Would this 24V cable converter be safe to use?

Raymond Zananiri · January 30, 2021

I have a lot of 14.8V Gold mount batteries. I'd like to be able to use them as a 24V power source using this cable converter. Namely for the Moviecam SL.

https://www.bescor.com/product-page/14vto24v

Has anyone tried it before?

Your thoughts!

David Sekanina · January 30, 2021

it really depends on the maximum amperage the boost converter (step-up-converter) in the middle can handle.

when starting up your moviecam, it will draw more amps than when running normally. some DC-DC converters switch off electronically when this happens.

so i would ask them how many amps their converter can output and measure the max amp on you moviecam.

Edited January 30, 2021 by David Sekanina

Phil Rhodes · January 30, 2021

That's a really physically small converter. As David says, it depends on exactly how much power you want, but eesh, that's a tiny converter to run a film camera. Ask for the specifications.

Dom Jaeger · January 30, 2021

You need to be able to supply at least 3A at 24V for trouble-free operation of a Moviecam SL, more if operating under 6 degrees Celsius when mag heaters kick in, or powering extra accessories from the camera. On certain batteries the D tap outputs are limited to 50W which wouldn’t be enough.

That converter looks pretty dinky to me too, and honestly if they can’t be bothered giving you any technical specs at all on their product webpage I personally wouldn’t be bothered buying from them.

Satsuki Murashige · January 30, 2021

I’m part of the beta tester group for the Rencher Industries Lock-On Battery Booster:

https://www.instagram.com/p/CFDQxM9h8cu/?igshid=3xfi3yc9ncvg

It is supposed to boost or buck 14.4/28.8v battery sources to regulated 24v for cameras like the Moviecam SL, Arriflex SR3 and 235, etc. I haven’t received my unit yet, but it seems like the right tool for the job.

Personally, I will be using my 28.8v 2F1 Block Battery on-boards thru an 28v Anton Bauer adapter plate. You may have issues with pulling too much amperage from 14.4v batteries, depending on the make and model.

Aapo Lettinen · January 30, 2021

from the looks of the Bescor converter I would believe it being made for something like 2A maximum current or something like that. Maybe they have specs somewhere to check it out.

It is much easier to put two 14.8V batteries in series to generate somewhere around 30 volts and then use a easily available generic step-down switching converter to convert it to the voltage you want, for example the 24 volts. There is adjustable converters like this available for cheap (in eBay for example) and there is lots of different models with for example 10A or 20A or 30A maximum current handling. Prices starting from couple of bucks.

Building a step up converter is not super complicated but because there is tons of different step down converters available which are perfectly suitable for this 24v Moviecam task I would use the two battery approach and the step down converter instead. Helps with the current limitation of the batteries too

Raymond Zananiri · January 31, 2021

Thanks guys,

Very helpful. I'm not worries about the batteries I have. They can deliver 12A continuous with 14.8V. So I assume they would deliver at least 6A with 24V and the SL needs 2.5A. But I suspect that little cable converter might not be reliable enough. Will call the company on Monday and check the specs. I hate to have to buy brand new batteries for 24V use. I'll keep searching for another kind of converter that has higher specs. Satsuki, please tell me if that prototype gets to market.

Satsuki Murashige · January 31, 2021

2 minutes ago, Raymond Zananiri said:

Satsuki, please tell me if that prototype gets to market.

Alan Rencher posts here, so I’m sure he will mention it here if and when that happens.

Raymond Zananiri · February 3, 2021

Just curious: Is there anything in a video camera application that requires a battery built solely for that purpose?

I am looking at some 24V batteries with enough current draw that are 1/10 of the price of gold mount or v mount batteries with the same specs. Such as this one:

https://www.folkbattery.com/24v-6ah-7s3p-18650-battery-lithium-battery-24-v-electric-bicycle-moped-electric-lithium-ion-battery-29-4v2a.html?fee=1&fep=296&gclid=CjwKCAiAjeSABhAPEiwAqfxUReIYWunzqJzaXPVcgqqhMCUVJO5QAm2GwDlik6fFt0DG9FO2iExD-RoCGvUQAvD_BwE

I can easily solder a 4 pin connector to such a battery.

I have to wonder though why I don't see anyone taking such an approach. People are using $2000 block batteries all the time with their camera. Is there anything special about the chemistry or design of a battery made specifically for professional cameras?

Satsuki Murashige · February 3, 2021

1 minute ago, Raymond Zananiri said:

Just curious: Is there anything in a video camera application that requires a battery built solely for that purpose?

I think most camera people these days are used to video-specific batteries that communicate to the camera and convert remaining voltage to battery percentage, have external charge indicators, d-tap and other accessory ports, camera-fitted form factors, fast reliable charging on a variety of existing multi-chargers, etc.

If you don't need these things, then I suppose you can use something much more basic. Batteries originally made for film cameras were much less fancy in that regard - the only thing they had to do was to supply the correct voltage and amperage, be rugged and portable, and have the right connectors for the camera. Also, most people who shoot on film cameras these days also shoot on video cameras, so it's nice when the same batteries can be used for both purposes.

Aapo Lettinen · February 3, 2021

33 minutes ago, Raymond Zananiri said:

Just curious: Is there anything in a video camera application that requires a battery built solely for that purpose?

I am looking at some 24V batteries with enough current draw that are 1/10 of the price of gold mount or v mount batteries with the same specs. Such as this one:

https://www.folkbattery.com/24v-6ah-7s3p-18650-battery-lithium-battery-24-v-electric-bicycle-moped-electric-lithium-ion-battery-29-4v2a.html?fee=1&fep=296&gclid=CjwKCAiAjeSABhAPEiwAqfxUReIYWunzqJzaXPVcgqqhMCUVJO5QAm2GwDlik6fFt0DG9FO2iExD-RoCGvUQAvD_BwE

I can easily solder a 4 pin connector to such a battery.

I have to wonder though why I don't see anyone taking such an approach. People are using $2000 block batteries all the time with their camera. Is there anything special about the chemistry or design of a battery made specifically for professional cameras?

you can build custom batteries from separate 18650 cells for example. They are very affordable and you don't need much additional stuff other than the battery holders if having some sort of protection circuit for them or just being very careful.

One can build a in-battery or a external charge indicator using a small microcontroller circuit. for example one which has couple of led lights which indicate the remaining battery power in percents and cuts off the power or gives a warning if the battery voltage goes too low. adding a oled display is possible as well though will be much more complicated.

Raymond Zananiri · February 3, 2021

Thank you guys. Very useful.

Matthew Parnell · February 21, 2021

If it’s a case of you having v lock batteries around and wanting to make use of them, there are a handful of different dual v lock systems out there, which use two v locks and a boost/regulator chain to give a 24v output. A lot of those are good for 10 amps with decent v-locks.

Phil Rhodes · February 21, 2021

2 hours ago, Matthew Parnell said:

If it’s a case of you having v lock batteries around and wanting to make use of them, there are a handful of different dual v lock systems out there, which use two v locks and a boost/regulator chain to give a 24v output. A lot of those are good for 10 amps with decent v-locks.

I guess depending on what the equipment can tolerate in terms of "24v" then two batteries in series requires no converter.

But do check.