You may be a craftsman with questions about the batteries you use every day. You know there are several voltage differences in cordless tools, but may not fully understand the details. Here is a discussion from DEWALT about battery basics. Read about the differences between types of batteries and what to look for when you’re buying new cordless tools.
What Is Voltage?
A battery’s voltage tells you how much power the cell generates in ideal conditions. It signifies the maximum energy potential of a battery and serves as a necessity to produce an electric current.
What Is Current?
While a battery’s electrical potential is called “voltage”, the term “current” signifies the amount of electricity moving through a circuit.
Consider voltage and amp-hours when you research specific batteries and during cordless tool comparisons. Voltage measures the battery’s energy, and amperes measure current. Batteries with higher voltages work with more powerful cordless tools and provide the energy required for most high-torque applications. Some types of batteries lose voltage during discharge while others remain mainly stable.
What does AH Mean?
Amp-hour (AH) ratings determine how long a battery holds a charge during use. These ratings differ depending on manufacturer and application but work as general indicators when comparing similar products. Check the AH ratings when you need to compare different batteries. More intense applications will benefit from batteries with higher AH ratings, allowing for a longer use with less frequent recharging.
For example, consider a cordless grinder that runs on 20V batteries. It runs on the same voltage batteries regardless of whether that battery advertises 3AH or 5AH, but a 20V battery with 5AH will allow you to use the cordless tool for significantly longer before it runs out of juice.
Cordless Tool Comparison
Understanding how battery voltage differences affect cordless tool performance will help you choose the right options. Tools with higher voltages may perform more effectively when used for heavy-duty applications, and they tend to cost a little extra. A hammer drill is a good example of a tool that benefits from a higher voltage.
Modern Battery Types
There are three different types of batteries used in the best cordless tools:
Nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) batteries
Consumer-grade nickel-cadmium (NiCd) batteries were among the first released into widespread usage. Modern nickel-metal hydride (NiMH) batteries came later. Both of these battery technologies allow you to recharge between uses, and both come with similar benefits.
Some batteries should be discharged deeply before recharging. NiCd and NiMH batteries both allow users to use the full capacity of the battery without damaging future performance. NiCd batteries handle this especially well, and you can store them with no charge without losing efficiency. While many types of batteries lose their voltage as they discharge, NiMH batteries sustain their voltage over long periods of use. They also store energy more efficiently than NiCd batteries.
Lithium-ion (Li-Ion) batteries
Lithium-ion (Li-Ion) batteries came after both NiCd and NiMH technologies. These batteries rely on a more formidable technology than the other models, and it quickly grew into widespread usage among all cordless tools. This happened because Li-Ion batteries store energy with greater efficiency than NiCd and NiMH batteries. They don’t require power-cycling to sustain performance over time, and they self-discharge less during storage.
Li-Ion batteries, like those used in the DEWALT® cordless combo kits, are preferred in top-rated cordless tools because of their efficient energy discharge and their high storage capacity. They don’t require the same maintenance as other batteries, and they can be recharged even after short periods of usage without damaging the cell’s performance.
Battery Voltage in Cordless Tools
Some cordless tools require more power than others. Tasks that use more torque need batteries with a higher voltage to complete the toughest jobs. For this reason, large cordless shears may require 20V batteries while measuring instruments may only require 12V cells for adequate performance. Battery voltage in cordless tools makes sense this way: the simpler the operation, the smaller the necessary energy supply. That’s why many craftsmen choose to use the 20V MAX* instead of the 12V battery for the toughest jobs: higher voltage generates more torque.
You may notice some cordless rotary hammers and drills with lower voltages than average. The options at the lowest end of the spectrum often come with smaller motors than the tools with more powerful energy requirements. These often serve as household solutions, and may not offer enough power for industrial applications.
Standard Voltages for DEWALT Cordless Tools
20V MAX* Combo-Kits include various types of tools, and these tools can all work with the 20V MAX* battery. Regardless of the cordless tools included with the kit, these sets often come with power supplies that work with your other tools. When you have one DEWALT battery, you can use it to power any of your DEWALT cordless tools that share a voltage requirement. DEWALT’s 12V MAX* batteries work the same way; they just generate less voltage than the 20V MAX* batteries. They also weigh less. While the full-size 12V MAX* battery weighs about 1/2 pound, the compact 20V MAX* battery weighs more than 1-1/2 pounds.
Battery Discharge Rates in Cordless Tools
Depending on the type of battery you use, you may notice a difference in discharge rate. Voltage differences in cordless tools aren’t the only factor in how long a charge lasts. While two different batteries may both have the same voltage rating, one may discharge faster than the other. This primarily occurs because of variations in capacity, but the age and condition of the battery also play a role.
Battery Storage Capacity Vs. Discharge Rate
While you can check the battery’s AH to compare batteries with similar voltages, the performance of your cordless tool depends on a number of other factors. A new cordless drill may have more kick than another you have carried in your toolbox for years. While both drills share the same general specifications, the age of the older unit may affect the rate it discharges. But the age of the battery isn’t the only thing that matters, so does where you store your tools. Most battery technology does not account for extreme heat or cold without affecting performance, and different types of batteries require different methods of storage.
Both NiMH and NiCd batteries should be stored without any remaining charge on the battery. These types of battery can “remember” how much charge they received the previous time, then won’t take more charge than that in the future. To prevent this, they need a full charge from time to time. Li-Ion batteries don’t require a full discharge before you stow them. Instead, they work most effectively with more frequent charges. You can store them with a half-charge for best results. When you pull Li-Ion batteries out of storage, any top rated cordless tools should be able to use them again right away.
DEWALT MAX* Battery Packs
These battery packs use Li-Ion technology to store more energy without adding extra weight to cordless tools. They don’t discharge as quickly as other models and produce consistent levels of power while you use them. These packs are a reliable option for work in all sorts of conditions, even extreme cold. They come in several varieties, including all the most popular voltages in cordless tools.
DEWALT Battery Chargers
A single-dock battery charger is a simple solution for everyday tasks. If you have two batteries, you can leave one on the charger and use the other in your cordless tools. Charging stations often accept only one battery voltage, so check for compatibility before you make a purchase. Some DEWALT MAX* chargers accept multiple voltages, so you don’t need several chargers for your cordless tools.
Similar to single-dock chargers, dual-dock battery chargers replenish batteries quickly. Instead of a single station for your backup battery, these chargers come with two docking stations, allowing you to charge two tools at once. This solution cuts down the time you need to charge multiple batteries, as you don’t need to wait for one battery to finish before you start the next.
Versatile battery chargers, including the DC9310 7.2V-18V NiCd/NiMH/Li-Ion Fast Charger, handle more than one type of battery. These chargers include all the technology you need when working with different batteries, so you don’t need to carry multiple chargers everywhere you go.
Cordless Tool Battery Care and FAQ
Do I charge a battery every night after work, or must I drain the energy entirely to ensure long-lasting battery performance?
Whether to drain a battery entirely depends on the type of battery technology you use. Older NiMH and NiCd batteries rely on a sort of memory to hold their charges. For these batteries, deeper discharges allow the batteries to sustain a larger energy capacity for longer periods of time. Modern Li-Ion batteries don’t have this sort of requirement. When you use a Lithium-ion battery to power your cordless tools, a shorter discharge time keeps the battery working as long as possible. You can charge these batteries after every session without damaging the unit’s performance. It should be noted that Li-Ion batteries should not be run until completely empty. These batteries should be recharged after you finish using them, regardless of how little energy discharged during the task.
Why should I use DEWALT batteries with my cordless tools?
DEWALT engineered top-quality batteries for use with all of their cordless tools. When you use these specially designed batteries, you get a reliable supply of energy that stores more energy on every charge.
Which type of battery works best?
Different situations call for different technologies. While NiCd batteries served as a preferable alternative to alkaline batteries for years, NiMH batteries surpassed their energy storage capacity. Li-Ion batteries provide higher storage capacities as well, and all three work as common solutions for those working with top rated cordless tools.
What are the benefits of lower voltages in cordless tools?
While a lower voltage means less overall power, it can also mean a lighter battery. Many home repair jobs don’t require the same amount of power as industrial projects, and some craftsmen may prefer these lightweight designs for everyday tasks. While higher voltage in a drill provides more torque, it also adds weight to the base of the tool. Those who want a lightweight solution may choose a lower voltage to reduce the weight of their cordless tools.
No matter which type of batteries you work with, voltage differences in cordless tools play a major role in overall performance. Higher voltages work in conjunction with more powerful motors to produce greater torque. As you shop for the best cordless tools, consider the battery voltage and AH to ensure optimum performance.