UPDATE Continued...I think this is caused by SE renaming the block. Sometimes when I look it is the normal name and sometimes SE has added [right] or [forward], etc. If the script could look for a string within the name rather than an EXACT name it would fix this.

UPDATE...I found room for the normal block and it fixes the update of the Custom Data area....apparently the Admin block doesn't update. I still have a problem however with the script not finding the block 30% of the time. It will find it eventually, but then loose it...only to find it again. This results in the display toggling between "not found" and the % charged.

This does not work for me. There are two issues. One is that SE changes the name of your space anchor adding [Forward] thinking your block is a thruster. I can compensate for this by changing the name again in the script. The other issue is that the Custom data field in the block is not being updated with the current charge level. It always reads 0 of 25 despite the info field of the block being updated correctly. I am using the Admin 1x1x1 block because I built my ship before your larger blocks were made. Perhaps that is the issue?