BMMCC 14.8V Battery Module by RADIOPROEKTOR

[shijan]

All Battery Enclosures and Chargers are SOLD OUT.

Other BMMCC accessories by RADIOPROEKTOR are still available.

Time to time i was in communication with users who use external batteries. Based on their requests and suggestions i decide to start new project BMMCC 14.8V Battery Module by RADIOPROEKTOR

Some ideas also came from these threads
http://www.bmcuser.com/showthread.php?21049
http://www.bmcuser.com/showthread.php?21004
http://www.bmcuser.com/showthread.php?21520

Expected key features:
14.8 voltage same as any common V-Mount Battery.
Usable for heavy duty applications, continuous working current up to 10A
You can choose any 18650 battery cells. 4x quality 18650 battery cells will give you 14.8V 3A (44.4 Watt hours) for $20-25 total.
Clamps directly to camera with passive dummy LP-E6 base.
LP-E6 base can be user removed and replaced with V-lock base or any other.
Built-in mini cheese plate with threaded holes.
Built-in splitter allows to plug multiple devices simultaneously.
Built-in capacity meter.
Built-in ON/OFF switch.
Perfect cable management.
Low profile gimbal friendly.

Parts used:

• 4 high quality Li-ion 18650 Battery Cells (SAMSUNG INR18650-30Q, or SONY US18650VTC6 30A, or Panasonic NCR18650B 3400mAh
• 4x18650 Battery Holder
• 4s Li-ion Lithium Battery 18650 Charger Protection Board
• 4S 16.8V 18650 Lithium Battery Capacity Indicator
• 2 or 3 DC power sockets
• DC power switch
• 16.8V 1A DC Charger
• Short angle DC cables

DIY parts still in development:

• 3D printed or CNC LP-E6 mounting clamp
• 3D printed or CNC enclosure
• Small aluminum CNC made cheese plate.

[Stelvis]

interesting idea Shijan

maybe 4*2 cells might be better (twice the runtime and with the micro we need to power a monitor as well as the camera)
even 3*2 could work well (ie nominal 11.6v rather than 14.8)

I bought 8 samsung cells a while back to do something similar

[shijan]

Main problem is more batteries - more weight. I am afraid that LP-E6 mount is too weak for larger battery sizes and there is a risk to break camera. Sure 4 cells is not a large V-mount battery competitor, but probably allows about 3 hours runtime of BMMCC + Video Assist.
That Charger Protection Board is durable and can deal with 8x 18650 cells, for more you can just put different larger Charger Protection Board. it s also possible to mount battery with Arca Swiss or Nato clamp to camera cage instead of LP-E6 base.

P.S. done some more detailed sketches today:

[Denny Smith]

I like your idea Shijan, for the smaller 4-cell unit, 3 hkursmis good for average shooting situations. So the battery unit mounts to the LPE6 mount on the camera, but uses the cord to connect to the power plug on your breakout box?
Cheers

[shijan]

So the battery unit mounts to the LPE6 mount on the camera, but uses the cord to connect to the power piers on your breakout box?
Cheers

Correct

[Denny Smith]

Thanks, You can put me down for one of these kits.
Cheers

[shijan]

A little notice about Protection Boards for DIY community:

I plane to use simple and very common board that have only Charger Protection circuit. It charges all battery cells together and stop charging when first single battery reach 4.25V. It needs simple inexpensive 16.8V 1A charger. Due to its simplicity it provides less lifetime for battery cells than smarter balanced boards. This circuit type is very common in heavy duty hand tools battery packs.





To charge each battery in more gentle separate way, you need additional Balance Board. This adds complexity and additional cables. Also it is probably requires different charger. Balance Board usually recommended if use battery cells with different age. It is also highly recommended for large battery arrays with dozens of cells.





There is also same sized 8A Protection Board with integrated Balance Circuit, but from tech specs it needs different expensive smart charger with CC/CV charging states and 18V output. Also it seems that build-in Balance Boards usually very tiny and ineffective.

[core_50]

love the idea!
I also would love it to be 3*2 or 4*2 in size, but ready to buy this anyway

[shijan]

Internal layout:

[shijan]

CNC machined body allow bypass additional cheese plate.
Rear shell may be 3D printed from hard rubber material Elastan D70. Easy snap on and off.
Dummy LP-E6 base may be 3D printed from Nylon or similar heavy duty material.
5 metal 1/4"-20 inserts build in LP-E6 base.
Fits exact to width and corner radius of SmallRig Mounting Cheese Plate 1598

[Stelvis]

some nicework there

maybe the battery life indicator button and LED placement is not ideal though?

[tmronin]

oh man, I do love this...but this would be the 5th battery system I have for my BMMCC.
- Stock Canon LP-e6 (a slew)
- 2x Sony NP-F with Cheesy Cam bridge (2 Big NP's and 2 smaller)
- Juice BoxV1 (2x with one being a bit wonky)
- Mini V-Mount on a smallrig plate with a custom DTap y-cable

won't lie - quite love the V-mount system at the moment. The smallest Juicebox v-mount is actually lighter than the IndiePro Mini

IMG_8405.jpg
IMG_3219.jpg
IMG_0257.jpg
IMG_6249.jpg

(apologize for not rigging the dtap in the mini shots, but I just can't even today...)

[shijan]

some nicework there

maybe the battery life indicator button and LED placement is not ideal though?

Yes, indicator placement is a compromise because space is limited. There is just no any other place for it. Currently i experiment with body length and slightly move things.

P.S. Today i finally found nice button cap for battery indicator button https://www.aliexpress.com/item/50PC...79377179.html?

[shijan]

oh man, I do love this...but this would be the 5th battery system I have for my BMMCC.
- Stock Canon LP-e6 (a slew)
- 2x Sony NP-F with Cheesy Cam bridge (2 Big NP's and 2 smaller)
- Juice BoxV1 (2x with one being a bit wonky)
- Mini V-Mount on a smallrig plate with a custom DTap y-cable

won't lie - quite love the V-mount system at the moment. The smallest Juicebox v-mount is actually lighter than the IndiePro Mini

(apologize for not rigging the dtap in the mini shots, but I just can't even today...)

As i noticed earlier this battery is not a replacement for large V-Mount power source. It replacement for Juice Box/Sony NP-F but with better ergonomics and slightly larger capacity. Also price expected to be way lower than V-Mount battery with typical V-Lock plate with build-in connectors splitter.
Also probably for request it will be possible to fit additional voltage regulation board inside to output additional 7.4V.

P.S. Almost done the sketch of capacity circuit indicator board holder. Those parts will be 3D printed.
Need to design clamps for rear shell now...

[shijan]

After some tests i back to cheese plate version. It is just simpler and more universal concept.