Really these batteries are great, better than the batteries that we know commercially. I put one in my flashlight and it lasts very very long time and help light a battery with a normal battery. Easy to insert. When calculating the battery price (per set of 4) it does not worth buying even more the case recharge, especially since it is expensive and on top of that, so you have to recharge the batteries again current use for 8 hours. But hey everyone sees how it operates.