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 Battery pack idea I found surfing around 
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Joined: Fri Dec 09, 2011 8:58 am
Posts: 40
Post Battery pack idea I found surfing around
Thought this might be useful to fellow TS forum people as it seems it might be good for time lapse.

http://itschriswinter.com/dslr-video/th ... l-battery/

I just wondered if this will work with the D7000 it has a 12v and 9v output. Using it on 9v would it be safe for the Camera?
I assume the dummy battery has a built in power regulator to make sure the power is at the right level for it.


Mon Jul 28, 2014 10:41 am
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Joined: Thu Feb 14, 2013 12:24 pm
Posts: 284
Post Re: Battery pack idea I found surfing around
There's been a few posts on this stuff, and a bunch of webpages as well.

I don't think the dummy battery has any circuitry besides hooking up the power.

Some people made DIY sony NP-F series mounts for the same thing.
A good brand for the type of battery pack in the vid is anker, they seem to be more reliable than the other stuff out there.

http://nofilmschool.com/2014/05/power-c ... aleb-pike/
http://www.diyphotography.net/how-to-ma ... es-longer/

I have a bunch of NP-F chargers I bought (like $5 each) to try to do the second method.
I have made a test and confirm it works with the dummy adapter (I used it on Canon cameras)
But I have not gotten further than that yet... with grip, Canon FF can shoot practically all day so unless multi-day is needed this is a make-work project.


Tue Jul 29, 2014 7:42 am
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Joined: Wed Sep 03, 2014 5:09 am
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Post Re: Battery pack idea I found surfing around
If you are using a dummy battery, just buy 'raw' batteries from the likes of Hobby King.

I can run my Canon 5d3 for 10 hours on a pack made of two 6 Ah packs from Hobby King.

A standard Canon battery is 2 series Lithium cells, so just search the site for 2s Lithium packs.

Two of these will give you near on 20 hours run time with a 5d3.

buy a high capacity charger too, also from HK , a 12 volt powered one, so you could have a backup, on charge in the car. If you made your harness with a diode or two and suitable switch, you could easily plug in the new battery while the old one is still powering the camera, so creating a hot swap system.


Wed Sep 03, 2014 5:20 am
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Joined: Wed Apr 03, 2013 7:20 pm
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Location: Brisbane, Australia.
Post Re: Battery pack idea I found surfing around
NeilP wrote:
I can run my Canon 5d3 for 10 hours on a pack made of two 6 Ah packs from Hobby King.


Hi Neil - have you had any problems with the 7.4v LiPo batteries - cutting out when the voltage drops, etc? I'm still deciding whether to go for the 2cell (7.4v) or 3cell (11+v) batteries, I have a dummy battery voltage converter for powering from up to 12v so higher voltage is no problem.

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Wed Sep 03, 2014 7:50 pm
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Joined: Wed Sep 03, 2014 5:09 am
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Post Re: Battery pack idea I found surfing around
My pack is made of 2s LiPo, 6ah packs.
I have two packs in parallel giving 12 Ah

I also used a Celllog voltage monitoring device on the pack 'balance leads' , which are the thin multi coloured leads with white connectors.

The camera started flashing that battery was low when cell voltages dropped to about 3.7 volt per cell, starting from fully charged at 4.2 per cell.

This was after 7 3/4 hours use on the 5d3, in live view mode, 25s exposures, interval of 30 seconds. Over 1300 shots.


I never logged the total Ah either used from the pack or put back in on charge, so don't know what %age of battery capacity remained.

If you have ever seen a LiPo discharge curve on graph you will see they reach a plateau where most of the Ah discharge occurs and then voltage drops sharply at 3.6 ish volts. So below that sort of voltage you don't have so much usable capacity left.

Until I saw actual spec from Canon saying my camera was good for 3s LiPo, (4.2 x 3 = 12.6 volts) I "d be scared to attempt shoving that voltage up it for fear of frying it.


Next time, I'll put an Ah meter in line ( plenty on flea bay). or try a Cycle Analyst Stand Alone e-bike data logger, and see what total Ah I use from the 12 Ah pack.

I suppose if you wanted to try 3 series, you could always construct a basic voltage dropped /regulator from a correct voltage Zener diode, a power transistor and a few resistors to regulate the 12.6 volts down to 8 volts,or a basic LM317 voltage regulator. The cost would be pennies.


Wed Sep 03, 2014 9:18 pm
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Joined: Wed Sep 03, 2014 5:09 am
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Post Re: Battery pack idea I found surfing around
http://en.wikipedia.org/wiki/LM317

http://www.ebay.co.uk/itm/like/16078566 ... 0&ff14=108

I reckon that would be an answer..LM317 just need two other resistors. Not worked any figures, yet


Thu Sep 04, 2014 10:10 am
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Location: Brisbane, Australia.
Post Re: Battery pack idea I found surfing around
Thanks for the info. I was talking to a photographer over the weekend who was running a couple of 3S batteries and dropping the voltage down to 7.4v - he'd told me about low-voltage/current problems from the 2S LiPos.

I've got one of these, just need to wire up a cable from any batteries, but also means I can run the Canon (also 5D3) off the large 12v SLA batteries my MoCo gear runs off:

http://www.ebay.com.au/itm/171297896598?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

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Thu Sep 04, 2014 2:41 pm
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Joined: Wed Sep 03, 2014 5:09 am
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Post Re: Battery pack idea I found surfing around
That is great
I'd ditch the heavy SLA battery though .

Look up Bamboo Lithium. A drop in replacement for gel SLA batteries, but Lithium pack, therefore a third or less of the weight.

I have a box of LM 317's and large quantities of LiPo packs so I'll just build my own voltage dropper.

But I am going to run some tests, logging the actual Ah drawn from my 2s LiPo pack, I may even rig an original battery to run through the adapter to compare.

I had noticed though, that if I run my 5d3 with the battery pack extension grip, with two original packs, I do get more shots per battery ( when run as a pair) than I do without the battery grip and I use each battery individually.


Thu Sep 04, 2014 7:39 pm
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Joined: Wed Apr 03, 2013 7:20 pm
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Location: Brisbane, Australia.
Post Re: Battery pack idea I found surfing around
Those Bamboo Lithium batteries may be light, they are also 3x the price of SLAs! Can't seem to find them here in Aus anyway.

May look at powering the MoCo (TB3 and slider) from 12v of LiPos, if possible.

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Sun Sep 07, 2014 4:06 pm
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