NI-MH batteries
I inherited a charger and 4 MI-MH AA batteries that I use in my camera. When I got done charging them they only showed 1.42V. Thought They were shot then I looked at the battery and they said they wer...
Forum Discussion
With the exception of a few voltage sensitive devices, most devices have a critical low voltage cut off at around 1V per cell. As long as you stay above that it doesn't matter if the initial voltage is 1.2 or 1.5. So a point and shoot camera that uses 4AA cells will shut off at 4V.
Like mentioned earlier, alkaline chemistry does not allow for high current, the internal resistance is too high. When placed in a high drain device like a point and shoot, or my kids leap pad, the alkaline battery can't meet the current demand which causes the terminal voltage to sag. The alkaline batteries very quickly come off 1.5V and then quickly sag below that 1V threshold and the device shuts off. The voltage then rebounds and when you test the battery it looks ok, and in fact can still be used in something like a remote.
The NiMH batteries, while having a lower initial voltage, can supply the current, have almost no voltage sag, and will not drop below that 1V threshold until almost completely exhausted.
Example: My kids leap pads use 4AA batteries and is a high current device. A set of alkaline lasted 2 hrs. I pulled them out and they tested ok but would not power up the device. They lived the rest of their life in remotes and clocks. The eneloop NiMH batteries lasted over a WEEK of on and off usage.
If you are looking for NiMH rechargeable, the standard eneloops are some of the best. While they have a lower overall capacity than some others, they are hybrids so they do not self discharge very fast, and they have one of if not the best voltage support under load in the industry. Costco usually has a good buy on them. I have enough now that I do not buy alkaline anymore. Some of my eneloops are 4 years old
Like mentioned earlier, alkaline chemistry does not allow for high current, the internal resistance is too high. When placed in a high drain device like a point and shoot, or my kids leap pad, the alkaline battery can't meet the current demand which causes the terminal voltage to sag. The alkaline batteries very quickly come off 1.5V and then quickly sag below that 1V threshold and the device shuts off. The voltage then rebounds and when you test the battery it looks ok, and in fact can still be used in something like a remote.
The NiMH batteries, while having a lower initial voltage, can supply the current, have almost no voltage sag, and will not drop below that 1V threshold until almost completely exhausted.
Example: My kids leap pads use 4AA batteries and is a high current device. A set of alkaline lasted 2 hrs. I pulled them out and they tested ok but would not power up the device. They lived the rest of their life in remotes and clocks. The eneloop NiMH batteries lasted over a WEEK of on and off usage.
If you are looking for NiMH rechargeable, the standard eneloops are some of the best. While they have a lower overall capacity than some others, they are hybrids so they do not self discharge very fast, and they have one of if not the best voltage support under load in the industry. Costco usually has a good buy on them. I have enough now that I do not buy alkaline anymore. Some of my eneloops are 4 years old
