Alright, here's the deal.
If you want the batteries to stick, you need to do this:
Step 1) Make your 4 batteries and scatter them throughout the map. Name them all "battery".
Step 2) Make 4 more batteries and place them where the batteries will go. Once you have the position perfect, turn them into info_targets and name them "BattLoc1","BattLoc2", etc.
Step 3) Make trigger boxes around the locations. When a held battery touches one, it'll be warped, so don't make it too small or too large. Give them unique names and make them trigger_teleport.
Step 4) Make a filter for these teleports, letting only entities named "battery" through. On teleport, freeze the battery, turn off the trigger, and open a trigger relay.
Step 5) Once all 4 trigger relays are open, it means all batteries are in place and you're good to do what you want.
If these steps are unclear, too bad. Read up on these:http://www.zombiemaster.org/smf/index.php?topic=439.0http://www.zombiemaster.org/smf/index.php?topic=4044.0