How does Alkaline rechargeables compare to that of NiMH batteries? Are rechageable Alkalines the same to that of normal Alkalines?
Oddly enough, I was an early adopter of Rayovac's rechargeable alkalines called Renewal back in the 1990's and I still have almost all the AAs and AAAs I bought back then. I had them stored away, and even though I lost the charger (I moved in 2001) I found the batteries a few months ago and sure enough they were fully charged they registered from 1.3 to 1.47 volts. I found some in a light box for viewing slides. They held their charge for more than 6 years inside the device and the box lite up like if I had just installed them.
Its true what Torchboy said. They tend to be weak batteries. However, I bought a new charger from Rayovac and their new charger does all three chemistry, NiMh, Rechargeable RAM Alkalines, and Nickel Cadmiums. I went further and order a newer generation from Pure Energy and they now have a version that can be recharged 500 times (only with a shallow discharge) and have higher capacity then the older Rayovac. They don't say what the capacity is. I also bought their charger. Also another company called "Juice" markets what I believe to be the Pure Energy RAMs which are made in Canada.
The bottom line is that the RAM (rechargeable Alkaline Manganese) have a very strong market niche. First of all, they have a shelf life of 5 years fully charge. There is no self-discharge like with even the eneloops, and secondly they come off the charger at around 1.6 volts. But they decay fairly linearly with power drainage unlike the NiMh which hold on between 1.3 and 1.2 volts during their drainage.
In my case, I have a AM Radio that I use in my office that is sensitive to voltage. Its a low drain device, I can get 40 hrs out of a set of 3 AA. But it likes fresh Alkalines. Once the batteries drop to about 1.3 volts the static increases because the stations I listen to (Talk Radio shows mainly) has lots of interference from all the electrical things in my office. But anyhow, the RAMs are a perfect fit because I can top off the battery for another month. Hence that radio always has fresh batteries in it between 1.5 and 1.4 volts. NiMh work, but not nearly as well because the starting voltage is where the alkalines drop off. The NiMh that I used to use would literally self-discharge faster than the actual radio would drain.
I would say that the RAMs are a good choice for a flashlight that will get little use like a car flashlight. It can sit for months and years in a hot car then be used when occassionally needed. Then you always have the option of topping off the batteries after a short intermitten use.
they worked ok.
