Power wheelbarrow

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power-up
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Power wheelbarrow

Good morning.
I am building a powered wheelbarrow with a hub motor that I purchased from NuSun Inc. It was marketed as a utility cart or wheelbarrow kit.
I have a few questions about my set up and would appreciate any input at all.
For my project I need a low speed / high torque motor! The wheelbarrow will have to carry 2 to 3 hundred pounds of concrete through grass and rough terrain in wet and dry conditions.
The hub kit is a 48v/800 watt motor that came with a controller, twist throttle, battery charger and brake lever. All these components seem to be from an electric scooter or ebike. If the hub motor is the same, it would be to fast without gearing it down and not enough torque for my project. Would it in fact have been built or reconfigured for what it was advertised as??
My other questions are in regards to the best battery options and set up. The kit is suggesting to use 4-12volt gel cell packs in series, supplying 48volts of coarse. Could someone explain to me the basics of what and how the performance would change with different pack set ups, such as different voltages and amp hour batteries? How does changing the amp hours work?
Can I use 8ah,10ah,12ah,15ah or even higher? Can this motor and controller be run on only 2 -12v batteries at 24volts? What am I giving up by doing this...... run time,speed or torque? (sorry for my lack or basic knowledge on this).
Once again, I'm looking for low speed with high torque and like everyone else "decent run time".
Other questions are:
-Since this kit didn't come with a volt or amp gauge and I understand that these batteries should not be run below 20%, should I be incorporating some short of indicator to monitor the battery charge? Or is there another way of knowing when the batteries are getting low?
-Can this hub motor be switched from forward to reverse? If so, from where.....between the battery to the controller or from the controller to the motor? Do these controllers require a certain polarity coming into them?? Because it would be easier for me to reverse the polarity from the battery to the controller as apposed to doing it between the controller and the motor as the motor has 3 power leads from it!

Sorry for all the questions and thank you in advance for any help.

Mik
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Re: Power wheelbarrow

An interesting idea, a motorised electric wheelbarrow!

But I have my doubts if you can pull this off without a transmission of some sort.

You basically want much better performance than a mobility scooter carrying a very overweight person that needs to make it up a steep hill / wheelchair ramp. A top speed of 5km/h will easily do, unless you want to run after the barrow.

But, unlike the heavy wheelchair passenger, you and you wheelbarrow are more than likely to encounter hard bumps and steps in the terrain, often with a totally stopped barrow that needs to overcome a "stuck in a pothole" situation.

You need much more torque than any other EV I can think of!

The other important factor IMHO is to keep the weight down. For most other EV's a swappable battery makes little sense, but I bet it would be the best option for a wheelbarrow.

I would design the battery pack to consist of three or more fast-swappable packs, so that you can always have at least one pack on fast-charge.

The water-proofing must be quite rigorous for a concreting tool, so you can blast any remaining concrete off forcefully without damaging the electronics.

Quite a challenge indeed. Good luck with it!

This information may be used entirely at your own risk.

There is always a way if there is no other way!

power-up
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Re: Power wheelbarrow

Thank you for the comments Mik.
I will try to get some pics of it today and post them if I have time.
Its mostly done except for the power supply.
I am skeptical as well as to how the 800 watt motor will do under load. Do you have any suggestions as to what batteries I should buy to get the most torque out of this motor and without burning out the controller?? I'm assuming the controller is match to the motor capacity.
Can I use seal acid batteries or is it best to use gel cell like in a scooter? What ah will give the best performance?
Thanks again.

ToyTank
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Re: Power wheelbarrow

Hey mike what a great Idea! You get the same torque all through rpm range so no worries there. You do not want to switch polarity between controller and battery, that would be bad. You can switch it from controller to motor SHOULD be ok, as long as it is a DC motor(I am no expert) I think your kit will be ok torque-wise, it was probably a mobility scooter rated 400lbs. 10AH should be plenty for you, unless you want to take the "Ebarrel" more than 10 miles in a day

Total Energy or watt hours(Wh) in a battery is nominal voltage multiplied by amp hours(ah)

Battery--> Either of these choices perform better when frequently charged. Deep discharges are not that harmful, but you should recharge a couple hours after use, and every month or so during long periods of no use.
You don't want to mess with higher voltages, your controller is 48V rated, and may work with 36V(or not) but going higher could be bad. Your main choices are the SLA(sealed lead acid)or lifepo4(lithium phosphate) batteries. A gel cell is a type of SLA.

SLA "deep cycle" is OK. You could buy these locally. These are big, heavy, toxic, voltage curve is bad(starts strong, drops fast) but are cheap and easy to charge/maintain. Good for 200/300 cycles. One SLA cell is 2V. A 12V car battery is 6 of these wired in a series so voltages multipy, but amp/hours stay the same. 4 12V 10AH SLA batts in another series makes the 48V 10AH

Lifepo4 is superior in every way, except initial investment. >1000 cycles >85% capacity left. >3000 cycles <70%. These are safe as can be, don't age like li-ion or li-poly do, enviromentally friendly, and best of all have a sweet shallow voltage curve. This means start strong, stay strong, fade at the very end. Anyway these are 3.2-3.3V per cell, and are chained just like the SLA above are to get a near 48V source. These are finicky about charging, and require BMS to manage charge and discharge of the battery. These are pretty much turn key, so all you need to know is if you buy a lifepo4 pack, make sure it comes with BMS & Charger.

SLA 48V 10AH is about $100+50 for a charger if you need it. Last 200-300 cycles or 3-5 years(Mine in RV only lasts 2-3) whichever comes first and is dead at that point.
Lifepo4 48V 10AH is about $250-$350 Shipped (with BMS and Charger) You would have to order it from china, takes couple weeks.Lasts 1000(85%)-3000(70%) cycles or 7-10 years. Still usable even after that at the decrease capacity.

Lastly safety. Any SLA type even a gel cell if something you don't want to rupture on you. I just bring this up because of the heavy stuff, and your motor is 8/10 of a horsepower. Lifepo4 are harmless, won't burn, non toxic.

I hope this helped. Know all my voltages are rounded, and that is accumulative in a series, so a "48V" battery isn't really 48V. I would really recommend a lifepo4, if for nothing else the steady performance you get compared to the dropping voltage of a SLA, oh and lifepo4 is < 1/3 weight of SLA.

Mik
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Re: Power wheelbarrow

I would also consider NiMH batteries as the power source.

If you can get hold of a used Prius Gen1 or Gen2 pack you could make 4 swappable packs of 36 cells each.

SLA are too heavy and LiFePO4 might be hard to find used and in good condition. Not so NiMH, depending on where you are.

Have a look at this thread: https://www.endless-sphere.com/forums/viewtopic.php?f=14&t=6726&sid=474aceed4a94972798fe41c1084d220c

This information may be used entirely at your own risk.

There is always a way if there is no other way!

ToyTank
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Re: Power wheelbarrow

True if you can find a 48V NiMH pack. Lighter than SLA, but no more than 500 useful cycles AFAIK. Kinda expensive too but very safe. You'll want a battery that is rated for 15-20 or more amps continuous, since it is a 800watt motor.

Please post pics as you get this together. I think it is a wonderful idea. Even put shopping cart wheels on the back.

power-up
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Re: Power wheelbarrow

Hello and sorry for the late reply, I was away for a bit.
Thanks for all the useful info and comments.
I am going to purchase 4-12V/15ah SLA batteries that are local to me. The 15ah packs are the same physical size as the 12ah and only $5 more to buy at $45 each. It will be a tight fit to get them into my prototype but I think I can do it. It meant bending and fabricating my own battery and controller box to fit tightly between the chassis of the wheelbarrow under the drum and waterproofing it. (By the way, is there any issues putting the controller in such close proximity to the batteries?? Maybe heat? Not that I have much of a choice on this model)
I have some pics of the prototype that I am trying to post on here for all to have a look and maybe spot any problems that I might run into.
You will notice the very aggressive tread on the drive tire! That's because I had a hard time finding a 10" tire that would fit on this powered hub. This tire is off some small tractor I'm guessing but I figure it wouldn't hurt for this, just be a little hard on the lawns but lots of traction, lol.

power-up
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Re: Power wheelbarrow

I'm having a hard time trying to insert my pics into the forum.
I am hitting on the first icon above "Insert/edit image" and then browsing. My pics come up in another window but I don't know how to transfer them into my message?
Thanks, Terry.

power-up
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Re: Power wheelbarrow

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sj
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Re: Power wheelbarrow

I'm so glad to come across this post. I am thinking of ordering this wheel kit, and was wondering how your power 'barrow turned out! A few questions: is the throttle water proof? How strong is the power going uphill with a load? Any comments on it's general performance? If it works well, there are a lot of small farmers who will be thrilled :) Anything you can share about it would be great.

Thanks!

colin9876
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Re: Power wheelbarrow

As you dont need huge range on a wheelbarrow, but need the AMPS for torque, Id use a Dewalt 36v drill Lifepo4 pack. Those A123s are 2.3amphours but they can deliver 50amps continuous no problem!

At 1kg, That would really save weight!

Buy 2 for around $100 each, then you can have one on the fast charger while the others in the wheelbarrow.
Would be so much better than SLA's.

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