Cleanup BatterySystem (#41298)

* cleanup

* fix fixtures

* this belongs into the next PR

* review

* misc

---------

Co-authored-by: ArtisticRoomba <145879011+ArtisticRoomba@users.noreply.github.com>

Content.Server/PowerCell/PowerCellSystem.cs

@@ -174,7 +174,7 @@ public sealed partial class PowerCellSystem : SharedPowerCellSystem
             return false;
         }
 
-        if (!_battery.TryUseCharge(batteryEnt.Value, charge, battery))
+        if (!_battery.TryUseCharge((batteryEnt.Value, battery), charge))
         {
             if (user != null)
                 _popup.PopupEntity(Loc.GetString("power-cell-insufficient"), uid, user.Value);