Saw this question was asked 7 years ago, but asking again due to this mod having been through many refinements and updates. Electric rails to make it more realistic? Connect one rail and any train on the network doesn't need charging maybe? Like one item that connects like rail signals do to regular rails, just gives them power/carries circuit signals. Then all trains just get infinite power.

I've been giving this more thought lately but I'm a little divided on how to handle it, whether to add those mechanics alongside the existing ones or to split it out into a separate mod entirely that doesn't keep obsolete/redundant features like batteries. I don't like the idea of using electrified rails personally as it very quickly becomes a means to distribute power around instead of using the power lines, and I don't care for that. If it becomes a question of mapping power from separate grids only into the rails, that opens up further questions about implementation and balancing draws and so on.

I think the better option would be to have to 'electrify' the railway by coverage from the power poles that already exist in the game and track whether the train is within the pole's coverage. As it stands (and I've been thinking about changing this too) the train has to be on a schedule and stopped at a station for the EEI that represents its internal storage to be spawned and draw power from a grid. That method works pretty well and the mod is the most popular one on the portal that isn't part of a huge integrated revamp so it seems a lot of people agree. So then the scripting side of things becomes a matter of keeping the EEI paired to the locomotive within the same network as the locomotive's current physical position. That should be doable, it's just a question of how performant it is.

Or you could try out another mod like Realistic Electric Trains and see if you prefer that, I dunno. It might be good, I haven't tried it yet because I've been on a minimal mod SA playthrough for a while.

The way I would do it if you were concerned about rails replacing power poles is to have a special kind of power pole that runs alongside rains that have to be placed manually, allowing for a simple but well balance way of upgrading existing rail networks (similar to realistic electric trains) but with the added functionality of not being required for the trains to run, just negates the need to consume battery charge to run, and then the stations can still charge like normal. These power poles do not have a powered radius like other power poles, but can be connected to them manually. Although admittedly I am not a factorio modder or scripter, so I'm not sure how one would go about programming this functionality in or how difficult it would be. Also hybrid options might be cool, like trains that will prioritize electricity but when not available, can burn fuel. Or even nuclear trains, simply running on reactor fuel, very efficient, but incredibly punishing if they crash. Just food for thought.