DIY Project: Battery Charger / USB Connector Center

Continuing our obsession with better battery management, we would like to share a post by photographer Julian Eichhoff. Looks like Julian not only cracked the system for battery charging, but managed to build a whole portable uber-photographer-power-and-data-james-bond-case.

I own several cameras and every camera requires its own battery type. In total I need four different chargers for my batteries. In addition to that every camera/device needs another USB connector. Every time I need to charge a battery or download files I am recabling. I was sick of that for a long time, now I have built a solution to end the cable madness. What I have done is basically taking a wooden box and installing the chargers, a 7-port USB 3.0 hub and a harddrive docking station inside using velcro. It’s nothing fancy but it is practical. Long story short, here is the result:

The finished box
The finished box

The finished box
The finished box – Openned

A look at the components and wiring
A look at the components and wiring

The chargers are fixed with velcro
The chargers are fixed with velcro

Remember that some components need space to be operated (here: battery is inserted sideways into the charger).
Remember that some components need space to be operated (here: battery is inserted sideways into the charger).

The bundle of USB cables coming out of the box
The bundle of USB cables coming out of the box

To find the right size of the box I compiled all the components I wanted to install and measured them. Then I made rough layout on the table and measured the dimensions. Finally I ordered the box via eBay.

When you have all the stuff you need (shopping list at the end of this post), take the components you want to fit in the box and position them. Make a “dry run” to see if the wiring will fit into the box. Remember that cables have a minimal bending radius (the smallest radius you can bend them without damaging the leads). Also the connectors need some space. This has to be tested and is usually a lot faster than measuring and drawing everything. My dry run looked like this:

Then the hands-on work can start. First I cut two long holes into the sides of the box to make an opening for the power and USB cables. This was done by drilling two 10 mm holes on each side and sawing the material between the holes away. The detail work was done with files. Then I covered the openings from the inside with duct tape and spraypainted the box from the outside. I used a 200 ml can of paint and that was a tad less than necessary. Use a bigger spray can for multiple coats (the box I used is 40x30x15 cm).

After the paint had dried I put a strip of velcro on the floor of the box. The chargers were outfitted with a corresponding strap of hooks to secure them safely. Velcro has the nice advantage that you can take the charger out of the box without any problems if necessary (i.e. if you sell the camera and need another charger or if you are travelling).

Routing the cables is tricky. I used special cable clips to get some kind of control. Finding the best layout takes a little try and error, but it is not rocket science. See the video – routing and organizing the cables takes up most of the time. Be patient.

Here is the shopping list (suggesting all necessary USB cables and chargers/power cords are already in your posession):

  • A wooden box (in my case 40x30x15)
  • USB 3.0 hub
  • A can of white spray paint
  • Cable clips with self-adhesive tape
  • Cable binders

Necessary tools:

  • Electric drill
  • Saw
  • Set of wood files

Three Months Later

After using the box for three months, I have some insight to share.

First of all, having all chargers in hands reach and not having to bother about the wiring is great. I am so relieved that don’t have to rummage around in a box for the correct charger anymore or find a spare power plug. Charging your batteries (I have four different battery types to charge) is now achieved in a very convenient way.

The USB hub also provides extra comfort. I can plug my camera directly to one of the cables from the bundle and I am ready to go. So same thing here – life has become easier. But the design turned out not to be perfect. When I connected my D800 to the USB 3.0 cable of the hub Lightroom stopped importing the images from the camera at random points. I got an error message that the files were not readable. I had to reconnect the camera and import again. At first I thought of a faulty memory card, but after a while it dawned on me that the USB hub might be the issue. So I used another USB cable and connected it directly to my iMac. The result – a smooth import, no problems. I am not sure what exactly causes the problem. Perhaps the combined cable length of the USB cable and the cable which connects the hub to the iMac is too long and packet loss occurs. Just a theory.

But I am pretty sure about the cause of the second problem I encountered. While I can connect and charge my iPhone perfectly with a cable connected to the hub my iPad won’t charge. The cause is clear – not enough voltage. Note that there are USB hubs on the market with dedicated charging ports for smartphones and tablets. These ports put out more juice. I saw such hubs when I chose the one for my box but did not buy it since the distribution of the ports on the hub did not go well with the component layout I planned (some ports would not have been accessible).


To wrap it up – nothing is perfect at the first attempt except Chuck Norris. But despite two minor issues the box made my battery and cable management a lot easier. The components are easily accessible, can be removed if necessary (velcro !) and stored out of sight when not needed (close the box). It is an effective and inexpensive solution (you have to buy the box, some paint if you like and a USB hub).

About The Author

Julian Eichhoff is a photographer based in Hannover, Germany. You can follow his blog here, and his Facebook here. this post was originally published here.

  • david d

    Two comments:

    1- The lid should never be closed when charging any anything. Doing so will trap heat inside the box, potentially starting a fire.

    2- I have never seen a 7 port USB hub that comes with an appropriately sized power supply. At the proper minimum of 500mA per port, the wall wart should be rated for 3.5A, at a minimum. As noted above, some phone chargers are rated at 1A or 1.5A, and the phone will take that if it can (it will keep drawing until the voltage sags to a certain minimum). (The other thing cheap hubs I’ve seen do not do is have proper current limiting on each port individually as required by the USB spec.)

    I would use a separate, high-quality hub for data transfer. Any charging going on should happen elsewhere, since instantaneous spikes in current can cause a drop in voltage which could in turn affect the data transfer.

  • John

    I wonder if it would be practical to put a small power strip inside so there would only be one power wire coming out.

  • patiferoolz

    just be careful with heat/fire threat

  • Rona E Philpott

    What about heat displacement?

  • Lumenatic

    Thanks for the comment about the heat generation. I left the lid open instinctively when charging a battery, thought that was quite obvious. But you are right – it is not obvious. I have not added such a remark in bold letters to the posts on my blog to make sure people won’t come into danger.

    @John: I pondered installing a small power strip in the box. But then I would have needed short cables or shorten the cables by myself in order not to have a mother mess with the wiring (“cable salad” is the appropriate term in German). So I opted for leaving all power cables at their original length and guiding them out of the box.