Everyday we get asked about the DEWALT 20Vmax cordless range. Why don't we sell 20VMax in South Africa? Can I use 20VMax batteries on 18V tools? Can I use 18V batteries on 20VMax tools? This post will hopefully shed some light on the topic, as we will explain the similarity of DEWALT 18V and DEWALT 20VMax batteries.

18V batteries are sold in Europe and South Africa, whilst 20VMax batteries are sold in the USA. The composition and performance of these batteries are the same.

Here is a detailed explanation.

Composition of a lithium battery

Let's start by first looking at how a battery pack is assembled.

  1. A power tool battery is made up of cells that are able to store a charge. As seen in the image below.

  2. The accumulative voltage of the cells (cells connected in series) will be the voltage of the battery.

  3. Each battery cell has a nominal voltage of 3.6 volts and a maximum voltage of approximately 4 volts.

  4. In the case of a lithium-ion battery, the nominal voltage of each cell is 3.6V.

Hence to build an 18V battery, the manufacturer would use: 5 cells x 3.6 volts (nominal) (connected in series) = 18 volts

Inside an 18V battery and a 20V MAX battery you will 5, or multiples of 5, cells.

One set of 5 cells make up a 2.5 Ah 18V battery while adding another row of cells in parallel could make up a 5 Ah 18V battery. (as shown above)

Maximum vs Nominal Voltage Ratings

In the USA, DEWALT battery drill is marketing the same product but only expressing the specifications differently. 

If you look inside a 20VMax 5Ah battery and a 18V 5Ah battery, you will see that both batteries consist of 10 cells x 3.6 volts.

The battery packaging is marked 20V Max. The word max indicates that the battery is rated at its maximum voltage. In the USA, the manufactures can rate the batteries at their maximum output voltage, whilst in Europe and South Africa, the manufacturers have to rate the battery at its nominal voltage.

So essentially a 20V Max battery produces 20 volts maximum and 18 volts nominal voltage. Which is exactly the same output as a 18V battery.

We hope that this explanation has helped you understand the similarity between 20Vmax and 18V batteries. If you need and further help chossing the right battery or charger, you can always call us on 011 434 1170.

Buying from CIB Webstore:

CIB partners serves the industrial and DIY market through this e-commerce store. We deliver across South Africa with popular courier companies such as : The Courier Guy, DSV, Kargo National or Right Side Up. All orders are dispatched immediately on the day you order as we only sell products we have in stock.