I made a bit of a schoolboy error when we first got our hands on the MōVI M10 - I fried the battery charging cable! It's very easy to short out the charging terminals if you (stupidly) disconnect the banana plugs from the charger before unplugging the battery from the red JST connector. My fix for this is to coil up the charging cable and shroud it and the banana plugs in "Polymorph". It's also possible to colour the Polymorph material with special powders. I made some black up and used a few blobs of it to fill in the gaps next to the charger switches so they can't be accidentally moved. In our situation, these mods will provide us with a bit more peace of mind when hiring our MōVI to the less technical users.
That´s clever, Matt. I had that happen once to me and once to my wife who wanted to help me out charging the batteries. It didn´t happen with MoVI batteries, but with other 4s LiPo. It´s freaking frightening when the sparks appear.
Hi Wolfgang. Yes, it was very scary and could have caused a fire. In the panic I burned my fingers slightly (pun intended) trying to separate the charging cable (which was going up in plumes of smoke) from the battery. My inexperience with RC batteries probably meant I wasn't thinking carefully enough to take the right precautions. Now, that was in the controlled and relaxed environment of our workshop. I could just see this sort of thing happening very easily to one of our operators out on location, especially after a long day.
In a stupid rush yesterday I did this.. I forgot to unplug my power strip and POOF! Very scary.. I was below deck on a 3 million dollar sail boat.. Lots of smoke and could have turned out much worse!! SCARY! This should really be a STICKY maybe a Safety sticky!
In fact your solution (perhaps in a more fashionable way ;-)) should become a kind of norm, or standard for the industry. Why on earth hasn´t this been regulated a few years ago?
It sounds like the danger is the banana plugs coming in contact with one another. How about I run some laser-cut brackets which keep the banana plugs apart at the correct distance? If anyone is interested, please send me an email at jason@CinemaOxide.com
Those parts may already exist ... the M10 charger is identical to the charger that come with the Phantom, except black v white, and different label on it .... the phantom charger has the brackets to keep the banana plugs separated ... so the parts should be out there, it may be easier to order a bulk lot, and then distribute those....? bracket photo
Thanks Chris. This is probably a better plan, someone may have to point me towards a US supplier of the brackets. I'll supply them to the community if you guys want.
Even with that white spacer plug, with a LiPo connected, those two banana plugs are an arc welder looking for a place to happen. Very, very dangerous. It might be preferable to tape those banana plugs on to the charger so they cannot accidentally come out. Andy.
You could even go so far as to pop the case open, and solder the banana plugs in place from the inside, and close it all back up. Then the arc welder can't get loose .... we could call that the Poke-yoke fix
I hate this charger. It is such a hobby / toy / joke for a professional system. On set, with interns, trainees, camera assistants, production assistants… it's an accident waiting to happen. I really expect a lot better from FreeFly.
I tend to agree with Ben. I think Freefly just has their hands full with the production of the Movi and critical components. The charger "works", so they would rather work on developing accessories that are truly "needed" right now.
Maybe I'm too accommodating, but I realize that this is coming from a hobby lineage. Not a film production background. Like I said in a blog way back when. There is little to nothing that is "approachable" or "common knowledge" about most of this, which thankfully gives us operators a foot in the door. However this post is brilliant if approaching the biggest safety issue. After a few weeks of not flying, I reversed the prongs and fried a charge absent mindedly. Charger was ruined in a second. I'm thankful it was only that. I decommission batteries once they start bulging and take whatever precautions I can, because I DO NOT want to be the MoVI guy whose cart went up in flames. Bravo for a great safety net. And yeah, I thing Sugru or whatever is the proprietary eponym (Band Aid) of polymorph.
Let's hope they tie up this loose end. In the meantime, our sensible workarounds should be enough to prevent accidents. The ultimate mod, which I might have a go at doing, is to fit a JST socket inside the charger. There's no panel mounted socket available as far as I can tell but I think there's enough space, in the right place on the charger to do this securely and safely with an in-line connector.
Sugru's okay if you need something to cure with a rubberised finish but for most of my prototyping work or when the proporties of a Polypropylene plastic are needed, Polymorph wins hands down. It never goes off (unlike sugru - it's biggest flaw) and can be reused over and over again simply by heating it up. It's pretty amazing. I've been experimenting with making moulding tools for it to make up little brackets and doo-dads - a poor mans 3D printing if you will. Also, it's so much cheaper than Sugru and you don't have to commit yourself to buying the different colours, just add pigments as and when needed.
Here's a datasheet I found http://www.rapidonline.com/pdf/87-0090e.pdf It says the flash point is 275 degrees C but I don't know how useful that figure is. Even with a banana plug spacer in place you still have to be in attendence when the batteries are charging.
'Being in attendance while batteries are charging'… whoever spec'd these for use by film crews has not spent any time working on a film crew.