I'm looking to buy Nikon SU-800 flash and I noticed that it uses CR123A batteries. I found a lot of options on eBay and Amazon but most of them have low or mixed reviews. Does anyone use these type of rechargeable batteries and chargers and have recommendations?
I have used Tenergy Li-ion CR123A batteries in the past but that was a few years ago. Link here They worked well and I never had any issues with them, but not having tried any other ones I cannot compare them to the competition for you.
The problem with rechargeable batteries is they are always lower capacity and usually have different voltage ranges. Capacity matters a great deal for high draw items like a flash. Voltage range tolerance depends on the specific equipment (manufacturers never specify). 900mAh seems to be the highest a rechargeable can get compared to the standard 1500mAh. That right there is worth a comparison during a long photo shoot.
Many rechargeable CR123As peak off the charger at over 4V. That could be a problem. While other batteries may not specify their peak voltage range, certainly a 3.6V battery will peak higher when fully charged. With some looking I've found 2 notable contenders, both of them boldly stating their safe voltage:
I can't find capacity mentioned for the Delkin and it's more expensive so Tenergy is the winner. Note: there are two different Tenergy CR123A rechargeable batteries. One is lower capacity at 750mAh with a 3.2V nominal peaking at 3.9V. Avoid that one.
Last note: the linked site sells single batteries but also has a 4 pack, with charger and free shipping for $19 right now. Best choice and best deal.