I have a couple 7/8 critters that need a bit of care. I ordered a pair of batteries from Tenergy for them.
The first is a little Mancha mine trammer locomotive. That was an easy swap for a new plug and battery, and everything fits nice and tidy.
The second is a larger Simplex locomotive. This one had a more complicated on/off/reverse/speed system in it, that I never used to its full extent. Currently figuring out where to best locate the on/off switch.