Just so anyone else doesn't have to learn this the hard way like I did. The MOVI batteries lasted about 5min from full charge to nothing this past week on a shoot I was doing in Nashville. I just thought I would warn anyone before they went out and tried to shoot.
I think most batteries have trouble in the cold. Here's a small tip I learned while doing aerials in helicopters in cold weather-- Keep the spare batteries as close to your body as possible. The body heat will keep them at an optimal operating temperature. Obviously you'll have to start this procedure hours before a shoot.
Jeff, Whether it be a cell phone, iPad, portable MP3 player, automobile car battery, DSLR, camcorder, monitor, etc., any device that makes use of a rechargeable battery technology has always been affected by variations in temperature. Please refer to page 01-P1 of the MoVI user manual for general guidelines and warnings regarding the LiPo batteries. http://freeflysystems.com/pdf/FFS_moviManual-v1.pdf Please let me know if this helps or if you have anymore questions. Best regards, Chris
Oh trust me, I am not faulting the MOVI by any means. I was just honestly stunned just how fast those batteries died. I was told by someone that the LIPO's typically do die faster than others in a colder climate. One work around I heard and wanted to share was just tying those hand warmers you get for skiing around the battery cage. Next time I'll get those in advance and try it.
Sorry Jeff, I never thought you were faulting the MoVI. I was just making simple technology comparisons. I have also seen those "break & shake" type of warmers that you can get accessory pockets for and also keep them warm that way. Chris
Best hand warmers are called Hot Hands and they last for up to 10 hours. The cheapest price is to by them by the box: http://www.amazon.com/HotHands-Hand-Warmers-40-pairs/dp/B0007ZF4OA They take about an hour to warm up -- they work by oxidizing iron in an exothermic reaction when exposed to air so it takes a while for them to warm up. I use quite of few of them -- enough that I wondered how to "stretch" the use of them if I'm only outside for two or three hours. Answer: Use a Food Saver or equivalent vacuum sealer and simply put them in a small plastic bag and pull all the air out. Alternatively, stick them in a Ziplock bag, then lower the bag into water with the opening above the waterline -- this forces almost all the air out of the bag -- then zip the bag shut. There will be a small amount of air in the bag but that gets used up by the reaction pretty quickly. The chemical reaction stops until you cut open the bag and expose them to air again. Not that I'm cheap, you understand.... Andy.
Hmmm... its about that temperature here and mine sit in the car all day and all night long in this cold (in a pelican case) and haven't noticed a short time like 5 minutes. I use mine for 20 minutes at a time, 3-4 times a day and I charge my batteries about once a week.
This might not look good, but it worked well. My Lipos lastet about 5-10 minutes in -10 C. With two hand warmers taped around the battery they lasted around 30 min. Just have to figure out a better way to get the handwarmers around the lipo
Double sided velcro tape (hooks one side, loops on the other), holding on a piece of closed cell foam acting as an insulating blanket? Or make up the foam into an "envelope" in which the battery goes before you attach it to the battery plate with the Velcro? Andy
Tried to improve it today. Wrapped the battery cage in aluminum foil, gaffa tape around it, and then a pocket underneath the battery where I can slide in a handwarmer. Found a elastic strap to hold the handwarmer in position. Try it tomorrow, hopefully it works.
Aluminum foil is a good heat conductor, though Even, so a lot of the handwarmer's heat will be conducted off into the air. Hence the suggestion for close cell foam which is good insulator. Andy.
Thanks for the tip Andy. Wrapped it with some cell foam from a sleeping mat. Works really good. Now I´m back at 30-45 min of runtime on the Movi. Used it in -5 C and 17 m/s wind on the mountain last week. Just important that you keep the batteries in warm case. Here`s a new picture, and also a picture from the set last week, shooting for a WW2 TV series, cold and windy Even
Glad to hear it worked --- you look really cold in Rjukan.jpg...perhaps the same technique of cell foam would work for the crew? Andy.
Had the same experience with batteries only lasting 3-5 minutes in the cold when skiing. Was about 5 degree. Each of the 5 fully charged batteries failed and were dead with in 5 mins.
All LiPo batteries have that problem I suspect. Electrochemical reactions don't happen in the cold. Andy.
Same problems with the freefly lipos. I have solved the problem y using bigger bats (more C and more mAH). It doesn't fit the bat cage but it works. For me the problem witht MOVI + Freefly bats, is that we cant't parameter the Lipo alarms : I can't discharge them more thand 50/60% by 5/10°C.... Maybe it will be possible in the new firmware?