I found the build quality to be cheap as the cases are thin plastic, not metallic like alkaline batteries. Also the charger doesn't charge to a full 9V as others have noted, 8.5VDC. I would not puncture the case! It will probably catch on fire readily and plan to try that out in controlled conditions. We'll see how the batteries hold charge. Also the outside labels have bubbles in them - the whole case just feels cheap.
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