I might have missed it in the manual but got a few questions. 1. How do I know what the battery has left for a charge while on the movi without using the app? 2. When storing the batteries, it seems like I am not suppose to store them for long period of time with a full charge? What is the proper way to store them? Any best practices? What do I do if I have batteries at full charge that need to be stored? 3. Will the Movi quit working if the minimum voltage is not present or does the performance just deteriorates and I will have to keep an eye on the rig/video footage? Thanks in advance.
Good questions, I can answer the fist which helps somewhat for the second: the solid green lights on the back indicate charge; 3 is full.
I will let someone else offer more specific advice on #2 than what I can offer at the moment, but I can take #3… Yes, the Movi has a protection circuit to turn itself off before overdischarging the battery. I find it's best to change it before that happens anyway. Note that using the Freefly batteries to power other accessories, the voltage needs to be manually monitored because in that scenario there is no protection circuit.
I ordered a voltage monitor so that I can safely use the movi batteries with accessories. When the battery is fresh the voltage monitor usually steps through No1, No2, No3, No4, and All and displays around 4.0, 4.0, 4.0, 4.0 and 16.0. How low can I run the voltage before I need to remove the battery pack? Also do I need to pay attention to the individual cells or the "all" voltage? Last but not least: do you usually just keep the voltage checker plugged in the entire time or does that drain the batteries too much? Id greatly appreciate any insights on this! Thanks, Philipp
The final state of the LEDs, once the MōVI has initialized, represents the remaining battery voltage. Store them when there is about 50% of their voltage between fully charged and fully discharged. For the 4S LiPo that is used for the MōVI, that would be around 15.1 volts. Don't get too anal about whether it's 15.1 or 15.4 or 14.9...just in the midrange between fully charged (16.8v) and the minimum safe voltage of 13.2 (the MōVI will have shut down if you ever let a battery get this low). If my memory is correct, it shuts down. I normally change batteries when it's down to just one LED or even before that. A fully charged LiPo cell would normally show 4.2 volts -- but the particular FF charger is a little kinder to the battery and only takes it to 4.0 volts, it appears. The lowest you ever want to discharge a 4S Lipo is 13.2 volts total, and you don't want any cell to go below 3.3 volts. If you go lower than that, then there is a risk that you will damage the LiPo's ability to store a full charge. If it's the kind that beeps when the voltage drops too low and you really want to piss off other people on the set, do keep it plugged in. The other guys really like the loud beeping noise it will make. You can otherwise keep it plugged in all the time -- the current draw is minimal. Andy.
Hi Andy, Thank you so much for the response! I just learned the hard way and ruined one of my batteries while powering my Blackmagic 4k camera with it. Three of the cells were still at 3.5 but one of them dropped down to 2.9. Ugh. I was hoping they'd discharge more evenly. Also it looks like the lipo will only be able to power my camera for about an hour. Less than I was hoping for as well. I'm having a really hard time coming up with a better solution to keep the blackmagic powered up in the rig. If anyone has suggestions id love to hear them!
Phillipp: You may not have ruined the Lipo. By all means try charging the battery up -- if it charges, well and good -- but check each cell to see if it is holding it's charge. I've also "flat lined" some of my LiPos, but recovered them by gently charging them back up -- although I did use a very different charger to do it. But if you went down to 2.9 volts, just charge it up -- you may find that all is well.... As to the BM4K -- can you mount a second 4S Lipo? Andy.
Hey Andy, Usually when I charge a lipo all 5 lights turn red. When I connect the "damaged" lipo to the charger only one of the top 4 lights and the main light blink back and forth. So I removed the battery from the charger after 15 minutes cause I got worried. The battery now actually shows more than 3v on each cell again but I was worried because the charging lights are behaving so differently. I have no experience with lipos. And yes, I could easily mount another freefly lipo on my rig. Is there a way to combine them into one "big" battery, though?
Phillipp: Yeah, based on what you say, that LiPo might have departed this life. Because of the residual stored energy you may want to discharge it fully to render it inert and take it to a recycling center that accepts LiPos. The way to discharge it fully it so connect it up to a 12v automobile EDIT bulb-- the bulb will get very hot....also this is best done outside on concrete because there have been reports of LiPo fires when the batteries get down to a total voltage of two or three volts....just before they become completely inert. You can certainly connect two batteries in parallel to get twice the capacity at the same voltage. You connect them up with a "Y-cable" so that the red wires of both batteries are connected together and the black wires of both batteries are also connected together. However -- be sure before you connect the two batteries to the Y-cable check that the total voltage of each battery is within 0.1 volts otherwise there will be an "in rush" current from the higher voltage battery to the lower voltage battery and Bad Things may happen. Here's an example of the cable you would need -- assuming the connectors you want are the same as you had on the MōVI when you first got it: http://www.amazon.com/Boom-Racing-WRA0001-Y-Cable-Adapter/dp/B00C3Y4C0K The technical specification is "JST Y-Cable with two female connectors and one male" -- the gender of the connector is determined by the plastic housing not by the pins/sockets inside. So search for that description and you'll find numerous vendors -- you may find that your local hobby shop carries them -- it kinda bugs me to buy a $2 cable and pay $5 for shipping! Hope this helps. Andy.
Andy: thank you. Such great info. I just order this cable: http://www.ebay.com/itm/171253296751 free shipping. So if I connect these two batteries via the adapter I would still have two voltage checkers (one for each battery) connected though, correct? And as soon as any of the 8 cells drops below 3.3 I disconnect both batteries and recharge? Also, just to make sure I understand correctly: I should connect the dead lipo to a 12 car BATTERY? Because right after you talk about a bulb. I just want to make sure I understand correctly. So I would have to cut the connector off of the battery and connect the red cable to plus and black one to minus, right? Thanks!
It would be safer to have two voltage checkers to start with, but you may find that they march in lockstep and you only need one. Aieee....NO! Sorry to shout...but connecting a LiPo to a car battery is very dangerous and the LiPo might blow up in your face. How silly of me to write that! I apologize. Bonus points for asking. I've edited the post above. What I would do is make up a discharging set up something like this -- you'll have to use a JST connector, of course -- the one in this image is a different kind (it looks like an Anderson PowerPole in case anyone cares): Doesn't matter which way you connect the red or black wires -- really all the light bulb is doing is acting as a dummy load resistor to draw the current out of the LiPo. Put the whole assembly and the LiPo out on some concrete or the ground so that if the LiPo bursts into flames it will not do any damage (search on YouTube for "lipo fire" if you want to see what I mean). Then leave it there for a few hours -- the bulb will ultimately go out -- and then leave test the LiPo with the voltage checker. If it reads 0 volts then the LiPo is now inert and can be disposed of. Hope this helps -- and sorry about the "brain fart" in my original posting. Andy.
In terms of when to pull the battery, is it under load or not? When I'm using Lipos to power the Epic, should I pull it when it says 14.4V which means 14.8-14.9 not under load or when it says 14.8 under load? Want to keep the battery at that 20% level when it's pulled.
Personally, I'd pull it when it's 14.4 under load. The voltage will immediately bounce back up a volt, but I would argue it's the "under load" condition that counts. Not a very strong argument, but... Andy.
True -- you will have to let experience be your guide -- if the MōVI starts going limp or losing stabilization, it's telegraphing that it's time to change the battery regardless of what the voltage is. If you're concerned about over-discharging the battery, the voltage to worry about is 13 volts, so at 14.x you're well above that. if you're concerned about storing the battery for several days, then the optimal voltage is 15.2 volts. Andy.
As far as storing Lipos, how do I know that I am at half full? Is there a decent volt checker with the little white 5 pin plug can plug into? I do leave the movi for up to a month with out using it and want to take care of my batteries. Suggestions... Hook them up to something for an hour before putting them away?
Charlie: Do a Google search for Lipo Voltage Checker. To bring the LiPo's up (if they've been discharged) or down (if they're fully charged) to storage voltage, you need to either use a LiPo charger that has a "storage" setting or put the LiPo voltage checker on the LiPo and use a real or dummy load. So you could plug them into the M10 and switch it on until you see a voltage of around 15.2v, or see message #12 above for a dummy load made out of a car light bulb. Note that the M10's LiPo, fully charged is 16.8v so you'll need to get a bulb capable of that voltage otherwise you will re-invent the fuse! Andy.