This battery checker is the best I've ever found:<span class="Apple-style-span" style="font-family: Verdana, Arial, Helvetica, sans-serif; color: rgb(0, 33, 49); font-weight: bold; ">Robbe 8511 Digital Battery Checker</span><div></div><div>Great little gadget, it gives you virtually all possible information on your battery pack</div>