I rotate a pair of these in my wireless mouse. It is an earlier model that eats up batteries much faster than the new generation ones. I used to have to swap them out every 4-7 Days but these last for 3-4 weeks with heavy use. It's also true that they hold their charge when not in use. I've seen it first hand. I will not be buying any other Ni-MH than Hybrio. I came here looking to buy a bunch of them on the cheap and am shocked to see the price here. They are $TEN at Fry's every day! $Fifteen here at time of writing this. :(