Where cordless power tools are concerned, voltage is the main determinant of power. Cordless jigsaws are available with voltages ranging from 12V to 36V.
Jigsaws with a greater voltage deliver more power which enables them to more effectively cut through thicker and denser materials than those with a smaller voltage.
Application
For light-duty and infrequent cutting through materials such as softwoods or plastic, a cordless jigsaw with a smaller voltage of 12V will be sufficient.
On the other hand, if you will be working extensively with denser materials such as hardwood or metal, then you will require a tool with a voltage of at least 18V.
Although cordless jigsaws are usually thought of as being less powerful than their corded counterparts, cordless saws with a high voltage are able to perform equally as effectively as the corded tools.
Duration of use
Generally, jigsaw batteries with a higher voltage also have a greater capacity. This means that they are able to run for longer between charges.
If you are looking to use your jigsaw extensively for long periods, a machine with a bigger voltage will be able to provide you with the cutting power you need over longer intervals of time.
Weight
As cordless jigsaws become more powerful, they also become heavier as a result of their larger batteries. This is something to bear in mind if you plan to use your tool regularly.
However, nowadays, this is less of a problem than it used to be as advances in battery technology mean that batteries for power tools are lighter than ever before.
Cost
Because they are more powerful, it is also important to note that batteries for jigsaws with a higher voltage tend to be slightly heavier and less affordable.
If you will only rarely require the power of an 18V jigsaw, there is no need to spend a lot on a high voltage model.
On the other hand, if you plan to use your tool extensively to cut through particularly hard materials, then it is worth spending the extra money to ensure that your jigsaw provides the power that you need.
Other power tools
If you already own, for example, a cordless circular saw, then it is worth buying a jigsaw made by the same manufacturer with the same voltage. You may find that you can use the same batteries (and charger) with both tools.
This might make your jigsaw more affordable, as you may not have to buy a battery with your tool. On the other hand, you could end up having an extra battery to use with either tool, which would come in handy during an extensive job.
Which voltage should you choose?
The majority of cordless jigsaws have a voltage of 18V and are capable of completing most cutting tasks.
However, if you will be using your saw regularly for heavy-duty cutting tasks, a heavy-duty tool with a higher voltage would provide you with the greater power and longer run time you require.