Direct Drive Vs Geared Hub at 48V possible replacement

[Ltc433]

This is just a new thread so it will help other people as the previous one was off topic

Here is the older thread:

https://endless-sphere.com/forums/viewtopic.php?f=2&t=103065&p=1508961#p1508961

So it turns out they told me I had the wrong controller!

I do not have a 14 amp controller but a 30 amp one Why didn't I check? I had water proofed everything and sealed it. So I took it all off just now. Everything you have said did not tally up with the performance I was getting. However my performance was too good. It can go about 30mph and pull a lot.

With your BIG wheels, you need to go w/ a low-speed range (201) motor and I would recommend a geared motor to get the best performance w/ your batt. pack.

I agree, a lighter geared motor would be better.

Next, you need to see what the discharge rating of your pack is, which you cannot exceed.

How can I figure that out? I have a turnigy watt meter. I know its a 15a/h dolphin 48V

Edit I have found out is 12ah not 15. Its was 36V @15, 48V @12

The Q128C will like a controller in the 25 to 30 Amp range and is said to produce good "torque" (really a misnomer), probably partly due to high compound gear ratio (like the Q100).
Next step up would be the "large" geared motors like the BPM, Mac, Ezee, etc. Controller rating that match well w/ these can range quite a bit, but figure 30 to 40 Amps."

I have had no problems at all pulling so far but the motor is just so heavy and the cogging is terrible. Do you think I can just change the motor and keep the controller etc?

I had a 12 fet controller on my Mac 6T conversion . up to 48 volts and 40 amps.

I would get a 12 fet or bigger controller when using a Mac or a DD rear hub from now on.

Right now I have a infineon Clone 36-72 volt 30 amp 9fet on my DD rear hub bike and I could really use a 12 fet 40 amp or more.
Same
On my latest conversion the GNG cyclone 3k It has a lyen 9 fet that I can use up to 72 volts on but only 30 amps , It has stalled twice now trying to go up very steep and long mountains around where I live.
For
the Mounatains around me I really need a 40-60 amp controller , but I must sell off some other parts first to pay for a new/different controller, so I can not report the performance gains until that happens off in the future .

I really don't like the cogging on the direct drive and the weight so I was thinking of a mac 8t with upgraded gears. The hauling is only occasional. Do I need an infineon 12 Fet controller? What do you use?

the Mounatains around me I really need a 40-60 amp controller ,

So is the amount of amps the amount of power you deliver to the motor and your controller isn't powerful enough right now? I am new to this and its helping me understand why there are so many variants. I also think I have worked out why I was having problems hauling. My controller is a 36V running at 48V 14amp on a 1000w motor. It is fine on smaller hills, pulling power but its heavy. My Q100C controller goes up to 17amps. My controller is KT36ZWS-XFCF01R.

First thing, you can't think about electric motors like they are gas engines, so forget everything you know about ICE's.
In very simple terms, the motor, controller and batt. are a system and should be thought of as such.
The controller responses to the demand it "sees" from the motor, think electrical feedback.
The rating on the motor is a guideline to how much power in Watts (A X V = W) it can sustain. A crude "rule of thumb" is hub motors can do 1 1/2 to 2 times their rating in reasonable outside temps.
The controller rating equates to Max. Amps, a spike that occurs at or right after start and tapers off.
The single most important Rule of Elect. Motors is;
Never allow the climbing speed to fall below 1/2 the top speed. To use one ICE analogy, don't "lug" the motor, because around this point, the motor starts to produce more heat than locomotion.
So you are looking up a long steep hill and wondering; Is it better for me to have a high Amp controller, or one w/ a lower value?
Although it might seem counter intuitive, it's better to start out w/ the highest power your system will handle. Why? To maintain as much speed up the hill before reaching that dreaded "half speed". The "safety valve" is between your ears, knowing when to jump off and push.
Of course there are limits and a geared mini-motor, being the weakest sister, makes a good example. Mini-motors, when fed by controllers at and above 20 Amps start to experience "motor shocks" that can damage the gears. Sine wave controllers, w/ their sine wave form are "softer" in this regard than a square wave controller and in general more power can be fed w/ a sine wave. High performance square wave controllers like older Infineons and the "hot rod" Lynn's can really hammer a sm. geared motor.
The key to an efficient and non heat prone system is matching the components and expectations. In particular, whl. size, pack Voltage, MOTOR SPEED RANGE, and controller rating to achieve the desired reasonable top speed.

Thank you for a reasoned and logical explanation.

Now I understand why the 17A on my Q100C is fine. However on my DD 1000w a 14 amp controller may be too low perhaps? Its ok as I was thinking of replacing the whole system anyway as I only need occasional trailer pulling. Id much rather trade the 6kg weight of the DD for a 4kg mac or bafang hub motor. I'm just undecided on mac vs bafang etc. I think the Q100/Q128 wont be able to handle pulling a trailer at all. The mtb is a 29inch, using the same voltage 48V, i was hoping just to swap the motor out but at 14 amps the controller may not be powerful enough.

Your DD motor is severely amp-starved. That is a 1000W motor, which will likely handle easily double that for fairly short periods, and you are only giving it a bit over 700W.

It is important to have some sort of INTERNAL temperature monitoring to avoid melting the motor, but you can safely feed that thing double the current amp load, again, for fairly short time periods. A few minutes, maybe even 10-20, but that leads back to the necessary temperature monitoring, and again, INTERNAL temp sensor.

That leads to oil or ATF fill, or Statorade, and/or external heat sinks.

Thank you for a reasoned and logical explanation.

Now I understand why the 17A on my Q100C is fine. However on my DD 1000w a 14 amp controller may be too low perhaps? Its ok as I was thinking of replacing the whole system anyway as I only need occasional trailer pulling. Id much rather trade the 6kg weight of the DD for a 4kg mac or bafang hub motor. I'm just undecided on mac vs bafang etc. I think the Q100/Q128 wont be able to handle pulling a trailer at all. The mtb is a 29inch, using the same voltage 48V, i was hoping just to swap the motor out but at 14 amps the controller may not be powerful enough.

Yes, DD motors really start to sing when fed lot's of power.
Trailer pulling, like most things w/ hub motors, is all about the hills.
Your Q100C w/ it's "soft" controller, would have little problem pulling a trailer,....in the flat. Start adding hills to the mix and something will have to give.
With your BIG wheels, you need to go w/ a low-speed range (201) motor and I would recommend a geared motor to get the best performance w/ your batt. pack.
Next, you need to see what the discharge rating of your pack is, which you cannot exceed.
The Q128C will like a controller in the 25 to 30 Amp range and is said to produce good "torque" (really a misnomer), probably partly due to high compound gear ratio (like the Q100).
Next step up would be the "large" geared motors like the BPM, Mac, Ezee, etc. Controller rating that match well w/ these can range quite a bit, but figure 30 to 40 Amps.
Top speed for all these combos will be around 20 MPH, due to the low-speed range motor. If you were to use 26" wheels, you could go to a mid-speed range motor, add a couple MPH and climb almost as well.
If the Large geared motor on 40 Amps doesn't pull the trailer as well as you like, you will need the pick a less hilly route, because the next step up in power will require more Volts and an expodental increase in component costs.

 

[Ltc433]

Right now I have a 7 Speed freewheel on the hub motor though the gearing is 9 speed. The reason for this is that with such a big motor only a 7 speed would fit. If I get the Q128C would a 9 speed cassette fit?

 

[john61ct]

Maybe link back to the old thread, the one that got derailed, for some context?

 

[Ltc433]

Done.

 

[Ltc433]

With regards to battery performance. Full voltage at 54.1V. I cycled 13.4 miles at about pas3 (350W-500W) at about 24mph. At the end of the journey my readout said battery zero. I used the watt meter and it had dropped from 54.1V to 48.3V. So it dropped 5.8V at a relatively high PAS and went to Zero. Is that normal? I have nothing to gauge it against. You said (think) 10% of battery capacity per volt used. So thats 5.8 or 58% battery used, not 100% so why is it reading zero battery?

 

[john61ct]

I'm not parsing through it all, over my head, but battery SoC is not easy, cannot be accurate from voltage.

Even a coulomb counter's will just be a guesstimate, often 10% off is best can be expected even using say a CA v3.

But, if you get to know your own battery, and have the tools you get familiar, especially if the terrain is predictable.

 

[john61ct]

14S ?

full charge is 58.8V, ~57V would be better for longevity giving up very little range.

48.3V is 3.45Vpc, pretty good conservative definition of 0% to get a decent cycle lifespan.

Some may set LVC at 3.2V, certainly lower will mean a much shorter life with little gain in range.

Putting a CC load on the battery and precisely timing from your defined top to bottom will give you the most accurate Ah capacity.

 

[shane_da_bean]

discharge ratings:

firstly find out what cells the battery uses, brand name; model/capacity per cell. then google for a datasheet on them. the discharge rating will be something like 2c or 3c etc. which simply means 2 or 3 times the storage capacity of the cell. eg. if your cells are 2200mah capacity with a 2c discharge rating then that is 2X2200 = 4400mah or 4.4ah per cell.

then you can time the 4.4ah per cell by number of parallel cells in your pack e.g. 13s4p would have 4 in parallel, so 4.4ah per cell X 4 cells = 17.6Amps max output for my example. hpoe this helps.

 

[john61ct]

Except the actual discharge rating is usually much lower than that claimed by the maker.

But yes, specific model# of cell used is the starting point.

Or test yourself, keep increasing current rate in 3 minute bursts, recharge if needed, stop when you can feel cells getting hot.

 

[Ltc433]

14S ?

full charge is 58.8V, ~57V would be better for longevity giving up very little range.

48.3V is 3.45Vpc, pretty good conservative definition of 0% to get a decent cycle lifespan.

Some may set LVC at 3.2V, certainly lower will mean a much shorter life with little gain in range.

Putting a CC load on the battery and precisely timing from your defined top to bottom will give you the most accurate Ah capacity.

Ah good so 48V is 0% at full charge my pack is 54.4V. Ive had it 3 years but I don't use it every day, more likely 1-2 every 2 weeks.

Its a dolphin hard pack so I can't tell the cells used.

 

[john61ct]

Sorry but did you confirm that yours is a 14S pack?

Ah good so 48V is 0% at full charge my pack is 54.4V. Ive had it 3 years but I don't use it every day, more likely 1-2 every 2 weeks.

My point, if it is, is that at 54.4 / less than 3.9Vpc, you are very far from fully charged.

To get decent range you need a charger that gets you to at least 57V, maybe 58V.

 

[john61ct]

And 48V **at rest** still has a fair bit of range left.

Of course under load, how close that (or any) voltage is to functionally empty, depends on how big the recent discharge current was. Wait an hour you may see that SoC is actually quite high.

An Ah counter would be better to help you guesstimate.

 

[motomech]

Right now I have a 7 Speed freewheel on the hub motor though the gearing is 9 speed. The reason for this is that with such a big motor only a 7 speed would fit. If I get the Q128C would a 9 speed cassette fit?

I haven't used the Q128 (I'd like to), but from what I've read, it seems like a Q100 on steroids and I like the idea of a more power-capable motor that retains the sm. diameter that hides behind the cassette/.free wheel. But that sm. diameter means extra width to achieve stator area and like other minis, that can create some fitment issues.
But not what you are thinking of.
To digress a bit, as power goes up, there becomes less need to shift gears and high number gears sets are not needed. Even w/ my low-powered Q100C, I seldom use more than 3 gears (the 4th on the steepest hills). But having said that, I know installing a 9-speed cassette on a Q100C brings the motor width out to 137 M/M, which means the chain stays need to be spread slightly and an additional washer installed between the drop-out and the cassette spline end. This is NBD.
The issues I've had have been because of housing width, not drop-out width. W/ my MXUS mini (in between the Q100 and the Q128 in size), the sloping side cover would just touch the brk. caliper and spoke heads and I had to grind them down a bit.
The Q100 w/ the free wheel is not too bad, but w/ the Q100C w/ it's long cassette spline, the center-line of the motor is off to the side and the whl. has to be dished alot to bring the rim back to the center. On the three bikes I've installed Q100C's, one I just couldn't get the wheel dished far enough to make everything line-up. Not every bike frame is built on the same jig, but probably it's fairly rare for the Q100C not to be able to fit.
My Ezee's (same size as the other 5 Kg. geared motors, BPM, Mac, etc.) are a snap to install, they just fall in w/ no dishing.

 

[Ltc433]

Sorry but did you confirm that yours is a 14S pack?

Ah good so 48V is 0% at full charge my pack is 54.4V. Ive had it 3 years but I don't use it every day, more likely 1-2 every 2 weeks.

My point, if it is, is that at 54.4 / less than 3.9Vpc, you are very far from fully charged.

To get decent range you need a charger that gets you to at least 57V, maybe 58V.

Oh I had no idea I could do that? I am just using the charger that came with the battery.

 

[Ltc433]

And 48V **at rest** still has a fair bit of range left.

Of course under load, how close that (or any) voltage is to functionally empty, depends on how big the recent discharge current was. Wait an hour you may see that SoC is actually quite high.

An Ah counter would be better to help you guesstimate.

Yes, I have a Turnigy watt meter I just haven't finished the build yet. Is that what you mean by Ah counter?

 

[Ltc433]

To digress a bit, as power goes up, there becomes less need to shift gears and high number gears sets are not needed. Even w/ my low-powered Q100C, I seldom use more than 3 gears (the 4th on the steepest hills). But having said that, I know installing a 9-speed cassette on a Q100C brings the motor width out to 137 M/M, which means the chain stays need to be spread slightly and an additional washer installed between the drop-out and the cassette spline end. This is NBD.

I just installed a 9 speed cassette onto the Q100C and it fit into my frame without needing a washer thankfully. I am definitely thinking of a Q128C build but it will be a while before i built it anyway.

 

[Ltc433]

Sorry but did you confirm that yours is a 14S pack?

Edit I have found out is 12ah not 15. Its was 36V @15, 48V @12

I thinks its probably a 13s pack. Its a cyclotricity 48V frame pack, I don't think its the 16a/h one.

No, they are two different chemistries with different voltages per cell. Typically most commercial 48V packs are 13s for 54.6V charged, but you could go 14s for 58.8, or 15s for 63V. Assuming the Panasonic cells are 4.2V charged and not 4.1V

My point, if it is, is that at 54.4 / less than 3.9Vpc, you are very far from fully charged.

To get decent range you need a charger that gets you to at least 57V, maybe 58V.

Oh I had no idea I could do that? I am just using the charger that came with the battery.


I found this post

You can use any li charger that outputs the right voltage for you pack. 99% sure you have a 13s,, so 54.6v is your top of charge voltage. The dillenger charger is not just a power supply, there is some "smart charger" stuff in there too, that switches it off when it should. you can charge with just a PS if you want, but bear in mind a 48v PS that outputs 48v is not what you need. you need 54.6v.

Go buy a 48v power supply, and charge your battery to 48v. But to get it full,, you need a 54.6v power supply.

Nobody said anything conflicting, you need a charger that puts out 54.6v to charge a "48v lithium battery". The reason I specifically stated 54.6 is because there are "48v lithium batteries" that charge to 58v. Nowdays, those are mostly called 52v, but at one point lots of the options out there for 48v did charge to 58v. YOUR BATTERY,, is 13s and needs 54.6v to fully charge.

 

[john61ct]

Step zero has to be, find out what the pack layout is.

Personally I can't imagine buying something without knowing that level of detail, like asking about troubleshooting your car engine and not knowing how many cylinders it has.

Also, learn what an Ah counter is (Ah totalizer, Wh meter, coulomb counter), rtfm for your own tool dude.

 

[Ltc433]

Step zero has to be, find out what the pack layout is.

Personally I can't imagine buying something without knowing that level of detail, like asking about troubleshooting your car engine and not knowing how many cylinders it has.

Also, learn what an Ah counter is (Ah totalizer, Wh meter, coulomb counter), rtfm for your own tool dude.

Or buying a computer and not knowing how many pcie lanes it has or number of memory channels? I disagree. People buy cars all the time without knowing the exact bore size of the cylinders. Once they buy the car they may then be interested in how it works as they try to repair it, fix it, tinker with it.

Also it didn't come with a manual.

I already asked, multiple times, what the specifications of the battery are, as well as the entire system. The supplier can't tell me.

You have a limited amount of knowledge in a certain area. At this present moment in time, you have more knowledge and are using that to make silly comments. It serves little purpose You are incorrect in your statements as a 14s can go up to 58V and a 13s is standard at 54.4V. this was based on my earlier statement that I think its a 15ah but after checking its a 12ah.

rtfm for not being a tool, dude.

The comment below was helpful:

discharge ratings:

firstly find out what cells the battery uses, brand name; model/capacity per cell. then google for a datasheet on them. the discharge rating will be something like 2c or 3c etc. which simply means 2 or 3 times the storage capacity of the cell. eg. if your cells are 2200mah capacity with a 2c discharge rating then that is 2X2200 = 4400mah or 4.4ah per cell.

then you can time the 4.4ah per cell by number of parallel cells in your pack e.g. 13s4p would have 4 in parallel, so 4.4ah per cell X 4 cells = 17.6Amps max output for my example. hpoe this helps.

.

 

[john61ct]

Yes of course an ignorant end user can buy anything, but they then must ensure they only deal with good vendors that are able to answer questions and help the noob learn more.

Very unlikely to get good value for money that way.

Ask the important questions **before** purchasing. Do not give money to sellers that can't answer them to your satisfaction.

Avoid technical products that don't have good documentation.

> 14s can go up to 58V

yes this is correct

> 13s is standard at 54.4V

yes that is OK too.

But you need to be certain of which you have. Really is not optional, figure out how, or maybe ask!

Personally I think also true for the brand / model of cells inside.

It is very likely you were sold a very poor quality pack that will need replacing soon.

Also, do not assume you were sold the correct charger, most sellers are scam artists and/or know nothing about what they are selling.

> I think its a 15ah but after checking its a 12ah

Which is not relevant to voltage, just C-rate and range.

You need to do most of the work in educating yourself, not waste the time of people you are asking for help.

I am spending my time here trying to help you, just because you don't like the answers does not make me a jerk.

And yes, @shane_da_bean did give you good info too.

 

[Ltc433]

Everyone is ignorant initially. It is how you learn. You clearly have not read my response. You waste my time by not explaining the difference between a a 14s and 13s. I have already informed you in the thread that I have asked the vendor before purchase, after purchase to which the answer is has been we don't know. You are assuming much. The seller is one of the largest and most reputable, which is why the responses from the seller were surprising. It is likely I was not sold a poor quality pack as the seller is reputable but due to a change in staff, knowledge was lost.

"You need to do most of the work in educating yourself, not waste the time of people you are asking for help."

No you need to explain things properly, stop making assumptions, and see the other responses here were people have explained things clearly. For example:

"Which is not relevant to voltage, just C-rate and range. "

You explain things in halves so please don't bother as the end result is just confusing everyone.

The entire point of the questions was to try and identify the pack through deduction and inference.

 

[Ltc433]

discharge ratings:

firstly find out what cells the battery uses, brand name; model/capacity per cell. then google for a datasheet on them. the discharge rating will be something like 2c or 3c etc. which simply means 2 or 3 times the storage capacity of the cell. eg. if your cells are 2200mah capacity with a 2c discharge rating then that is 2X2200 = 4400mah or 4.4ah per cell.

then you can time the 4.4ah per cell by number of parallel cells in your pack e.g. 13s4p would have 4 in parallel, so 4.4ah per cell X 4 cells = 17.6Amps max output for my example. hpoe this helps.

It helped greatly thanks. Its in a dolphin pack.

Samsung INR18650-29E 2900mAh
3.1. Nominal Capacity 2,850mAh (0.2C, 2.50V discharge)
3.1.1. Typical Capacity 2,850mAh (0.2C, 2.50V discharge)
3.1.2. Minimum Capacity 2,750mAh (0.2C, 2.50V discharge)

2x2850mAh = 5700mAh per cell or 5.7mAh. There are 52 cells in a 13s4p so 5.7Ah x 4 = 22.8 Amps max output.

The full voltage is 54.6V. The configuration of cells in the battery is:

4 4 4 5 5 5 5 5 5 5 5

Edit:

Using this:

http://key4design.co.uk/ebikecalculator.htm

Individual Battery Pack Size (e.g 6s) - 13
Individual Battery Pack Nominal Voltage (e.g 22.2) Volts - 3.65
Individual Battery Pack Mah (e.g 5000) Mah - 2850
Individual Pack C Discharge Rating (e.g 20) - 0.2
Individual Pack C Max Discharge Rating (e.g 30) - 0.2
Number of Individual Packs in Paralell In Each Group (e.g 4) - 4 Packs In Each Group
Number of Pack Groups In Series (e.g 3) 1 - Group Packs In Series
Battery Pack Layout :
13s4p

Battery Pack Layout : 13s4p
Battery Pack Total Nominal Voltage : 3 Volts
Battery Pack Total Max Voltage : 54.60 Volts
Battery Pack Discharged Voltage : 46.80 Volts
Battery Pack Total Amp Hour : 11.4 Amp Hour
Battery Pack Nominal Total Watt Hour : 34.2 Watt Hour
Battery Pack Max Total Watt Hour : 622.44 Watt Hour
Battery Pack Max Continuous Amp Draw : 0 Amps
Battery Pack Max Burst Amp Draw : 0 Amps
Battery Cell Max Voltage : 4.20 Volts
Battery Cell Discharged Voltage : 3.60 Volts
Battery Cell Critical Voltage : 3.00 Volts

Done (i think)

13s4p pack with 52 cells. 54.6 Volts matches measured voltage. 11.2 A/h battery.

 

[Ltc433]

Delete this duplicate post.

 

[Ltc433]

Delete this post

 

[john61ct]

> The seller is one of the largest and most reputable

Why would you not name them? Someone here may have a knowledgeable contact there.

For the seller to not know what they sold you, is the very definition of a poorly run outfit.

> the difference between a 14s and 13s

I'm not sure what you mean, 13 cells in series vs 14 cells in series, but you know that.

You gave an Ah spec as if that was relevant to voltage, so I was clarifying it is not, I do not understand why you would complain about that?

Anyway I am now inferring you are certain it is

> Samsung INR18650-29E 2900mAh

vendor max discharge spec is 0.2C, is that really correct? Seems very low for a battery supposed to be used for propulsion.

OK anyway so now if you know the cell used, that's a big step.

> 13s4p pack with 52 cells. 54.6 Volts matches measured voltage. 11.2 A/h battery

If that is the case, how did you find out?

If that is not the case, there are many ways to tell what it is, easiest is to just open it and look.

> 2x2850mAh = 5700mAh per cell

makes no sense, the above is 2S, so 4S is 11.4Ah

> Ah x 4 = 22.8 Amps max output

No, you take the total Ah capacity times the C-rate
so 11.4Ah * 0.2C (if that is correct)

so 2.3A is max discharge, or ~109W

something is wrong there for sure, but that's the math anyway.

If you're sure those are your cells do some googling and link to some real-world tests, threads discussing those cells, datasheet etc.

The configuration of cells in the battery is:

4 4 4 5 5 5 5 5 5 5 5

I don't know what that's supposed to mean.