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Discussion Starter · #1 ·
Hello, so I wanted some different opinions and views on my project

I work in drainage, I have a petrol drain jetter can pack on my van. Current spec is a Honda GX630 petrol engine/ Interpump ws202 (200bar/21litres per minute)

I want to build A new drain jetter/pressure washer but with lithium ion batteries.

can anybody help advise me on the most suited BDLC motor and battery’s required.

so far I have found a 15kw bdlc motor that can be run with 72vdc.
The batteris supplying the motor will be from victron energy Google (HE lithium ion 25.6v 200ah)
I was looking at purchasing 3 batteries (25.6v and 200ah each) but connected in a parallel/series. These 3 batts would provide me with 15kwh (5kwh x 3)

do I need to compare the NM torque of Honda to specify the bdlc motor im looking at (golden Motor/EVMotorsport) are the two websites selling what seems to be suitable alternatives?

really appreciate if anyone can reply their views and if I’M on the right page.

A company called RIONED in Holland have built an electric drain jetter that has 6x 25.6v 209ah batteries in a series and it lasts all day. I only need something to last 4hours a day. And they have given no spec on the Motor they use.

tney are charging £80k plus for there machjne. The HE 25.6v 200v batteries are 3.7k each so I know it’s going to be expensive but I’m confident I can buiof for significantly less.
 

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The flow rate and pressure need about 14HP, so your motor sizing may not be too far off. But that depends on the RPM the motor power is rated at.

You need to back into the pump RPM for your flow and pressure specs to determine the rest. Like if you need reduction pulleys...
 

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Discussion Starter · #3 ·
The flow rate and pressure need about 14HP, so your motor sizing may not be too far off. But that depends on the RPM the motor power is rated at.

You need to back into the pump RPM for your flow and pressure specs to determine the rest. Like if you need reduction pulleys...
Thanks Remy for your quick response. The BDLC motor spec says RPM 2000-6000…but I know on my current Honda/Gesrbox I fitted a reduction to about 1450rpm I think
 

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The batteris supplying the motor will be from victron energy Google (HE lithium ion 25.6v 200ah)
I was looking at purchasing 3 batteries (25.6v and 200ah each) but connected in a parallel/series. These 3 batts would provide me with 15kwh (5kwh x 3)
I'm not sure what "connected in a parallel/series" was intended to mean, but if you have enough modules you can connect them in a combination of parallel and series, but with only three they're either all in parallel (combining for 25.6 V and 600 Ah) or all in series (combining for 76.8 V and 600 Ah). The total energy is the same either way.

Presumably all would be connected in series.
 

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do I need to compare the NM torque of Honda to specify the bdlc motor im looking at...
No. You only need to match the power of the Honda at the speed it is operated with the power of the electric motor, and choose gearing (or belt drive) to put the motor at a speed suitable for it. If the electric motor runs at a different speed from the Honda engine, it will be producing a different amount of torque. Which is essentially what remy_martian has posted.
 

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Your rating is steady-state; [at least some] motors use trickery to rate their outputs so be aware of the difference between what the manufacturer states and what the actual rating is once it is installed. The motor cooling system will need to reject around 600W constantly when operating which is enough to keep a bedroom cozy on a cold day. The motor design will also need to support that amount of heat rejection, i.e. forced air cooling or liquid.

An industrial 3 phase motor and VFD might be a better option as they are more established technology with realistic power curves.
 

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Discussion Starter · #8 ·
Thanks for the input guys. Unfortunately the company who have now developed this 72v 30kwh electric jetter have been very secretive about what motor they have used. It was only my own research initially that went down the path of the BDLC Motor. And yes they do come with an option of liquid cooled/fan cooled. But I’m now going to look into other option suggested….industrial 3 phase….vfd….using DC power supply. I’m not electrically minded. So I’m really out my depth here.

I just want the same spec but run on batteries…without paying $84k

batteries are in series. 3 x 25.6v

here’s link if anyone is interested in seeing what I’m trying to achieve (I’ve got 3 less batteries as this has been massively over spec to jet all day and I only ever jet for 1-2 hr max

 

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It's not spec'd to run all day - not sure what gave you that idea:

"3000psi @ 13gpm (200 bar / 60 lpm). It is ideally suited for use in city centres where strict emission requirements apply and in areas that are completely or partially enclosed.

* * *

With fully charged batteries, the unit can handle up to 6 unblocking operations or run continuously for 60 minutes on full power."


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So, you know their continuous flow and pressure spec, which sets your motor size. You also know it runs for 60 minutes on full power on a 30kWh pack which verifies your motor size if you back out pump and motor efficiency.

Their price includes their margins, so of course you can build one yourself for less, especially since there's not much scale for these. Most businesses make more on their time than paying for something that has a warranty and service, and recognize a bodge with downtime a few times a year would have paid the cost difference.

edit: they have two strings of 24v 200Ah batteries that it appears they select, so your statement of 3x is not quite correct. They have 6x as 2x 3s.
 

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Discussion Starter · #10 ·
It's not spec'd to run all day - not sure what gave you that idea:

"3000psi @ 13gpm (200 bar / 60 lpm). It is ideally suited for use in city centres where strict emission requirements apply and in areas that are completely or partially enclosed.

* * *

With fully charged batteries, the unit can handle up to 6 unblocking operations or run continuously for 60 minutes on full power."


---

So, you know their continuous flow and pressure spec, which sets your motor size. You also know it runs for 60 minutes on full power on a 30kWh pack which verifies your motor size if you back out pump and motor efficiency.

Their price includes their margins, so of course you can build one yourself for less, especially since there's not much scale for these. Most businesses make more on their time than paying for something that has a warranty and service, and recognize a bodge with downtime a few times a year would have paid the cost difference.

edit: they have two strings of 24v 200Ah batteries that it appears they select, so your statement of 3x is not quite correct. They have 6x as 2x 3s.
Thanks for finding And correcting my statements. 6 unblocking jobs in a day is totally unrealistic for me,
And this blog I have never read. Weird how it runs for 6 unblocking jobs or 60mins. So 10mins a blockage….sounds like they have lots of work to get through….

I understand they have margins etc but at the same time I don’t have the finances to justify spending that sort of money. As you seem to know lots more about this than me? Would you mind recommending/spec a motor and pump that would work for this set up of battery?
 

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Nope, sorry - your project. Pay me for my time and the $84k unit will look cheap 🤓

I just jump in here to take a break from my own stuff and to stir up thinking, challenge thought processes, offer opinion/advice with minimal effort, provoke dialogue, and to stir up the occasional hornet's nest 😂 for fun. Oh yeah...and to gang up on Brian now and then 😈

Seems pretty straight forward. You have the diagram and everything they use/spec. Lots of knowledge here to nudge you, but here everyone does their own heavy lifting.
 

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Discussion Starter · #12 ·
Nope, sorry - your project. Pay me for my time and the $84k unit will look cheap 🤓

I just jump in here to take a break from my own stuff and to stir up thinking, challenge thought processes, offer opinion/advice with minimal effort, provoke dialogue, and to stir up the occasional hornet's nest 😂 for fun. Oh yeah...and to gang up on Brian now and then 😈

Seems pretty straight forward. You have the diagram and everything they use/spec. Lots of knowledge here to nudge you, but here everyone does their own heavy lifting.
I don’t have the full spec, thats the reason I came on here. I don’t know what motor to use as I’m speculating what motor Rioned use. Also I’m only going to use 1 series of 3 batteries oppose to 2 series of 3. So instead of 30kwh it will be 15kwh.
 

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There are calculators online that compute motor power if you feed them flow & pressure. I gave you the numbers from those. You can also back out the motor consumption knowing they can run for an hour on their pack and that the batteries in their pack are 24V 200Ah each.
 

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What is your purpose for doing this? Imo you are making one or both of the two most fundamental mistakes people make when looking at alternative power sources.
1) doing it to save money, and
2) doing it to save the world, or some variant of that concept.

Making your business model suit the upfront cost of buying one will be a better outcome in the bigger picture, even though that might not make sense right now. How many jobs can you lose because your hacked together gear failed half way through? What is the cost to your reputation? What is your lost income due to having to build, fiddle with, maintain, repair, fault-find this home made solution? How many jobs do you lose because your battery is flat at 3pm and you need three hours at home to charge it? What is the cost of having an employee misuse/destroy it? Or the lost opportunity cost of not being able to give it to a future employee because it is too hack? All these factors go into the true cost of ownership.

IMO: go back to basics and ask yourself why do I need this
 
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