Re: Battery Powered Lawn Mowers - All Junk - Why?

Joel Kolstad <JKolstad71HatesSpam@xxxxxxxxx> wrote:
> "Spehro Pefhany" <speffSNIP@xxxxxxxxxxxxxxxxxxxxxxx> wrote in message
> news:p9ps61lq070cl663hi3cupi06f9b6vicmv@xxxxxxxxxx
>> But maybe it could be 1/5 or 1/10 of that, I'm not sure about your
>> assumption.
>
> I think you're onto something here -- presumably grass is effectively cut with
> the blade spinning a certain minimal speed, so with a feedback control system
> the power delivered by the motor could be increased or decreased as needed to
> maintain the cutting speed, and in 'light' grass probably nothing near 5HP
> would be needed.

Existing petrol ones do this, owing to a nasty tendancy to explode if they
don't.
I suspect that if you really wanted to optimise for energy use,
taking a petrol mower, and replacing the engine with a motor,
and the fuel tank with a battery is a bad plan.

Especially if you're automating it, and the time it takes isn't so important.
Take the speed way down, and go with a more shearing action, rather
than trying to beat the grass into submission with a bluntish blade
going at thousands of RPM.
Of course, as you drop the cutting speed, you can decrease the damage that
happens when you hit a rock.
.

Relevant Pages

  • Re: Lawn mower - small lawn!
    ... |> gets a fair amount of abuse, and has hardy grass. ... |> For this size you will want a petrol mower. ... |> 16" push machines. ... I'm not disagreeing but I like my self-propelled petrol mower for my ...
    (uk.rec.gardening)
  • Re: Lawn mower - small lawn!
    ... |> gets a fair amount of abuse, and has hardy grass. ... |> For this size you will want a petrol mower. ... |> 16" push machines. ... an affordable petrol job. ...
    (uk.rec.gardening)
  • Re: Petrol lawn mower - auto cut out
    ... I'm thinking of buying a petrol mower & don't really want to pay more ... I stop to empty the grass box the engine will need re-starting? ...
    (uk.rec.gardening)