Direct Drive Vs Geared Hub at 48V possible replacement

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

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

Just found this:

https://www.electricbike.com/52v-battery-3077-fet/

"How high can we raise the volts?

C) Charge pack to 4.1V per cell for max life (instead of 4.15V, or 4.2V)
Now, if each step in adding a series-string to a pack design is a step of 4.1V, and a common 13S pack (nominal 48.1V) is 53.3V when fully charged. Then, one step up to a 14S pack would be:
51.8V nominal (3.7V X 14), and 57.4V when charged (4.1V X 14), so…for the purposes of this conversation, lets call a 14S pack a 52V pack."

https://electricbike.com/forum/foru...-voltage-when-drained-52v-dolphin-pack-13-5ah

No, I figure that a 52 volt Dolphin battery ought to go as low as 43-44 volts. You can run an 18620 cell between 4.2 and 3.1 volts. A 52V battery uses 14 series groups, so 14 x 3.1 equals 43.3 volts. Similarly, a 48V battery with 13 series groups can go down close to 40-41 V, and a 36V battery with 10 series groups can go to 31-32 volts.

If the layout is 13S, 48V nominal, 54.6 max charging V, as you found, stopping at 53V is indeed better for longevity.

Not sure why you also discuss the specs for 14S / 52V nominal nor 10S / 36Vnom? Not relevant, if you are sure your pack is 13S.

Max discharge rate is a specification of the cells, expressed in mA or amps.

Which we usually convert to a C-rate, proportional to the mAh capacity.

Some cells are much better than others in reality when holding that max spec'd C-rate

as in not dropping voltage too deep, which can hurt runtime, makes it hard to determine the LVC setpoint, for 13S 41-42V **at rest** is pretty low for good cycle lifetime. Ideally an Ah counter / SoC meter should be your guide rather than voltage while under load.

also a good criterion for how cells are handling max continuous C-rate is not getting too hot, which is a symptom of short cycle lifespan.

If the cells are the Samsung INR18650-29E 2900mAh

their max discharge is rated by Samsung at 2750mAh, just below 1C.

So no idea why you keep getting this wrong:

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

If the layout is 4p, then 11A is your spec'd maximum discharge at the pack level.

Rather than relying on Samsung's rating, better to research real member testing data discussions on the various 29E iterations

john61ct said:
So no idea why you keep getting this wrong:

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

If the layout is 4p, then 11A is your spec'd maximum discharge at the pack level.

Speculating on two possible reasons;

OP didn't do a unit check that would reveal the flaw in the equation:
Ah x number = A which is obviously flawed through an arbitrary removal of the time element

OP not understanding the Ah specification, which if abbreviated most of the time, but includes a time assumption. In this case, the full Ah specification would read 22.8Ah @ 2.07h; so the battery's capability is to discharge the full 22.8 amp-hours of energy in 2.07 hours, which assumes the C rating of the cells. So now, solving for current the right way, by adjusting out the time element: 22.8Ah/2.07h = 11A

1. I know it’s a 13s4p pack.
2. You stated " I'm not parsing through it all, over my head, but battery SoC is not easy, cannot be accurate from voltage."That is correct you are not parsing it all and you are the one who is getting confused.
3. You then stated " 14S ? full charge is 58.8V, ~57V would be better for longevity giving up very little range."
4. You then stated "48.3V is 3.45Vpc, pretty good conservative definition of 0% to get a decent cycle lifespan."But it isnt 0% and not the 0% lowest voltage tested which is what I was asking for.
5. You then stated "Sorry but did you confirm that yours is a 14S pack?, 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."
which is wrong because you are talking about a 14s pack and not a 13s pack.
6. Then you state " And 48V **at rest** still has a fair bit of range left." contradicting the previous point at which point actual 0 is.
7. I then states this explicitly "I thinks its probably a 13s pack. Its a cyclotricity 48V frame pack, I don't think its the 16a/h one."
8. Then you state I have probably been sold a poor quality pack, which I haven't. The cells are genuine. Then you state I am not stating the vendor when I have, its cyclotricity. "Why would you not name them? Someone here may have a knowledgeable contact there."
9. You then state :"Not sure why you also discuss the specs for 14S / 52V nominal nor 10S / 36Vnom? Not relevant, if you are sure your pack is 13S."TO MAKE SURE NO-ONE GETS CONFUSED BY YOU.
10. "So no idea why you keep getting this wrong:"

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

To let motomech see the mistake in their calculation using their method. 2 is the discharge rating or 2C.

11. "Rather than relying on Samsung's rating, better to research real member testing data discussions on the various 29E iterations

All I wanted to know is what the pack is a 13s4p at 11.4 ah. That’s it.
12. You are being pedantic, not following the full thread and making many mistakes. You even admit this yourself. If my initial calculations are wrong, that's fine , its how we learn but the only thing you are doing is not making much sense and not explaining things properly which is what you should have done in the beginning. You didn't and now here we are. You keep saying "you have no idea" and you are right, you have no idea so please stop.

OK done, leave it to others

motomech said:
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.

Does the Q128CST come in a 32 hole? I cant seem to find a 32 hole version only the 36 hole. It looks like only the Q100CSt comes in a variety of spoke holes.

A little late but here goes. First the cell data.
https://lygte-info.dk/review/batteries2012/Samsung%20INR18650-29E%202900mAh%20(Blue)%20UK.html
Assuming you have a 13s4p pack.
rec. charge rate is ~.48C, 5.5A. max charge rate is ~.95C, 11A.
Rec. continuous discharge rate is ~.95C,~11A. Max is ~2.8C, 32.4A.
Pack rated capacity is 11.6AH when discharged at .95C, capacity drops at higher discharge rates.

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