Low Self Discharge rechargeable AA battery test results

Just last week, Digital Photography Review forum member arcae86 completed a battery capacity test that took several months. The test measured the retained capacity of 8 different brands of AA low self discharge (LSD) AA batteries. The brands tested were Sanyo Eneloop, Duracell precharged, Hybrio, Powerex IMEDION.  Battery capacity measurements were taken 1 hour after charging, and again after 1 week, 1 month, and 3 months. At all measurements periods saw the Powerex IMEDION AA battereis to have the highest capacity of all 8 brands tested.

Read all the details of the test here

For simplicity’s sake, I have taken the figures from the 4 commonly available brands available in Australia  (Sanyo Eneloop, Duracell precharged, Hybrio, Powerex IMEDION) and graphed the results below:

AA rechargeable battery test in a Nikon SB-800 flash

Glen from the DSLRusers.com forum recently did an extensive test of AA battery performance in his Nikon SB-800 flash, mounted on his Nikon D300 DSLR. I believe this is the first time a series of rechargeable AA batteries have ever been tested to see the real world results in a flash, and I am sure a lot of photographers will find this controlled test of real world value when choosing your batteries.

For the test, Glen compared four sets of 4 AA rechargeable batteries to see how many flashes could be achieved from each. Results are as follows:

Powerex 2700mAh = 266 flashes
Energizer 2500mAh = 242 flashes
IMEDION 2100mAh = 218 flashes
eneloop 2000mAh = 204 flashes

If you donʼt use your batteries as soon as you charge them, then test results are different. Some batteries are better at HOLDiNG their charge than others. Here are the results of the same test, 3 weeks after the batteries are charged.

Powerex 2700mAh = 250 flashes
Imedion  2100mAh  = 211 flashes
Energizer 2500mAh  = 208 flashes
eneloop 2000mAh =191 flashes

The Powerex 2700mAh have a higher energy retention rate than the Energizer 2500mAh. The Energizers were found to have a high self discharge rate, so much so that after just 3 weeks, the 2100mAh IMEDION batteries provide more flashes than the higher capacity 2500mAh Energizers.

Glen has noted that he is happy to conduct the test with other batteries if you want to know how yours compare to the four types already tested.

For capacity results and testing procedure details, read the full review here.

Visit Maha Powerex at PMA Australia Photography Expo May 30 – June 1 2008

The full range of Maha Powerex AA rechargeable batteries and battery chargers will be demonstrated at the PMA Imaging and Technology Show from May 30 to June 1 in Brisbane. If you live in Brisbane, or you are attending the expo, come by Stand 217 and say hello!

Which 9V battery for a radio microphone: 8.4V 300mAh or 9.6V 230mAh?

Older radio microphones needed the full 9V that alkaline batteries provided, so 7.2V and 8.4V NiCD and NiMH batteries did not last long before dropping below the minimum voltage needed by the microphone. In response to this need, MAHA developed 9.6V rechargeable batteries. More recently, newer mics have been designed to work with the standard NiMH battery voltages of 8.4V. As a result of this development, Maha released their 8.4V rechargeable battery. As they have 7 cells inside the battery instead of 8, each cell can be bigger, and the battery has a higher capacity of 300mAh.

If you have mics that are less than 3 years old, we recommend the higher capacity 300mAh 8.4V batteries which will give you around 5-6 hours from a full charge. If you have older mics, go for the higher voltage 9.6V 230mAh batteries to ensure compatibility with your microphones. The 230mAh 9V’s will still give you around 4 hours of runtime.

At our church, a service is typically 90 to 120 minutes, plus a rehearsal of 90 minutes. The batteries are fine to run for the rehearsal time and the service. We use the 8.4V 300mAh batteries some of the radio microphones and in the wireless foldback headsets. Just last month we started using SHURE SLX radio microphones. We are using Powerex 2700mAh AA rechargeable batteries, and these are also lasting through rehearsal and the service. We recharge the batteries after every service, as the NiMH chemistry is fine to be topped up, and does not need to be fully discharged before recharging.