R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 12-03-2003, 05:40 AM   #1
Tech Initiate
 
Join Date: Sep 2003
Posts: 44
Default Battery management question

Hi, I have seen many rules regarding to how people manage their new/old 3300 ni-mh cells. Some suggested that I should discharge the pack down to 5.4 before storing it. There are people also suggested that I should discharge each cell down to 0.1v or 0.2v before storing it for the next race. When I want to charge the pack for race, should use those expensive "tray-type" to fully discharge (0.1v each cell) my pack? Some people would store it shorted until the next time charging it too...So, which rules should I follow?

Please advise. Thank you!

Last edited by discus18; 12-03-2003 at 05:50 AM.
discus18 is offline   Reply With Quote
Old 12-03-2003, 06:00 AM   #2
Tech Elite
 
John Fontaine's Avatar
R/C Tech Charter Subscriber
 
Join Date: Mar 2003
Location: SouthEast PA
Posts: 2,699
Trader Rating: 2 (100%+)
Send a message via AIM to John Fontaine
Default

If you ask 1000 people, 1000 difference responces will be given. So for that, I will give my 1 response that has given me the best power/punch from the pack without hurting the pack leading to long life.

I discharge and store GP3300's at 5.4v/pack for 6 cell, 3.6 v/pack for 4 cell packs.

The morning of the race day, I tray the cells down so the cells are all equalized. I then charge the pack on my CE GFX at 6 amps for stock, 5 amps for mod (to gain runtime but less voltage) at .03 - .05 peak detect. The cells should be 145-155 degrees. I try and have them peak as close to running the race that I can. If the race isn't run withing 5 minutes from peaking, I repeak at the same amperage rate at .01 so they do not over heat the cells. After the race is finished, and I won I discharge the pack down to 5.4 v/6 pack and 3.6v/4 pack and let the air cool (No cooling fans!) atleast an hour and a half before recharging so the internal cell structures rest. I never race the pack more than 2 times a day.

This process has awesome results for me, but could vary do to temperature/humidity. I gain the best results from the pack from local environment of 75-85F.

Hope this helps, if you have any questions please let me know or check the Fukuyama Racing thread here at RCTech for more discussion.

John
__________________
Xray and Serpent....very dusty!
John Fontaine is offline   Reply With Quote
Old 12-03-2003, 06:10 AM   #3
Tech Rookie
 
Join Date: Oct 2002
Posts: 17
Default

i was wondering if you tray them don't you loss run time? and maintain voltage?
porky-ninja is offline   Reply With Quote
Old 12-03-2003, 06:33 AM   #4
Tech Initiate
 
Join Date: Sep 2003
Posts: 44
Default

So, when I choose a tray discharger, which one should I choose? some discharge to 0.1 some to 0.5...quite confusing to me. Thanks!
discus18 is offline   Reply With Quote
Old 12-03-2003, 06:43 AM   #5
Tech Elite
 
John Fontaine's Avatar
R/C Tech Charter Subscriber
 
Join Date: Mar 2003
Location: SouthEast PA
Posts: 2,699
Trader Rating: 2 (100%+)
Send a message via AIM to John Fontaine
Default

There are a lot of different trays. I have a trinity Realtime 2 and it brings each cell down to 0. I keep an eye on the bulbs and use a multimeter to check voltages while traying but i dont let them go to 0. Some trays like the integy have a .9 volt cutoff. It all depends on what you want to get. I'm sure the search function here could tell you all about different types of trays.

John
__________________
Xray and Serpent....very dusty!
John Fontaine is offline   Reply With Quote
Old 12-03-2003, 08:14 AM   #6
Regional Moderator
 
disaster999's Avatar
 
Join Date: Aug 2001
Location: Hong Kong
Posts: 3,181
Trader Rating: 1 (100%+)
Default

got any suggestions for those ppl who isnt a team driver and only have 3 packs of battery and cant afford only letting the pack run twice a day?
disaster999 is offline   Reply With Quote
Old 12-03-2003, 08:58 AM   #7
Tech Elite
 
John Fontaine's Avatar
R/C Tech Charter Subscriber
 
Join Date: Mar 2003
Location: SouthEast PA
Posts: 2,699
Trader Rating: 2 (100%+)
Send a message via AIM to John Fontaine
Default

Try and let them rest as much as you can after you discharge. Also, keep your best packs fresh for the 3rd qual and main if you can.

John
__________________
Xray and Serpent....very dusty!
John Fontaine is offline   Reply With Quote
Old 12-03-2003, 11:55 AM   #8
Tech Elite
 
highwayman's Avatar
 
Join Date: Apr 2002
Posts: 2,334
Trader Rating: 2 (100%+)
Default

Quote:
Originally posted by discus18
So, when I choose a tray discharger, which one should I choose? some discharge to 0.1 some to 0.5...quite confusing to me. Thanks!

i'd get the one with a cut-off... bringing down the voltage more than .9 volts hurt the cells in the long run.
highwayman is offline   Reply With Quote
Old 12-03-2003, 07:22 PM   #9
Tech Adept
 
Join Date: Nov 2001
Location: Hong Kong
Posts: 171
Default

Quote:
Originally posted by highwayman
.. bringing down the voltage more than .9 volts hurt the cells in the long run.
Hi Highwayman,

Can you tell why to the cells hurt or what happen to the cells if we bring down the voltage more than 0.9 volts ??

Thanks !
Anthony
Anthony Yuen is offline   Reply With Quote
Old 12-03-2003, 07:33 PM   #10
Tech Elite
 
highwayman's Avatar
 
Join Date: Apr 2002
Posts: 2,334
Trader Rating: 2 (100%+)
Default

There are 2 things that you can do, that are very bad for the cells, overcharge them, thereby overheating them, and leaving them without charge... (bringing it down more than .9 volts)

as to what exactly happens, chemically inside, i don't know why...

my $.02
highwayman is offline   Reply With Quote
Old 12-03-2003, 08:08 PM   #11
Tech Master
 
UCHEATULOSE's Avatar
 
Join Date: Dec 2002
Location: birth place of oval! daytona beach!
Posts: 1,083
Default

lemme throw a wrench into this..

with the second generation cells in stock and 19 turn oval

store them dead shorted!
use a real time tray or integy tray to bring them down..dead short with solder. charge them until they reach 140-150 deg ..again this is for race conditions not for back yard bob..and i race oval..all of my packs have dropped in IR and gained in voltage..but lost 30 sec run time on avg..only works on generation 2 GP cells..and i have no idea what the new 3rd generation cells will do when dead shorted..i have packs that are over 3 months old and still perform like new or better..but an oval car comes back with over 60 sec run time at 30 amps in 19 turn and over 100 sec in stock..the touring scene may need that run time?
UCHEATULOSE is offline   Reply With Quote
Old 12-03-2003, 09:16 PM   #12
Tech Elite
 
highwayman's Avatar
 
Join Date: Apr 2002
Posts: 2,334
Trader Rating: 2 (100%+)
Default

UCHEATULOSE:

as for me... i need the run time in modified TC, that's why dead shorting doesn't appeal to me...
highwayman is offline   Reply With Quote
Old 12-03-2003, 09:29 PM   #13
Tech Master
 
Maj. Teeth's Avatar
 
Join Date: May 2003
Location: Southern California
Posts: 1,130
Default

Quote:
Originally posted by highwayman
There are 2 things that you can do, that are very bad for the cells, overcharge them, thereby overheating them, and leaving them without charge... (bringing it down more than .9 volts)

as to what exactly happens, chemically inside, i don't know why...

my $.02
I'm a little in disagreement with the bringing down below .9volts part. We're experiencing some gain in runtime but it is to be determined. So far we've brought the cells down to about .05 and hold it there for 5 minutes before charging them right away and it has yield a higher charge and peak with better runtime. Just something we're working on.

Dan
Maj. Teeth is offline   Reply With Quote
Old 12-03-2003, 09:38 PM   #14
Tech Elite
 
highwayman's Avatar
 
Join Date: Apr 2002
Posts: 2,334
Trader Rating: 2 (100%+)
Default

Quote:
Originally posted by Maj. Teeth
I'm a little in disagreement with the bringing down below .9volts part. We're experiencing some gain in runtime but it is to be determined. So far we've brought the cells down to about .05 and hold it there for 5 minutes before charging them right away and it has yield a higher charge and peak with better runtime. Just something we're working on.

Dan

good to hear that... keep us posted.

... just a question... is that already on an assembled pack or cycled on a T35?
highwayman is offline   Reply With Quote
Old 12-03-2003, 09:41 PM   #15
Tech Master
 
Maj. Teeth's Avatar
 
Join Date: May 2003
Location: Southern California
Posts: 1,130
Default

Quote:
Originally posted by highwayman
good to hear that... keep us posted.

... just a question... is that already on an assembled pack or cycled on a T35?
hehe.. that's on a built pack that's been ran by racers (my own pack. ).

Dan
Maj. Teeth is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Yokomo Battery Management System ImSkitzoAndSoAmI Australia For Sale/Trade 2 10-24-2006 07:33 AM
Spintec Battery Management Still Bill Electric On-Road 2 03-19-2005 09:21 PM
Pro Trak Battery Management System - I need help tornado Electric On-Road 2 12-28-2004 10:18 PM
Yokomo Battery Management System (BMS) edseb R/C Items: For Sale/Trade 3 10-20-2004 10:38 PM
Pro-Trak Battery Management System For Sale Tres R/C Items: For Sale/Trade 10 08-19-2004 06:08 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -7. It is currently 02:50 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net