Energy efficiency and embodied energy split from "gas&q

BritDownUnder · Post by **BritDownUnder** » 06 Jun 2018, 23:25

My experience of the cordless tools available in Australia is actually very good with one exception - hammer drills. I find drilling a large hole into brick or concrete - a mains powered hammer drill is much more effective for diameters greater than half an inch. Where you need a steady high torque for long periods I find that most cordless tools are no good. This is very rare outside of hammer drilling. The only other case was using an auger type drill to drill a one inch hole through a very hard hardwood timber in my house to put a network cable through. So far cordless heatguns (for heat shrinking seals over electrical joints) are prohibitively expensive, though I do have very useful cordless and gas soldering irons.
I have also yet to find a Ryobi (most commonly available brand in Australia) cordless belt sander which is the only tool that I have managed to cut, or at least cut through to the conductors or the cable, with the tool itself. Cordless are more than adequate for small bursts of energy.

There has been a warning by Australian safety authorities that cordless circular saws are more dangerous as they are lower torque and are more likely to jam and jump away from the line of cut and injure the user. I have not myself used a cordless circular saw as most of my sawing using this tool is in a controlled environment inside the garage. I also see them being used a lot on TV DIY shows one handed which for me is a big no-no.

Another one of my mad ideas is to set up a compressed air system along with associated tools. Maybe even use a wind turbine powered compressor pump along with mechanical regulator to keep a very large (>1000 litres) air reservoir at the required pressure. Compressed air tools will be EMP proof as well, so long as the reservoir is replenished by mechanical means only.

I have had good experiences with cordless chainsaws, polesaw (my personal favourite tool) mowers and brush trimmers in a household garden situation. I cannot comment on clearing overgrown ground or woodland but for my uses the cordless garden tools I have are adequate. Two exceptions are my small woodchipper which is 2.4kW mains powered and a corded rotary hoe at 800 watts which makes digging the garden (without a backbreaking use of a fork) a breeze.

Lurkalot · Post by **Lurkalot** » 07 Jun 2018, 07:37

At the moment dewalt seem to be going for a bigger is better approach with their flexivolt range. Essentially a battery with three banks of cells at 18v with a switch to change it into a 54v battery. It simply changes the cells wiring from series to parallel and can thus be used at 18v for things like drills but can also be used at the higher voltage , but lower amph , for chop saws , bench sawsandthe like. I think when I said to the salesman that the way things are going with the voltages someone's going to connect right to the mains at one point went right over his head.
Anyway whether cordless tools are the best thing since sliced bread or not wasn't really my intention to talk about . This thread is about energy efficiency and as I said I was wondering if using them consumes significantly or only slightly more energy than a tool connected directly to the mains.

Post by **adam2** » 07 Jun 2018, 08:41

There is no simple answer to the question about the relative energy consumption of mains operated versus cordless tools that are recharged from the mains.

The batteries and chargers involve considerable losses, but OTOH the limited energy available from a battery encourages efficient design of the tool.

I would not worry about it.

emordnilap · Post by **emordnilap** » 07 Jun 2018, 10:21

I have 'Ego' brand lawnmower and chainsaw, which take the same battery, a 56v 4Ah. They're for domestic use.

I have to say, I much prefer them both to corded or petrol versions.

The lawnmower does all our grass on one charge (just) and it's not as noisy as a petrol mower, more like a loud washing machine spinning. It's also very easy to push. You can stop the mower the instant you finish a patch or need to empty the trimmings and it restarts virtually instantly.

The chainsaw does enough on one charge to give me sensible breaks, during which I can charge the battery and/or sharpen the chain, have a coffee, shift cut wood etc.

The chainsaw has the great advantage of being silent when not in use

and
doesn't suffer from starting problems - amateurs' nightmare with two-strokes.

For domestic use, I would recommend them. As to longevity, this is yet to be seen but both machines come across as reasonably high quality.

Little John · Post by **Little John** » 07 Jun 2018, 20:01

I use a mains electric chainsaw. It serves all of my needs. Electric chainsaws used to be rubbish, but have much improved over the years. My main reason for having it is the fact it is massively more reliable and much cheaper than a petrol one. I can also run it off my genny if needs be.

emordnilap · Post by **emordnilap** » 07 Jun 2018, 20:14

I'd convert all my power tools to battery if I could; I find that electric cords present one extra, unnecessary hazard. I sling the cord over my shoulder but stillâ€¦

Post by **adam2** » 07 Jun 2018, 20:28

emordnilap wrote:I'd convert all my power tools to battery if I could; I find that electric cords present one extra, unnecessary hazard. I sling the cord over my shoulder but stillâ€¦

Hopefully you use an RCD ? not a cure all by any means, but it does significantly reduce the risk of fatal electric shock from a damaged cable.

Lurkalot · Post by **Lurkalot** » 07 Jun 2018, 21:24

adam2 wrote: I would not worry about it.

I'm not going to lose sleep over it for certain. It's more one of those "I wonder" type of questions like I wonder ..how many less power stations we'd need if all the tv's , DVD players , radios and so on were made without that little red standby light. Not that I lose sleep over that one either .

vtsnowedin · Post by **vtsnowedin** » 07 Jun 2018, 22:57

I was at the J.D. tractor dealers shop the other day waiting for them to mount a new tire for the riding lawn mower. ($68. after two days plus an hour

)
They had a display stand full of electric battery powered tools labeled as "commercial" . weed whackers, hedge trimmers, leaf blowers etc. that worked off either a small battery on the tool or a five times bigger battery carried in a back pack. The back pack sized battery could be popped into the slot on a 24 inch push lawn mower.Seems to be the coming thing and maybe it will make suburbia a lot quieter on the weekends.

BritDownUnder · Post by **BritDownUnder** » 07 Jun 2018, 23:44

adam2 wrote:
emordnilap wrote:I'd convert all my power tools to battery if I could; I find that electric cords present one extra, unnecessary hazard. I sling the cord over my shoulder but stillâ€¦
Hopefully you use an RCD ? not a cure all by any means, but it does significantly reduce the risk of fatal electric shock from a damaged cable.

I managed to cut through the cable with an electric belt sander. Whilst wearing the correct gloves, mask and goggles and using an RCD (I am not sure whether it was earthed and not many things are these days) I had the sander on automatic and the surface suddenly felt rough. I turned over the sander to inspect while still running as was running on automatic and I noticed the cord sticking out of the belt where it had been drawn into. I quickly turned it back the other way and started to find the switch to turn off with my gloved hands and there was a massive bang and sparks resulting in consumer board circuit breaker for the garage circuit tripping.

It was quickly fixed with a soldering iron and lots of heat shrink and black electricians tape. Now the new setup is better as the cable going into then sander is stiffer and wont get pulled into the belt as easily.

I have now banned all gasoline tools from my property. I don't have a big garden and I have always found substitute electric tools.

I gain enormous pleasure shredding or cutting things in my garden or using the electric rotary hoe just using my own solar generated electricity.

emordnilap · Post by **emordnilap** » 08 Jun 2018, 10:09

adam2 wrote:
emordnilap wrote:I'd convert all my power tools to battery if I could; I find that electric cords present one extra, unnecessary hazard. I sling the cord over my shoulder but stillâ€¦
Hopefully you use an RCD ? not a cure all by any means, but it does significantly reduce the risk of fatal electric shock from a damaged cable.

Is that on the main house circuit board? Shows how much I know.

Post by **adam2** » 08 Jun 2018, 10:38

emordnilap wrote:
adam2 wrote:
emordnilap wrote:I'd convert all my power tools to battery if I could; I find that electric cords present one extra, unnecessary hazard. I sling the cord over my shoulder but stillâ€¦
Hopefully you use an RCD ? not a cure all by any means, but it does significantly reduce the risk of fatal electric shock from a damaged cable.
Is that on the main house circuit board? Shows how much I know.

Your fixed electrical installation MIGHT be equipped with a suitable RCD, but don't count on this unless confirmed by inspection and tested to confirm that it works, and that it protects the sockets used for power tools.

If in the slightest doubt, purchase RCD adaptors for your power tools. These plug into a standard socket, and the power tool then plugs into the RCD adaptor.
Alternatively, purchase RCD plugs for the power tools, these are fitted instead of the standard plug. This is probably preferable but may be more expensive.

Either approach greatly reduces the risk of fatal electric shock from a damaged flexible cable.

vtsnowedin · Post by **vtsnowedin** » 08 Jun 2018, 11:10

BritDownUnder wrote:
adam2 wrote:
emordnilap wrote:I'd convert all my power tools to battery if I could; I find that electric cords present one extra, unnecessary hazard. I sling the cord over my shoulder but stillâ€¦
Hopefully you use an RCD ? not a cure all by any means, but it does significantly reduce the risk of fatal electric shock from a damaged cable.
I managed to cut through the cable with an electric belt sander. Whilst wearing the correct gloves, mask and goggles and using an RCD (I am not sure whether it was earthed and not many things are these days) I had the sander on automatic and the surface suddenly felt rough. I turned over the sander to inspect while still running as was running on automatic and I noticed the cord sticking out of the belt where it had been drawn into. I quickly turned it back the other way and started to find the switch to turn off with my gloved hands and there was a massive bang and sparks resulting in consumer board circuit breaker for the garage circuit tripping.

It was quickly fixed with a soldering iron and lots of heat shrink and black electricians tape. Now the new setup is better as the cable going into then sander is stiffer and wont get pulled into the belt as easily.

I have now banned all gasoline tools from my property. I don't have a big garden and I have always found substitute electric tools.

I gain enormous pleasure shredding or cutting things in my garden or using the electric rotary hoe just using my own solar generated electricity.

I would like to say I have never been that careless but it would be a big fat lie.

My circuit breakers have always popped open as they should and just need to be snapped closed at the panel after unplugging the now free end of the skill saws cord.

emordnilap · Post by **emordnilap** » 08 Jun 2018, 11:16

adam2 wrote:If in the slightest doubt, purchase RCD adaptors for your power tools. These plug into a standard socket, and the power tool then plugs into the RCD adaptor.
Alternatively, purchase RCD plugs for the power tools, these are fitted instead of the standard plug. This is probably preferable but may be more expensive.

Thanks adam2. Nicely explained (as usual) and hugely useful (again as usual).

Potemkin Villager · Post by **Potemkin Villager** » 08 Jun 2018, 11:24

Folk should be aware that an RCD does not "prevent" electric shock. You still get quite a belt, before the RCD trips, if the volts on the live conductor finds it's way to earth through your body.

My personal preference is for a mains powered lawn mower (compost material generator) as I am particularly allergic to exhaust fumes. Over many years I have never tripped the household RCD. Having to unroll and manouver a long mains lead is a bit of a pain but not as much a pain as the price of cordless batteries.

Finally I am coming around to considering an electric chain saw, but not a battery powered one.