How to choose a cordless drill or impact driver?
It is a few things to consider to find a suitable cordless drill or impact driver.
Technical basics you need to know:
1. What is Volt (symbol: V)? - The volt is the electromotive force, commonly called Voltage.
The higher the voltage number, the higher the Force/Torque will be.
2. What is Ampere-hour (symbol: Ah)? - The amount of energy charge in a battery that will allow one ampere of current to flow for one hour. 3.3Ah capacity Li-ion battery provides 25% more run time than 3.0Ah battery.
3. Battery Types:
NiCad: Nickel-cadmium battery low cost battery type was invented in 1899. Should i say anymore?
NiMH: Nickel-metal hydride battery. Development from NiCad. NiMH batteries have up to 30% more energy capacity than NiCad. However
discharge a bit quicker. Marked commercial in around 1990.
Li-ion: Lithium is a very light metal. Lithium-ion batteries are most expensive but can hold twice as much energy than NiCad type batteries.
There is more, but 3 above is most commonly seen on the tools, performance and the price tag depends on it.
What is impact driver?
In shot it works like a drill, but when more torque is needed while rotating it produces hammering affect as well as maintaining contact with the fastener. Unlike normal drill impact driver does not kick back to you hand to produce impact force. Impact driver great for driving Tapcon screws into concrete, hex-head, drywall screws, and deck screws with ease.
Below is a chart which is in my opinion can be helpful in choosing the product for your needs.
| Use | Price | V (Voltage) | Ah (Ampere-hour ) | Battery |
| House hold | 50-100 | up to 14V | up to 2.5 | Ni Cad |
| Occasional Commercial Use | 100-300 | 14V | 1.5 - 3.0 | NiMH, Lithium-Ion |
| Every day Commercial Use | 300+ | 14V+ | 3.0 + | Lithium-Ion |
Also i must say that if you already have some cordless tools it may worth to consider buying a new tools of the same brand. Just check the compatibility. Your old battery or charger may be compatible to a new tool thus will save you a bit of money on the long run.
Memo:
Cordless tools are definitely convenient, but if you don't use power tools often then don't buy cordless versions, but the corded. A corded one will cost less and last longer.
Comments are welcome.
