After arriving to Compound, the train's nav computer can be powered by selecting the corresponding option without even touching the battery compartment, just like in preceding locations.
My game version is GOG 1.2.0.9 obtained by applying the 1.2.0.8 -> 1.2.0.9 patch. In 1.2.0.8, recharging batteries was required, as expected.
UPD: I discovered that this bug is triggered by interacting with the instrument panel (even if you leave the dialog immediately) before the train departs or at the first stop. So only if you don't touch the panel before arriving to Compound, you can't then turn on the power without recharging as intended. Since I don't remember what I did in 1.2.0.8, it's possible that this bug is not version-specific.