eli5: Why do regular batteries last for so long whereas rechargeable ones have to be recharged so frequently?
In: Technology
There isn’t huge different between capacities, since they are somewhere around 2500mAh for modern batteries, it’s just that some devices can’t use all of that due to lower cell voltage.
At around 1.2V standard alkalines are pretty much dead while NiMhs still have about 40% of capacity. So with around 2500mAh cells, you are only getting about 1500mAh. That means that if device was designed to shut off at around 1.2V, you might get 30 min of use for device that might last 1 hour with standard batteries.
Rechargeables also have higher self discharge, which means they shouldn’t be used in low power devices like clocks or TV remotes since they would drain itself in few months (there are low self discharge versions, but they still have higher self discharge than alkalines and they cost a bit more).We also tend to use alkalines in devices that aren’t power hungry so they last long while most power hungry devices use rechargeables.
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