There is some confusion in our industry around understanding voltage in outdoor power equipment. If you look across some of the top brands in the industry, Echo has a 56V, Makita has 18V, 36V, 40V and 80V, and then Greenworks Commercial offers 82V. But what does all this mean? Is the 36V twice as good as the 18V?
Not necessarily. It all comes down to the size of the battery pack in the piece of equipment. The battery pack is loaded with an 18650 lithium ion battery cell, which is the standard for the industry. That 18650 battery cell has a minimum of 3 volts and a maximum of 4.2 volts, and it is up to the manufacturer to select a value somewhere in that range to establish total volts for the piece of equipment. Clear as mud? Let’s look at an example.
Echo has selected 4 volts to be the basic unit of measure for its product line. Their battery pack has 14 cells, so 14 cells multiplied by 4 volts each equals 56 volts. Stihl, on the other hand, uses 3.6 volts as the basic unit of measure for each battery cell. Their backpack unit has 10 cells, which totals 36 volts. But however the manufacturer measures total volts, they are all using that same 18650 lithium cell.
So what about run time? How do you calculate total run time you will get from your battery powered? The simple answer is, it depends.
- How big is the battery?
- What are the conditions? For example, is the grass heavy?
- How often are you “letting up” on the throttle
But a quick calculation to help you get an estimate is to simply calculate total watt hours, perhaps better understood as “the electrical gas tank”. The equation is:
Voltage X Amp hours = Watt hours
Back to our Echo example, the battery pack is 56V and has 5 amp hours, which totals 280 Watt hours. The Makita X GT Battery is 40V and 5 amp hours, which gives you 200 Watt hours. The more cells, the longer it lasts. So why not just add more cells? Simply put, the more cells, the heavier the equipment. Equipment manufacturers are working hard to find a balance between comfort and power to deliver the best performance.
The more we understand battery equipment the more we realize the innovations to the product is changing the power equipment landscape. To learn more about the different products available at Horizon go to Battery at Horizon.