The basic rule of getting a replacement battery is that it should have the same voltage as the original. An 18V drill cannot run on a 12V battery. It can only run on a 18V battery. The other thing is that the physical packaging of a battery can be different from company to company. A 12V Ryobi battery may not fit into a 12V Makita cordless drill unless the battery has the right physical dimensions. So make sure the replacement battery looks the same as the old one before you order it. Also, if you are looking for a replacement battery of the same voltage rating and by the same company, know that battery technology is changing rapidly. An 18V lithium-ion battery has a different physical packaging than a NiCad 18V battery.
These units were too small for 9 volt batteries so they were designed for the smaller CR-123A cobalt ontario. These provide longer life although a lithium battery cost more than an alkaline.
Most battery packs are of the Nickel-Cadmium (Ni-Cd) type. These offer reasonably long cobalt mining canada life and will take hundreds of re-charge cycles. As far as re-charging goes, I recommend giving a short shock burst into the air every month or so. Make sure the spark is as loud and strong as when you first tried it after your first full charge. If not, re-charge.
Recalibrate: We suggest a full discharge every 30 charges for batteries with fuel gauges, like laptops and mobile phones to recalibrate the battery. Just let it run until it stops, then recharge.
One of the cool features of a lithium drill is that the drill maintains it's power until the battery is drained then it just quits. With this in mind, if you get to the site and your battery is dead, if you charge it for 5-10 minutes, you will have full power (I said full power, not full run time. You need the full charge for both!). This is a great trait of the lithium mines ontario drill and many trades and service techs will benefit from this feature.
Some will likely read this article and think "No, way! I don't have time for that!" Others will read it and think "This is great! I'm going to invest lots of time so that I can be as prepared as possible." This article is written for those of you in the latter category.
The Makita BHP451 has an exceptional amount of power, is lightweight and comfortable to hold, has a really great battery system, and tons of other cool features. All around, I think this is an awesome hammer drill/driver and it's worth checking out for yourself.