I burned out my Canon 580 EXII Flash (High Speed Synch, Rechargeable Batteries). Ughhhh.

Last weekend, I was shooting with my Canon 50D in extremely bright, harsh Colorado sunlight. I was using my Canon 580 EXII Flash, with a Gary Fong diffuser to cut the harsh light down to a softer level. As I wanted to be semi-stealth, I was at the back of the amphitheater, and was shooting with my 70-200 f/2.8 lens, with a 2X Extender. Total maximum reach = 400 MM. With the 1.6 crop factor of the APC sensor, that means an equivalent 600 MM f/5.6 lens on a full frame camera. I’ve used this same setup to shoot images of the moon with clearly visible craters. So, I needed to shoot handheld, as I was moving a lot. I needed a fast shutter speed, greater than the maximum flash synch speed of 1/250 of a second. So I put the Canon 580 EXII Flash into High Speed Synch mode, which essentially taxes the flash a lot more than in regular synch mode. Couple that with a hot 98+ degree day (37 degrees Celsius), and the flash basically melted. According to the manual, it’s supposed to go into a safety mode for 15-20 minutes until everything cools down. I’m not sure why it didn’t turn back on, even a day later, but I had to send it back to the factory for a “reset.” I admit I was shooting rapidly. At an event like a Bat Mitzvah, there’s one one chance to get a great image of special moments. And shooting from 80 feet away, I wanted to increase my chances of success with several images. As far as I can tell, it may have something to do with the eco-friendly, rechargeable AA batteries I used for the flash. They tend to keep a charge a lot longer than normal AA batteries, and then you don’t have to throw them away. (I live in Boulder, Colorado, where you are scorned by neighborhood children if you forget to compost your leftover vegetables.) It could be that the rechargeable batteries had something to do with it? I’m not sure. Regardless, it was wonderful to have a second (albeit smaller) backup flash with me. I sent it back to the factory for repair, but as I have an upcoming photo shoot, I had to buy a new one off the shelf at the local camera store. Good news: when I get the other one back, I’ll have two. Has this happened to you? Let me know your story / what you think might have contributed to it.