diff --git a/code/modules/power/apc.dm b/code/modules/power/apc.dm
index ae3dc7189e..ca2c259bb5 100644
--- a/code/modules/power/apc.dm
+++ b/code/modules/power/apc.dm
@@ -1373,7 +1373,7 @@
 	// next: take from or charge to the cell, depending on how much is left
 	if(cell && !shorted)
 		if(cur_excess > 0)
-			var/charging_cell = min(cur_excess*GLOB.CELLRATE, cell.maxcharge * GLOB.CHARGELEVEL)
+			var/charging_cell = min(min(cur_excess*GLOB.CELLRATE, cell.maxcharge * GLOB.CHARGELEVEL), cell.maxcharge - cell.charge)
 			cell.give(charging_cell)
 			add_load(charging_cell/GLOB.CELLRATE)
 			lastused_total += charging_cell