Leaf motor Build/Questions

Hi,

I have been reading the forums for quite some time. I will soon be in a position where it is practical to own an electric bike for commuting

I was initially looking at getting a MAC 8t complete kit from EM3ev.com as I wanted plug and play simplicity however, after reading about Neptronix and the LEAF motor I thought it would be better than the MAC.

I understand they are completely different motors and if EM3EV supplied anything like it there never would have been a debate but the DD motor is going to be a lot more reliable and is faster and way more efficient!!

Right now the kit im thinking about is the following

Leaf motor 26" 1500w rear (leafbike)
22.1AH 25R Triangle + charger from (Em3EV)
Half twist throttle and ebrake sensor (Em3EV)
18 Fet controller (Em3EV)
CA V3 (Em3EV)
Grin Tech Rev 4 Torque arm (Em3EV)

Am I missing anything?


I intend to draw 60A continuous from the Battery so am I right in thinking I will need some sort of custom BMS? as the standard one from EM3ev is 40A.

The controller is rated for 60A continuous so that doesn't seem to be an issue.

Following Neptronix I then intend to adjust the phase amps to 180A. With this in mind I also was wondering whether Leafbike can install a CA compatible temp sensor?

As I was looking for a plug and play setup does anybody have an idea about what sort of connectors the Leaf motor comes with and if EM3EV can create matching connectors or visa versa?

I understand that Leafbike will supply 3mm phase wires now? is this thick enough for the wattage I intend to put through them? 58.8v x 60A = 3528W

I know a lot of questions, oh and im new so please go easy :wink:

As an update,

I contacted Leaf bike who informed me that it is possible to have 3mm phase wires and a 10k thermistor installed.

EM3EV has informed me that he does not stock a 60Amp BMS for 14S. I may be confused about BMS
If i intend to run the LEAF Motor at Max 60 Amps do I need a 60 Amp BMS?


Further to this i found a link about maximum amps throught different thicknesses of wire
http://www.powerstream.com/Wire_Size.htm

According to that table 3mm wire will take between 64-73 Amps

Last time I looked Em3ev sold DD motors.

If you plan on pulling 60amps continuous from your pack,
Then make sure the pack is more than capable of producing
that energy with little to no voltage sag. Keep stress off the
pack and it will have good longevity. As for the BMS, I'm a non
BMS user. I personally do not like the voltage drop on the output
side. But to answer your question, the 60amp rated BMS output
should be able to continuously provide 60amps. It probably has
An eighty or 100 amp peak before it goes into protection mode.
Read up on BMS's.

48v x 60 amps is 2880w and pretty close to the operating limits of the leaf motor. I guess you want to see how far you can take that motor huh? Lol I think Nep was seeing 40mph on 30 amps........ :?

Tommy L said:

Last time I looked Em3ev sold DD motors.

Click to expand...

He does sell DD motors but only 500w rated ones which are not suitable at these power levels

Tommy L said:

If you plan on pulling 60amps continuous from your pack,
Then make sure the pack is more than capable of producing
that energy with little to no voltage sag. Keep stress off the
pack and it will have good longevity. As for the BMS, I'm a non
BMS user. I personally do not like the voltage drop on the output
side. But to answer your question, the 60amp rated BMS output
should be able to continuously provide 60amps. It probably has
An eighty or 100 amp peak before it goes into protection mode.
Read up on BMS's.

Click to expand...

So do you think that the standard 40 Amp BMS would be capable of 60A peaks?

wineboyrider said:

48v x 60 amps is 2880w and pretty close to the operating limits of the leaf motor. I guess you want to see how far you can take that motor huh? Lol I think Nep was seeing 40mph on 30 amps........ :?

Click to expand...

I saw a vid on youtube of Neptronix running 48v at 65A = 3120W which he said was fine for the motor. I do not intend to run this wattage all the time and will most likely travel at 30mph
which happens to be the best speed for efficiency.

I'd say its a shame for the cycle life and capacity of the pack to make a 60 amp pack that you are hardly going to use if you plan to drive 30mph.

make a pack yourself that can handle a current that stays within reasonable specs. For example make a pack of 3200mah Samsung INR18650-32E or LG LG INR18650MH1, you can get those for about 4 dollar a piece. In a 14s5p setup that would be 70 cells=280 dollar. Plus costs of sending, bms and soldering tabs about 350 dollar for a whopping 800whr pack. The max amp on that pack would be 50 amps but i wouldn't draw that all the time. At 30mph (+-600w) that would give you a 30 mile range.

I'd buy 16 5000mah 20C 4s hardcase packs for $400, wire an 80A 16s bms to them for 16s4p 1184Wh 20ah pack for less than half the cost for more power and range, and have a simple unplug and replace modular battery for ~$500 that should last as long or longer than the $1000+ pack. I say this with 3 years and 11k+ miles on my current $275 10ah 24s2p pack made from the same 4s packs, but without a bms.

I think we need to examine your intended use more closely. You want to do 60 A continuous, but travel at 30 mph. Do you have some long, steep hills to climb? Otherwise the numbers seem inconsistent. It might be possible to scale things back a bit which would resolve the BMS issue.

So more details about terrain, distances, etc. would help to clarify things.

Ok I'm probably allowing the hooligan to get the better of me

I need a range of around 20 miles for round trip as no chance of charging at work

It is mostly flat with very slight inclines possible. I would like to travel at 30 mph.

The hooligan in me wants to go 40 mph for fun weekends etc

wesnewell said:

I'd buy 16 5000mah 20C 4s hardcase packs for $400, wire an 80A 16s bms to them for 16s4p 1184Wh 20ah pack for less than half the cost for more power and range, and have a simple unplug and replace modular battery for ~$500 that should last as long or longer than the $1000+ pack. I say this with 3 years and 11k+ miles on my current $275 10ah 24s2p pack made from the same 4s packs, but without a bms.

Click to expand...

I like this idea as I am looking for a battery that has a simple plug in and charge system

For your needs, the 48V 1000W kit should work fine with a 12-14s 20ah lipo pack and bms for single point charging.
http://www.ebay.co.uk/itm/E-bike-conversion-kit-Electric-bike-motor-kit-ebike-rear-drive-500W-1000W-hub-/261916508283
A 12s pack should get you ~28mph. A 13s pack should get you ~32mph. And a 14s pack should get you ~35mph. if that's not enough, get a 72V controller for ~$50 and go with a 20-24s pack. Add a voltmeter to the kit if it doesn't come with a display and you'll be set.
http://www.ebay.co.uk/itm/led-Digital-Voltmeter-DC-15-120V-Motorcycle-Waterproof-Voltage-Panel-36v-48-96v-/261555264017

wesnewell said:

For your needs, the 48V 1000W kit should work fine with a 12-14s 20ah lipo pack and bms for single point charging.
http://www.ebay.co.uk/itm/E-bike-conversion-kit-Electric-bike-motor-kit-ebike-rear-drive-500W-1000W-hub-/261916508283
A 12s pack should get you ~28mph. A 13s pack should get you ~32mph. And a 14s pack should get you ~35mph. if that's not enough, get a 72V controller for ~$50 and go with a 20-24s pack. Add a voltmeter to the kit if it doesn't come with a display and you'll be set.
http://www.ebay.co.uk/itm/led-Digital-Voltmeter-DC-15-120V-Motorcycle-Waterproof-Voltage-Panel-36v-48-96v-/261555264017

Click to expand...

That kit looks good but there is no mention of what amps the controller is capable of

Where would I get a 80 amp bms?

I have been doing some further reading on em3ev about the 25r
Battery pack. Em3ev claims that even with a 40 amp bms the pack is capable of 60 amps for extended periods. The 25r cell is 5c continuous rated so I don't see a problem drawing 60 amps max from it.

Here in the US, controllers in 48V 1000W kits are either 26A or 30A and limited to 63V by the 63V caps in them. I imagine that's pretty everywhere. if you want to boost acceleration with a higher amperage, then you'll have to either do a shunt mod to increase it by 50%, or buy another controller capable of the voltage an amperage you want. You can find them up to 120A here and other places online.
http://www.aliexpress.com/store/313864
They also sell BMS's and lots of other parts.

Paul at em3ev got back to me with the following information about the 25r pack

Hi Michael,

The BMS cannot limit current. A BMS is either linked and allowing voltage and current to pass, or it trips and nothing passes. There is nothing in between.

The 40A BMS can deliver much more than 40A, it just can’t deliver it for very extended periods. You should be fine with extended bursts of 60A. I’ve ran these BMS at those levels before without any problems or with the BMS tripping.

Thanks
Paul

Click to expand...

So it appears there would be no issues at all running an 18 fet controller at 60amp max with a 22.1ah 25r pack with a 40amp continuous BMS.this is provided I don't draw 60 amps all the time which would be ok. I would only be drawing that when accelerating.

Especially considering the pack can easily deliver over 100amps with minimal voltage sag

Opinions?

Also to remember is that your speed will be limited by your voltage.
More Amps will not give you more speed, just torque.
(This last statement is a general rule)
But you do need the right combination of amp and volts for
a speed you have in mind based on motor KV.
Yes, just another thing to understand about electric propulsion.
KV is How many volts does it take to do 1 revolution of the motor.
Then you need to factor in the circumference of the wheel to figure
Your speed. Then there are no load speeds and motor with load speeds.
Then a speed to maintain with a headwind.
Given all the right e parts, I've done 30mph using 600watts.
The same trip with headwind was 1200-1500 watts continuous.
So one must also consider possible energy consumed under
Different conditions for same trip.

People are always talking amps here, but if we talk with watts too,
This may help total understanding as you increase or decrease voltage
depending on the KV of motor and wheel circumstance.

I hope this to be helpful for you.

On my Ebikes, I use 2 different controllers.

Example controller 1:
Battery voltage: 76v nominal
Speed: 30mph
600-1500 watts wind dependant
Amps: 7-16

Controller 2:
Battery voltage: 128v nominal
Speed: 30mph
600-1500 watts wind dependant
Amps: 4-12

With controller 1 my max speed is 30mph restricted due to
voltage and my motor KV and wheel circumstance.
With controller 2 and the pack voltage increased, if I increase
my amps (which will increase my wattage) I can hit 50mph.
This happens because I have the voltage to make the wheel
spin faster. But I also have the needed amps needed in order
to reach this speed.

I really enjoy pulling less amps and using higher voltage.
It can have efficiencies over lower voltage builds.
High amp and voltages at 36-48v need big wires.
Higher voltages can use smaller wires.
So read up on that as well.

I have a 28 pole 10 turn motor. Because it has 10 turns per pole,
It requires more volts to reach speeds. On 48v my motor in a 26"
wheel may go 20mph or maybe less.

Tommy L said:

Also to remember is that your speed will be limited by your voltage.
More Amps will not give you more speed, just torque.
(This last statement is a general rule)
But you do need the right combination of amp and volts for
a speed you have in mind based on motor KV.
Yes, just another thing to understand about electric propulsion.
KV is How many volts does it take to do 1 revolution of the motor.
Then you need to factor in the circumference of the wheel to figure
Your speed. Then there are no load speeds and motor with load speeds.
Then a speed to maintain with a headwind.
Given all the right e parts, I've done 30mph using 600watts.
The same trip with headwind was 1200-1500 watts continuous.
So one must also consider possible energy consumed under
Different conditions for same trip.

People are always talking amps here, but if we talk with watts too,
This may help total understanding as you increase or decrease voltage
depending on the KV of motor and wheel circumstance.

I hope this to be helpful for you.

Click to expand...

All good information.

At 58.8v max charge top speed will probably be around 40 mph loaded which is more than enough and at this wattage / speed it will still be 80% efficient.

If im travelling at 30mph the efficiency will hopefully increase to around 90% efficiency.

For maximum range trips I can still maintain over 80% efficiency at all other speeds below 30.

thanks for the info about KV

You are most welcome !
I really like the CA. Cycle Analyst.
The information that it provides is very
useful.
In realtime you see voltage, amps, watts,
Watt hours used.

Watt hours used is very important info as
This is the amount of capacity you pack has.
How many watt hours in a pack?

Voltage x amp hours = watt hours.
If you have a 10ah pack at 50v nominal,
You have 500watt hours. You can pull 500 watts
For 1 hour. But always put a 20% or more safety margin in there.
So 400 watt hours max. 400 watts for 1 hour or 800 watts for 30minutes.
Or 1600watts for 15minutes.
Since your watt draw varies during riding conditions, the CA
Can keep track of that vital information.
Glad to see its on your list!!!!

Neptronix has tested this motor in a similar configuration as im suggesting. He has 48v at 65Amp max. He came up with the following

12mph = average about 100w
20mph = average about 350w
25mph = average about 500w
30mph = average about 900-1000w
37mph = about ~1650w ( not really confirmed in this video as she was still accelerating a bit )

Click to expand...

The 22.1ah 25R pack has 1111Whrs

This would mean that I could draw 1111 watts for 1 hour which is similar to travelling 30mph for 1 hour (as shown above in Neps quote) which means a 30 mile range!!!!

Thats much more than i expected at 30 mph.

So,

The new leaf motors now come with 3mm phase wires

Does anybody know what the max current I can put through them before melting?

I'm looking to set phase amps to around 180A for a 1:3 batt to phase ratio

Unless you're using a controller that actually senses individual phase current, you don't really have a way to set or know what the phase current is. So it doesn't matter much what the wires' limit is, without knowing what the controller actually puts out.

(typical ebike controllers can't, usually ones with "ratios" of battery to phase just means the controller guesses at it based on battery current, "assuming" the phase will be at that ratio to the measured battery current.

This includes the EM3EV controller listed in your OP up top, AFAIK)

That said, there are a number of threads that discuss size of wire vs the AC phase current thru them, mostly in the high-power motor threads, including several active ones near the top of the motor technology forum.

The wiki may also have an article about it.

In basic, since there are 3 phases and current only flows thru two at a time, there will be heating in the wires for only 2/3 of the time.

That is really great information amberwolf

So am I right in thinking the controller cannot see the actual phase amps being delivered to the motor but can roughly guess using a calculation based on battery amps being drawn?

I am only really concerned about melting the phase wires so as long as my rough current limit is below that I should be fine

I can't find any information on safe amperage for different thicknesses of wire

mchlpeel said:

The new leaf motors now come with 3mm phase wires
Does anybody know what the max current I can put through them before melting?
I'm looking to set phase amps to around 180A for a 1:3 batt to phase ratio

Click to expand...

I find that really hard to believe. 3mm is larger than a 9 awg wire. If it's true, you'll probably burn up the windings before the phrase wires. I think the phase wires on my 1000W motor are ~1mm, ~18 gauge, and on my 3000W motor ~2mm,~13 gauge.

They list it as 3mm but they could mean 3mm2 which would be 12-13AWG

The listing is here
http://m.leafbike.com/mobile/products_desc.php?ProId=998

3mm2 probably makes more sense