C Cab Hot Rod Power Advice

[Just_Ed]

Good info...I'm learning. keep it coming folks.

Using two of the 1800w motor is not a bad idea. If you can figure out a way to independently gear each rear wheel, the dual motor setup can work like a differential to allow easier turning. With brushed motors, you can easily use two with a single controller.

I always thought the axle would be split. Therefore, if two motors were used, as you suggest, I'm thinking each would have their own jackshaft (to change gear speed).

Another thought that comes to mind is during turns, would the frictional force from the tires/ground, cause one of the motors to be stressed in some manner? I think I figured this one out, but feel free to answer it anyway....you know, just in case.


Thinking 'Out-Of-The-Box'

On the subject of a single controller. Another ...What If ....Two motors,(brushed or brushless), (two controllers, connected together electrically), then connecting to a single point, i.e, the throttle. Wouldn't each motor feel better and react correctly, if the single signal, (from the throttle), is split to each of the controllers? Wouldn't each motor react, as if there was just one signal. Also some of the other accessories, could run off of one controller, or some off one controller, and some off the other.

With a jack shaft or large ratio single reduction, you should be able to gear down enough to make the motors happy. You could even possibly have more than one gear using a derailleur or internally geared hub. I've seen some pedicabs that are close to your project so you may want to look at various pedicab designs. Most have a differential but with dual motors you could avoid the need for one.

Good thought. I'll look into the pedicab reference.

If you can accept relatively short range, you can keep the battery size fairly small. I would be looking at used Nissan Leaf batteries for something like that. If you find the range is too short later, you can always add more batteries.

So if I plan/build a 48 volt system, I could use it with, lets say 36 or 24 volt of battery power. Net loss would be maybe, less speed or less longevity/distance.

Just to let you know, all this incoming information, is really really helpful.
Thank you to all contributors.

 

[amberwolf]

On the subject of a single controller. Another ...What If ....Two motors,(brushed or brushless), (two controllers, connected together electrically), then connecting to a single point, i.e, the throttle. Wouldn't each motor feel better and react correctly, if the single signal, (from the throttle), is split to each of the controllers? Wouldn't each motor react, as if there was just one signal. Also some of the other accessories, could run off of one controller, or some off one controller, and some off the other.

this is the 2wd / awd / etc i was talking about. there's a lot of threads, including my sb cruiser and crazybike2, doing that. teklektik has a great thread for his yuba mundo that documents *everything* including wiring, etc., that you would benefit from.

the controllers would not be connected together except at the battery and throttle signals. (and forward/reverse if you're using that, and ebrakes if you're using those).

all the motor hall and phase signals would be independent, each controller goes to just one motor.

take a look at those threads for 2wd / awd.

So if I plan/build a 48 volt system, I could use it with, lets say 36 or 24 volt of battery power. Net loss would be maybe, less speed or less longevity/distance.

the conttrollers will likely have an lvc that will only let them operate above the low voltage cutoff (lvc) of the battery votlage they're intended for. a 48v battery tha'ts somewhere around 40-42v. you have to check the controller yo'ure going to buy to make sure it can do as low a voltage as the battery you're going to use will be at when it's empty.

additionally, if you use a controlelr with an lvc for say 24v battery, and then later get a 48v battery, the controller can not protect the 48v battery from being overdischarged. so you would have to manually do that. (don't rely on a bms to shut off the battery, because the bms is only there as a last ditch protection, the controller lvc is usually higher by a bit so it protect the battery without being hard on it).



you would get a lower speed, proportionally to the lower voltage, unless you gear it proportionally for that (whichyou'd then also have to change again when you go up to a higher voltage).

you'll als get lower torque.

 

[Just_Ed]

this is the 2wd / awd / etc i was talking about. there's a lot of threads, including my sb cruiser and crazybike2, doing that. teklektik has a great thread for his yuba mundo that documents *everything* including wiring, etc., that you would benefit from.

OK, I'll play along, where are they....a link would help :lol:

the controllers would not be connected together except at the battery and throttle signals. (and forward/reverse if you're using that, and ebrakes if you're using those).

And that's how I envisioned them being connected. So we're together so far.

all the motor hall and phase signals would be independent, each controller goes to just one motor.

Good to know. That's what I was thinking. Still together...yay!

I'm feeling like I/we are getting somewhere.
I've just been looking into what it would take to replace my existing 3/4" axle with a 7/8" go kart axle, such as this...https://www.scooterpartscatalog.com/rear-axle-assy-complete.html?utm_source=googleshopping&utm_medium=cse&gclid=EAIaIQobChMIx5-Jt-OT5wIVVyCtBh2GfgX6EAkYECABEgIxafD_BwE

or this...https://www.ebay.com/itm/Drift-Trike-Go-Kart-Rear-Live-Axle-Kit-Sprocket-Hub-Brake-Assembly-Chain-Hub/303317060763?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D20160908110712%26meid%3D36b3fc632c984bf7ab733443cab94e82%26pid%3D100677%26rk%3D1%26rkt%3D30%26mehot%3Dpp%26sd%3D133266691896%26itm%3D303317060763%26pmt%3D1%26noa%3D0%26pg%3D2386202&_trksid=p2386202.c100677.m4598

 

[amberwolf]

OK, I'll play along, where are they....a link would help :lol:

my signature has links to mine, but my threads ramble and wander and have a lot of experiments in them, and stuff that isn't even relevant, side discussions, ideas, etc., so while you *can* figure out what i did by reading them, it's giong to take a while and lead you places you probably didn't intend to go. :lol: i keep thinking aobut making an index to them for the good stuff, but don't have enough time and energy (which is also why i haven't provided specific links before, as it takes time to find them).

the others are findable (generally) in the following searches. sorry i don't ahve specific thread links, but you should be able to see what's relevant or at least interesitng, from the titles.
https://endless-sphere.com/forums/search.php?keywords=2wd&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

https://endless-sphere.com/forums/search.php?keywords=awd&terms=all&author=&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

there's other threads that don't show up in those specific searches, but most likely those will help you. if teklektik's doesn't show up you can look at the threads he's started, many of which are useful and/or interesting on their onw
https://endless-sphere.com/forums/search.php?keywords=&terms=all&author=teklektik&sc=1&sf=titleonly&sr=topics&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

 

[Just_Ed]

OK, I'm good at looking around for things.

 

[fechter]

If you are using brushless motors, you need a separate controller for each motor but you can split the throttle input to control both. When making a tight turn, the motor on the inside will be effectively geared taller so will take more current. The controllers have current limiting so nothing bad happens.

With brushed motors, you can put the motors in series (this requires a battery with double the rated motor voltage) and a single controller. In series, the current to both motors will always be the same and it will function like a differential. The motors can be put in parallel too, but this will be more like a limited slip differential and the two will fight each other slightly on a tight turn.

The downside of a dual motor approach is it would be difficult to have more than one gear ratio. Both sides would need to shift at the same time.

 

[ZeroEm]

Just wondering, using a torque throttle with dual brushless motors, controllers would work good in turns.

Like this project, would go with 2 single sided motors but that cost money.

 

[Just_Ed]

If you are using brushless motors, you need a separate controller for each motor but you can split the throttle input to control both. When making a tight turn, the motor on the inside will be effectively geared taller so will take more current. The controllers have current limiting so nothing bad happens.

The downside of a dual motor approach is it would be difficult to have more than one gear ratio. Both sides would need to shift at the same time.

OK then. I think with the help from you and amberwolf, I have come to decide, that the dual motor system, might be the way I should go. I think I will go ahead and replace my 3/4" axle, with a 7/8" go kart axle, that comes with the brake system and drive sprocket as well.

I will dwell on this decision, and ultimately contact a supplier with a desire list.
While dwelling, I need to read up on the references you've given me.

Oh, another thought about the axle. I'm thinking at the low speed of 20-25 mph, and knowing how little road use this project will likely get, that leaving the axle a solid piece, shouldn't be much, if any problem. I mean go karts do it that way and they are traveling a lot faster than I would be. However because there's a dual motor set up, there may be an affect. What say you ?

 

[fechter]

A solid axle connected to both wheels will have a real hard time going around corners. Go karts have enough power to make the tires skid. You really want the axle split so each wheel can be driven independently.

 

[Just_Ed]

A solid axle connected to both wheels will have a real hard time going around corners. Go karts have enough power to make the tires skid. You really want the axle split so each wheel can be driven independently.

I kind of thought that would be the case. My frame is already set up, for the axle to be split.

Parts Update:

I have put out three requests for price quotes on the motor package.
All three went to Dallas, Texas. Probably all to the same office. I'll let you know how it comes out.

 

[Just_Ed]

I've heard back from two suppliers from EBAY. TDPRO and Alpha_Wheel

TDPRO
$519.99 + tax and they throw in a couple of 'gift items'
https://www.ebay.com/itm/303024861914

Alpha_Wheel
I've tossed them aside.
Their offer came back broken down which was a little less money,
but they couldn't fill the exact parts I wanted. Even though the parts were in Dallas,
I had to use the translator to read their web page. That and the shipping delivery time was suspect.

2011motorparts

Haven't heard back from them yet.

Battery or Batteries, that be the question

I would swear I posted about battery use yesterday, but it doesn't seem to be anywhere.

So here it is again..sorta.

Before I lay out the money for the motors, the subject of batteries should be addressed.

If I'm using two 48 volt 1800 watt motors, I'm thinking there will be additional drain on one set of (4) 12v SLA batteries, or one li battery. I'm leaning toward using a lithium battery so lets start there.

So the big question is;

If I'm using a 48 volt battery, then the (ah) comes into play...right?
Can 48 volts in either type battery, handle the load from two motors?
Does the ah need to be increased? If so, to what level? 15 ah, 20 ah, 30, 40 ?
Does the voltage need to be increased? (Not sure this can/should be increased)

These questions go directly to the cost of using two motors vs one.

Finger is on the button, but I'm not ready to push it, just yet.
I need to feel a bit more comfortable that,
(1) I know what I'm doing, (2) I have done what I can, to ensure it's not money wasted.

 

[fechter]

1800w at 48v works out to 37.5 Amps. In real life, this will be a peak value and you would normally draw somewhat less than this other than accelerating or going up a hill if you have the gearing right.

Let's just ballpark it at 40A per motor. 80A total. From this you can estimate how large of a battery you need. Lithium batteries come in several types. The more typical Li-ion cells can handle about 2C discharge rate, which means you would need at least a 40A-hr pack. Less than this size you may run into battery heating issues and short life. Some cells can handle much more than 2C so you could make it work with a smaller pack, but your range will be less.

Personally, I would be looking at used Nissan Leaf batteries (these come in 60Ahr modules) or possibly Chevy Volt batteries (47Ahr?).
Leaf battery modules come in pairs so you would need 7, which would be a nominal 52v. A 48v motor and controller will work fine with 52v. You can get a set for around $500.

Lead-acid batteries will give you about half their rated capacity and weigh at least 2x more than lithium. They will also have a short service life by comparison. It's totally worth it to go with lithium.

 

[amberwolf]

TDPRO
$519.99 + tax and they throw in a couple of 'gift items'
https://www.ebay.com/itm/303024861914

something you want to verify once you get the controller, is that the power wires actually are reversed like it shows in the picture on their ad:

if they're not, and you hook them up the way they say to (battery positive to black, battery negative to red), it will probably destroy the controller instantly.

so when you get it you'll need to open the controller's endcap on the side away from where the wires are, and see where the big fat red and black wires are soldered on the board. the negative wire will generally be right next to the shunt wire and big capacitors, and the positive will usually be nearer the edge of the board away from teh shunt but still near the big capacitors.

 

[Just_Ed]

1800w at 48v works out to 37.5 Amps. In real life, this will be a peak value and you would normally draw somewhat less than this other than accelerating or going up a hill if you have the gearing right.

Let's just ballpark it at 40A per motor. 80A total. From this you can estimate how large of a battery you need. Lithium batteries come in several types. The more typical Li-ion cells can handle about 2C discharge rate, which means you would need at least a 40A-hr pack. Less than this size you may run into battery heating issues and short life. Some cells can handle much more than 2C so you could make it work with a smaller pack, but your range will be less.

Personally, I would be looking at used Nissan Leaf batteries (these come in 60Ahr modules) or possibly Chevy Volt batteries (47Ahr?).
Leaf battery modules come in pairs so you would need 7, which would be a nominal 52v. A 48v motor and controller will work fine with 52v. You can get a set for around $500.

Lead-acid batteries will give you about half their rated capacity and weigh at least 2x more than lithium. They will also have a short service life by comparison. It's totally worth it to go with lithium.

Wow, I never dreamed of getting this deep into the power needs of this project.
It's daunting, yet exciting, the deeper I go.

I'm treading water, as we speak, but I can swim, so I'm not fearing catastrophe.
I'm hoping it's not like quicksand, so deep, it's going to be over my head.

Anyway I went looking for Leaf batteries, and found these;
I'm not sure this is what you were referring to.

After the jolt of not seeing what I call a normal battery, this looks to be promising.

The seller/company say's the batteries are;

"They are used 60% Capacity (Not sure what that means for my use )
90 days return policy. 1st 30 days we pay the return the rest the buyer pays"

https://www.techdirectclub.com/48-volts-nissan-leaf-battery-g1-module-lithium-ion-3-kwh-66-amh-lot-of-6/
https://www.techdirectclub.com/nissan-leaf-battery-g1-module-lithium-ion-3-kwh-48-volt-66-amh-lot-of-6-with-parts/
https://www.techdirectclub.com/solar-rv-powerwall-nissan-48-volt-battery-g1-lithium-ion-3-5-kwh-66-amh-w-option-and-1-bms-lot-of-7/

Here's the charger for these batteries;

" We have this charger and I can asked to adjust the voltage for 12S. Once you purchased let me know so I send the request to adjust the voltage "

https://www.techdirectclub.com/delta-electronics-power-supply-36v-110-220v-15-30-amp-golf-cart-backup-charger/

They have this one as well, so why not get/use it?
https://www.techdirectclub.com/delta-electronics-power-supply-48v-110-220v-15-30-amp-golf-cart-backup-charger/

Not sure what they mean by 'adjust the voltage for 12S'.
Doesn't 12S, mean the number of cells?
If so what's the 'adjustment' ?

 

[Just_Ed]

TDPRO
$519.99 + tax and they throw in a couple of 'gift items'
https://www.ebay.com/itm/303024861914

something you want to verify once you get the controller, is that the power wires actually are reversed like it shows in the picture on their ad:
s-l1600.jpg
if they're not, and you hook them up the way they say to (battery positive to black, battery negative to red), it will probably destroy the controller instantly.

so when you get it you'll need to open the controller's endcap on the side away from where the wires are, and see where the big fat red and black wires are soldered on the board. the negative wire will generally be right next to the shunt wire and big capacitors, and the positive will usually be nearer the edge of the board away from teh shunt but still near the big capacitors.

Thanks for the tip, I may not have caught that.

The wiring diagram that comes with it is just the opposite.

 

[amberwolf]

it's always fun when the seller provides conflicting information about their own products.

it often means they don't actually know what they are selling, or that they sell a bunch of different products under the same item, or that they go out and buy what they're going to send you *after* you pay for it, so they may never even have the same item twice, and the item you get may not even match the specs of the item you paid for. there are a number of places posted about on es that appear to do these things; bmsbattery seems to do the last one a lot.

sometimes it just means they changed products at one point, but didn't change the item page...but it still means you may not be able to trust the info on the page. if they send specific info with the actual unit, then hopefully you can trust *that*.

anyway...i thought of another test you can do before ever connecting the controller to anything, instead of disassembling it to verify wiring.

if you have a multimeter with "diode test" function, you can set it to that, it looks like an arrow with a bar
across the pointy end of the arrow. hook up the red and black leads from it to the same colors on the controller power wires. the reading should change for a while and then stabilize.

if the reading holds at some number around 1000 or less, it's reversed polarity, meaning that red is battery negative and black is battery positive.

if the reading ends at "ol" or a blank screen or 1... or whatever the meter normally shows when the leads are not connected to anything, then it's normal polarity, and red is battery positive like it should be, and so black is battery negative.

if you get the normal reading, then you should verify by reversing the meter leads, and then you should get the number aroudn 1000 or less. if you still get the "no reading" normal reading from it, then this test either can't tell polarity on this controller, or something is wrong with the meter leads or meter or connections, etc. you can verify the meter leads/connections by touching them to each other, and it should read about zero while doing that.

 

[Just_Ed]

OK, I will keep this check, to be accomplished when and if I get those motors/controllers.

I'm talking/emailing with Tech Direct as we speak.
I'm trying to get a sense of the 60% battery capacity, and how, if any, difference it will mean to my project.

Also why must I have 7 bats, vs six. Both options are listed as 48 volt.

 

[Just_Ed]

Got this back from Tech Direct

The voltage for
6 Modules is 36V - 49.5V
7 Modules is 41-58V
Most inverter works with 41-58V

OK, got it...I think !
Still reading and learning....some of it sticks...other, not yet.

Nominal voltage is 7.5 x 6 = 45
Nominal Voltage is 7.5 x 7 = 52.5

Now I understand where the 52v comes from in your post.

Leaf battery modules come in pairs so you would need 7, which would be a nominal 52v. A 48v motor and controller will work fine with 52v. You can get a set for around $500.

Please correct me if I don't have this right.
With this battery, I will only need one, to operate both motors. (Module of 7, that is)
https://www.techdirectclub.com/solar-rv-powerwall-nissan-48-volt-battery-g1-lithium-ion-3-5-kwh-66-amh-w-option-and-1-bms-lot-of-7/

 

[fechter]

Please correct me if I don't have this right.
With this battery, I will only need one, to operate both motors. (Module of 7, that is)
https://www.techdirectclub.com/solar-rv-powerwall-nissan-48-volt-battery-g1-lithium-ion-3-5-kwh-66-amh-w-option-and-1-bms-lot-of-7/

Correct. You can run two motors off the pack. 60% capacity isn’t great but will work. It means your range will be less. You might be able to find better ones but they will cost more.

 

[Just_Ed]

In my quest to learn all my brain cells can absorb about the batteries, I might be using,
I found this video about Nissan Leaf batteries and Tech Direct Club.

It's not all technical, just some info about the batteries, how they are put together, and an opinion about Tech Direct Club. https://www.techdirectclub.com/

https://www.youtube.com/watch?v=FlCz40bCZZM

And I did find on their site some G2 batteries with 70+ capacity left. $564 plus tax, free shipping.
G1 batteries were/60 % capacity.

 

[Just_Ed]

Thank you fletcher and thank you amberwolf

You guys have been a lot of help, toward making this happen.

I have pushed the button. No turning back now.

Here's the final order:

TDPRO ... "You can purchase two of this"

: https://www.ebay.com/itm/48v-1800w-Brushless-Motor-Speed-Controller-Foot-Pedal-Reverse-Switch-Chain-Sproc/303024861914?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

"We can adjust the package contents to the below"

2 x Model: 48VDC 1800W Brushless Motor, w/Sprockets: T8F 9 Teeth
2 x Controller
2 x Rear Axle Sprocket (T8F 54 teeth)
2 x T8F chain
2 x Wiring Harness
1 x Ignition Key
1 x Throttle Pedal
1 x Forward / Reverse Switch
1x T8F chain breaker
1x T8F 11t sprocket
2x terminal blocks

I will also be ordering one additional T8F 11t sprocket, and one additional T8f chain

Total cost including shipping/tax.....$526.97

I have really looked into the Leaf battery suggestion, and the more I learn, the more money it will cost me.
But I like what I'm seeing/learning about these batteries, and will more than likely purchase them in due time.

Thanks again for your help
Ed Jackman

 

[Just_Ed]

Here is something I learned about increasing voltage and ah.
Get your popcorn and soda and watch the next 4 1/2 minutes

[youtube]9n0oo2hHZv8[/youtube]

This is what I got from watching the video.
If I made the drawing correctly, then maybe, just maybe, I'm starting to learn something.
If not, oh well, back to class.



Assuming the above method of increasing the voltage, as well as the ah, is correct and doable.
This may be a less expensive alternative. The cost difference alone would pay for battery tenders for the 4 batteries.
Something like this.(Minus my 10% veteran discount)

If I used this particular battery, @ 22ah, then the total ah would be 88ah...I think.
https://www.lowes.com/pd/Mighty-Max-Battery-Rechargeable-Sealed-Lead-Acid-12220-Backup-Power-Batteries/1001097148

At 13 lbs (52 total) they are less than the Leaf Modules would be, which was 7 x 8lbs =56 lbs.
And the physical size works well with a couple of placement choices I have, in the frame or behind the seat.

 

[SlowCo]

If you put 4 of those batteries in series then the voltage will be 4x12V=48V but the Ah will stay 20Ah (22Ah for the batteries in your link). If you use them in parallel then the voltage will stay 12V and the Ah would be 4x20Ah=80Ah. And if you put some serious load on the batteries put in series with only 20Ah then the usable Ah of those lead acid batteries will drop significantly.

 

[Just_Ed]

If you put 4 of those batteries in series then the voltage will be 4x12V=48V but the Ah will stay 20Ah (22Ah for the batteries in your link). If you use them in parallel then the voltage will stay 12V and the Ah would be 4x20Ah=80Ah. And if you put some serious load on the batteries put in series with only 20Ah then the usable Ah of those lead acid batteries will drop significantly.

True.
So with that being true;

I want to increase the voltage from 12 volts to 48 volts ....Series
I want to increase the ah from 20 ah to 80 ah ................Parallel

Result is a battery bank with 48 volts @ 80 ah ...............Series & Parallel combined (See drawing)
If both motors draw 32 amps ( 64 amps total), would that not leave a reserve of 80-64 = 16 ?

As I understand, what is in the video, and what I drew up, is that the series and parallel are combined, as shown in the latter part of the video. In their example they only used a 24 volt example, thus doubling from 12v to 24v AND doubling the ah from 115 to 230.

At least that's how I understand what they did.

 

[SlowCo]

As I understand, what is in the video, and what I drew up, is that the series and parallel are combined, as shown in the latter part of the video. In their example they only used a 24 volt example, thus doubling from 12v to 24v AND doubling the ah from 115 to 230.

At least that's how I understand what they did.

No...

They put two batteries in series to double the voltage which keeps the Ah the same as one battery. Then they put two of those block parallel so the Ah doubles but the voltage stays the same (as two batteries in series). The drawing you made of simultaneously connecting all 4 batteries in series as well as parallel will just short them (lots of sparks and melted cables). Look at your drawing and see that you just connected the positive to the negative side of the battery together.