All about the Different types Cordless Tool Batteries
As we find more and more uses for cordless gadgets, rechargeable battery technology is at the forefront of advances. Any power tool is only going to be as good as its battery, so the battery is very important!
There are different types of battery out there, the three main types are Nickel-Cadmium, Nickel-Metal Hybride and Lithium-ion, these are the market leaders.
A variety of different voltages are available as well ranging from 3.6V and 48 V. The voltage of the battery will also determine the weight of the battery, an important consideration considering it is a hand tool!
The actual power of your tool is not entirely dependent on the battery either as a lot depends on the transmission also. In other words it depends on the tools efficiency at transferring the power to the tool end. So for example a good quality tool with voltage of 14.4V may be more powerful than an inferior product with 18V. Small cordless screwdrivers and drill drivers will typically be between 3.6V and 12V.
Another factor affecting the weight and charging time of your battery is amp-hour (Ah) value. The normal values range between 1.3Ah and 3.3Ah.
These are commonly used for power tools and have some pros and cons
- They are the cheapest rechargeable batteries in use
- They are strong and therefore relatively difficult to damage
- They perform well in cold temperatures
- They can be recharged up to 800 times
- They have lower energy density making them heavier than newer batteries with the same voltage
- They have a fairly high self-discharge rate
- They lose power slowly during usage
- Often suffer “memory effect”
- Have a maximum 2.4Ah capacity
- Contain toxic cadmium
Nickel-Metal Hybrides (NMH)
Appeared to be the “new” answer for the cordless battery operation with some pros and cons
- They have higher energy density making them lighter
- Are the most environmentally friendly of all rechargeable battery types
- Are less prone to “memory effect”
- Can only recharge up to 500 times
- Do not perform well in lower temperatures
- Require regular discharge
- Have high self- discharge rate
- Are more expensive
- Slowly lose power during use
These may be the preferred “new” technology for rechargeable batteries with more work on overcoming any cons, with new elements being used to make them safer, less toxic plus electronic cell protection to prevent any overheating, overloading and over discharging.
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- They have the highest energy density which makes them the lightest with respect to voltage and capacity
- They run constantly at the highest power
- Have very low self-discharge rate
- Can be taken out and used before being completely charged
- Do not need to be fully discharged before recharging
- Require very little maintenance
- Can be recharged up to 1500 times
- Now have built in protection against undercharging, overcharging and draining
- Perform well in colder temperatures
- Are relatively “green”
- Are the most expensive option
- Can easily heat up if used on high drain cordless tools
- Do not perform well in high temperatures
I nearly forget to mention “memory effect”! Sorry about that, I am solar powered.
Rechargeable batteries are subject to what is known as “memory effect” and this can result in a reduction of their capacity, here is a list of causes;
- When a battery is discharged again and again to exactly the same level, then recharged
- When a battery becomes old
- When a battery gets charged too slowly
- When a battery is exposed to overly high temperatures
- When a battery is completely discharged
- Most common reason for this problem is when a battery is overcharged
The “memory effect” can affect the running time of your battery powered tool, so it is important to ensure that you follow the instructions for best practice when it comes to maintaining your battery.
By following the manufacturer’s precise instructions you can avoid the loss of memory in your battery. A new Li-ion battery is designed to last a long time, provided you remember all the do’s and don’ts.
Another factor is the temperatures you will be working in, these new batteries work well in colder temperatures whereas they do not like higher temperatures so that is worth considering. If you are going to be working in a hot climate it may be worth downgrading to a more compatible battery type.
- Always switch your power tools off before disconnecting the battery and never allow any metal to come into contact with the terminals.