01
.Introduction
We test 15 NiMH rechargeable AA batteries
The latest range of rechargeable AA batteries use NiMH (nickel-metal hydride), delivering a higher capacity than the older NiCad (nickel-cadmium) rechargeable batteries and less of a memory effect when recharging. It only takes a dozen or so uses before rechargeable batteries make economic sense compared to purchasing alkaline batteries to power your devices, and you also help reduce the number of dead batteries going into landfill. However, not all rechargeable batteries are created equal.
Self-discharging batteries
Some rechargeable batteries lose some of their power everyday, even when not in use. This continues to be an issue when powering infrequently used devices, such as an emergency torches or cameras, as the batteries will go flat over time. In such situations, alkaline batteries are commonly used because they have a much better shelf life and can be trusted to work even if left unused for a year.
The Sanyo Eneloop was, in 2006, the first low self-discharge (LSD) battery to deliver a higher capacity for much longer periods compared to other NiMH batteries. It helped make rechargeable batteries a better option for infrequently used devices. The latest low self-discharge (LSD) batteries claim to retain up to 85% of their charge after 12 months of non-use whereas standard NiMH batteries may lose 50% of their charge.
For more information on camera
accessories see,
Cameras and camcorders.
The ability to immediately use the batteries out of the packet is another handy feature of an LSD or ‘ready to use’ NiMH battery, particularly with the demand to immediately power up the latest birthday or Christmas present.
We put 15 rechargeable AA batteries to the test to see which ones last longest, can be recharged the most often, and don’t lose their charge when left unused. We included five “ready to use” batteries.
Models tested
- Arlec CPCD1392
- Duracell 99474895
- Duracell Active Charge 98577668
- Energizer Recharge NH15BP4T
- Eveready RE15BP2T
- Kodak KAARPC-4
- Panasonic HHR-3XPT/2B
- Powertech Enekeep SB-1750
- Powertech SB-1738
- Sanyo Eneloop 4HR-3UTG-SAPP-2
- Sony NH-AA-B4KN
- Uniross Hybrio U0229609
- Vapex 92087
- Varta Power Accu 56756 412 404
- Varta Ready2use 56706 412 404
We also measured two Lithium non rechargeable batteries (Duracell Ultra Lithium and Energizer Ultimate Lithium) and an Alkaline battery (Panasonic Evolta) finding their discharge over the test period to be imperceptible. So if you depend on your device to operate straight away after long periods of inactivity, you still may want to consider a lithium or Alkaline battery for some situations.