I've spent the past year learning how to write better, working, and improving other areas of life (including finishing up my education).  So all my hobbies had to take a back seat for a while.  Anyways, I recently decided to build a full-on movie camera out of my Sony a6100 for upcoming projects.

One problem with Sony cameras is that their normal battery, the NP-FW50 battery does not last very long when recording video.

This is where the Sony NP-F battery comes in handy.  The batteries come in a variety of capacities ranging from about 1000mAh (1Ah) to 10,000mAh (10Ah).  The exact capacity will vary depending on the manufacturer, but the height of the battery can range from being really low-profile and short to really tall and bulky.

These batteries, by themselves, are pretty much useless for model railroaders.  But companies like Smallrig have started making NP-F battery adapters.  These adapters accept the NP-F batter and output voltage via a plug.  Most adapters output 7.4 volts (the same as the battery), but I noticed that on my adapter there's an additional plug for 12 volts.  This happens to be a very useful voltage for model railroaders.

Now then, there are some limitations.  HO scale and N scale can't use these batteries onboard since they are simply too small for these camcorder batteries.  There are other battery formats that would work better for small scales.  But O and G scale have plenty of space to hold these batteries.  With one of these battery adapters, it's possible to power a BlueRailDCC reciever or a similar unit that controls the locomotive.

An alternative use is for small, micro-sized train layouts.  Plugging in a battery to power a small layout is pretty simple and eliminates the need for power supplies.  Here are the advantages as I see them:

• NP-F batteries can be changed out in seconds and charged separately, meaning the downtime for a locomotive is only a minute or two rather than hours.
• The batteries are replaceable and cheap.  If a battery goes bad it's a simple task to replace it with a different battery.  $84 on Amazon got me a total of four 5200mAh batteries. 
• These batteries are high capacity for their size. Boosted to 12 volts for a model train, I currently have about 3Ah worth of battery capacity for a model train.  A single battery only weighs a few ounces and has a smaller footprint than a credit card.
• The batteries use a pin-mounting system that look like miniature banana plugs.  I could 3D print a battery adapter plate and then combine it with a bridge rectifier and a voltage booster for something that can fit within the scale 7 foot width of a diesel switcher.  These batteries will easily fit in a cab unit.
• Batteries could be linked together inside of a cab B unit or a boxcab.  Linked up, capacity could be doubled or tripled.
• Using low-profile motors or powered bogies like NWSL's Stanton drive, it's possible to free up a lot of space under an engine cab.
• For steam engines, the batter could be located just under the coal load or oil bunker in the tender.  When the battery runs low, it would be easy to lift out a hatch and swap the battery.

For On30/On3, these batteries could be used as auxiliary power in a battery car.  For longer runs or at a train show, this battery could be linked up while a smaller, built-in battery could provide power when the engine is detached from the train.  It's also possible to trickle-charge other batteries from Sony's NP-F batteries.  People already do this with cell-phones and remote controls for cameras.

So, what does everyone think of this for a power source?  I'd like to build an O scale engine from scratch that is idealized for battery power. Using smaller battery formats like Sony's BG1, it's possible to power even HO scale locomotives this way.  Imagine being able to swap and replace batteries as needed.