battery conversion

[PaulieG]

I have 3 older Bachmann steam trains from 1992, 1994, and 1995. I would like to convert them to battery. I am considering Railpro and Soundtraxx. What parts will I need for the conversion? Is it better to convert all lights to led and will I need a resister in line with the lights? What type of battery charger will I need? I do have an electrical/electronics background just need to be pointed in the right direction. The trains will only be run indoors.

Thanks,

Paul

[GAP]

I have 3 older Bachmann steam trains from 1992, 1994, and 1995. I would like to convert them to battery. I am considering Railpro and Soundtraxx. What parts will I need for the conversion? Is it better to convert all lights to led and will I need a resister in line with the lights? What type of battery charger will I need? I do have an electrical/electronics background just need to be pointed in the right direction. The trains will only be run indoors.

Thanks,

Paul

When I modified my old bachmanns I gutted them completely and started from scratch; Motor Controller directly to the motor, Sound to the motor Controller (I use MyLocoSound). For the lights I used LED's wired directly across the motor controller outputs, back lights wired in reverse to the front so as the direction changes one is always on. I put a resistor in their line.
I looked for a resistor calculator on line like this one for example but there are others https://au.mouser.com/en/technical-reso ... 4mZrOfbvve

[ge_rik]

I recently converted three Bachmann Big Hauler ten wheelers of various vintages to battery RC. As Graeme mentions, the value of the resistors you use with the LEDs depends on the battery voltage you opt for, the characteristics of the LEDs you use and how bright you want them to be.

I used three li-ion cells in each battery pack which gives, nominally, 11.1v. The locos worked happily off that voltage. You could increase the battery to 4S (four cells = 14.8v) if you want a higher top speed. I used 150R resistors with the 11.1v packs, as I wanted the white LEDs to be quite bright.

Here's my account of the conversions - https://riksrailway.blogspot.com/2026/0 ... r-4-6.html




Rik