Protecting Movi Batteries with accessories

Discussion in 'Batteries & Power' started by Justin Dyck, Oct 4, 2014.

  1. Justin Dyck

    Justin Dyck New Member

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    For those of you powering your Wireless video or follow focus with Movi batteries, how are you making sure you don't discharge them all the way? We were swapping every 45 minutes and still managed to lose two in a matter of days.
     
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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  3. Justin Dyck

    Justin Dyck New Member

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    That looks like it might do the trick! Has anyone tried one of these?
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I'm going to order one up. "It should work," as we say in the software biz. :rolleyes:
    The only caveat seems to be that the devices get powered from the balance leads, not the main JST connector.

    Andy.
     
  5. Mark Harris

    Mark Harris Member

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    Lots of options for this (in no particular order):
    http://www.hobbyking.com/hobbyking/...2_8s_cell_checker_with_low_voltage_alarm.html - lets you set an alarm voltage. If you are going to be using this or any other alarms hand held, I highly recommend that you cover the opening for the alarms with electrical or masking tape as they are *loud*.

    http://www.hobbyking.com/hobbyking/...er_6_lipo_life_li_ion_cell_checker_alarm.html - has a LED as well as two stupidly loud alarms.

    http://www.hobbyking.com/hobbyking/store/__10952__Cell_Log_8M_Cell_Voltage_Monitor_2_8S_Lipo.html - configurable alarm, tone, and voltage display.

    http://www.hobbyking.com/hobbyking/...iversal_Digital_Battery_Checker_Balancer.html - no alarm, but certainly nice packaging that would look fine mounted on a movi to give you a constant voltage display. I havent seen these before, will be ordering one for myself.

    These don't provide an alarm, but I recommend putting one in your kit in any case: http://www.hobbyking.com/hobbyking/store/__10328__Hobby_King_Battery_Medic_System_6S.html They are a fantastic tool to quickly test battery voltage, and allow you to balance a pack.


    All of these work on the balance plug, you still power the device from the main leads.
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Good point Mark.

    I suspect there might be an issue on set with all the new friends you will make when those Hobby King alarms go off mid-take. :)

    Andy.
     
  7. Mark Harris

    Mark Harris Member

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    Haha, yeah well I guess it depends on what it is being used for... hence the ones with no alarm and just a voltage, or a configurable alarm.
     
  8. Vin Guglielmina

    Vin Guglielmina New Member

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    Andy, did that Lipo saver work in your first link? Would love to rock that thing if it does what it says.

    Does anyone know how to tell if one of my batteries is damaged? Ive defiantly, accidentally, left a battery connected to the movi overnight.
     
  9. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Vin:
    Apologies...I received the LiPo saver last week but have not had a chance to test it.

    If you left the LiPo connected to the MōVI I'm afraid there is indeed a chance that you have over-discharged it. Try charging it up and see if it will accept a charge. If you have a type radio-controlled aircraft or car charger you might be able to coax it back to life if the FF charger indicates a problem. Do a Google search for: reviving dead lipo

    EDIT: DO NOT WALK AWAY FROM THIS LIPO WHILE YOU'RE TRYING TO CHARGE IT -- there is a risk it might ignite.

    Sorry for the delay.

    Andy.
     
  10. Andy Post

    Andy Post Member

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    I tried that lipo saver. Granted I'm new to this and may have wired it incorrectly.... I connected it to a monitor & battery to see when it "cut off" in order to save the lipo. 2.5 hrs later I had a dead battery. So.....
     
  11. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Can you post a chicken-scratched diagram showing how you wired it up, please?

    Andy.
     
  12. Andy Post

    Andy Post Member

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    Andy,
    I did find this http://forum.freeflysystems.com/index.php?threads/lipo-saver-wiring-question.2072/ so you might know if I've done something wrong in my wiring.

    Also, the specs at the manufacture have a typo, I'm assuming when they describe what it will do. They say...
    Voltage range 4s: Warning below 13,5V, Switch off below 12,5V
    Voltage range 4s: Warning below 10,5V, Switch off below 9,4V (I'm assuming this should be for 3s)

    I've attached a photo of the Mikorkopter Lipo Saver. http://www.quadrocopter.com/LipoSaver_p_1315.html

    If I understand correctly, it can be wired two ways; to the power output of the battery, or to the balance plug.

    Balance Plug Method
    • Push the balance lead pin set through the holes that are to the left of the +/- input and solder. You'll connect your balance leads here.
    • On the other side, connect the leads to your device to the out+ and out -
    • If you are using a 3s battery, solder a short between the two patches next to the 3s label that is above the output connections

    Power Output Method (the one I used
    • Rather than wire one to every battery I had, I soldered male battery connector to the +/- inputs you see on the right of the board.
    • This is supposed to work with either 3s or 4s batteries. I was using a 3s, so I soldered a short between the between the two sockets where the balance plugs would go for the other connection method. Short the two that are at the - end of the row of 5 connections.
    • The output is the same as the other method, and I also shorted the two 3s patches.

    That's what I remember, but I'll dumpster dive around and see if I still have the original wiring harness. Pretty sure I tossed it.

    Let ne know if there is a better way to do this. I'd love for this to work.
     

    Attached Files:

  13. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Sounds like your wiring was this: http://gallery3.mikrokopter.de/tech/LipoSaver_3 and you shorted as shown here: http://gallery3.mikrokopter.de/tech/LipoSaver_3sb

    The specs at http://wiki.mikrokopter.de/en/LipoSaver don't have the typo to which you refer -- but you may be referring to another page...either way, you're correct, the second line of your posting refers to 3S (see the link I cite).

    Did you hear any beeping? It's hard to understand that it would go from good voltage to zero voltage without a sound -- and without cutting off the voltage -- that's more "Lipo killer" behavior than "Lipo saver" isn't it?

    Andy.
     
  14. Andy Post

    Andy Post Member

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    I forgot to do my dumpster diving last night, and will make an alert to do so when I get back to my shop. Yep, those are the pics I'd referred to some months ago when I tried this thing. When I ran the test, I connected it between a 3s battery and a 7" monitor and just left it running on my desk while doing paperwork. I was never more than a few feet away and never heard a peep. I let it run until the monitor shut off assuming that interrupting the circuit was what it was designed to do. When I checked the voltage on the battery it was way low (don't remember the exact voltage) and my charger would have nothing to do with it.

    I've got another. If I try that again, I'll put a voltage monitor on the balance plug and watch that. In the mean time, I've switched gears and have the little 1" square monitors (with the alarm turned off) on any battery that doesn't have any protection in place.
     
  15. Steve Maller

    Steve Maller UAV Grief Counselor

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    Keep in mind that the little LiPo monitors do draw a small amount of power and can actually kill a LiPo themselves. I made the mistake of leaving one connected to a MōVI battery on the MōVI and it completely drained the battery. The MōVI was disconnected, but the monitor wasn't. #SMH :( Took a few days (I think), but the battery was rendered inert and dead.
     
  16. Andy Post

    Andy Post Member

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    I discovered that with a BEC that I left plugged in all night. Next day DOA. But this one was right there next to me. As soon as the monitor went off and the static (I left the volume up as well) went quite, I disconnected and checked the battery, and it was dead. Everything dies, I just hate when I have a hand in it....
     
  17. Andy Post

    Andy Post Member

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    omg....OMG
    There is a small sticker on the warning buzzer that says "Remove seal after washing". What that means in whatever the original language is I don't know. But I do know (now) that if you don't remove it, you can't hear the warning. It's not really loud, but it does go off as promised. Imho the warning voltage is pretty low at 3.5V/cell. My little tester tells me I've got 7% left on the battery, and I generally try not to go below 20%.

    By the time it "cut off" on my first test the battery was dead. It's cut off point is 3.13V/Cell which is perhaps so close to dead that if it's not a great battery (mine was a new battery, but maybe not a well made one?) it ends up being unusable anyhow?

    Share your thoughts....

    Have you used and loved this item before?

    Is it really dishwasher safe? ;-)
     
  18. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    The washing would be in a bath of solvent after soldering the components on. It is NOT dishwasher safe!

    EDIT: But that explains why you didn't hear it beep. :(

    Andy.
     
  19. Andy Post

    Andy Post Member

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    I had an intern years ago who was looking for something to do. We had some old 4X5 film holders that needed a good cleaning as we were headed out to a location where loading film was problematic. After sometime we went looking for the intern who was in the kitchen with a cup of coffee leaning on the counter by the dishwasher which was humming away. Yep, those were some clean film holders. We did not take up the practice....

    Thanks for all your help.
     
  20. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Ha! I like it. But that's the role of the intern, isn't it? :)
    btw: if you ever need to silence a beeper while you're working on the copter, just stick a small Post-It(r) on it. It will stop the beeping from driving you crazier. :)

    Andy.
     

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