1.What type of battery does it include.When buying cordless drill, there are two batteries to choose from.Nickel, cadmium and lithium ion.Nickel-cadmium batteries are cheaper, so cordless electric drills are usually cheaper, but the downside is that the batteries don't last too long and it takes more time to charge.For lithium-ion batteries, they are much more expensive, so the drill bit usually reflects this and costs more, but the battery is charged longer and used longer.The battery is also charging much faster.2.How much electricity do you need?Power and torque are completely different.The power supply is the power supply mode of the drill bit, in volts.The 12 v Drill is usually enough to meet the needs of a regular DIY \ 'er, while the 18 v Drill is good enough for any job in the home and for some small business work.If you're going to buy a drill, think about how much the drill will be used.If the drill bit will be used a lot, you 'd better spend a little more and buy an 18 v drill and then you know that your drill bit can do the most demanding job.3.How much torque do you need to get from the drill bit.The higher the torque level, the greater the force the bit must drill.If you're going to drill a lot of hard surfaces like concrete or steel, the drill bit needs more force.Do you know what material you're going to make with the drill bit? Even if you only use the drill bit for strange hard surfaces like steel, you need to make sure you have enough torque when you need it most.4.When you buy a cordless drill, how many batteries does the drill have.If you are only going to use your drill for odd, occasional work, then you should be OK with a battery, but if the drill is used a lot, then you need to buy a cordless drill with multiple batteries.The time saved by having 2 batteries is very important for a long time-consuming job.A battery is in use, a charge so you don't waste time because the battery is dead or waiting for a battery to charge.Most cordless drills have variable speed control.Even if the cordless electric drill has a lot of strength, you should not buy a cordless electric drill that only runs at one speed.You should always buy a cordless electric drill with variable speed control, which can easily be changed and adjusted according to the work you are doing.This way, you won't suddenly lose power if you press the trigger power supply hard.Variable speed control allows you to drill the most difficult work, but also to drill those subtle jobs where more care is needed.