Tesla relays will no longer draw power from the local APC when their device's cell is full.

code/modules/integrated_electronics/passive/power.dm

@@ -101,6 +101,6 @@
 		return
 	var/area/A = get_area(src)
 	if(A)
-		if(A.powered(EQUIP))
+		if(A.powered(EQUIP) && assembly.give_power(power_amount))
 			A.use_power(power_amount, EQUIP)
-			assembly.give_power(power_amount) // give_power() handles CELLRATE on its own.
+			// give_power() handles CELLRATE on its own.

html/changelogs/MagmaRam - Tesla Circuit.yml

@@ -0,0 +1,36 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes: 
+#   bugfix
+#   wip (For works in progress)
+#   tweak
+#   soundadd
+#   sounddel
+#   rscadd (general adding of nice things)
+#   rscdel (general deleting of nice things)
+#   imageadd
+#   imagedel
+#   maptweak
+#   spellcheck (typo fixes)
+#   experiment
+#################################
+
+# Your name.  
+author: MagmaRam
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, all entries are changed into a single [] after a master changelog generation. Just remove the brackets when you add new entries.
+# Please surround your changes in  double quotes ("), as certain characters otherwise screws up compiling. The quotes will not show up in the changelog.
+changes: 
+  - bugfix: "Tesla relays no longer draw power when their attached power cell is full."