BMCC and External Batteries Shutting Off When Camera is On

Anyone know why every cheaper external battery I get shuts off and stops working if the camera is turned on?

I tried the 30 dollar ebay solution and then tried this: http://www.amazon.com/gp/product/B005NG ... UTF8&psc=1


I'm trying this one next:
http://www.amazon.com/gp/product/B00B45 ... UTF8&psc=1


I just can't spend 300 dollars on the switchtronix battery. ITS JUST A BATTERY. Even the 200 dollar bescore is too much and its a weird form.

What do you guys do?

Anyone know why every cheaper external battery I get shuts off and stops working if the camera is turned on?

I tried the 30 dollar ebay solution and then tried this: http://www.amazon.com/gp/product/B005NG ... UTF8&psc=1


I'm trying this one next:
http://www.amazon.com/gp/product/B00B45 ... UTF8&psc=1


I just can't spend 300 dollars on the switchtronix battery. ITS JUST A BATTERY. Even the 200 dollar bescore is too much and its a weird form.

What do you guys do?

It's not just a battery, it's a professional battery. ¿How can you expect to power a professional device with a battery made for powering Tablets and Cell Phones? You need to invest, you just got a Cinema Camera, hope you find a better solution. Cheers.

Anyone know why every cheaper external battery I get shuts off and stops working if the camera is turned on?

I tried the 30 dollar ebay solution and then tried this: http://www.amazon.com/gp/product/B005NG ... UTF8&psc=1


I'm trying this one next:
http://www.amazon.com/gp/product/B00B45 ... UTF8&psc=1


I just can't spend 300 dollars on the switchtronix battery. ITS JUST A BATTERY. Even the 200 dollar bescore is too much and its a weird form.

What do you guys do?

It's not just a battery, it's a professional battery. ¿How can you expect to power a professional device with a battery made for powering Tablets and Cell Phones? You need to invest, you just got a Cinema Camera, hope you find a better solution. Cheers.

I hear what you are saying for sure. If this one doesn't work I'll just get the switchtronix.

I believe it auto shuts off when the draw from the camera is low. Try without a battry, or when its charging (not 100%)

It's not just a battery, it's a professional battery. ¿How can you expect to power a professional device with a battery made for powering Tablets and Cell Phones? You need to invest, you just got a Cinema Camera, hope you find a better solution. Cheers.

Actually, this is not true.

DC power is DC power...it is a stream of electrons at a certain voltage (in the case of cameras usually 12-24vdc) pushed by a certain volume which is measured in amps. There may be reasons not to use batteries primarily designed for other uses because their current is incorrect or they don't have the capacity to actually run your device, but I don't believe the user is experiencing problems because the power source itself is faulty. From what I can see of the batteries he is using they are adequate to run a charge to the camera as they are rated at 2amps @12 volts.

Put a volt meter on your battery source and if it is putting out in the area of 12 volts DC and has enough amperage to run the camera (in the case of the BMCC, 23 watts, which is a little under 2 amps at 12 volts) than the issue is elsewhere.

I suspect it is as as Rob says that you are close to fully charged on the internal battery and that signals to your external battery that it is topping off which reduces the current flow.

I have found powering the Blackmagic Pocket camera with an external source , in this case Sony BPU-60 (professional) batteries, that I have to unplug the external power source before I turn on the camera. Only then can I plug in the external battery. Otherwise the camera will not turn on. I suspect it has something to do with the charging cycle overriding the power sensor but until I enquire further with Blackmagic I am not sure.

Patrick, I think you are missing something in your calculation.
When the external battery is plugged to the BMCC it has not only to supply power to the camera and SSD, but also power to charge the internal battery, the combined surge will be higher than the Astro can supply.
There is a reason V-Mount batteries have output currents of 5A and 14,4 V.

Patrick, I think you are missing something in your calculation.
When the external battery is plugged to the BMCC it has not only to supply power to the camera and SSD, but also power to charge the internal battery, the combined surge will be higher than the Astro can supply.
There is a reason V-Mount batteries have output currents of 5A and 14,4 V.

I am not really clear that the camera shifts the power usage totally to the external power source. It seems that the current from my external battery is immediately directed at toping off the internal battery and it still stays in the powering loop only when the internal battery drops below its full status.
Its actually one of the things I have put in my wish list to Blackmagic, that we have a way to shut off the internal charging cycle so I can accurately gauge my power requirements from external batteries and leave my internal battery for emergency or completely stripped down run and gun back up power source.

The camera is rated at a 23 watt draw from what I can find. I suppose that could be camera use alone and not trickle charge but I would find that odd. I would be curious if he discharged his internal battery whether he would experience the same problem?

Mostly my response was about dissuading people from searching out less expensive alternatives to film batteries. I own a full V mount system but rigged up at plate for Sony BPU60's because they are smaller and lighter weight for run and gun. Both are Lithium ion, each may have different cell designs but has the same voltage rating the only real difference for the user is in the amp hour capacity.

There are lots of high quality lithium ion batteries on the market which are perfectly adequate less expensive alternatives to heavy large V mounts.

If you think about it, the internal battery for the Cinema camera is likely the equivalent (in terms of design and ratings) of a computer battery.

Perhaps you know something about the charging powering requirements that I haven't been able to track down. If so I would love to have the full specs for external power load, both charging and running the camera combined?

thanks

Why not just take the battery out of the camera?

Or, did you mean make it so that the external battery reads on the display?

I can power my camera up with the D-Tap plugged into the camera, and power it with just the external without a battery inside of the port.

Why not just take the battery out of the camera?

Or, did you mean make it so that the external battery reads on the display?

I can power my camera up with the D-Tap plugged into the camera, and power it with just the external without a battery inside of the port.

I assumed from the users post title we were talking about the Cinema Camera here and not the Pocket camera. The Cinema camera does not have a removable internal battery. And if you plug in an external source you have no choice over its power being directed at recharging the internal battery. I would prefer to know the remaining capacity of my internal battery and use external sources independently for the very reason we are discussing now. I am not sure what the draw of the charging cycle is on the battery, whereas for the functions of the camera alone I can make a pretty good estimate.

Oh gahd sorry, my mind put a P in the middle of the B and M. Like every topic is BMPCC

Really sorry about that!

I use 3 of those 4500mah "CCTV" tv whatever cheap chinese batteries.
I was having the same issue and what i noticed is that I had to completely charge the internal battery of the camera with the AC adapter first then use the batteries to power the camera once it was charged. If the camera tries to charge it's own battery and power all the stuff its doing at the same time it draws too many amps and will not use the external supply. (or the external supply gives up)

So charge camera, then use external batteries and last resort use the internal.
Each of the 4500mah bateries ($30) give me around 2-3 hours of use.

What's wrong with V-Mount batteries?

I bought all of mine used - usually around 50 bucks.
Sure they don't perform as new, but with two bricks I last a whole day of shooting, powering the camera, and a monitor.

Where's you find V-Mounts for $50??

Since typical ENG camcorders are pretty power hungry, rental houses usually sell the bricks after a certain amount of hours/charging cycles. But they are still good enough for a half day of BMC.
Also Ebay and forums.

What's wrong with V-Mount batteries?

I bought all of mine used - usually around 50 bucks.
Sure they don't perform as new, but with two bricks I last a whole day of shooting, powering the camera, and a monitor.

There is nothing wrong with V mounts. I own several and love them. But they are bulky and heavy. One of the beauties of these cameras (say over an Alexa) is their smallish form factor. They can be easily built up to a full studio rigging, but for run and gun I prefer a much smaller footprint and weight for the camera. A couple of BPU 60's and I can run for a number of hours but don't have to dress the camera out with iris rods etc. I am just talking about designing for the times when I want to be as compact as possible.
Right now I have an entire cinema camera package (less the tripod) that I can shoot all day with that fits into a carry on flight bag. I accomplish that by economy of design around the spare support components.

I agree guys. The issue is that the batteries I've tried don't have enough amps to charge the camera and power it while recording, cutting the external battery off. I'll let you know how it goes with the more powerful one I ordered today. I think it will work.

OK, I did some non scientific measurements on the external power supply of the BMCC to find out, how much power it draws.

BMCC with internal battery 100% full - external power supply connected: 24 W without recording, 30W peak during booting and initializing the SSD.

BMCC with interal battery 50% full - external power supply connected: 38 W without recording and internal battery charging, 42W peak during booting and initializing the SSD and charging internal battery.

That easily explains, why an external battery with 2A is not enough.

What about using the Sony BP-U30 and U60 batteries?

I know they are expensive but they are rated 14.4V, 2400mAh (35Wh)... just reading this off my battery which is a generic version. I am testing right now.

A couple of BPU 60's and I can run for a number of hours but don't have to dress the camera out with iris rods etc. I am just talking about designing for the times when I want to be as compact as possible.
Right now I have an entire cinema camera package (less the tripod) that I can shoot all day with that fits into a carry on flight bag. I accomplish that by economy of design around the spare support components.

Patrick, that sounds interesting, what battery adapter are you using to power up the BMCC with the BPU 60's? And what is the running time you are getting with them without touching the internal battery?
Thanks

The BMCC power supply has an output of 12V @2.5Amps. Your battery need to be capable of this so the first one you linked to won't work. The 2nd one should. I've used this and it works http://tinyurl.com/nofdmfk

Well I got the Anker Astro Pro2 and it works like a champ. It was 100 bucks. Not sure what my record times are yet. Its a little weirdly shaped, but I can velcro it to my rig and it'll be fine. no big deal.

I've used this and it works http://tinyurl.com/nofdmfk

And what record times are you getting?
Thanks

I've used this and it works http://tinyurl.com/nofdmfk

And what record times are you getting?
Thanks

Sorry I haven't had a chance to test it longer than an hour yet as I've only just got it.

OK, I did some non scientific measurements on the external power supply of the BMCC to find out, how much power it draws.

BMCC with internal battery 100% full - external power supply connected: 24 W without recording, 30W peak during booting and initializing the SSD.

BMCC with interal battery 50% full - external power supply connected: 38 W without recording and internal battery charging, 42W peak during booting and initializing the SSD and charging internal battery.

That easily explains, why an external battery with 2A is not enough.

great job, Robert
that explains a lot!
Patrick

A couple of BPU 60's and I can run for a number of hours but don't have to dress the camera out with iris rods etc. I am just talking about designing for the times when I want to be as compact as possible.
Right now I have an entire cinema camera package (less the tripod) that I can shoot all day with that fits into a carry on flight bag. I accomplish that by economy of design around the spare support components.

Patrick, that sounds interesting, what battery adapter are you using to power up the BMCC with the BPU 60's? And what is the running time you are getting with them without touching the internal battery?
Thanks

I use this battery plate.

BPU battery plate

$T2eC16Z,!zQE9s3stvEIBR+IeI1s,w~~60_14.JPG (956 Bytes) Viewed 13442 times

http://www.ebay.com/itm/181189393637?ss ... 1439.l2649

I like it because it comes with a 1/4 x 20 set screw which is universal for camera mounts plus it has an additional power power on the side for powering peripherals, Or I suppose you could use it for a charging cycle.

I am afraid I don't as of yet have a very accurate estimate of the exact amount off recording time per battery. Obviously, the power draw is less during standby then recording and I am still in the testing phase of the camera (as I received it only recently) and have been rigging and testing my Pocket cinema as well.

In going out and doing (albeit short) latitude and exposure tests for the better part of a day, intermittently turning the camera on and off, including about an hour long time lapse, I exhausted one BPU-60 and showed a 1/4 charge left on the second.

It seems to me that the camera runs on the internal battery and the external source only works to trickle charge the internal but I may be wrong about that.

If we base it on Robert's findings of an average 30 watt draw when recording, (although I have seen it rated anywhere from 18 watts to 23 watts), by calculation, one BPU-60 should power the camera alone continuously for an nearly two hours of recording, obviously longer if the camera is in stand by mode a lot (its rated at 57 watt hours @14.4volts)

if I thought I would need longer times for a run and gun day, I would switch to a battery belt, or move into studio mode with V mounts if the day called for it.

A couple of BPU 60's and I can run for a number of hours but don't have to dress the camera out with iris rods etc. I am just talking about designing for the times when I want to be as compact as possible.
Right now I have an entire cinema camera package (less the tripod) that I can shoot all day with that fits into a carry on flight bag. I accomplish that by economy of design around the spare support components.

Patrick, that sounds interesting, what battery adapter are you using to power up the BMCC with the BPU 60's? And what is the running time you are getting with them without touching the internal battery?
Thanks

I use this battery plate.

$T2eC16Z,!zQE9s3stvEIBR+IeI1s,w~~60_14.JPG

http://www.ebay.com/itm/181189393637?ss ... 1439.l2649

I like it because it comes with a 1/4 x 20 set screw which is universal for camera mounts plus it has an additional power power on the side for powering peripherals, Or I suppose you could use it for a charging cycle.

I am afraid I don't as of yet have a very accurate estimate of the exact amount off recording time per battery. Obviously, the power draw is less during standby then recording and I am still in the testing phase of the camera (as I received it only recently) and have been rigging and testing my Pocket cinema as well.

In going out and doing (albeit short) latitude and exposure tests for the better part of a day, intermittently turning the camera on and off, including about an hour long time lapse, I exhausted one BPU-60 and showed a 1/4 charge left on the second.

It seems to me that the camera runs on the internal battery and the external source only works to trickle charge the internal but I may be wrong about that.

If we base it on Robert's findings of an average 30 watt draw when recording, (although I have seen it rated anywhere from 18 watts to 23 watts), by calculation, one BPU-60 should power the camera alone continuously for an nearly two hours of recording, obviously longer if the camera is in stand by mode a lot (its rated at 57 watt hours @14.4volts)

if I thought I would need longer times for a run and gun day, I would switch to a battery belt, or move into studio mode with V mounts if the day called for it.

Thanks a lot Patrick. I'm trying to figure out the best battery option for extended hiking (and shooting from tripod) and your experience helps a lot. The BPUs are pretty lightweight and if I can get about 2 hours from each, 5 batteries would weigh about one kilo and give me close to 10hs recording time. The switronix/bescor/v mount option seems to have a similar weight but would power the camera for about 5-6 hours.
Perhaps an alarm battery could also be a viable solution.

I'm trying to figure out the best battery option for extended hiking (and shooting from tripod) and your experience helps a lot. The BPUs are pretty lightweight and if I can get about 2 hours from each, 5 batteries would weigh about one kilo and give me close to 10hs recording time. The switronix/bescor/v mount option seems to have a similar weight but would power the camera for about 5-6 hours.
Perhaps an alarm battery could also be a viable solution.

I recommend you think about a battery belt. They are comfortable to wear and keep the weight of the camera to a minimum (and therefore off your arms). They are in affect (depending on the design) usually about six lithium ion batteries (not much smaller than the BPU's) wired together in parallel

I additionally recommend looking into a manfrotto fluid base monopod and just take a very light weight tripod for shots where you really need it rock solid. Remember you can do a lot of magic in post with stabilization and a monopod only gives you the slightest drift from your breathing.

Have fun!

Thanks Patrick, I'm looking at them right now on bh

Thanks Patrick, I'm looking at them right now on bh

I wired one of these each into an XLR as well as a car adapter to power the camera from my belt.

$(KGrHqR,!rQFGtVSq-mSBR)67rN3!!~~60_3.JPG (48.43 KiB) Viewed 13380 times

http://www.ebay.com/itm/251229101735?ss ... 1439.l2649

I stil have the issue on my camera with the charger as well as any external power source that I have to start it from the battery first and then plug in external power otherwise it won't start. Not sure if that is a problem others have experienced or singular to my camera. But with this 5' cord you can operate the camera freely from your belt pack.

I've been looking at battery belts, but got a bit lost with the numbers (not good at electricity).
BMCC, according to what Robert measured above has a 30W draw when recording, at 14.4 V that would be 2Amp. If I have a battery rated by the manufacturer at 7Ah/20Hr how do I calculate the capacity?

7Ahx14.4V=100.8Wh. If the draw is 30W then the BMCC could be powered for 3.3 hs? And I read elsewhere that it can be safe to use a 0,7 efficiency multiplier. That would be just 2.3 hours of recording time for a 2.7kg battery?
Is that correct or am I doing something wrong in my calculations?
Thanks!

OK, I did some non scientific measurements on the external power supply of the BMCC to find out, how much power it draws.

BMCC with internal battery 100% full - external power supply connected: 24 W without recording, 30W peak during booting and initializing the SSD.

BMCC with interal battery 50% full - external power supply connected: 38 W without recording and internal battery charging, 42W peak during booting and initializing the SSD and charging internal battery.

That easily explains, why an external battery with 2A is not enough.

Hi Robert,
I am double checking back with you on how you came up with the measurements you did. Did you put an ammeter on the line in during useage? You said they were non scientific and since we are all trying to estimate battery life based on power draw the accurate numbers are important. I have read elsewhere in the Wolfcrow Blog (http://wolfcrow.com/blog/master-guide-t ... ra-part-5/)
that the camera is rated at 18 watt draw.
Somehwere else, can't find it now, I saw it rated at 23 watts

I have seen various estimates on the actual power draw of the BMCC . In this thread:

viewtopic.php?f=2&t=7870

Aaoron Scheiner quotes testing the BMCC at 16 watts

In the BMD FAQ for the BMPCC it says the power draw is 6.8w , which at 12V implies 0.57 amps.

From my previous calculations (which I'm too lazy to locate) a 70WH battery lasts about 4.5 hours on my BMCC, implying a power usage of approximately 16w (or 1.3A @12V) (naturally this will change depending on the lens used {IS}, screen brightness, SSD used, etc.) .

Your's is the highest estimate I have seen by far and exceeds what I seem to be drawing on my battery systems. Can you verify how you came to your numbers?
thanks

Patrick - I was using a Wattmeter plugged into the power outlet. The power supply of the BMCC was plugged into the Wattmeter. Then the camera was started and I took note of the power drawn during the initialization of the camera and the power drawn in camera idle mode.

Then I unplugged the power supply and let the camera internal battery drain to 50%, then did the same procedure as written above again.

OK, I did some non scientific measurements on the external power supply of the BMCC to find out, how much power it draws.

BMCC with internal battery 100% full - external power supply connected: 24 W without recording, 30W peak during booting and initializing the SSD.

BMCC with interal battery 50% full - external power supply connected: 38 W without recording and internal battery charging, 42W peak during booting and initializing the SSD and charging internal battery.

That easily explains, why an external battery with 2A is not enough.

It seems the estimates for power draw are a bit all over the charts. I finally found this quote from Kristian Lam from Black Magic in a thread entitles Power amps and wattage back in November of 2012. Clearly ,it goes up more than a bit based on your tests and numbers when it engages the charge cycle. It more than doubles???


Kristian Lam
Blackmagic Design
Posts: 233
Joined: Tue Aug 21, 2012 5:11 am
Re: Power amps and wattage
Sun Nov 04, 2012 8:25 pm

It's generally around the 20W mark, this is factoring a maximum 5W draw from the SSD. This may go up a bit of the battery is simultaneously charging (i.e. when it's not fully charged).

It seems the estimates for power draw are a bit all over the charts. I finally found this quote from Kristian Lam from Black Magic in a thread entitles Power amps and wattage back in November of 2012. Clearly ,it goes up more than a bit based on your tests and numbers when it engages the charge cycle. It more than doubles???


Kristian Lam
Blackmagic Design
Posts: 233
Joined: Tue Aug 21, 2012 5:11 am
Re: Power amps and wattage
Sun Nov 04, 2012 8:25 pm

It's generally around the 20W mark, this is factoring a maximum 5W draw from the SSD. This may go up a bit of the battery is simultaneously charging (i.e. when it's not fully charged).

Well, so basically Kristians's answer does fit quite well with my findings.

It's generally around the 20W mark, this is factoring a maximum 5W draw from the SSD. This may go up a bit of the battery is simultaneously charging (i.e. when it's not fully charged).

Well, so basically Kristians's answer does fit quite well with my findings.

Well he is saying it would go up "a bit" when in the charging cycle. I don't think of doubling of the wattage draw as going up "a bit". Fort those of us trying to spec amp hour capacity on external battery solutions that is a misleading answer. For instance, the very thing that happened in this thread where I was assuming the amp hour capacity of the poster's battery would likely be enough for his needs. During the charge cycle, according to your findings, the battery has to have at least a 3.5 amp hour capacity at 12 volts...

Well he is saying it would go up "a bit" when in the charging cycle. I don't think of doubling of the wattage draw as going up "a bit". Fort those of us trying to spec amp hour capacity on external battery solutions that is a misleading answer.

Well, just think about it. To charge a battery faster, you have to raise the amperage. The BMCC internal battery should have ~ 30 Wh - to charge that in 2 hours you need at least 1 A. That is not a bit, that would be 12 Watt.

For instance, the very thing that happened in this thread where I was assuming the amp hour capacity of the poster's battery would likely be enough for his needs. During the charge cycle, according to your findings, the battery has to have at least a 3.5 amp hour capacity at 12 volts...

That's right.

I have been using these Dionic 90 knockoffs for over 5 years and they are still going strong, as good as the day I bought them:
VSN092

GBCOMAU-ENLARGED-VSN092.082_2-450x300x0.jpg (58.91 KiB) Viewed 13162 times

http://www.global-batteries.com.au/anton-bauer-camcorder-batteries-cPath-2_888-products_id-10089.html

http://www.reduser.net/forum/showthread.php?31037-Battery-Repair&p=435609&viewfull=1#post435609

They have doubled in price since I first bought them and were unavailable for a couple of years.
I bought a couple more a year ago.

One of them would power a BMCC all day including all peripherals.

You can get a charger for $200 and a Goldmount plate for $200ish.
http://www.ebay.com.au/itm/like/261197508158?lpid=87

Would a Bosch (or other brand) power tool battery not work? Bosch in particular makes a VERY lightweight lithium ion 18v / 1.5ah battery that's available for around $35 new online. Because they're made for high-load tools, Bosch says you can draw up to 14 amps off of them (which drains them quickly, obviously). Could be good for an hour of runtime, the advantage being the weight, a few ounces. And it has a "fuel gauge" LED strip built in so you can see how much juice is left.

They also make a 4ah 18v "fat pack" that can be found new for $45 to $65. Throw in $35 for a charger and you're at $100. You'd need to fabricate a plate with a couple of blade connectors to tap the battery.

The "fat pack" would yield 72ah, maybe 2.5 to 3 hours of shooting?

The specs for the camera say the DC power in is 12v to 30v, so the 18v should work, right?

I don't want to fry my camera, so if there's something really basic I'm missing here please set me straight!

Thanks!

Geoff
Makes perfect sense. Many thanks!!