From what I know, the Imedion battery is the same as a standard AA battery. If that is the case, they should not have caused a problem with your SB-900s. Do you own a volt meter? If you do, check the actual voltage of each of the Imedion batteries. Maybe one or more of them is not to spec resulting in the SB-900 problem. Keep us updated.
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Fri 01-Mar-13 04:21 AM | edited Fri 01-Mar-13 04:24 AM by jrp
Glad to hear you could power your flash with the alkalines.
I remember reading in one rechargeable batteries forum that there were several problems with the first batches: proper contact of terminals and the charger stopping at 1,100 or less mAH of charge. Unfortunately did not bookmark it and have no idea of the reliability of the poster.
I had similar problems with some older Imedions. They apparently were manufactured physically out of spec, so that the positive tip was too short to reliably contact the terminal in two of my SB-800's. I threw them away and never tried Imedions again after that.
Thanks Russ!!! That explains it. I thought the battery in the top bay, positive end up, looked short in both flashes. I removed the other three and felt good contact with the door, so I dismissed it as an optical illusion.
I threw them out too, so at least I can use the newer ones without concern.
Scott Chapin Powder Springs, GA, USA Nikonians Team Member