52-inch battery-powered mower that does more than
cut grass. It takes aim squarely at the frustrations
that people have with gas-engine models and partic-
ularly with range anxiety—the concern of whether a
battery mower can finish a large lawn without run-
ning out of juice. The company rates the ZT5207 as
being able to mow four acres on one charge. To do so,
it equipped the machine with six removable 56-volt
lithium-ion batteries, each a massive 12-Ah power
pack. Its rated run time is two hours at slow speeds
or about 100 minutes at its top 8 mph.
As substantial as this mower is, it’s not an iso-
lated development. Lithium-ion power is meeting
the demands of more homeowners and even pro-
fessionals. Manufacturers tell us it powers nearly
40 percent of all residential outdoor power prod-
ucts sold—everything from handheld equipment
to riding mowers. Even longtime gas-engine man-
ufacturer Briggs & Stratton is building battery
packs, including those big enough to power com-
mercial mowers. “Today, we’re power agnostic,”
said Carissa Gingras, the company’s senior direc-
tor of marketing for power applications. “We’re a
power provider.” The new batteries will be used on
the EVZ, a commercial mower built by Scag Power
Equipment, which builds some of the toughest com-
mercial grass cutters in the industry.
Meanwhile, Hydro-Gear—an Illinois-based
manufacturer famous for building hydrostatic
transmissions for gas-engine riding mowers and
tractors—is building transmissions, batteries,
and motors for electric zero-turn mowers. “We’ve
already sold out our inventory for 2022,” said Scott
Wellman, the company’s marketing manager.
Clearly, the trend is electric, and that necessi-
tates some pretty sophisticated battery engineering.
To ensure the batteries’ durability, Ego’s engi-
neers developed a unique shape in which the cells
are arranged in an arc that allows for maximum
airf low and cooling. Each battery’s location, its
thermal performance, and current f low are mon-
itored by its circuit board and software. Ego calls
the system Peak Power. The batteries communicate
with the mower’s software such that the electrical
loads for the blades, drive motors, and system elec-
tronics are evenly distributed among the batteries.
That means you, the operator, never need to shift
battery positions so that each one sees equal elec-
trical wear and tear over time.
Compared to a gas-engine mower, winter storage
is a snap. There’s no concern of sludge forming in the
crankcase or ethanol gas chemically degrading and
fouling the carburetor. All you do is remove the bat-
teries and bring them inside (they’re rugged enough
to withstand temperatures as low as 4 degrees Fahr-
enheit, in case you keep them in a shed). After 30
days of storage, the Peak Power system initiates a
slow self-discharge cycle, reducing their charge to
about 30 percent. Other batteries simply go dor-
mant; they lack the ability to be self-maintaining
for the sake of protecting their electrochemistry
through a regulated movement of current.
As to lifespan, the batteries are designed to
retain 80 percent of their charge after 500 cycles.
Ego estimates that should be more than sufficient
for northern homeowners who will cut their lawnThe user interface
screen provides
information on
battery charge, and
the operational
setting selected.May/June 2022 87