DIY Battery Packs

When powering strobe lights on location, a reliable power source can be a huge issue. One option is to bring your own power solution but that either means a loud generator or heavy battery packs. Paul Buff, Inc. makes a portable power solution based on a seal lead acid battery they call Vagabond II, and just recently introduced a lithium version called Vagabond Mini. Profoto also makes a portable battery solution for their D1, ComPact and Acute2 flash equipment they call the BatPac. All of these solutions are reliable and extremely useful on location but they can be pricey!

Luckily there are some do-it-yourself options which will save you quite a bit of money. I do have one disclaimer: I am not an electronic specialist. I took an electronics class in high school and can do some basic soldering but that's about it. What follows is my personal experience and not a professional recommendation. My goal was to build three batteries, one for each one of my strobe heads. That way I could attach one pack to one head and have the freedom to move my lights around without tripping on extension cords. Here's how I built three individual battery packs for less than the cost of one Profoto BatPac.

STEP 1: FIND THE RIGHT POWER INVERTER

The key to getting this system to powering your lights correctly is finding the right power inverter. There are a lot of cheap power inverters that will convert volts to watts but they don't output that power correctly. What you need is called a "Pure Sine Wave Inverter" and the best inverter I found for this project is made by a company called Samlex. The model I found to work best is the PST-300-12A. That's a 300W Pure Sine Wave Inverter that converts 12V of DC current to 120V of AC current.  $140 at Amazon.

STEP 2: FIND A SEALED LEAD ACID BATTERY

These are pretty easy to find at electronic stores or automotive stores. This particular battery is used for boats, scooters or battery backup systems. I found a lot of 5 from an eBay seller for a steal (although I paid a lot for shipping as these batteries are heavy!) because I knew I wanted to build a few of these packs. The SLA batteries I purchase were Rhino 12V 18Ah. These are $38.99 on Amazon right now. The important thing to keep in mind when buying the battery is getting the voltage and amperage correct. It should be at least a 12V and 18Ah.



STEP 3: FIND A CONTAINER

At this point the only other item you would need is something to house and carry the battery components. I went through MANY different iterations, including small tool cases and assorted bags until I finally found the perfect carrying case for my battery packs. I bought three SLR Zoom cases from Case Logic for $23 each on sale. These cases held my power inverter and SLA battery in a vertical configuration exactly like I wanted with no room to spare.  The vertical position is important because it allows me to unzip the bag and plug my lights right into the power inverter which is pointed up.

STEP 4: FIT AND FINISH

I was really trying to avoid the DIY look for my power packs so I went the extra distance and purchased 3 socket power couplers (Like the cigarette or power adapter in your car) so that I could recharge my batteries easily. Then I bought a standard SLA battery charger and soldered a power socket to the business end so that I could easily plug the sockets together to charge each battery. This may be an important detail - be sure to buy a proper Sealed Lead Acid battery charger. SLA batteries can be finicky in how they hold/charge/discharge and you don't want to ruin your new batteries so be sure to buy a proper charger for them.

STEP 5: ASSEMBLY

At this point, once you have all the components you need, it's an easy task to wire everything together. Use some heavy gauge wire and get creative with the electronic connectors you might find at Fry's or Radio Shack. I used standard 1/4 inch studs to secure the wires to the batteries. Keep positive to positive and negative to negative (but if I have to tell you that than you probably shouldn't attempt this project!) and shove everything into the case.  In the photo you can see my battery pack from the top down.  The lid is zipped open, the battery is on it's side and the power inverter is standing up on end.  You can also see the charge socket which is wired to the battery for easy recharging.  To use the pack I simply unzip the lid and plug in.  To recharge the unit I plug one end of my charger into the wall and the other end into the charge socket.