Battery Powered vs. Track Powered

Young and new recruits to the LEGO train scene will never have known anything other than the current generation of power functions. Battery packs coupled with infrared receivers and remote controls, each taking up precious space in your build. However, it didn’t used to be this way. The previous generation of trains (ignoring the aborted RC train theme) used metal rails to directly power the motors. Both generations had their own advantages and disadvantages, which I will attempt to shed some light on. In a follow up article, I will go over some advanced applications of each, and hybrids that combine the best of both technologies.

Batteries take up space. In my eye, this is Power Function’s main drawback. Additionally, the current generation Infrared (IR) Receiver is quite large and the sensor on it needs to be visible from outside the locomotive for the signal to reach it.

IR Receiver with the shell removed. Why is this thing so big?

Trying to incorporate the AAA/AA battery pack and the IR Receiver into a model is often very tricky, especially when working with 6 or 7 stud wide models. Additionally, batteries need to be recharged or replaced after several hours, so the battery pack needs to be accessible or removable.  When running for many consecutive hours at a convention, swapping batteries becomes a chore. For home use, it is not such a big deal. The IR receiver also has difficulty reaching more than a few feet when there aren’t any walls or ceiling to reflect the light off of. On the other hand, the IR receiver and battery boxes are still currently in production, which means they’re cheap.

PF track Vs. 9V track

Track power has always been my preference and I’ve iterated through several generations of electrical systems searching for the best configuration. LEGO’s classic 9V train controller is simple, turn the knob and your locomotive starts to move. The biggest limiting factors are being limited to metal equipped track and the original 9V train motor, (meaning no double crossovers). Additionally, laying out certain track geometries will cause short circuits. Also, once your loop gets to a certain length, additional power hookups are required so as to avoid slow downs. Of course, the main drawback is price. Expanding or building a new 9V layout is very costly. 9V straight track hasn’t been manufactured in almost 10 years and averages $3.50 each used and $5.50 new on the aftermarket. Original 9V train motors average $35 each used and $75 new.  Many clubs still use 9V systems, and with ME Models finally shipping their metal track, will continue to do so for years to come.

Things start to get interesting when you get rid of LEGO’s speed controller and start substituting your own electronics. Swap in the third party Bluetooth controlled SBrick in lieu of the IR receiver and not only save space, but also gain control range, gain 2 more channels for a total of 4, and lose the line of sight requirement.

In addition to being gigantic, the output power per channel is low.
2 Channel PF IR Receiver3rd party SBrick, approx 8x available power output in a smaller footprint

 

Get rid of the LEGO 9V train controller and use constant track power to feed a Bluetooth motor controller. No batteries! Or better yet, use batteries and track power together: constant track power feeding a Bluetooth motor controller, with batteries for backup. With such a system, a track powered locomotive can continue through double crossovers, over draw bridges, maintain consistent speeds through spotty connections on dirty track, or possibly even charge itself. With the track providing power most of the time, the batteries will rarely need to be recharged.

Read about my experiments in hybrid systems in depth in my next article.

3 thoughts on “Battery Powered vs. Track Powered”

    1. Picking up track power is the hardest part honestly. I’ve done some tricky stuff like decoupling the motor inside the shell from the pickups, and instead using the pickups to power a Bluetooth motor controller. The original motor is still used, but isn’t tied directly to the track.

  1. I used to play with the 4.5V system as a little boy back in the early 1970s, loved the trains but hated messing around with those batteries, and that hasn’t changed much since. When I resurrected from my dark age in the early 2000s, the 9V system was already over the hill, but I liked the genious power pick-up concept. I hoped they would extend it (e.g. power pick-ups separate from the motor) a/o digitize it, but production was too expansive and they dropped it in favor of PF. So, yes – let’s see where we get by combining the best of 9V, PF and the missing links that the aftermarket gives us. Great idea for an article!

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