One of the primary factors differentiating rechargeable battery packs sold by a particular power brand is the voltage. Ryobi, for example, has both 18V and 40V battery packs for regular handheld power tools and larger, heavier-duty implements, respectively. In addition to the voltage, though, a secondary factor to be aware of is the ampere hour, or “Ah” for short. If you check power tool batteries on any online storefront, you’ll usually see the battery’s Ah rating in th...