Each Sony NPF style camcorder battery runs at 7.4V. By running them in series, it works at 14.8V which is the minimum power required for the 600 and 900 LED light panels at full brightness. I took two basic Sony NPF battery chargers, gutted them, and then wired them in Series to provide 14.8V DC.
Remove two screws under the rear sticker and then pry apart case
To wire up the cases for Series, basically you take the Negative wire from one and the Positive wire from the other and connect them to the barrel plug. The other two wires (negative and positive) from each charger would be connected together.
Sorry for poor diagram
Next I added a bit of extended wire and used my Barrel Plug (shown here) to connect directly to the LED light. The Barrel Connector is super easy to work with (no soldering), and is clearly marked with + and - for positive / negative placement. It's a very simple and cheap DIY to provide portable power for these large LED panels. If you want use heavier batteries, just make the wiring longer and mount to your light stand.
[Disclaimer] Attempt this DIY at your own risk. Using your batteries in other ways than intended may cause premature failure of your batteries, or damage.
Here's a few parts links related to this DIY:
Sony NPF Style Battery Charger
thank you so much.
I would want to create a DIY light source using LED stripes: is it possible?
if yes, what kind of calculation should I consider (I mean, how should I figure out what and how many batteries/charger I need?
From what I understand about Lithium batteries their risk of explosion is due to overcharging (or puncturing) a cell. Properly built Lithium-Ion (and Lithium-Polymer) batteries have a "cell balancer" in them to ensure each cell is discharged equally. If one cell (in the battery) is discharged faster then the others then that battery will read as dead although the other cells still hold a charge; the risk is when recharging that battery, the charger will continue to charge the battery until ALL the cells read full capacity, so if one was lower then the rest during charging the others would start to get overcharged, if the gap is too much and just one cell gets more charge than it can take BOOM! BUT Properly designed Li-Ion chargers have "Cell Monitors" that checks each cell's capacity to prevent overcharging any cell. Discharging two properly designed Lithium batteries in unison should not cause an explosion but "daisy chaining" or connecting them "serially" is potentially dangerous (Battery 1 is connected to Battery 2 and Battery 2 is connected to your device), so Battery 1 is charging Battery 2 as Battery 2 is being discharged and since Battery 1 has no way to monitor for an imbalanced cell, if the balancer in Battery 2 were to fail then your would know immediately as battery would explode (one cell at a time) and probably take your device with it.
I've never used this setup and couldn't tell you if it's safe but it looks dangerous, this setup connects the positive+ wire of one charger to a negative- wire on the other, so these batteries are connected together and current would be flowing from one battery to the other... A potentially safer (no completely safe but safer) design might be running the two negative wires from both chargers together and separately running the two positive wires together all the way up to the barrel plug.
UPDATE: Sorry. Actually worked fine. One of the batteries suddenly went bad. Hope I didn't short it out or something. But replaced that battery with another and it worked as promised in the demo. Altho' Tomy's post from May 30 has me a little spooked.
This didn't work for me. And I can't figure out why. Same light as in the demo (ePhoto 600 LED), same chargers, I followed everything to the letter, the batteries are new and fully charged -- and nothing. Zero output from the light. Any suggestions as to what I might've done wrong?
@Stephen Brock - That adapter looks great, but a single Sony battery is only 7V. I've tested my lights with other batteries at 12V at it did not get to it's full output. The lower the voltage the less output on the LED light.
As an additional alternative has anyone seen one of these? https://www.bhphotovideo.com/c/product/605674-REG/IDX_A_NH2E_A_NH2E_Battery_Adapter_Plate.html
Anyone know if there's a way to do this type of thing and still retain the battery life indication on the camera (specifically the Blackmagic Cinema Camera)?
Would decoded batteries work for this?
Great site Emm!
Also interested in how you are getting on with these, would love to add these to my kit, but the vlock and tekkion batteries are way out my price range at the mo.
Any new results?
Any update on this? Has anything backfired?
I just completed testing on a 600 LED panel, First a correction; I tested dual MaximalPower 7200mAh batteries that were purchased from Amazon.
My test started at 6:54 and ended at 9:42. Therefore, I was able to get over 2.5 hours on full brightness. I'm very pleased. Obviously, this configuration doesn't offer any battery life indicatory like is found on the Tekkeon. But.. this is a small price to pay IMO for the savings and added performance. Plus these same batteries will work with the bicolor 312's.
Emm- I would just like to thank you for posting this DIY up. It works like a champ. I'm presently charging up a couple 7700mah big sony batteries to do a duration test. My Tekkeon only lasted around an hour and fifteen minutes. The Tekkeon's are awesome but they do get expensive. If I can get the same or longer run time for half the price I'm going to call this a big win. I'll keep everyone updated.
Emm make me and one and I'll buy it off you!!! Add to your https://www.photographyandcinema.com/ product line.
@Stephen Brock - I don't know of a particular brand. The generic ones i've been using have been with me for almost a year now, and I still use them today. There's no name brand on it. With generic stuff, i'm sure there's always a hit and a miss. Just make sure you grab them from someplace that will do an exchange if you get a dud. Amazon has a simple return policy or try B&H which carries a generic brand under 'Pearstone'.
@Emm, I've been shopping around amazon and ebay for some generic NP-F970's but there's a lot of mixed reviews. Do you know of a specific manufacturer/seller that has decent longevity?
@ben - I'm familiar with the smaller brick types and it's also cheaper. I made something similar with my Canon LP-E6 batteries, but decided to try the Sony because Canon doesn't have larger capacities.
@ Emm - I look forward to seeing your run time test results. Nice work!
nice one emm... but why not buy the dual chargers? like so?
fitting this nice and clean on the base of a v-mount battery (as adapter vmount -> sony or whatever ) would be a nice product.
maybe you can fit some active parts (dc-dc konverters) in to meet all power requirements
It is important to use the same battery type with equal capacity throughout and never mix different brands and sizes. A weaker cell causes an imbalance. This is especially critical in a serial configuration *hint* and a battery is only as strong as the weakest link.
LithiumIon batteries are way more complicated that the usual LR6. Because of the charging and discharging electronics inside the battery, you can not connect them serially without risking to damage the cells (or even cause an explosion).
The only way to connect LithiumIon in series is by connecting the cells and only then to apply the electronics.
Take care while following this DIY instruction.
HAHA I was gonna say "You're a genius" but Serge beat me to it. I studied electrical and electronics and school and wonder why i didn't think of this. Perfect combo of voltage and series wiring to meet the minimum for the lights. I have the largest version of the sony battery and it is a "brick" it runs a 160LED for a good 4 hours.
@johnson - I still have to run a test. I don't expect much from these batteries, but they do sell larger versions.
@Dollar Bob - industrial Velcro
How did you attach the battery plates (formerly chargers) to the back of the light?
Emm, conpared to say Tekkeon do you notice degrade in power lumination off the bat? Def coat effective for folks who have a bunch of these.
@Serge - 14.8V required. This meets the requirement.
You sir are a GENIUS!
What is the voltage request by manufacturer on the lights?
or you barely providing enough power or over power?
any idea on the running time?