Ed's 'StreetRunner' Quad Build

You have a online calculator here
https://www.rapidtables.com/calc/electric/Watt_to_Amp_Calculator.html
The motors you choose are rated at 1800W and 48v.
They will give higher wattage occasionally, but most of the time run on a lower wattage.
But I will calculate what you need to run the motors at 1800W.
So 2 motors at 1800W or 1.8kw is 3.6kw, use the motors for 1 hr you need 3.6Kwh, 2 hr 7.2Kwh.
If you divide the wattage with the voltage you get the amperage.
So 2 motors at 1800W is 3600W divided by voltage 48V gives 75A, use for 1 hour 75Ah, 2 hr 150Ah.
A important value to check is what max Amps the battery packs can give, called Maximum continuous discharge current
Your motors need 75A to give out 3.6kw so the battery pack should have a Maximum continuous discharge current higher than 75A,
The value is not directly present in your suppliers data, so ask them.
 
pegasus said:
You have a online calculator here
https://www.rapidtables.com/calc/electric/Watt_to_Amp_Calculator.html
The motors you choose are rated at 1800W and 48v.
They will give higher wattage occasionally, but most of the time run on a lower wattage.
But I will calculate what you need to run the motors at 1800W.
So 2 motors at 1800W or 1.8kw is 3.6kw, use the motors for 1 hr you need 3.6Kwh, 2 hr 7.2Kwh.
If you divide the wattage with the voltage you get the amperage.
So 2 motors at 1800W is 3600W divided by voltage 48V gives 75A, use for 1 hour 75Ah, 2 hr 150Ah.
A important value to check is what max Amps the battery packs can give, called Maximum continuous discharge current
Your motors need 75A to give out 3.6kw so the battery pack should have a Maximum continuous discharge current higher than 75A,
The value is not directly present in your suppliers data, so ask them.
Click to expand...

Great ! Feedback Pegasus, thank you

Short, factual, yet educational
I've bookmarked the calculator.

Questions
I understand that 75Ah would be 'best' case, meaning throttle on continuous for a whole hour...correct?
So as an example, driving in a parade, with throttle (on and off), would need (use) less amp hours to drive the vehicle, thus extending the range some...Correct?

These batteries (if I read their specs right) are rated at 66 AH per module.
A pack of 7, would still be 66Ah.... OR ..... are they accumulative ? (66 x 7 = 462)
So if I need 75Ah minimum, these batteries won't work as presented anyway......correct ?

I used this calculator to change the Ah to Wh ( https://convert-formula.com/ah-wh )
I converted 75Ah to Wh and came up with 3600 Wh.
The batteries are presented as having 500 Wh per module.

Question is, will they remain at 500 Wh for the pack of 7 ?
Thus 500 - 75 = 425 Wh surplus ?



Here are the specs for the batteries.

500 watt hour per module
Each Module has 4 cells ( 2 in Series and 2 in Parallel )
8 volts
500 watts hour
66 amp hour
Dimensions are : 12 L x 9 w x 2 thickness
Weight is: 8 lb
Voltage sensing terminal M4 nut

Nominal Capacity 66Ah
Nominal voltage 7.5V

Maximum charge Voltage 8.3V
End of discharge voltage 5.0V

Maximum continuous charge current 130A

Maximum continuous discharge current

Each cell voltage should be less than 4.15V per cell
Each cell voltage should be more that 2.5V per cell

25 ℃ , SOC0-100% charging
25 ℃ , SOC0-100% discharging

(Can you explain the numbers below?)

0.05c 3.31 A
0.5c 33.1 A
1C 66.2 A
2C 120.4 A
2.5C 153.5 A

This is very helpful

Thanks
Ed
 
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edspedalcars said:
I understand that 75Ah would be 'best' case, meaning throttle on continuous for a whole hour...correct?
So as an example, driving in a parade, with throttle (on and off), would need (use) less amp hours to drive the vehicle, thus extending the range some...Correct?
Correct

These batteries (if I read their specs right) are rated at 66 AH per module.
A pack of 7, would still be 66Ah. So if I need 75Ah minimum, these batteries won't work as presented anyway......correct ?
You don't need 75Ah, 66Ah would last you along time.
But if you race up a mountain the battery would last less than a hour, and the motors will get very hot.
But on a slow ride on the the sea front in Venice the battery would last for hours.
Even a battery which has 20Ah would work, but you don't get very far.
What you need is that the Maximum continuous discharge current to be more than 75Amp.

Maximum continuous charge current 130A

Maximum continuous discharge current
There is no value, so ask the supplier

Each cell voltage should be less than 4.15V per cell
Each cell voltage should be more that 2.5V per cell

25 ℃ , SOC0-100% charging
25 ℃ , SOC0-100% discharging

(Can you explain the numbers below?)

0.05c 3.31 A
0.5c 33.1 A
1C 66.2 A
2C 120.4 A
2.5C 153.5 A
C stans for the battery packs total amp for charge? or discharge?
My guess is that the battery maximum discharge current is 2.5C = 153.5Amp but is it continuous, I don't know.
So ask the supplier.
Normally a battery has a higher discharge that charge current, and the max continuous charge current is 130 A.
Click to expand...
 
OK, learning, learning,learning 🧐:)

Thanks I have a couple of questions to ask the supplier.
I used this calculator to change the Ah to Wh ( https://convert-formula.com/ah-wh )
I converted 75Ah to Wh and came up with 3600 Wh.
The batteries are presented as having 500 Wh per module.

Question is, will they remain at 500 Wh for the pack of 7 ?
Thus 500 - 75 = 425 Wh surplus ?

Don't I have to connect the modules in parallel to increase?
 
edspedalcars said:
OK, learning, learning,learning 🧐:)

Thanks I have a couple of questions to ask the supplier.
I used this calculator to change the Ah to Wh ( https://convert-formula.com/ah-wh )
I converted 75Ah to Wh and came up with 3600 Wh.
The batteries are presented as having 500 Wh per module.

Question is, will they remain at 500 Wh for the pack of 7 ?
Thus 500 - 75 = 425 Wh surplus ?

Don't I have to connect the modules in parallel to increase?
Click to expand...

As far as a can understand you are muddling up Ah and A and Wh and W.
The battery pack is rated for 66Ah, which is fine.
If you are using the full 2 x 1800W the motors can draw together 75A, so the pack would last about 50 min.
The Ah value on the battery has nothing to do with the max current (A) the battery can give.
Like I said before I think the battery can give a max current of about 150A, which also is fine.
But ask your supplier
Each module is 500Wh and Nominal voltage 7.5 Volt. 500Wh / 7.5V= 66.6Ah
So 7 in series make 7 x 7.5V = 52.5V and 66.6Ah.
To calculate the Ah they are using the nominal voltage value.
 
pegasus said:
As far as a can understand you are muddling up Ah and A and Wh and W.
The battery pack is rated for 66Ah, which is fine.
If you are using the full 2 x 1800W the motors can draw together 75A, so the pack would last about 50 min.
The Ah value on the battery has nothing to do with the max current (A) the battery can give.
Like I said before I think the battery can give a max current of about 150A, which also is fine.
But ask your supplier
Each module is 500Wh and Nominal voltage 7.5 Volt. 500Wh / 7.5V= 66.6Ah
So 7 in series make 7 x 7.5V = 52.5V and 66.6Ah.
To calculate the Ah they are using the nominal voltage value.
Click to expand...

I've sent the questions in. Waiting on reply.

While I'm waiting, I'm revisiting the SLA idea of 4 x 12v x 90ah batteries. (4320 wh)
If I connect these in series, I get 48 volts x 90 AH. Cost out the door, without core trade in, is +/- $450.00.

TechDirect is already suggesting that I go up to their G2 $600.00 stack, vs their G1 $450.00 stack. Both having the same specs, except maybe 10% more capacity on the G2 stack. 60 % vs.70% +/-.

I know, I'm flip-flopping, but sooner or latter, the tremors will stop..... 😃
 
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edspedalcars said:
I went looking for formula's to answer this without having to bother you guys more.
Click to expand...
Speaking for myself, you are not "bothering" us. That's what this site is for, not for bothering, but for imparting assistance.

There is a balancing act between supplying enough information to answer the questions, and supplying too much information, thereby creating overload and more confusion. Anyway, I guess you know how that goes.
 
I suspected you may have been confusing Ah and Wh but didn't want to delve into that and, by so doing, add to your headache-producing learning. When you said you didn't want to get into Ohm's Law, I packpedalled (a cycling term that I borrowed).

Some things are essential when dealing with electrics and it would probably make it easier for you to wrap your head around things by having a look at : https://www.electricaltechnology.org/2013/10/ohms-law-with-simple-explanation.html. You could always bookmark it and refer to it as required.

A Google for Ohm''s law diagram would also be of great value as it doesn't rely on you rembering Ohm's Law - just place you thumb over what you don't know the value of and use the formula to find out.

Simple Explanation:

1. A battery's Ah (amp/hours)rating is its ability to deliver a particular, continuous current for a stated period of time - so many amperes for so many hours. That current delivery over that period of time gives Wh or power consumed from the battery.

The W stands for Watts, the unit of power, and the product of voltage x current.

2. Wh is how much power for how many hours. A kWh is one kilowatt (1000W) for a period of one hour. The kW part is current x voltage. On its own, it doesn't do anything. You have to use it or consume it for a period of time - so many Watts for so many hours.
 
vk3ckc said:
Speaking for myself, you are not "bothering" us. That's what this site is for, not for bothering, but for imparting assistance.

There is a balancing act between supplying enough information to answer the questions, and supplying too much information, thereby creating overload and more confusion. Anyway, I guess you know how that goes.
Click to expand...

For sure I do. Both on the giving and receiving end.
 
Well I've received back an answer from TechDirect, to 'one' of my questions.

The difference between the $450 and $600 is the capacity.
Which I already knew the answer to....
Gen 1 = 2011 - 2015 at 60% Capacity
Gen 2 = 2014 - 2018 at 70% Capacity

But they seem to be avoiding any of my other technical questions.
This surprises me a little, after looking into their website, and video of the company.

So I guess, I'm/we're left to work it out on our own.
 
Oh! Oh! I had a thought ! 💡

While mulling over the posts from everyone, and trying to keep it all straight,
my mind thought of this....dangerous I know.

The motors I bought are rated for 48 volts. They run at 4500 rpm +/- each.

I have been trying to satisfy the battery need to meet that requirement.

Because of the high rpm, I got appropriate sprockets to reduce that rpm.

My thought.

What if I were to run the motor on just 36 volts, or even 24 volts.
The motors would run slower....correct?
Not sure about cause and affect, in doing so. (i.g. - are the controllers affected?)
Gear ratios would surely need to be changed.

But the availability of 12 volt batteries is greater, and making a pack 3 for 36 volts, would require only three batteries.

Advantages: Less weight, less cost

The resulting speed of the vehicle would also be affected, just how, as of this thought, not sure of yet.
But it seems that it would reduce the top speed, and acceleration.

Is this an accurate thought?
 
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If you lower the battery voltage to 36 the motors power is reduced from 1800W to 1350W, and for 24V to 900W.
The problem will be with your controller they require a minimum voltage.
Look at your controller you will find a Min voltage value, my 36V controller have a min voltage of 30V.
If your intention is reduce your voltage to 24V you better of running 1 motor only on 48V with half the battery size.
I would have installed 1 motor first with its own battery pack for a test and if needed add the second motor and a second battery pack.
 
pegasus said:
If you lower the battery voltage to 36 the motors power is reduced from 1800W to 1350W, and for 24V to 900W.
The problem will be with your controller they require a minimum voltage.
Look at your controller you will find a Min voltage value, my 36V controller have a min voltage of 30V.
If your intention is reduce your voltage to 24V you better of running 1 motor only on 48V with half the battery size.
I would have installed 1 motor first with its own battery pack for a test and if needed add the second motor and a second battery pack.
Click to expand...

Because my brain cells are not working, as well as they used to, I considered using less SLA to save weight and cost.
I bought the larger motors, (1) because most everything I needed was in a package, (2) most of the advice seemed to steer me in that direction,
i.e. needing the extra wattage. Ultimately the decision to go with two motors was mine.

Thought maybe with 3 x 36 x 90 Ah, it might work well enough to get me moving, even if at a reduced speed.
At least for now. I can upgrade later. Time is wasting, and nothing is getting built.

I have already checked my controllers and their lvc is 20 volts, so I guess I'm OK there.
 
I got a reply from TechDirect.

TechDirect says;
They say that with the pack (in link) I will get 7-10 miles.
https://www.techdirectclub.com/48-volts ... -lot-of-7/
This amount should be doable, but of course it would depend on real world use.

BatteryHookUp Specs
According to specs @ 'BatteryHookUp', the continuous discharge is 240A.
https://batteryhookup.com/products/niss ... dule-gen-1
Am I right in thinking this is good, or does it mean a quicker loss of capacity? Thus less range.

NOMINAL VOLTAGE : 7.7V
FULLY CHARGED: 8.4V
FULLY DISCHARGED: 5.6V
AMP HOUR: 64
WATT HOUR 500WH
CONTINUOUS DISCHARGE: 240A
PEAK DISCHARGE: 540A
 
For what it is worth, it is all a matter of speed and acceleration - what top speed is essential, and how quickly do you wish to reach it? The higher the required top speed and required acceleration is where the power comes into it. Walking speed, if that was all you required, could be done with pedals, without stating the obvious.

To throw more mud at it, my Bafang BBS01 e-Assist ratings are: 36V (rated voltage), 250W (rated power). The battery is supplied with a 20A fuse. The rating plate, according to a document says: 15A (limited current), and 25km/h (max speed). Incidentally, the maximum assisted speed is adjustable to 39km/h or so. The rated power should actually be motor output power, not input power, which would be somewhat higher. All that equates approximately to another rider assisting.

Mine comes with a 36V/15Ah battery - and controller to match, of course. The battery has a full charge cutoff at 46V without looking it up, maybe slightly less. This voltage drops a little after sitting there and it doesn't take long to start heading South of 42V during use. The remaining capacity indicator, whatever it is showing at any time, is an approximation - 4 bars = 80-100%, 3 bars = 60-80%, 2 bars = 40-60%, 1 bar = 20-40%, and 0 bars < 20%. I have no idea what the low voltage cutoff is as I haven't found it mentioned anywhere and didn't have my added voltage/current monitor installed the only time it shut down. During use, the indicated voltage drops down through 36V and the system would probably shut down around 34V or so, maybe 32V as that is a common cutoff value for 18650 cells. I usually don't try to get that low as I would then have to pedal harder.

The supply current, depending on what I am doing, varies quite a bit and depends on the incline or starting gear. It is sometimes 3-4A, other times 4-5A, on a steep climb 8A, and I think I have seen it around 10A once. Not sure what happens on the flat as I have never really taken any notice, probably not using it at the time and, in any case, it would depend on how much I was contributing. I might do some test.

There is a website that I saw years ago that provided a calculator to calculate the power required to propel a wheeled vehicle. A Google search might find it and lay a number of variables or unknowns to rest for you.
 
My last message was out of sequence with yours. You posted yours while I was typing mine.

That 240A continuous discharge should be what the batteries can deliver. In other words, if you needed a continuous current of 240A, they could deliver it. They are also able to deliver a peak of 540A.

Funny, with all that, a Leaf's performace seems to be falling behind the rest of the world as far as electric vehicles are concerned.
 
Your motors only need a continuous discharge of 75A on max speed so the cells are more than adequate.
The cells only looses the capacity you are using.
The batteryhookup don't mention a BMS, which is a must, and are enclosed in the techdirectclubs kit.
They mention bottom balancing, I'm not an export but it something like if the cells in your pack are not bottom balanced
one cell could be empty and you have still power left in the other cells, but you can't use that power because of the empty cell,
so you balance the cells to cut out simultaneous.
A BMS ballance the cells when they get charged, but not when they get empty, it cuts out when the first cell reaches it's lowest level.
 
pegasus said:
Your motors only need a continuous discharge of 75A on max speed so the cells are more than adequate.
The cells only looses the capacity you are using.
The batteryhookup don't mention a BMS, which is a must, and are enclosed in the techdirectclubs kit.
They mention bottom balancing, I'm not an export but it something like if the cells in your pack are not bottom balanced
one cell could be empty and you have still power left in the other cells, but you can't use that power because of the empty cell,
so you balance the cells to cut out simultaneous.
A BMS ballance the cells when they get charged, but not when they get empty, it cuts out when the first cell reaches it's lowest level.
Click to expand...

The stack they say is better is at 70% capacity. (Of what?) I'm not sure if the stated 66Ah is the 'result',
(or) if it should be 66Ah minus 30%? (result only 46% capacity in reality).
Something to ask TechDirect about.

And yes, I will fork out the extra $$$ for the BMS, less BS, keeping track of things.
I'm trying to get some technical advise from them, but they seem to be stingy, when it comes to helping a potential paying customer.
 
I'm waiting for TechDirect to respond back with a clarification of this offering;
https://www.techdirectclub.com/48-volt- ... h-66ah-g2/

The description states:
48 volt Nissan Leaf Lithium ion Mini Power Pack Battery for golf cart 3.5 kwh G2 With Delta charger
Click to expand...
So I've asked them, does it come with a battery charger or not?
I'm waiting on their response to my question.

They are naturally steering me to the $930.00 version. The resale value of this just went up!

Anyway, I have another mind bender, for those that would take on the task.

Hypothetical set up.

I have a pack of 7 modules, with a total of 66Ah. If I add a second pack of 7 modules, in parallel, I get 132 Ah, Right?
I'm back to the series parallel thing again.

Here's the question

Is it possible to connect a set of 7, with a set of 2? Thus increasing the Ah, but not actually doubling it?

Is that even possible, if using SLA batteries?
 
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