ComfyFactorio/modules/charging_station.lua

--made by Hanakocz
--charge your armor equipment from nearby accumulators!
--change global.charging_station_multiplier if you want different conversion rate than 1:1.
local Event = require 'utils.event'

local function draw_charging_gui()
	for _, player in pairs(game.connected_players) do
		if not player.gui.top.charging_station then
			player.gui.top.add({type = "sprite-button", name = "charging_station", sprite = "item/battery-mk2-equipment", tooltip = {"modules.charging_station_tooltip"}})
		end
	end
end

local function discharge_accumulators(surface, position, force, power_needs)
  local accumulators = surface.find_entities_filtered{name = "accumulator", force = force, position = position, radius = 13}
  local power_drained = 0
  power_needs = power_needs * global.charging_station_multiplier
  for _,accu in pairs(accumulators) do
    if accu.valid then
      if accu.energy > 3000000 and power_needs > 0 then
        if power_needs >= 2000000 then
          power_drained = power_drained + 2000000
          accu.energy = accu.energy - 2000000
          power_needs = power_needs - 2000000
        else
          power_drained = power_drained + power_needs
          accu.energy = accu.energy - power_needs
        end
      elseif power_needs <= 0 then
        break
      end
    end
  end
  return power_drained / global.charging_station_multiplier
end

local function charge(player)
	if not player.character then return end
  local armor_inventory = player.get_inventory(defines.inventory.character_armor)
  if not armor_inventory.valid then return end
  local armor = armor_inventory[1]
  if not armor.valid_for_read then return end
  local grid = armor.grid
  if not grid or not grid.valid then return end
  local equip = grid.equipment
  for _,piece in pairs(equip) do
    if piece.valid and piece.generator_power == 0 then
      local energy_needs = piece.max_energy - piece.energy
      if energy_needs > 0 then
        local energy = discharge_accumulators(player.surface, player.position, player.force, energy_needs)
        if energy > 0 then
          if piece.energy + energy >= piece.max_energy then
            piece.energy = piece.max_energy
          else
            piece.energy = piece.energy + energy
          end
        end
      end
    end
  end
end

local function on_player_joined_game(event)
	draw_charging_gui()
end

local function on_gui_click(event)
	if not event then return end
	if not event.element then return end
	if not event.element.valid then return end
	local player = game.players[event.element.player_index]
	if event.element.name == "charging_station" then
		charge(player)
		return
	end
end

local function on_init()
	global.charging_station_multiplier = 1
end

Event.on_init(on_init)
Event.add(defines.events.on_player_joined_game, on_player_joined_game)
Event.add(defines.events.on_gui_click, on_gui_click)