Why did battery manufacturers change rechargeable AA batteries to 1.2 volts when they should be 1.5 volts ?
Older rechargeable alkaline AA batteries were 1.5 volts and lasted a long time. all newer ones are 1.2 volts and with electronics that shut down like cameras/game controllers, 1.2 volts dies out much quicker than need be. I don’t see the logic unless you’re forced into buying more batteries this way.
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5 Responses to “Why did battery manufacturers change rechargeable AA batteries to 1.2 volts when they should be 1.5 volts ?”
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I am not familiar with rechargeable “alkaline” batteries. But as far as I know the different technology for ni-cad or ni-mh batteries has always been a lower voltage than disposable batteries. But the internal resistance is lower, so they often worked better in older digital cameras that used more power compared with throw away alkaline batteries.
Ni-cad and to a lessor extent ni-mh have a memory and if you regularly recharge them without running them down, will no longer hold as much of a charge. Also rechargeable AA batteries vary somewhat in capacity (mA hours) depending upon brand.
Its the chemical structure that determines the voltage – eg. zinc/carbon = 1.5v , nicad 1.2v , lead acid 2.0v
Some devices have a switch to allow either type of battery to be used.
As the others mentioned, that’s just the natural voltage that you get out of Nickel-metal-hydride cells. Various kind of lithium rechargables are over 3 volts – unfortunately, the voltage cannot be easily tuned for a particular formulation.
But it’s not as bad as it sounds. Things like digital cameras last MUCH longer with NiMH than Alkaline, because the 1.2 volts is enough, and it holds steady at 1.2 volts for a long time, compared to the alkaline which decays rapidly from the starting 1.5 volts. Try the experiment – get fresh AA Alkalines, and see how many pictures you can take, then try fresh AA NiMH that have been charged, and see how many pictures.
The rechargeable alkaline batteries you are referring to had many problems. One, they were only good for around 800 cycles (discharge and recharge). Ni Cad’s can work for 1000 or more cycles. A good rechargeable to buy would be a NiMh at 2650ma or more. I currently get charged voltage of 1.28 – 1.3 under load.
yeah well that’s a bit of a sales myth
Rechargeable batteries also start of giving 1,5V, but drop real fast down to 1,2V, a voltage they are able to maintain a long time. So they are advertised as 1,2V.
Alkaline batteries also start of at 1,5 volt, and constantly drop in power (a little bit slower than ni-mh, but still fast enough). But they are advertised as 1,5V batteries.
In most cases you can use rechargeable batteries in any device, only when there is a high power drain (like the flash from a camera) the non rechargeable give a better performance over a longer period.
You really should compare the mAH value on the batteries, not the voltage. And don’t buy ‘heavy duty’ recharable batteries, they tend to die even quicker. Buy your batteries in a range of 2800mAH and up and go for a dependable brand. You’ll notice that recharable will run out quicker in your camera, but an extra set should get you trough the day, and you can recharge them. Alkalines where never recharable (the old recharable batteries where zink-cadmium types, we stopped using them because they are so bad for the enviroment).