When it comes to buying tools for your trade you often must decide if you want to buy corded tools or battery powered ones. If you are working on building sites you may find that you are not allowed to use 240V tools and either must use battery powered ones or 110v tools. You may nee to buy specific 110v tools or buy a transformer that converts 240v to 110v.
Battery power tools are often a lot easier to use as you do not have to worry about the cord getting in the way. It also means you can use the tools even when you do not have a power supply, which is often idea for electricians who may have to turn the power off when they are working. The downside with battery powered tools is that you have to remember to charge your batteries, and over time like any rechargeable batteries, they will lose their charge and need to be replaced. Tool manufacturers are always bringing out improved batteries but sometimes the newest batteries wont fit the older tools so you will need to upgrade which can be an additional cost that you need to consider.