Entry level lipo charger with "storage" option

Discussion in 'Batteries & Power' started by Spencer Weaver, Feb 12, 2016.

  1. Spencer Weaver

    Spencer Weaver New Member

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    Hello everyone, I'm the new guy :) And I know this is probably answered somewhere on the thread already...

    I have a MoVI m5 and I'm looking for info or suggestions on a good lipo charger that allows me to better maintain the batteries and discharge them down to "storage" mode.

    I have a multimeter and the original charger that came with the M5.

    What is the best way to discharge my batteries for storage?

    Thanks in advance!
     
  2. Steve Maller

    Steve Maller UAV Grief Counselor

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  3. Spencer Weaver

    Spencer Weaver New Member

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    Thanks for the link Steve! That was very helpful. I'm doing tons of research now!

    Here's what I've come up with.... Since the stock Freefly charger that came with the M5 has a balancer on it... I'm thinking the main thing I need is a way to discharge the batts to the 3.8v per cell for storage. My thought after some research is to use the automotive lightbulb draining technique and a voltage checker with a warming buzzer to bring my batts down to storage voltage.

    When it comes to battery maintenance are there other advantages I'm not thinking of if I were to pick up a basic charger like the one you linked to?

    Thanks for the coaching :)
     
  4. Steve Maller

    Steve Maller UAV Grief Counselor

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    If you spent the money for a MōVI, don't use a lightbulb to discharge your battery. Among other things, it's important to "balance" the four cells in the battery, and a light bulb won't do that. Don't waste your time. Any mistake you make is going to cost you 1/2 of what the "real" charger will cost. And I predict you will make a mistake.
    Ask me how I know. :rolleyes:
     
  5. Spencer Weaver

    Spencer Weaver New Member

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    Sounds like good advise :)

    So, is it fair to say then that the charger you referenced would do a better job of balancing the batteries as compared to the very basic charger included with the M5?
     
  6. Steve Maller

    Steve Maller UAV Grief Counselor

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    For a normal charge, not sure. But the additional options for storage discharge, display of current, etc., it's far superior. I use my Freefly charger when I need a battery charged and all my other chargers are occupied. But that's pretty rare.
     
  7. Graham Futerfas

    Graham Futerfas Well-Known Member

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  8. Steve Maller

    Steve Maller UAV Grief Counselor

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    I just saw this little charger advertised on the AMA newsletter. Looks interesting as a MōVI battery charger upgrade at $45. Does up to 6 amps, which is more than enough for a MōVI battery.

    http://bit.ly/1Ltu5NP

    [​IMG]
     
  9. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Not clear whether it can also take a LiPo to storage voltage....there are a couple of lines in the specification that hint that it might:

    Discharge Current Range: 0.1 - 2.0 Amps​
    Discharge Current Power: 10 Watts​

    Andy.
     
  10. Steve Maller

    Steve Maller UAV Grief Counselor

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    Definitely does storage discharging. Here's a section of the manual:

    Screen Shot 2016-02-18 at 2.29.51 PM.jpg
     
  11. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Nice. Thanks, Steve.
    Andy.
     
  12. Adam Reign

    Adam Reign New Member

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    Hi Graham, I just got the same charger you recommended but I am a little confused as to what settings to choose. Would you mind sharing some knowledge on this? I'm looking to accomplish "balance charging" and "storage" ... I'm using the M15 batteries. Thanks!
     
  13. Graham Futerfas

    Graham Futerfas Well-Known Member

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    Hi Adam, I typically charge at 3A, and Storage drain\charge at 1A. 4S 14.8V Battery setting when using the M15 batteries. The charger confirms you have 4 cell batteries.

    Settings are easy enough when you get used to the menu... You can Regular Charge (up to 5 Amps, I use 3 Amps), Fast Charge (5A), Balance Charge (super-slow at .1 Amps), Storage Charge (1A max).

    Any specific questions you have about the settings?
     
  14. Andrew massih

    Andrew massih New Member

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    So my screen on the tenervy charger reads
    _______________
    Lipo CHARGER
    5.0A 14.8V (4S)
    ________________
    I want tone make sure i don't die lol
     
  15. Graham Futerfas

    Graham Futerfas Well-Known Member

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    I typically change the 5.0A part to 3.0A. That affects how fast it charges, but I don't like to put too much current into them, so I dial it back a bit. I'm not sure if it's dangerous or not to go at 5 Amps, but I know the charger Freefly gives you works at 3 Amps max. I'd be curious what other people think about this, too.

    The 14.8V (4S) is correct for the Movi batteries, but I don't think it's right for the Alta batteries.
     
  16. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Based on anecdotal evidence, if you charge at a lower current, Lipos (a) take on more charge (as measured by how much charge they will deliver when you use them) and (b) you're being kinder to the LiPo by shoving electrons into it more gently so you extend its useful life.

    If time permits I typically charge LiPos at 1 x C where C is the capacity of the LiPo in Amp Hours (e.g. a 10,000 milliAmp/Hour has a C of 10, therefore the optimal charge rate appears to be 10 Amps).

    The anecdotal evidence is based on comments from other forum members as well as some experiments I did -- therefore it must be viewed under the general heading of "your mileage may vary" and you may be confronted with "alternative facts." :rolleyes:

    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  17. Kevin Shea

    Kevin Shea New Member

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    Typically for lipo storage, you would want to store them with at least 3/4 charge in them and not discharged to the minimum voltage!
    Click here for the best suggestion.
     
  18. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    To supplement what Kevin said, a fully charged Lipo cell is 4.2v. The "do not go below" voltage is 3.0v. Storage voltage is the mid-point for that.

    You can calculate that like this: The voltage difference is 1.2 volts, so the mid-point is half 1.2 volts and the storage voltage per cell is therefore 0.6v + 3.0v, or 3.6 volts per cell.
    For a 6 cell Lipo that's going to be 6 x 3.6 or 21.6volts.

    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     

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