My 480 ex II is not firing at all on my T2i. The pilot light is not turning red. It is brand new out-of-the-box and the first time i have ever tried using it. i followed all the directions and verified all the settings and it isn't firing at all. I am using 4 Energizer fully-charged, rechargeable batteries, each 2300 mAh. Can anyone help me troubleshoot this problem?

SOURCE: Amperege of 580 EX-II

Interesting Question!
The rating in milliamps is a matter of battery capacity and charging rates. The higher the better as you will get more flashes per charge as long as you have the correct charger to match the batteries’ capacity and use the correct charging times. Aside from this issue of duty cycle between charges- this has no effect on the power of the flash unit as to output. This cant burn out or damage the circuitry.

The issue here is VOLTAGE. Most AA alkaline batteries provide 1.5 volts. Most rechargeable AAs provide 1.2 volts. We are looking at a voltage differential of 1.2 volts (a 20% deficit) if 4 batteries are required. This MAY cause slower recycling times in order to attain a full charge for each shot. In SOME units that can cause a bit if overheating due to strain on the step up circuitry.

It so best to check with the manufacture or distributor of you flash unit before purchasing you rechargeable batteries and charger. If you units have a built in charging circuit this can definitely be problems if there is a mismatch in charging rates and voltage. If this is the case be sire to check your manual or with the manufacturer or distributor- there must be a list of compatible batteries.

Ed