Ed's 'StreetRunner' Quad Build

Twinkle

Super Moderator
Joined
Apr 14, 2013
Messages
3,634
Location
Peacehaven nr Brighton, Sussex ,UK
The change over switch would sit between the controller and motor . We have done this on some of the RC boat projects.
On initial setup you might need to swap over two of the wires to get both motors running in the same direction.
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
Already my mind is into fabricating boxes, brackets, and braces.

So here I am with all this motor paraphernalia, and can't go anyplace.
I don't want to put out the money for batteries and charger, just to have them sit around.

But I want to be able to function test my apparatus. How does one do that ???
I know, I can use the AC power from the shop 😱.... How does one do that ???

I know, I need some sort of ... 'erter'.
Do I need a .... converter ... inverter... diverter... inserter... asseter....so many 'erters' to choose from.:unsure:

How does one do that ???
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
The change over switch would sit between the controller and motor . We have done this on some of the RC boat projects.
On initial setup you might need to swap over two of the wires to get both motors running in the same direction.
Good to know. I'll be posting about doing the swap, in due time.
 

Twinkle

Super Moderator
Joined
Apr 14, 2013
Messages
3,634
Location
Peacehaven nr Brighton, Sussex ,UK
You will need a hefty power supply to run each motor off load . The motors using DC to the controller and a modified " 3 phase " output . Not easy to duplicate without a battery . Then you will also need a charger . Then you will wish you bought it all together when the item goes zero stock .

These motors will draw about 40amps each at 50volts . They are not toys !!!!!!!

Regards Emma
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
You had me at 'hefty'.........
Just the explanation, makes me want to run !

Is this a short term adequate fix?

Getting 4, 12 volt batteries, with say 1.5 ah, and connecting them in (series ?) to make 48 volts.
The ah need not be great just for momentary function testing...That's really a question.
 

Twinkle

Super Moderator
Joined
Apr 14, 2013
Messages
3,634
Location
Peacehaven nr Brighton, Sussex ,UK
I would think 7ah and 4 x 12v in series might work . But car batteries of 7 ah have only a useful current drain of 15 ah .for a short period . I used them on the original red trike and got 6 miles on a 500 watt motor . These small motors draw a lot of start up current dispute their size.
Btw did you get the emails ?

Regards Emma
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
I would think 7ah and 4 x 12v in series might work . But car batteries of 7 ah have only a useful current drain of 15 ah .for a short period . I used them on the original red trike and got 6 miles on a 500 watt motor . These small motors draw a lot of start up current dispute their size.
Btw did you get the emails ?

Regards Emma
Yes. I knew you had ..a view :)

I'm just checking around for inexpensive solutions to this matter.
I think this should work, for the purpose I intend them for.
https://www.batterymart.com/p-12v-1_3ah-sealed-lead-acid-battery.html

I have a car battery charger that would keep them up.
 

Twinkle

Super Moderator
Joined
Apr 14, 2013
Messages
3,634
Location
Peacehaven nr Brighton, Sussex ,UK
On your own head be it . Check what current they will draw . Personally l don't think so .
These are low current for fire alarms and burglar alarms and not suitable for motors of any type . I tried them in a rc boat for enough time to get to the middle of the pond and STOP.

Regards
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
On your own head be it . Check what current they will draw . Personally l don't think so .
These are low current for fire alarms and burglar alarms and not suitable for motors of any type . I tried them in a rc boat for enough time to get to the middle of the pond and STOP.

Regards
OK! point taken.
I will call my local battery mart tomorrow and see what they recommend.
I really don't want to buy batteries that in a few short weeks/months will just sit to ruin.

Intended Use
At worst they will work to function test the motors and jackshaft, under no/light load condition. (Drive wheels/axle, sitting off the floor on stands)
At best, they might be able to allow driving, within my yard, for a short function testing of the overall car.
Maybe 5 minutes worth...not sure.
 

Twinkle

Super Moderator
Joined
Apr 14, 2013
Messages
3,634
Location
Peacehaven nr Brighton, Sussex ,UK
3 off 5s 5000mah 25c lipos and a charger will give 100 amps discharge capacity. charge each lipo separately to recharge them.
THESE ARE SERIOUS BATTERIES BUT STORE IN A DRY PLACE AND CHARGE IN A FIREPROOF BAG .

BTW A 4S 5AH ONE WILL START A CAR .

Regards Emma
 
Joined
Feb 20, 2013
Messages
869
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Why not scrounge, purloin, steal (probably not a good idea), borrow, or otherwise obtain, get 4 a 12V car batteries and put them in series? That will give you 48V, near enough to 50V.They are used at well over 50 amps every time they start a car engine and they do that plenty of times during their life. The short term load kicking off your 2 x 1800W motors and ticking them over under light or nil load, shouldn't even make them blush. That should enable you to test your wiring, etc.

By the way, if you want to easily understand this secret electronics stuff, go to: http://www.ohmslawcalculator.com/ohms-law-calculator. You can then enter any two of the values requested, hit calculate, and the page will calculate all the applicable unknowns for you - all without knowing how they interact.
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
3 off 5s 5000mah 25c lipos and a charger will give 100 amps discharge capacity. charge each lipo separately to recharge them.
THESE ARE SERIOUS BATTERIES BUT STORE IN A DRY PLACE AND CHARGE IN A FIREPROOF BAG .

BTW A 4S 5AH ONE WILL START A CAR .

Regards Emma
It's really great to receive replies, with useful, intelligent information.
But one wonders sometimes, just how do I use it. What does it mean?
Enter, the learning curve.

I'm taking this suggestion, as it applies to the final battery purchase, not the temporary bats needed for testing.
The Nissan Leaf vs alternative choices. Am I right?

After a bit of checking this, and checking that, I have this question.
These batteries look so small. And much of their use seems to be for RC vehicles, not full grown vehicles.. 😁

As I understand the spec of the motors....each motor pulls 32 amps.
Two motors, and the load current stays at 32 amps?, .... or is it doubled?
The battery your suggesting, ( I did go looking for it ), has a discharge rate of 100 amps.
(100 - 32 = 68 amps in reserve ?) ( OR is it 100 - 64 = 37 amps in reserve?) ...Or D, none of the above

The answer could save me a ton of money.

Why not scrounge, purloin, steal (probably not a good idea), borrow, or otherwise obtain, get 4 a 12V car batteries and put them in series? That will give you 48V, near enough to 50V.They are used at well over 50 amps every time they start a car engine and they do that plenty of times during their life. The short term load kicking off your 2 x 1800W motors and ticking them over under light or nil load, shouldn't even make them blush. That should enable you to test your wiring, etc.

By the way, if you want to easily understand this secret electronics stuff, go to: http://www.ohmslawcalculator.com/ohms-law-calculator. You can then enter any two of the values requested, hit calculate, and the page will calculate all the applicable unknowns for you - all without knowing how they interact.
Yes the 4 x 12 volt batteries in series, is how this conversation started. But there is the issue of how high the amp hours need to be, for this particular, intermittent use.
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
Lets put a hold on the 'temporary' battery, for a moment, and look at this for the final battery pack.

Not necessarily from this supplier.

https://www.dhgate.com/product/safe-rechargeable-1800w-48v-20ah-lithium/400541812.html?f=bm|GMC|pla|1471809117|59782623991|400541812|pla-294573402136|103006001|US|zhangyu2016|c|2|&utm_source=pla&utm_medium=GMC&utm_campaign=zhangyu2016&utm_term=400541812&gclid=EAIaIQobChMI1ZHEj8yi5wIVFMpkCh0oBg_jEAkYCSABEgKm6_D_BwE

or maybe this one ?

https://www.dhgate.com/product/high-capacity-48v-30ah-lithium-battery-for/421653969.html?skuid=491348689687580674

Got to remember, that the Nissan Leaf comes with 66ah. BUT the charger for it is another $125. So the extra ah, that I still haven't determined is actually needed, for this project, and how it is intended to be used, is getting costly. Maybe more money, than I realistically need to spend.

Anyway more studying to do.

I'm still trying to wrap my head around the use of two motors, and how their spec's relate to each other, when deciding on which battery to use.

Still trying to learn all the formula's, and what goes with what, and what you put, with what, .....to get something else, etc.
Some of the suggested calculators work, and are understandable. Others not so much.

OK, back to class. :geek:
 
Last edited:
Joined
Feb 20, 2013
Messages
869
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Look at it this way. Two motors doing the same work, if they take 32 amps for 1800 Watts output, two motors will take 64 amps for 3600 Watts output. However, that would be under full load for each one at the same time. Flat ground or down hill will result in less current draw because it is easier. Like yourself when pedalling, the harder the job of pushing along, going up hill etc., the harder you have to work to push it. The more work required to push it, the more Watts (a unit of power) you have to put in. Your car has to burn more petrol to maintain its speed when you go up hill as gravity tries to hold it back. It requires less to go down hill as gravity is dragging it down for you.

The 32 amp rating of those two motors is for full load. Ordinarily, they should draw less than that. You have also stated or indicated somewhere that the drive is geared down, That also gives you a torque advantage - more axle twisting for the same power power provided by the motor.

Now, 3600 Watts is roughly equivalent to 14.4 fit humans output for a short while. Will your creation require 14 fit humans to motivate it? It would be pretty heavy if it did.

Another thing to consider is that batteries, the motor vehicle type, are rated for x number of cold cranking amps. This number of amps multiplied by the battery voltage will give you instantaneous Watts - that which is being used at any given time. However the battery can't keep it up for long. Batteries are also rated to be able to supply x amps for y amount of time and I have forgotten what that calculation is or how to apply it.

Thanks for reading this diatribe. If it helped you at all, let me know, if it didn't, tell me to shut up, but please do it politely.
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
Morning Kevin

You did a very good job of explaining it. But, I do have one question.....What's a 'diatribe'? o_O:unsure:
Should I be wearing anything special, or is it an ancestral thing ??? 😃
 
Joined
Sep 12, 2012
Messages
3,058
Location
Apple Valley, California, USA
I'm beginning to retain some of it..I think.

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

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-Bat ... 1001097148

At 13 lbs (52 total) they are less than the Leaf Modules would be, which was 56 lbs.
And the physical size works well with a couple of placement choices I have, in the frame or behind the seat.
 
Last edited:
Joined
Feb 20, 2013
Messages
869
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Morning Kevin

You did a very good job of explaining it. But, I do have one question.....What's a 'diatribe'? o_O:unsure:
Should I be wearing anything special, or is it an ancestral thing ??? 😃
I may have used it incorrectly. One of those words that one picks up, and uses, without really knowing its exact meaning. I thought it meant something along the lines of a "long-winded-waffle". I is, sort of, but I wasn't aware of the "abusive" component. I will plead guilty to long-winded but, of course, there was nothing abusive there at all. Glad you got something out of it and clothing is optional.

Simply put, series connection (a series "string" if you like, with 4 batteries is: Motor negative connection to battery 1 negative, battery 1 positive to battery 2 negative, battery 2 positive to battery 3 negative, battery 3 positive to battery 4 negative, and battery positive to motor positive. The available power (current x voltage) will be (sum total of battery voltages x the current capacity of the weakest battery). Assuming identical 4 x 12V batteries, each capable of delivering 100A, will be 48V @ 100A. That is 4800W for whatever length of time, dependent on the AH rating of the batteries.

Simply put, parallel connection with the same 4 batteries is: All negative terminals, battery and motor connected together, and all positive terminals battery and motor connected together . Using the same batteries as above will provide only 12V this time but at the sum total of the individual battery current capability. Let's do the math again to see something that you may not have expected. Using the same batteries, 4 x 12V is still only 12V in this case, but 4 x 100A is 400A. Now, 12V @ 400A is also 4800W - nothing more, or less, than we had with the series connection. Now you will have seen how it all fits together. Higher voltage, lower current for the same Watts. Lower voltage, higher current for the same Watts.

So, if you have 12V batteries and want 48V or so, you MUST connect them in series. Undercunstumble?
 
Joined
Feb 20, 2013
Messages
869
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
I should have included that what you have in your last diagram is 4, parallel connected, 12V batteries, providing only 12V out with a capacity of 48AH.

I think you may be getting confoozled with AH. This is a rating of the battery's ability to deliver so many amps for so many hours - the battery's "staying power" if you like. This is different to how many amps the battery can supply at any time - instantaneous.

I found this at https://www.batterystuff.com/kb/articles/battery-articles/what-does-20-amp-hr-rate-mean-.html

Lead acid batteries are complicated things. Take some lead and sulfuric acid, stick them in a container together and you end up with a potential chemical reaction that can produce electricity. The question is, when you need to know how much electricity is able to be created with that chemical reaction, what is the standard rating, and how is it set? We have answered this question the complicated way on the Peukert's Law Tutorial, but here's a more basic look at determining what you need to know.

Several years ago when you would go to buy a car, the little tag on the window of a coupe might have read 42 mpg. Of course everyone knew that the only way to make that car get 42 miles to the gallon was to drive at 25 miles per hour on a newly paved level track. So in 2008 when the EPA updated their standards, the ratings all dropped to much more realistic numbers that most light-footed people can achieve. Battery ratings are very similar. The faster a battery is drained, the less overall amperage is available. The battery’s AH rating goes down the faster you use it. This is not the same thing as saying you use up what is available faster, but you actually decrease the total overall capacity itself.

To ensure that ratings are given in a realistic way, lead-acid batteries have a few parameters on how they get that “AH” rating. In order to get an AH rating, the battery that is being tested has to be drained down to 0 over the course of a specified amount of time. The amount of amperage that it took to get it down to zero, over that specified amount of time constitutes the AH rating.

Because of the Peukert effect (aka, the faster a battery is drained, the less overall amperage is available), if you discharge a battery over the course of 100 hours, the AH rating looks higher than if you discharge that same battery over the course of 1 hour. So, there has to be a standard.

For deep cycle batteries the standard rating is 20 hours. So, if a battery has a rating of 100AH @ 20Hr rate, then that battery was discharged over 20 hours with a 5 amp load. Starting batteries, on the other hand, are typically rated at 10Hr rate, because they are used faster, so the 20Hr rate is not as important. So, that weird 20Hr rate that you see after the AH rating on batteries tells you that the rating in question is the realistic, common rating—rather than an over-inflated number to make the battery look better than it really is.


Now you should have all you need to understand it. The cables to the motor must be heavy enough to withstand the total current.
 
Top