Battery Amp Hour Ratings and More
When it’s time to find a new battery for your cordless power tool, you may discover that you have a number of options available to you. If you have a Makita 6349DWDE 18 Volt drill, for example, you will find that there are three Makita batteries that will fit your tool. There’s a Ni-Cd battery (nickel-cadmium) with a rating of 2.0 Ah (amp-hours), a 2.6 Ah Ni-MH (nickel-metal hydride) battery, and finally a pricier 3.0 Ah Ni-MH version; all of them are 18 volts. How confusing, and what a mouthful!
First of all, what is this amp-hour (Ah) rating all about? Simply put, Ah ratings indicate how long a battery will run following a full change. The higher the number, the longer the battery will last before needing to return to the charger. Note that an 18 volt battery, regardless of Ah rating, will always provide 18 volts of power and there is no power advantage when purchasing a higher Ah battery. With batteries compatible with your tool, understand that you pay a price premium for longer run times, not more power.
There is also the issue of battery type, and that’s where those strange abbreviations like Ni-Mh and Ni-Cd come in. There is tons of information on the internet regarding the strengths and weaknesses of the different battery chemistries, but such discussion is beyond our scope here. This little illustration should suffice:
Lithium-ion is greater than nickel-metal hydride which is greater than nickel-cadmium. As you move up the scale, battery memory disappears, amp hour ratings improve, weight decreases, and of course prices increase. NOTE: many power tools are compatible with Ni-CD and Ni-MH batteries, but not all chargers can handle both types. Chargers will usually indicate which types of batteries they can charge.
If you are using your tool for simple, lightweight chores around the house and you want to save some money, selecting a compatible low amp-hour Ni-Cd battery can save you money. If you’re a heavy duty user, such as a construction worker, cabinet maker, or any other professional worker, you may want to consider upgrading to a higher end battery if one is available for your cordless power tool. If you need help deciding, please let us know and we can find the right battery for your application.
