That's a real nice charger. I have a Dual Pro also. I fried mine a couple years ago. I unplugged the cord, tossed it in the battery compartment, and left not realizing the plug's ground prong came to rest upon the Positive post of the battery. Sent hundreds of amps down the cord's ground wire inside the cable, turning it into a glowing 6ft wand. Filled the motel parking lot with smoke. It was an exciting time that proved my tagline quote.
Anyway, I shipped it back to the manufacturer and they repaired it for a nominal fee that made it well worth it. Not sure if my owners manual page on LED indicators applies to your unit, but here it is in case it helps.
The more you practice, the luckier you get.