We are hard at work on the awesome gadget and we are of course thinking about the best way to power it. Basically: What kind of battery is the best for a photographer on location?
There are some alternatives:
|4 AA batteries
||You already have these in the camera bag. They are available everywhere in the world. You could travel without a charger if weight and space is limited. And you can use the same battery type on different gear (most likely other flashes).||They are not very powerful and they are heavy compared to the power they store.|
|8 AA batteries
||The only advantage I can see is that you don’t have to change batteries that often.||The device will have more bulk and heft.|
|Built in Li-Ion batteries
|A smaller and lighter flash. Li-Ion carries a lot of power in a small and light size.||Either you will have downtime while the battery charges, or the power adapter have to be big enough to power the light and charge the batteries at the same time. In any case, you will have to lug around the power adapter and potentially have to deal with incompatible wall sockets on international travel.|
|18650 size Li-Ion batteries
||These are replaceable and rechargeable Li-Ion batteries a bit larger than AA. Packs a ton more power than AA. You can ‘go all day’ without changing.||A lot less common, not likely to be available down at the corner. You will have to bring a dedicated charger and you can most likely not use them with other gear.|
The light will have some interesting features, but that also means that 4 AA cells is a bit on the low side for power. In heavy use you might have to change batteries every 45 minutes. With Li-Ion chemistry you could go for a couple of hours.
I asked the good citizens of strobist.com what would be the ideal battery for a speedlight-sized light source. The answer was basically this:
The thing have to be able to run off AA batteries. That is the baseline. Without AA batteries, it is going to be a hard sell. My bag is full of AA batteries already. Having to carry another type of battery is kind of a hassle. In addition to that, it should accommodate my favorite brand of aux power packs (where ‘my favorite’ is different from person to person).
The answers certainly shot down the option of only using an internal battery, and saving a battery door. Anything mechanical is ridiculously expensive, so saving a battery door was tempting. Another thing that is clear is that the aux power input have to be robust, efficient, and have a wide input range. I think it already is all of those things, so that one looks good. We should be able to connect to a wide range of power sources, and we should not assume that aux is always mains powered. It is easy to get lazy and think that aux power conversion does not have to be efficient.
I’m a bit concerned that with 4 AA batteries, the device is going to feel a bit underpowered. Hopefully, beta testing will show that.
Any thoughts on what is the the best (and worst) battery type? Hit the comments or strobist.com on Flickr.