Build your own Speedlight power pack – a pictorial with Manuel Cafini

March 1, 2016 by John Aldred 29 Comments

Photographer Manuel Cafini recently posted a great series of images on how he built up his own SLA based battery packs for his speedlights to help improve recycle times and give him a bit more power, and has allowed us to share it here on DIYP.

The tools and construction is fairly basic if you’re confident with a soldering iron, but you’re still dealing with electricity here, so if you try this, be careful.

It shouldn’t need to be said, but try this at your own risk, and using this may void your warranty if it fries your flash.

About John Aldred

John Aldred is based in Scotland and photographs people in the wild and animals in the studio.

You can find out more about John on his website and follow his adventures on YouTube and Facebook.

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Ruben Lyteheart

What I did is gutted the AA battery compartment, soldered a DC socket with the leads, and then made a cable for the DC jack plug with clips on the other end so I can use an SLA or Lantern battery that matches the 6volt power rating. The advantage to this is that I can still do mobile battery power, reducing weight of the speedlight, and allow for an AC/DC power adapter for the wall outlets.
- blickblocks
  
  Did your speedlight not offer a high-voltage input jack for external power?
raoul

Never do this. It is very dangerous to use 110/240 volt connectors and assume someone won’t plug them into a mains socket. Please use a more appropriate connector!
- Chris Rocco
  
  Nice hack, but I Totally Agree with raoul!
- Kaouthia
  
  Well, if you’re making it for yourself, you have to assume you’re smart enough to remember what you did. :)
  - Me, Myself and I
    
    You bring in someone as an assistant, he thinks he’s doing you a favor by starting to setup your lights … BOOM.
- Me, Myself and I
  
  Yes! Would be safer to use something less standard like a computer molex connector from a busted PC power supply or something of that nature.
  
  There are plenty of safer options than a standard wall plug.
- Mystic Reality
  
  Did no one notice this is an extension for a power supply cable and does not have the proper end, on any part of this, to connect to mains?
- frankyvee
  
  I was about to say the same your risky that someone else comes along and plugs in that 110 plug into 110 Volt socket.. Bye Bye speedlight
Sly

Nothing dangerous, Raoul. It’s just a battery charger connected to a 6 volts battery. Like other many devices in your home.
- Nuno Silva
  
  I think what raoul means is that someone could plug that connector (that one that connects battery and the wires going to flash) into another cable with the same connector type. A child for example.
- Christoph Matz
  
  raoul ist absolutely right- never do this! And also not for Yourself.
  There are plenty of low voltage plugs for such constructions.
steve

So elegant and simple! I absolutely love it and a lot cheaper than lugging a stack of replacement eneloop pros around.
Don Wise

What is the CTEK device?
- steve
  
  the battery charger
- Rick
  
  Looks like a CTEK multi xs 3600 http://www.amazon.co.uk/CTE-XS3600-Battery-Charger-3-6Amp-Functional/dp/B000RHWCNY which begs the question, is it a good idea to plug 6V batteries into 12V chargers?
steve

For all those concerned about the possibly of the cable being able to be plugged into a 240v socket, have a closer look, it’s a female adapter to protected pin male adapter. The other cable ends have either wood or insulated caps on them. It’s far easier for a child to stick a knife, fork or paper clip into a socket than this cable assembly.
- willdmo
  
  Okay, the 230 V part is save now, but leaving this cable attached to a Battery may lead to short circuits. This is the reason why this connector is normally used the other way round.
  - Leo
    
    Sorry, but noting is save as I mention.
    
    Please read my advice.
- no name
  
  Are the insulated caps actually rated for 240v? A thin sheet of plastic does not guarantee insulation when it comes to high voltages.
  
  Even if it is properly insulated, it’s still a bad idea to use a connector that’s meant for mains current if the device can only be used with low voltage DC. Connectors should be chosen so that they can’t be connected in a dangerous way.
  - steve
    
    *sigh* Firstly 240v is NOT high voltage, anything greater than 1000v is considered high voltage according to the IEC, IET, IEEE and VDE so ultra-thick insulation is not required. Secondly the insulated caps are thicker than the insulation around the cables themselves so yes, they can handle 240v. This brings me to the third point, there’s no way to connect this cable setup to 240v anyway (see: diagram) so there’s no need to make any component capable of >240v handling.
    
    Would you be happier if the OP used exposed-ended alligator clips like what is often used in 12v circuits instead of insulated ‘high voltage’ kettle plugs to make the circuit? Would that make the whole setup safer in your professional opinion?
    - no name
      
      My opinion is in no way professional, it’s a sceptical amateur view that I’m offering.
      
      There is a way to connect the circuit in a dangerous way. For example connecting 240v straight to the battery is a really bad idea. The point is not that this is likely.. rather that it’s possible and it shouldn’t be.
Leo

the idea is good, but the realisation is the worst you can do.
never … NEVER use power plugs for DIY low voltage assembly!!!

especially when you are not familiar with power voltage.

if someone else connect the plug for the battery with an regular power cord and plug it in a power socket … nice firework! :(
- steve
  
  You ‘fireworks’ would only happen on the condition that the battery is still connected to at the time, if the battery is not connected then a circuit will not be made an nothing would happen.
steven_nc

I often use multiple speedlights into an umbrella/softbox. Would I need multiple battery packs? Or could a splitter be used to power the multiple speedlights?
steve

For those which are concerned about possible safety issues by using a kettle plug connection, there’s a simple alternative and that is simply not use kettleplug connection in the middle at all…
Stefano Venneri

Here my project… made about one year ago ;)

http://www.sv-design.org/blog/diy-battery-pack-per-flash/
Frank Nazario

finally a no frills simple hack that definitively will give you all the power you need for your sitting… thanks again DIY… simple hacks that save money :-)… perfect
blickblocks

You’re aware that your SB900 there has a proper 300V high voltage power input designed for external power, right? That actually offers much faster recycle time when paired with a lithium-ion battery pack. Why would you buy a $500 speedlight and DIY something so clunky like this?