How to get more acceleration? (Mxus / Kelly / Multistar used)

I'm feeling that I don't get all acceleration from my bike what I could get. I would like to get the front wheel up

Motor is MXUS 3000 V3 3K Turbo, controller is Kelly KLS7230S and batteries are Multistar 6s 6600 mAh on 18s2p setup (totally 66,6 V and 13200 mAh).

Controller settings looks this:
https://i.imgur.com/RRFBfTr.png

What do you think about the settings, is there anything wrong? I have changed only Accel Time and Accel Release Time from 5 to 1. All other are default settings.

I know that Multistar batteries cannot give so much current that the manufacturer promises but what do you think could the batteries would be the reason for the bad acceleration? Theoretically batteries should give 132 A constant current (2 batteries in parallel * 10C * 6600 mAh) and 264 A in peak but if the real amps would like half of that it should still be enough for my bike.

All comments are more than welcome! And sorry about my English, hopefully it's good enough

How much voltage sag is there when you accelerate? The more sag (the lower the voltage), the less total watts you get to the controller, so the less total power to the motor. IF theres a lot of sag, youd probably have to parallel more cells to fix it (or replace the battery with a better one with less sag).

I recommend going to the http://ebikes.ca/simulator and putting your setup into the simulator settings, to see what voltage and current would be required to get the torque you need to do what you want. You should first calculate that torque requirement based on your weight and your bikes configuration. Once you know how much torque it will take, and what voltage and/or current is needed to get that torque, you can then tweak your setup to give that.

Cant view the link to the settings. Recommend attaching the image directly to the post, or typing in what the settings are as text.

Settings image attached to the original post.

Voltage sag is some volts, maybe 5 to 7. I have to check exact voltage sag.

Yeah, I think I have to get some more parallel batteries but before that I have to do some torque calculations.

Thanks!

Voltage drop on full acceleration is about 9 V (from 68 V to about 59). It's takes couple of seconds to get back to near 68 V. Is this 9 V drop too much or is this normal drop? What kind of voltage drops you have?

Do you have any ideas about the controller settings, is there something I have to change?

Thanks!

I'm not familiar with Kelly controllers, but have you played with the "acceleration time" setting? It sounds like an acceleration ramp and might be limiting torque off the line that would help pop the front wheel up.

Otherwise, 50A of battery current seems a little weak - unless that greyed-out phase current setting really is delivering 380A at low speeds. Typical ratio of batteryhase current is 1:2 or 1:3.

Personally I'd set the battery current to 100A and the acceleration time to zero and see what happens but you might want to check that won't cause the Kelly to blow its guts out first. You'll likely soon need more battery in parallel though!

You are over-taxing the Multistar. It is designed for low discharge rates. If you are seein g more than a few Volts sag, you have the wrong batteries. You need at least 25C. I recommend Turingy.

Good point, the battery current seems to limit the power so I have to try that. I have not tried yet the Accel Time 0 but I should have to try that too.

Yeah I know that Multistars are not the best ones but so many on this forum uses them so they cannot be so bad if there is just several of them connected parallel.

I try these settings and probably I'm going to upgrade the battery pack from 18s2p to 18s4p.

Thanks for the good tips

It's not a case of the Multistars being "good" or "bad", they are designed for a specific application
I've been using Multistars since they came out and they are great for those of us who don't need high discharge rates. What we get are a smaller and lighter pack, low price and a low volatility factor.
On my 2WD, I have an 12S/1P Aux pack on the frt. motor and I can go back and forth between Multistars and Turnigy 20C's and I can feel the difference and they are only 20C!
W/ as much sag as you are getting now, adding capacity is not going to make much of a difference, so if you buy more, you will just be throwing good money after bad.

Make sure the connectors are well soldered in place as any weak connection will drop voltage adding to the batteries sag. After a ride feel them for heat also the less connectors inline the better.
With my 15 amp rated 48v 12ah pack limited to 14.8A I see a 2v drop on the flats with 3 to 4v sag in the wind or on hills so switch speed from 5 to 4 or 3 to keep sag at 2 or 3v. I use one xt60 connection and stock phase connectors

Have read 3 to 4 volts is normal over sagging kills them

On my Cutes running 20 Amp controllers, I barely get any sag at all, yet they don't have the "punch" of my Turnigy's. They stay about the same until they are discharged past halfway and then they start to drop off.
They are perfect on an "assist" bike where system power is not too important. In fact, lower power forces me to pedal
I like that they are avail. in so many shapes and sizes, as I tend to stuff my LiPoly into various frame bags.
If only Hobby KIng would get them back on sale again(And fix their website, it's awful).

After 30 min test drive the battery temperature was 42 C / 108 F. Controller was warm but not hot, maybe some degrees less than battery. Motor was so hot that it was not possible to touch by hand. Battery parallel connectors or any other connectors was not warm at all.

Accel Time setting was changed to 0 and Battery Current setting was changed to 100 A. Front wheel stayed on the road

Sounds that my batteries just cannot push my bike fast enought

It sure does sound like you have the wrong batteries for the Motor. Curious how much sag you get at top speed ?

eCue said:

It sure does sound like you have the wrong batteries for the Motor. Curious how much sag you get at top speed ?

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About 1,5 - 2 volts. So not so much.

Motor was really hot after 30 min test drive. Controller cut the power to the motor couple of times. Motor temperature limit was set to 130 C degrees (266 F). It's interesting to know is this normal temperatuse for the Mxus V3 motor or is it too much for the motor?

I don't know your Motors top temp rating but likely the varnish will burn off first and short the windings if it overheats.

The windings are going to be warmer then the temp sensors reading so with it at 130 the windings could be 150c or higher which is approaching destruction...

With the multistar battery's I would limit the motors Amps for the acceleration. Also the heat is wasted energy

. .

amberwolf said:

are yo usure you have the rightphase/hall wiring combination betwen motor an dcontroller?

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No I'm not sure. But the wiring is the only which got the motor rotating. Here is more about my previous problem: https://endless-sphere.com/forums/viewtopic.php?f=2&t=93785

New question, is it possible that there is several possible wirings which get the motor rotationg but some wirings get motor running hotter than some other wirings?