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What do ya'll think about battery electric excavators?

C

cmohn0402

Member
Joined
Jul 11, 2023
Messages
6
Location
Midwest
skyking1 said:
Yes, the scale of the power used by an excavator as described above is much more than an over the road semi truck. Sure they have the same amount of power for starting out but once a big truck is headed down the road on flat ground. It doesn't take very much horsepower at all.
The excavator on the other hand is pulling hard all the time if it's digging. There's just no way to compare it. And there is no scale to describe the difference in how much current you're going to need to charge that battery pack.
Put pencil to paper and figure out how many kilowatt hours of battery pack you're going to have to have to give us 150 horsepower for 8 hours or 1200 horsepower hours.
Then you can say you've started to look at the problem.
The average EV uses a fraction of the horsepower going down the road.
Click to expand...
A rule of thumb you can use for converting gallons of diesel to KWh for a battery is… 1KWh = 0.30 gallons of diesel. So an 86 gallon tank of diesel is equivalent to a 287 kWh battery to get the same run time.

In other words, if you use half of an 86 gallon tank per day, then you would use half of the 287kwh battery per day.

A 287kwh battery pack would give you about 500KW of power or ~670 HP.

A tesla charger (250kW charger) can charge 287kwh battery in about 90 min.
 
C

cmohn0402

Member
Joined
Jul 11, 2023
Messages
6
Location
Midwest
CM1995 said:
It's not logistics - it's the electrical infrastructure required to be in place in order to build a temporary power service big enough to charge the iron on site.

OK great my 325 EX can now run an 8 hr shift on one charge. How long does it take to charge an electric motor to power a 55,000 excavator in addition to our 22,000 dozer, 10,000 lb skid steer and 12,000 lb mini-ex for starters in addition to all the other lifts, lulls and compact equipment on a typical small commercial site in the middle of the suburbs?

Who is going to pay for the power? The GC or the subs? How does that affect general conditions?

That is the kind of real time solutions that need to be found in order for this pipe dream of all electric equipment comes to fruition.

Just my $.035 adjusted for massive inflation.
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ideally, there would need to be a charging truck (similar to a fuel tanker, except has a giant battery on it) that would be dropped off at your job site and recharged every few days. You can fit a 3 megawatt battery pack on a small flatbed truck. Would be enough power for a week. It would cost $450 worth of electricity. Equivalent diesel would be about ~$3,500.
 
skyking1

skyking1

Senior Member
Joined
Nov 3, 2020
Messages
7,767
Location
washington
cmohn0402 said:
A rule of thumb you can use for converting gallons of diesel to KWh for a battery is… 1KWh = 0.30 gallons of diesel. So an 86 gallon tank of diesel is equivalent to a 287 kWh battery to get the same run time.

In other words, if you use half of an 86 gallon tank per day, then you would use half of the 287kwh battery per day.

A 287kwh battery pack would give you about 500KW of power or ~670 HP.

A tesla charger (250kW charger) can charge 287kwh battery in about 90 min.
Click to expand...
That's way off of what I found in a quick search. roughly by a factor of 10!
"
Diesel is the most efficient combustion engine fuel source, carrying 38 kilowatt hours of energy in every gallon — 27 times that of lithium ion batteries."


https://ckpower.com/battery-vs-dies...logy today,is efficient, clean and affordable.


another source:

https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent


Multiply all your battery requirements by 10 to get closer to reality.
 
W

Welder Dave

Senior Member
Joined
Oct 11, 2014
Messages
12,665
Location
Canada
That is from the maker of the electric loader. You can be sure it's skewed in their favor. Didn't read it all but does it talk about down time for charging or charging on remote sites? A 906 size is a small loader too.
 
Last edited:
CM1995

CM1995

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13,463
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Alabama
Occupation
Running what I brung and taking what I win
cmohn0402 said:
ideally, there would need to be a charging truck (similar to a fuel tanker, except has a giant battery on it) that would be dropped off at your job site and recharged every few days. You can fit a 3 megawatt battery pack on a small flatbed truck. Would be enough power for a week. It would cost $450 worth of electricity. Equivalent diesel would be about ~$3,500.
Click to expand...

How much will this truck outfitted with battery cost? Who pays for it? Will the GC need one for the lifts and lulls as well? What about the steel erectors with their electric crane, lulls and lifts?

How long does it take to charge the 3 megawatt battery? Who pays for the security guard to sit in the battery truck to keep thieves from stealing it?
 
CatKC

CatKC

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May 25, 2016
Messages
230
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North MO
IMO- Most people today are confusing electric powered equipment/machinery with –battery powered- equipment/machinery. Battery production for battery powered machinery is using up Rare Earth Minerals at a rapid rate and cannot be sustained for very long. As far as I know there is no method of recycling the used batteries. As such it is an ecological problem yet to be acknowledged in the headlong rush by everyone to get onboard. Electric power is a proven method of use for propulsion or work and if generated by methods -other than battery- will be around for a while.

Fuel cells such as used on space craft, hydrogen fuel or some yet to be invented method for producing electricity will likely be around for the future but battery operated electric machinery will soon ‘run down’ and fade away. The only thing left will be the costly environment ‘clean up’ of all the batteries that were created.
 
CM1995

CM1995

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Messages
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Running what I brung and taking what I win
CatKC said:
IMO- Most people today are confusing electric powered equipment/machinery with –battery powered- equipment/machinery. Battery production for battery powered machinery is using up Rare Earth Minerals at a rapid rate and cannot be sustained for very long. As far as I know there is no method of recycling the used batteries. As such it is an ecological problem yet to be acknowledged in the headlong rush by everyone to get onboard. Electric power is a proven method of use for propulsion or work and if generated by methods -other than battery- will be around for a while.

Fuel cells such as used on space craft, hydrogen fuel or some yet to be invented method for producing electricity will likely be around for the future but battery operated electric machinery will soon ‘run down’ and fade away. The only thing left will be the costly environment ‘clean up’ of all the batteries that were created.
Click to expand...

No confusion here. My questions are specifically for battery powered construction equipment that needs to be charged by an electrical source to operate.
 
skyking1

skyking1

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washington
The battery materials are changing rapidly, and will be much less dependent on rare materials. The battery tech will outrun the rest of the systems needed.
LOL I too wondered about the price of that truck, @CM1995 , and the value of it on the stolen goods market.
I hope to see some competition in the door walker sized minis for Tenant Improvement (TI) jobs and live office jobs.
As it is, I have to go work at night with massive fans going in live buildings. Being quiet and stink free is a huge benefit. The tech is very mature, there are millions of scissor lifts doing this every day and getting plugged in with a 15 amp cord at night.
If you needed more juice you could make a charger that used two different 15 amp circuits. All the commercial jobs have plenty of power for that. No need for an electrician to put in a dedicated circuit, and if you really needed that a spider box is a 50 amp 240 volt cable right there. That's a beefy charger!!
My guess is that would equal a 50+ sized machine for all day of work.
 
G

Gary Layton

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Georgia
Shoot, take the job. Real world experience exploring a situation where the answers are really not known yet but have to be worked out....and getting paid to do that exploration... that's wonderful. It sounds like cutting edge stuff that's got to be figured out by somebody. You already know how to ask good questions and aren't afraid to look around unusual places (here) to get some input on answers. Just keep us posted on how it's working out.
 
CatKC

CatKC

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Messages
230
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North MO
CM1995 said:
No confusion here. My questions are specifically for battery powered construction equipment that needs to be charged by an electrical source to operate.
Click to expand...
Converting diesel (or other) power (with the -energy loss- to do so) to charge a battery (with the -energy loss- to do so) which will convert battery energy (with the -energy loss- to do so) into electric energy seems counter efficient. Every time one form of power/ energy is converted to a different form there is a loss of energy.
Of course the -cost - of the original energy resource is a point to consider. If higher prices for the resource are forced higher by regulations or restrictions . . . . . . .
It's all about money and who controls the energy resource required. Todays -cheap- could be tomorrows -expensive-.
 
Jimothy

Jimothy

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Ontario
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When the sun gets bigger and hotter and the humans die the machines will run supreme.
 
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