Results 1 to 14 of 14
  1. #1
    RC Racer
    Join Date
    Oct 2011
    Location
    Central BC, Canada
    Posts
    139

    But, if we're not supposed to run them right down...

    I've read many times that we should stop running our NiMHs once performance starts noticeably dropping off.

    But, if we're not supposed to run them right down...

    The why is it okay to discharge them on our charger before charging them back up? (Or does the "discharge" function on a charger not take the battery all that low?)

    Thanks for any input, guys!
    1/10 Summit (x2)
    1/10 E-Revo
    1/16 E-Revo b/l

  2. #2
    Marshal ksb51rl's Avatar
    Join Date
    Nov 2006
    Location
    Northern NJ
    Posts
    16,975
    Unless you have premium side by side packs and a good equalizer tray, I see no need to discharge a NiMH pack. There is much more danger in draining a pack (or a single cell) too much than in leaving a pack charged.
    FWIW, 0.9 to 1.0 volts per cell should be the target range for maximum discharge.
    Alt-248 on the number pad =

  3. #3
    RC Champion
    Join Date
    Feb 2011
    Location
    UK
    Posts
    1,936
    I see performance drop offs every month or so this is when I discharge my pack to 0.9v per cell to regain performance. I wouldn't do it every time but once a month's good
    Does more $ = More fun?
    Rustler VXL

  4. #4
    Marshal ksb51rl's Avatar
    Join Date
    Nov 2006
    Location
    Northern NJ
    Posts
    16,975
    What packs or what cells? How do you discharge them?
    Alt-248 on the number pad =

  5. #5
    RC Racer
    Join Date
    Oct 2011
    Location
    Central BC, Canada
    Posts
    139
    Me?

    My charger has a cycle function (either discharge/charge, or charge/discharge, up to 5 cycles, user-selected) ... or you can set it manually. Discharge and charge rates are both programmable. It's a "Great Hobbies" branded item ... so I've no idea what it would equate to, south of the border.

    For batteries, I have Traxxas 3000mah and Duratrax 5000mah - both 7-cell, 8.4V. These are (obviously) for my 1/10 models.

    I generally charge and discharge these at 1 amp. (Charge at 0.5 when I'm trying to bring it up slowly without getting a false peak.)
    Last edited by AlHenderson; 11-16-2011 at 12:03 PM.
    1/10 Summit (x2)
    1/10 E-Revo
    1/16 E-Revo b/l

  6. #6
    Marshal ksb51rl's Avatar
    Join Date
    Nov 2006
    Location
    Northern NJ
    Posts
    16,975
    Quote Originally Posted by AlHenderson View Post
    Me?

    My charger has a cycle function (either discharge/charge, or charge/discharge, up to 5 cycles, user-selected) ... or you can set it manually. Discharge and charge rates are both programmable. It's a "Great Hobbies" branded item ... so I've no idea what it would equate to, south of the border.

    For batteries, I have Traxxas 3000mah and Duratrax 5000mah - both 7-cell, 8.4V. These are (obviously) for my 1/10 models.

    I generally charge and discharge these at 1 amp. (Charge at 0.5 when I'm trying to bring it up slowly without getting a false peak.)
    I was asking The VXL. But for you, that's a very low charge rate. You should have no trouble charging at 1C.
    Alt-248 on the number pad =

  7. #7
    RC Racer
    Join Date
    Oct 2011
    Location
    Central BC, Canada
    Posts
    139
    Okay, thanks!
    1/10 Summit (x2)
    1/10 E-Revo
    1/16 E-Revo b/l

  8. #8
    RC Enthusiast
    Join Date
    Nov 2011
    Location
    Englewood, FL
    Posts
    39
    Yes indeed we have been told not to totally drain NiMH cells, or risk damage. So I found it rather odd today when I saw this quote here on the TRX site !!

    "Storing Your Batteries
    Nickel batteries should be fully discharged before charging, and should be stored fully discharged (just use the battery in your R/C vehicle until the battery can no longer move it)."

    That goes against what 99.9% of us think and against other high end packs from SPC, ProMatch etc. !!!! Now if we were talking NiCD's well those are fine to totally dump, but hopefully a Mod can point this out to tech support.

    This is quoted from this page :

    http://traxxas.com/support/Traxxas-Battery-Basics
    Last edited by BTEMT; 11-20-2011 at 05:41 AM.

  9. #9
    RC Racer
    Join Date
    Oct 2011
    Location
    Central BC, Canada
    Posts
    139
    See, now THAT is the sort of conflicting info I've been running into. I've seen the same thing on this site (on the product side, that is) ... yet a techie where I've bought all my vehicles (all Traxxas, mind you) told me NEVER run it all the way down. *sigh*
    1/10 Summit (x2)
    1/10 E-Revo
    1/16 E-Revo b/l

  10. #10
    RC Enthusiast
    Join Date
    Aug 2011
    Posts
    35
    Lets say you did run them down all the way, can they be saved somehow? I have a couple Traxxas 3000 packs that were run waaaay down I think. The performance of the packs is not what it should be anymore. Will cycling them with a decent charger restore them?

  11. #11
    RC Racer
    Join Date
    Oct 2011
    Location
    Central BC, Canada
    Posts
    139
    From what I've heard, that's likely your best bet ... with a slow charge. Check first that there is no "physical damage" (that you can see) - splits in the paper, swelling, that sort of thing.

  12. #12
    RC Enthusiast
    Join Date
    Nov 2011
    Location
    Englewood, FL
    Posts
    39
    Quote Originally Posted by AlHenderson View Post
    See, now THAT is the sort of conflicting info I've been running into. I've seen the same thing on this site (on the product side, that is) ... yet a techie where I've bought all my vehicles (all Traxxas, mind you) told me NEVER run it all the way down. *sigh*
    I sent that page in to TRX support asking them to clarify, no response yet though.
    3905 Emaxx

  13. #13
    genXrated
    Guest
    The common knowledge I've known for years is that NiCad batteries HAD to be fully discharged b/c they would develop a 'memory' over time and slowly lose their capacity, whereas NiMh are more durable and their chemisty allows them to be partially discharged for a period of time without the same problem. However, each company has their own guideline and it's been generally accepted that you still store NiMh with a minimal voltage. Now what that # is I don't know offhand, but I had NiMh packs for years that would be run down until the vehicle stopped and that's how I'd leave them for storage without any adverse effects. Just my $.02 worth.

  14. #14
    genXrated
    Guest
    Oh, and cycling packs is not a bad idea either. It conditions the cells, so if you've had decreased performance over time, doing this sometimes will revive the pack. If it's already been thru 100's of cycles, then it may be dying.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •