link on de-sulfators.
> >
> >Rich
> >
> >
> >
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> ><*> To visit your group on the web, go to:
> > http://groups.yahoo.com/group/C-Car/
> >
> ><*> To unsubscribe from this group, send an email to:
> > [EMAIL PROTECTED]
> >
> ><*> Your use of Yahoo! Groups is subject to:
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
> >
> ---
> 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
--- End Message ---
--- Begin Message ---
Matt,
If this is helpful, I work in Generators and large gen sets all day.
Just for everyones FYI;
ALL of the HONDA generators use a 12V alternator and an Inverter (not much
different than the ones you buy anywhere) for the AC output, so while they DO
have the sine-wave out and are great for surge currents up to 2x their rated
outputs, they are not good at running inductive or transformer output loads
like many inverters. They are extremely quiet. They do not have a true AC
winding or output like any standard (non-inverter) generator. They are like
using your alternator and any inverter, hence the EU in the name. From Honda
"Honda EU3000is inverter-equipped portable generator delivers extremely
high-quality electricity ideal for powering a vast range of home and
professional equipment..."
Even the cheaps*** genny's tend to do better and if you use a 1:1 transformer
(although more weight) it will eliminate any risk caused by surges at low
fuel/sputtering when fuel is running out.
I hope this helps and is not off the mark here.
-Eric
--------------------------------------------------------original:
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
---------------------------------
Yahoo! Mail
Use Photomail to share photos without annoying attachments.
--- End Message ---
--- Begin Message ---
We are posting this for a friend. He is building a trike and looking
for a 48V 10-30A charger for sealed or AGM batteries, onboard. His
available space for it is 10" x 12" x 11", subject to change
depending on what he can get.
Contact him directly off-list: Perry Harrington [EMAIL PROTECTED]
Mike Brown
Electro Automotive POB 1113 Felton CA 95018-1113 Telephone 831-429-1989
http://www.electroauto.com [EMAIL PROTECTED]
Electric Car Conversion Kits * Components * Books * Videos * Since 1979
--- End Message ---
--- Begin Message ---
Christopher Zach writes:
>
> Hm. I wonder if I could have a MD police officer verify the above.
> Otherwise this is going to be a real pain. I wonder at what point I have
> to call in state legislators.
Or maybe look in the back of magazines like Old Bike Journal (if it's
still published, they focus on older motorcycles). There used to be
ads in the back for companies doing titling services (lost title, etc).
These companies would register your vehicle in some state with lenient
requirements and send you a clear title that you could then take to
your local DMV.
Ralph
--- End Message ---
--- Begin Message ---
Dana Havranek wrote:
> I too have been looking for a small, quiet controller to run my
> power steering motor... for now, I would just like to find a unit
> or a circuit. It's a 144 volt battery pack and a permanent magnet
> motor 0-180 VDC.
My suggestion is to build a small PWM controller. It's a good test case
before trying to build a full-sized controller; all the same problems,
but scaled down to a more manageable size.
I'd use a transistor/diode module. They cost more, but everything is
done for you. No need to parallel or match devices; you get an isolated
mounting plate, and a lower thermal resistance than you could have built
yourself. For example, an IR 50MT060WH, which has two 600v 114amp IGBTs
and two fast diodes, in an isolated 2.5"x1.3" package, for $60.57 from
Digikey.
For the PWM circuit, use one of the many inexpensive switching regulator
chips. You can get one with all the supporting parts by cannibalizing a
switchmode power supply.
--
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 ---
all of the above!
From: "jmygann" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Soldering terminals to 2/0 welder cable ??
Date: Thu, 16 Mar 2006 01:37:43 -0000
Newbie here .....
Is it best to crimp and solder or just solder ?
Special method or solder ?? Gap between insulation and ends ? Heat
shrink tubing ?
_________________________________________________________________
Shopping made easy @ tradingpost.com.au
http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fwww%2Etradingpost%2Ecom%2Eau%2F%3Freferrer%3DnmsnHMetagv1&_t=753082530&_r=emailtagline&_m=EXT
--- End Message ---
--- Begin Message ---
ProEV wrote:
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.
Testing small cells of equal chemistry isn't exactly the same,
but allows few hours cycles so accumulate life time data
relatively quickly. Assumption is it scales up with the cell
size and if initial *trends* more-less match, assumption is,
it can be extrapolated with high degree of confidence level.
The only "cheating" factor you can't circumvent by cycling
small cells is shelf life - cycle data grossly dominate
shelf life influence as thousands of cycles may be completed in
a couple of month. With large cells shelf life limitation may
bring unforeseen surprises later...
Victor
--- End Message ---
--- Begin Message ---
Bill Dennis wrote:
Thanks, Victor, that's what I was thinking. There will be extra capacity in
the 270Ah cell that I won't use anyway, since a 200Ah cell will reach bottom
first. So if the 270Ah cell has a little less capacity, it shouldn't be a
problem.
Yes, it's not a problem. The problem is if 70Ah will reach full first.
How do you
complete charging 200Ah one without overcharging 70Ah one if they are in
parallel? Just holding 4.25V
on both will take forever to do it.
Victor
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Victor Tikhonov
Sent: Wednesday, March 15, 2006 4:39 PM
To: [email protected]
Subject: Re: Different Cell Capacities
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: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Victor Tikhonov
Sent: Tuesday, March 14, 2006 3:13 PM
To: [email protected]
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
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Mark Ward wrote:
> Looks like it deserves a second look. Two of these could possibly
> do a 144 volt string as an inexpensive "opportunity" charger with
> a bigger one in the garage. I plan to use Hawkers that will take
> more abuse than the AGM types, so these might just work.
The price is great, but you get what you pay for! These are just a
transformer and rectifier in a box -- no "smarts" at all. They would be
barely adequate for floodeds, where you can add water and overcharging
won't (immediately) murder them.
But, using a cheap charger like this on an expensive set of Hawkers is a
very bad idea. Hawkers *are* AGMs. You will soon ruin them if you
overcharge them. And a charger like this *will* overcharge them!
--
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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On Wed, 15 Mar 2006 19:05:50 -0800 (PST), Eric Gorodetzky
<[EMAIL PROTECTED]> wrote:
>Matt,
> If this is helpful, I work in Generators and large gen sets all day.
> Just for everyones FYI;
> ALL of the HONDA generators use a 12V alternator and an Inverter (not much
> different than the ones you buy anywhere) for the AC output, so while they DO
> have the sine-wave out and are great for surge currents up to 2x their rated
> outputs, they are not good at running inductive or transformer output loads
> like many inverters. They are extremely quiet. They do not have a true AC
> winding or output like any standard (non-inverter) generator. They are like
> using your alternator and any inverter, hence the EU in the name. From Honda
> "Honda EU3000is inverter-equipped portable generator delivers extremely
> high-quality electricity ideal for powering a vast range of home and
> professional equipment..."
Almost none of this is true. The Honda EU contains a high voltage
three phase permanent magnet alternator that generates its power at
several hundred volts, depending on the engine speed. This power is
rectified and pulse-width-modulated into a very low distortion 60 hz
output. The harmonic content is typically lower (<1% according to my
testing) than utility power.
This is an "inverter generator" only in the sense that DC is
"inverted" to AC electronically. There is no DC/DC step-up or
step-down stage.
The EU handles loads with reactive components very well. Much better,
in fact than many cheap-sh*t (and even some non-cheap) conventional
generators. Many cheap-sh*t generators with marginal magnetics
actually tend toward triangle waveforms with capacitive (leading PF)
loads. The EU series has become the standard for RV trailer and 5th
wheel air conditioners, loads that tend to have a fairly low PF.
I don't own an EU but I've had an EU3000 and an EU2000 in my lab for
analysis. If the load fits within the EU line's capacity and the
budget, IMO, this is the best generator available.
Note too that Honda makes a line of cyclo converter generators that,
while they use electronics to down-sample the generated frequency to
60 hz, use no inverters. The waveform is a little higher in harmonic
energy but still better than cheap-sh*t generators.
> Even the cheaps*** genny's tend to do better and if you use a 1:1
> transformer (although more weight) it will eliminate any risk caused by
> surges at low fuel/sputtering when fuel is running out.
A transformer will have absolutely no effect. It will simply pass
through whatever components of the input waveform fit within its
bandwidth.
There is only one place where a transformer can help a generator. That
is when the generator has a tapped and non-reconfigurable 120/240 volt
winding and the load is primarily 120 volts. Connected directly, the
120 volt load can only be half the generator's rating and even then,
the cogging caused by loading only half the winding can cause
torsional vibrations, rough running and noise.
A 2:1 transformer (240 in, 120 out) will distribute the load across
all the generator's windings, will allow full load and smooth running.
I used exactly this solution recently to solve a client's severe
vibration problem in his 15kw off-grid diesel generator. It took only
a 2:1 dry transformer to completely stop the vibration.
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
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It is best to make a very solid compression mechanical connection on the
full length of a heavy duty plated brass terminal lug. If the wire inserts
1 inch into the terminal lug or battery post connection type, then you want
a full 360 degrees crimp 1 inch long all around the barrel, so the wire and
terminal becomes one solid mass.
This type of wire crimping removes all the air voids between the wire and
the terminal lug. The type of tool to do this type of crimp is a hydraulic
type with a full length die.
The next tool is a ratchet type, which the die a three corner type, where
the two half's forms a hexagon crimp. These dies are not as wide, about 1/4
to 3/8 inch wide. With this type of die, you must make several crimps which
is outline by the heavy duty terminal that had guild lines on it.
The ratchet hexagon crimp also performs a solid mass crimp.
To make up the wire to insert the terminal lug, first measure the insert
depth of the lug. Cut the insulation of the wire that depth plus 1/8 inch
longer. If you used a heavy duty ratchet crimpier, you can secured it in a
vise, place the terminal lug in the crimpier and push down on the handle to
just barely holding the lug, but not indenting it.
If you terminal lug has two crimp guild lines on it, first position the
crimpier on the out side guild line which should be about 1/8 inch away from
the wire insulation.
Now push the wire in hard as possible until the insulation butts against the
terminal lug and crimp that position of the lug. Then move inward toward the
ring of the terminal and crimp on the next guild line.
The reason you crimp first next to the insulation of the wire, is that if
you crimp too close to the ring terminal, you could make the wire slip back,
because that end of the terminal lug is taper.
Some terminal lugs have a long barrel that may have three crimp guilds,
these type are what we used for overhead line and switch gear. The two
crimp guild type is best for battery links.
The best type of terminal lug to used, does not have the small hole next to
the ring end.
If you just solder a cable end only without any mechanical connection, the
solder connection can act like a fuse. A short circuit connection will melt
at 330 degrees F.
If you think you have air voids in your crimping, than you can solder after
a mechanical connection is done first. Do not tinned the wire first before
it is inserted into the terminal lug. In are overhead and interial
electrical work, this is not permitted because this puts a bi-metal barrier
between the copper and the terminal.
If you are using a sharp point indenting tool to crimp the wire which is not
the best type, than allow about 1/8 gap between the barrel of the lug and
the wire insulation and use a wire lug with a hole at the ring end. This
allows you to add solder after you crimp the terminal lug.
Used a heavy duty shrink that has a wax type of glue in it. This heat
shrink has a wall thickness of about 1/16 inch and its very stiff, its not
the roll up type. You can get it in 3 foot lengths that looks like plastic
pipe. Cut these in about 2 inch lengths. Be sure you slip these on before
you put the last terminal lug on you wires.
We used these type of heat shrinks for underground electrical work. After
making a splice in cable and cover it with the glue type heat shrink, we can
directly bury it.
You can either shrink this type of heat shrink with a low temperature flame
heat gun that is design for this type of work, or used a 1500 watt heat gun.
The ratchet crimpier, terminal lugs and heat shrinks is made by Thomas and
Bettes and the heat gun is a Milwaukee type.
If you do not have access to a wholesale electrical supply house, you can
get all the above equipment from Home Depot or a EV Parts Store.
I used a heavy duty plated terminal lug on my battery links, but I do not
connected directly to the battery post. I found that the direct connection
has cause the plating to be tarnish by the direct connection to the lead
post. So I install a gold plated brass battery clamp that has a threaded
bolt hole for a thru bolt and a nut that connects to my battery links. Can
torque these units to about 15 ft lbs.
I found when you change batteries that may have a different post spacing,
you would have to make up new battery links every time. The gold plate
battery clamps can rotated to fit any post configuration.
Roland
----- Original Message -----
From: "jmygann" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, March 15, 2006 6:37 PM
Subject: Soldering terminals to 2/0 welder cable ??
> Newbie here .....
>
> Is it best to crimp and solder or just solder ?
>
> Special method or solder ?? Gap between insulation and ends ? Heat
> shrink tubing ?
>
>
>
>
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--- Begin Message ---
If you use high quality lugs and a good crimper, then there is NO need to
solder and in fact it is better to NOT solder.
A good quality crimp connection basically pressure welds the copper
together. There is no room for solder and a good copper to copper weld
has lower resistance than a soldered joint and is stronger mechanically
(solder has virtually zero mechanical strength).
> Newbie here .....
>
> Is it best to crimp and solder or just solder ?
>
> Special method or solder ?? Gap between insulation and ends ? Heat
> shrink tubing ?
>
>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
Jacob wrote:
> Lee, that sounds like this is all possible. Do you think it is made
> in one component vs. 2?
>> EV Digest 5253
Jacob, you quoted the entire digest. To which post exactly were you
referring?
--
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 ---
At 06:37 PM 3/15/2006, you wrote:
Newbie here .....
Is it best to crimp and solder or just solder ?
The Navy did a study. It is better to just crimp correctly.
If you want to save a few bucks, and you have access to a welder,
here is how to make 2/0 crimpers for $21.
http://www.haritech.com/crimp.htm
Special method or solder ?? Gap between insulation and ends ? Heat
shrink tubing ?
Heat shrink. Best if it has the sealant goo inside, especially if
you are planning on flooded lead-acid.
Bill Dube'
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Hi all
This is for an OT application for my customer, but relvant in the scheme of
things.
I have a customer with a piece of plant in development that they want to
keep running when the grid goes off, they are going to have a generator,
but would like "no-break". Since this will be running off a
variable-frequency drive (aka an AC motor controller), I have suggested
that they hook up a battery pack through a diode to power the DC buss when
the grid goes down. Rectified 415V 3-phase ends up sitting in between
570VDC and 600VDC, depending on its' "mood".
I've roughed 40 12V batteries (572V@ 14.3V/module) as being aproximate,
still 480V if it gets down to 12V/module, enough to keep things running.
They only need a few seconds of buss support - 5 to 20 seconds, depending
on the startup time of the diesel engine generator. When the plant is shut
down the battery would be isolated from the controller buss, so could be
'peaked up' then.
Since their full load is around 625kVA, that means pulling current at
approaching 1000A during demand times, so I'm thinking Exide Orbitals or
similar. Rudman regs or similar, but what about the charger? 10A would be
enough, 25A would be better. 415V 3-phase, or 240VAC 1-phase or a
transformer for whatever voltage. What's out there that can reach 570V (or
more) on the battery? Isolation is a must (or we throw a transformer on the
supply side), since there could be issues since the load is referenced to
the supply.
Rich, how high in voltage do you/are you likely to go?
Victor, have Brusa or anyone you deal with making anything in that range?
Anyone else with any ideas?
Thanks in advance
James
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