Results 1 to 11 of 11
  1. #1
    RC Turnbuckle Jr.
    Join Date
    Mar 2012
    Location
    Mojave Desert
    Posts
    3,028

    Lipo reaching capacity limit before full voltage

    My 3s lipo is reaching its 5000mah limit but each cell is still at 4.15 volts instead of the normal 4.20??? never happened before so what's going on?

  2. #2
    RC Turnbuckle Jr. DiggerPede's Avatar
    Join Date
    Apr 2011
    Location
    Texas, ChevronPhillips Chemical Plant along the Gulf Coast
    Posts
    7,176
    The charger should bring it up to full votage first then stuff the pack to capacity with Mah. Cycle the pack a few times and see if that changes. I would recommend running the pack to your set voltage then charging it again, maybe a few times of doing this and it will charge up correctly. If you have another charger or a friend that has one try and see if it does the same thing on it.

    The only other issue I would know is the Charger isnt doing its job correctly. A cheap charger tends to do this. What one are you using?
    Weak Revenge
    Strong Forgive
    Intelligent Ignore

  3. #3
    RC Turnbuckle Jr. JimmyNeutron's Avatar
    Join Date
    Oct 2009
    Location
    Alma, Michigan
    Posts
    12,314
    Charge your LiPo pack by voltage only. It is 100% normal for a pack to take more mAh that it is labeled for. Once it reaches 4.2 volts per cell, the pack is fully charged... charging by mAh values will either leave you with a pack that is not fully charged or a pack that is over charged.

    DiggerPede:
    "bring it up to full votage first then stuff the pack to capacity with Mah"
    ^^^ That is not how a charger works.
    Whatever it is I just typed... could be wrong.

  4. #4
    RC Turnbuckle Jr. DiggerPede's Avatar
    Join Date
    Apr 2011
    Location
    Texas, ChevronPhillips Chemical Plant along the Gulf Coast
    Posts
    7,176
    I'm sorry JN. I did word that wrong. Sorry. You are totally correct.

    Maximum Charge Voltage and Current
    A 3.7 volt RC LiPo battery cell is 100% charged when it reaches 4.2 volts. Charging it past that will destroy the battery cell and possibly cause it to catch fire. This is very important to note and keep in mind at all times. A computerized charger will stop the charge process when the battery reaches 4.2 per cell. A balanced computerized charger will do this for each individual cell.

    It is critical that you use a charger specified for Li-Po batteries and select the correct voltage or cell count when charging your RC LiPo batteries if you are using a computerized charger. If you have a 2 cell (2S) pack you must select 7.4 volts or 2 cells on your charger. If you selected 11.1V (a 3S pack) by mistake and tried to charge your 2S pack, the pack will be destroyed and most likely catch fire.

    Most good RC LiPo battery chargers will use the constant current / constant voltage charging method (cc/cv). What this means is that a constant current is applied to the battery during the first part of the charge cycle. As the battery voltage closes in on the 100% charge voltage, the charger will automatically start reducing the charge current and then apply a constant voltage. The charger will stop charging when the 100% charge voltage of the battery pack equalizes with chargers constant voltage setting (4.2 volts per cell) at this time, the charge cycle is completed. Going past that, even to 4.21 volts will shorten battery life.
    What I actually meant to say was towards the end of the charge the Charging Amperage trickles down to get Mah in there, wo going over the voltage. A good high end charger does a very good job at not going over the voltage. I set my PL6 to charge my packs to 4.19vpc. Probably still don't sound right. JN will probably correct me if i'm still wrong. LOL
    Last edited by DiggerPede; 04-17-2014 at 09:43 AM.
    Weak Revenge
    Strong Forgive
    Intelligent Ignore

  5. #5
    RC Turnbuckle Jr.
    Join Date
    Mar 2012
    Location
    Mojave Desert
    Posts
    3,028
    I'm using the EZ Peak Plus. never had this happen before so im wondering why it's happening. the pack has no signs of puff. I always balance it.

    @jimmieneutron so you're saying I can bring a 5000mah pack to 6000mah and that is normal???

  6. #6
    RC Qualifier
    Join Date
    Nov 2012
    Posts
    740
    5000mah to 6000mah is over what it can handle, but a 5000mah may charge to 5200mah, that is ok

  7. #7
    RC Turnbuckle Jr. JimmyNeutron's Avatar
    Join Date
    Oct 2009
    Location
    Alma, Michigan
    Posts
    12,314
    As long as voltages are not over 4.2v/cell, it does not matter what mAh is being stuffed into the pack.

    As a matter of fact, if two cells are out of balance and one cell is being bled off while the other reaches 4.2v, that extra mAh that is being bled off is not subtracted from the total "put in" the pack (the amount displayed).


    Digger:
    You are spot on this time around.


    Thanks for not taking my correction as a personal challenge.

    Whatever it is I just typed... could be wrong.

  8. #8
    RC Turnbuckle Jr.
    Join Date
    Mar 2012
    Location
    Mojave Desert
    Posts
    3,028
    thanks for the info guys. the charger had a cutoff set at 5000mah. fixed it now.

  9. #9
    RC Enthusiast
    Join Date
    Dec 2011
    Location
    Seaside,Oregon
    Posts
    35
    So I got a new 2s 2200 mah lipo battery and when it fully charges its at the 8.4v but is only at 1600 mah when fully charged . I got the charger at 2.2a for 2s and 7.4v and set on lipo balancing charge .Shouldn't the mah be 2200?
    Last edited by jon321; 10-10-2016 at 01:13 AM.

  10. #10
    RC Qualifier Panamon Creel's Avatar
    Join Date
    Oct 2014
    Location
    Central Mexico
    Posts
    427
    Quote Originally Posted by jon321 View Post
    So I got a new 2s 2200 mah lipo battery and when it fully charges its at the 8.4v but is only at 1600 mah when fully charged . I got the charger at 2.2a for 2s and 7.4v and set on lipo balancing charge .Shouldn't the mah be 2200?
    yeah thread revival after two and a half years

    The mAh the charger puts into the battery depends on how far the battery was discharged before the charging was started.

  11. #11
    RC Enthusiast
    Join Date
    Dec 2011
    Location
    Seaside,Oregon
    Posts
    35
    Quote Originally Posted by Panamon Creel View Post
    yeah thread revival after two and a half years

    The mAh the charger puts into the battery depends on how far the battery was discharged before the charging was started.
    I didnt want to start up a whole new post so I just added it here lol, but my lipo dilemma has been fixed,

Posting Permissions

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