Matching question

Old 12-06-2004, 01:12 PM
  #1  
Tech Rookie
Thread Starter
 
Join Date: Dec 2004
Location: Austin, TX
Posts: 5
Default Matching question

I have a CE Turbo 35 GFX. I know it's capable of matching one cell at a time. I am in need of some new packs and I was thinking about picking up 25-50 cells and slowly generating numbers one at a time and hopefully getting 1-2 race packs and several good but not great packs for practice, etc.

Say I am discharging at 30 amps and have a .9V cutoff, what are the chances I'm going to get 6 cells at above 1.170V average?

Or, how rare is it to get a cell that is say 390+ seconds and 1.170? 1 in 10, 1 in 20, etc.

Thanks a lot.
krentler is offline  
Old 12-07-2004, 10:04 AM
  #2  
Company Representative
iTrader: (15)
 
Join Date: Sep 2001
Posts: 1,700
Trader Rating: 15 (100%+)
Default

You will not have matched packs if your only working with 50 cells. the chances would be very slim.

it would be better to take the $ and buy 3-4 good packs.
Korgae is offline  
Old 12-07-2004, 10:16 AM
  #3  
Tech Rookie
Thread Starter
 
Join Date: Dec 2004
Location: Austin, TX
Posts: 5
Default Thanks

Good information.

I have some SMC cells that I really like. For reference, why does SMC discharge their cells while matching at 35A? Aren't you never going to draw 35A and your Vavg number will be lower, making it harder to compete with companies who show their numbers at 30A? I know the educated buyer would know that there was a difference, but also I don't think you would ever draw 35A. I guess you could draw 30A right at the start, but I can't believe you'd do that an entire race.

From the SPEC sheet for the GP3300 cells (from www.gpbatteries.com.hk, the cells are rated at 10C which would be a maximum of 33A discharge.

The only reason I can think of for this is that a higher discharge rate will allow a company to match more cells per hour, rather than buying more matchers.

Anyway, I love my SMC cells, and I just bought a ton of your battery bars. Thanks for answering my questions and making a great and affordable product.

Bob
krentler is offline  
Old 12-08-2004, 02:30 PM
  #4  
Company Representative
iTrader: (15)
 
Join Date: Sep 2001
Posts: 1,700
Trader Rating: 15 (100%+)
Default

Krenter- You could not be further from the truth.

1) Draw is much higher then 30 amps, if your statement was correct then racers would not have any issues with dunping in Mod or even 19 turn.

to be fair I understand your thinking but in tests it really shows the true amp draw.

the difference between disharging @ 30 and 35 is just over 1 minute, at the end of the day it would not even work out to a extra cycle in time saved. and trust me, we have more then enough machines

The reason we did 35 amps was to produce a tighter tolerance in the match itself. the more load we can test under the true performance of that cell will be uncovered with 35 but not nessarry with 30.

We must be doing something right, we just took 5 or the 6 classes at this years Indoor Champs.
Korgae is offline  
Old 12-15-2004, 03:39 PM
  #5  
Tech Adept
 
Join Date: May 2002
Location: Midwest
Posts: 147
Default

Krentler,

For a simple totally non-technical analogy, think of cells cycled and discharged at 20 amps as going through Air Force Boot Camp, those at 30 amps as going through Marine Corp Boot Camp, and those at 35 amps as going through Special Forces Training ... only the best of the best survive the process!
Luckyman4 is offline  
Old 01-05-2005, 11:38 AM
  #6  
Tech Apprentice
 
Baja's Avatar
 
Join Date: Dec 2004
Location: seattle
Posts: 56
Default

How long does a matched pack stay matched and what can be done to maintain a pack as evenly as possible?
Baja is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.