JUST DO THE MATH

STIHL battery lawnmower – breakthrough or con game?

STIHL has taken out a full page ad in the Globe and Mail to promote its new, lithium-ion super battery lawnmower.

The ad is visually appealing and has the dramatic tag line – at the top: No Gas, No Cord, No Problem.

The ad has at its core a price comparison and states that you will save some $428.80 over 10 years with their lithium-ion battery unit compared to normal gas powered lawnmowers.

But is the comparison accurate and fair?

First, I checked the company’s website, its YouTube promotional ad and made a call to a local commercial STIHL dealer as they are not sold at Canadian Tire or other retailers at the moment.

Here is what  I found out that the ad overlooks.

      1.  The cutting path is 14 1/2 inches wide; fairly common for electrics but small by gas unit comparison.  

       So cutting a large lawn will take a long, long time!       

2.    The battery’s run time for ‘normal height grass’ and ‘good conditions’ is 25 minutes for up to 3,200 sq. ft.  For larger lawns, the unit – which dies suddenly and shuts down – needs a recharge.

 To quote the Description tab info: 

“… can cover up to 3,200 square feet on a single charge, depending on operating and battery conditions. Need to cover more ground? The STIHL battery can be easily swapped out and recharged in less than 30 minutes with the optional rapid charger.”

·         So this mower also suffers from RANGE ANXIETY just like the Nissan Leaf and Telsa sports car.

·         The ‘optional’ rapid charger – which takes only 30 minutes - costs $75.00 ; not the $39.95 mentioned in the ad which is for the STANDARD recharger that takes 100 minutes to recharge (info from dealer)

·         A longer range battery (AP 160) is available at a cost of $199.00 compared to the standard battery (AP 80) at $130.00.

 

·         The YouTube video, while peppy, shows that for high grass, even a small lawn needs battery recharging after a few minutes.   In the video, it’s quick and easy as there is a second battery awaiting in the charger to quickly replace the dead unit.

So while battery removal and exchange is under 5 minutes or so (depending on how long it takes to get to the charger and back) the video recommends buying a SECOND BATTERY!

 

 

There are more ‘surprises’ as the newspaper ad’s FACTS and MATH do not work either.

Bi-annual service and blade sharpening

The ad states a gas lawnmower needs to be serviced every other year at a cost of $80.00 and the STIHL battery mower saves this cost and related time and trouble.

BUT you can learn to do the basic service from YouTube and parts/oil only cost a few dollars!                      And I know people who do not do a full service for years!

Moreover, for your $80 you always get a blade sharpening since blades need to be done EVERY YEAR.

So, STIHL makes 2 errors in this regard:

1. it forgets service usually includes blade sharpening and I would definitely expect this for $80.00!

2. STILH says its battery lawnmower needs the blade sharpening only every other year.  Good luck with that!  I have had a standard electric lawnmower and gas unit and can tell you the weaker, electric powered units need super sharp blades to work.  Gas units can chomp down grass even with dulled blades.

Cost of power to run the mower

The ad states gas units cost $14.19 a year (for gas and oil)  (based on  26 mows a year) and the RMA 370 electricity/recharge cost is only $1.31 a year.  Over 10 years the difference becomes $128.80

 

Let’s examine those numbers more closely.

A gas unit costs $0.55 per cutting of $3,200 sq. ft (as used in the ad).  That works out to just under  ½ a litre of gas at today’s Ontario costs.  This amount sounds reasonable.

The ad’s electricity calculation is more complex.

It multiplies volts times amps to get watts (which is correct) and then divides by 1000 since electricity charges are by the kilowatt hour (correct again), but then it does to interesting and surprising EXTRA calculations:

It multiplies the usage by 2 and then by 2.1.

As even a lawn of 3,200 sq. ft needs a recharge half-way or so, it (correctly) doubled the electricity cost as 2 charges are needed, accounting for the x2 element.

But what is 2.1 ??????

What it must be is the kilowatt cost of electricity.    The ad, put simply, assumes your utility’s electricity rate is  2.1 cents per kWh!

Nowhere in Ontario - if anywhere in North America -- is electricity so cheap.  Toronto hydro’s rate chart has no time less than 6.3 cents a kWh and that is only between 7 p.m. and 7 a.m. and weekends.

Other weekday rates are 9.9 cents and 11.8 cents – 50% to 80% more..

So, 2.1 cents kWh is a distortion at best. 

At weekend rate of 6.3 cents kWh, $1.31 becomes $3.93 and $39.30 for 10 years.

 

So, here is a revised comparison chart that matches the reality of using the RMA 370.

 

	10 year overall costs
	Gas powered	RMA 370
Purchase price	449.95	399.95	$734.95 using AP 80 batteries   $872.95 using AP 160 batteries
Quick Charger (AP160)		75.00
two  batteries		AP 80 $130.00 x 2 = 260.00 AP 160 $199.00x 2 =398.00
Annual blade sharpening	15.00 x 10 = 150.00	15.00 x 10 = 150.00
Service every    2 years	$65 max (deducting blade sharpening) to under $20.00 done 5 times = $325 to $100
Fuel/electricity	14.19 x 10 = 141.90	3.90 x 10 =  39.00
TOTALS	841.85 to  $1,066.85	$923.95  for AP 80 and $10612.95 for AP 160

 

So say goodbye to the ad’s claim of a $428.80 in SAVINGS over 10 years!

Gas powered is equal or cheaper!

 
________________

 

P.S. By the way, since when does a small diameter (14 1/2 inch) gas mower cost $449.00?  Canadian Tire will sell you a standard 20” gas mower for under $300.00!

Oh, and Canadian Tire  carries the GreenWorks line of Lithium-ion battery units which use 2 batteries at a time and can cut for up to 90 minutes!