New controller for 2WD ebike

[sleepingcat]

Hello,

This is my first post on this forum, I only recently bought an ebike about a week ago. I am very new to this all so please bear with me.

I have bought this bike from Alibaba, everything is ok with it. It drives great, goes up to 50kmh on full charge below 90/80% it goes 45kmh, I can switch between 1WD(rear) and 2WD, it supposedly has two 48v 1000W motors and 3 batteries totaling 70ah. The top mounted battery is 25ah and connected to only the front wheel, the two 22ah batteries are connected to the rest of the system.

Everything is working great and I am happy but I was supposed to be able to switch between limited (25kmh) and unlimited mode but they forgot to program that into the controllers, they want to send me new controllers with this limiter programmed into it but I will have to replace the old ones so I was thinking I might get a different controller(s). I saw VESC software on Reddit and that looked pretty cool but I looked at the hardware and it felt like I was trying to read a different language.

The issue is that I am completely new and even though I have been researching and looking at ebikes for about 4 months I can't wrap my head around the electronics.

With that in mind, where do I start? I was looking for controllers but it is kind of overwhelming. I wanted a controller that I can program/tinker with because I really want to learn how to work on the non-mechanical parts of my bike.

I would love to get a controller that I can at least change the basic behavior of the motors, set speeds/torque for PAS levels. I would also like to be able to monitor power usage and maybe better insight in battery charge state but I don't know if that is the controller or the BMS that would do that. Really something that is basic to set-up but still has some freedom to tinker and learn. And also not too expensive, I don't know the pricing on such controllers but 200 euro would be my cap.

I have added a picture of the motor and controller (I think this is the controller JH12GT) to this post. If you need more information/pictures I will gladly provide it.

Thank you in advance for any replies/help I really appreciate it and I hope I'm not too oblivious in making this post.

 

[amberwolf]

With that in mind, where do I start? I was looking for controllers but it is kind of overwhelming. I wanted a controller that I can program/tinker with because I really want to learn how to work on the non-mechanical parts of my bike.

I would love to get a controller that I can at least change the basic behavior of the motors, set speeds/torque for PAS levels. I would also like to be able to monitor power usage and maybe better insight in battery charge state but I don't know if that is the controller or the BMS that would do that. Really something that is basic to set-up but still has some freedom to tinker and learn. And also not too expensive, I don't know the pricing on such controllers but 200 euro would be my cap.

I think your best bet is to leave the unlimited controllers you already have (if they are high enough power for what you want), and use the Grin Tech Cycle Analyst v3 to take your sensor and throttle inputs, and convert that via settings you choose into a throttle signal that runs to both controllers to run them in whatever way you choose.

It's highly configurable in a number of ways, so you can use it to read a PAS cadence or cadence/torque sensor to make a throttle signal, whcih can be based on controlling the speed of the system, or the battery current (which simulates a torque-based throttle, easier to control on some systems). It can even monitor temperature (of an object of your choice, wherever you install a sensor for that), and change behavior of the system based on this if necessary.

It also monitors battery usage, to track Wh, Ah, W, V, A, etc, which can be useful for determining original capabilities of a system, and seeing how it changes over time, making it more visible when a problem may be beginning to happen beofre you might notice obvious symptoms (cutouts, etc).

This page has fairly complete info about it:
https://ebikes.ca/product-info/grin-products/cycle-analyst-3.html
and this thread talks about a lot of different things regarding it, for the many firmware versions and improvements over the decade since this version came out:
https://endless-sphere.com/forums/viewtopic.php?f=4&t=37964&hilit=beta
and there are a lot of other threads with various discussions of specific usage scenarios.

You would probably be best with the CA-SA version with separate speed sensor and separate battery shunt, so you can install the shunt between your battery setup and the controllers' battery input wires (assuming they all come together at a single pair before splitting up and going to the controllers), and the speed sensor on a wheel to easily monitor speed without interfering with the controllers doing whatever they do for this (if they do).

 

[amberwolf]

I use the CAv3 with the just-previous-to-current FW version (with plans to update and tinker with the new version whenever I have time) to run my 2WD SB Cruiser heavy cargo trike
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833

The CA takes a throttle signal from a single cable-operated hall throttle (moved by a metal ATV thumb throttle mechanism, since the plastic ebike ones break too easily), and a cadence PAS signal (from the cadence sensor part of a TDCM BB-torque sensor), and uses my settings to create a throttle signal that runs both of the dual rear wheel controllers. I use the PAS most of the time, with the throttle being there to help startup from a stop and to control it when my legs have a problem keeping me from pedalling (rare, but more frequent as the years go by).

In my case, power is not limited (it could be, though), and instead it's speed limited by the CA to 20mph to comply with local regulations defining ebikes at the time it was built.

It monitors the current out of the single battery to the dual controllers, and tracks lifetime and per-trip power usage, and since I put my charger on the ocntroller side of the shunt, it also can monitor recharging, as well as regen braking.


I don't use the feature, but it also can ramp up throttle, or ramp it down, or both, and there are a number of other tuning features to make a bike operate as close as possible to the way a specific rider wants it to.

 

[sleepingcat]

I think your best bet is to leave the unlimited controllers you already have (if they are high enough power for what you want), and use the Grin Tech Cycle Analyst v3 to take your sensor and throttle inputs, and convert that via settings you choose into a throttle signal that runs to both controllers to run them in whatever way you choose.

It's highly configurable in a number of ways, so you can use it to read a PAS cadence or cadence/torque sensor to make a throttle signal, whcih can be based on controlling the speed of the system, or the battery current (which simulates a torque-based throttle, easier to control on some systems). It can even monitor temperature (of an object of your choice, wherever you install a sensor for that), and change behavior of the system based on this if necessary.

It also monitors battery usage, to track Wh, Ah, W, V, A, etc, which can be useful for determining original capabilities of a system, and seeing how it changes over time, making it more visible when a problem may be beginning to happen beofre you might notice obvious symptoms (cutouts, etc).

This page has fairly complete info about it:
https://ebikes.ca/product-info/grin-products/cycle-analyst-3.html
and this thread talks about a lot of different things regarding it, for the many firmware versions and improvements over the decade since this version came out:
https://endless-sphere.com/forums/viewtopic.php?f=4&t=37964&hilit=beta
and there are a lot of other threads with various discussions of specific usage scenarios.

You would probably be best with the CA-SA version with separate speed sensor and separate battery shunt, so you can install the shunt between your battery setup and the controllers' battery input wires (assuming they all come together at a single pair before splitting up and going to the controllers), and the speed sensor on a wheel to easily monitor speed without interfering with the controllers doing whatever they do for this (if they do).

Hello Amberwolf, thank you very much for your replies.

I have looked at the Cycle Analist and that seems to be exactly what I am looking for, the CA-SA seems to be discontinued so I'll have to go for the CA3-DPS(?) when it gets back in stock or am going to look for something similar.

In the meantime I will be getting the new controllers as they are provided for free by the seller because they made the mistake to not limit it while that was in our agreement. I need the new controllers because I want my bike to be able to comply with EU laws, PAS to 25kmh and throttle to 6kmh (walk assist) I'm already running 2*1000watt 750watt (I removed the stickers and they're 750 not 1000, the upgrade to 1000 was "free" so that explains why) motors while 250watt is the max so I don't want to push it too much.

The ramp up function is going to be a life saver, I have ridden the bike some more and sometimes it just pulls away with the slightest movement of the pedals which can be sketchy at times. If I am understanding ramp up, it should also help with the front wheel slipping when starting from a stand still and when I tweak it enough it could feel like a torque sensor setup.

When I get the CA I will also have to look into running all 3 batteries in parallel as now they are split up between 1 for the front motor and 2 for the rear & system but I will have to do a lot of research before I even try and attempt that.

Also, I saw your ebike creation and it looks amazing. I've wanted a trike ebike originally so I could bring my cats with me but I live in apartments so I sadly don't have the space for it.

Again thank you so much for sharing your knowledge it is much appreciated.

 

[amberwolf]

I have looked at the Cycle Analist and that seems to be exactly what I am looking for, the CA-SA seems to be discontinued so I'll have to go for the CA3-DPS(?) when it gets back in stock or am going to look for something similar.

There isn't anything else like the CAv3, if you mean a different similar product elsewhere--other places than Grin Tech do stock various versions, but the Cycle Analyst is one of a kind.

If you get any "DP" versions, they are designed to plug directly into your controlelr's CA-specific connector, which yours won't have, so you will still need a separate battery shunt, so you can install the shunt between your battery setup and the controllers' battery input wires (assuming they all come together at a single pair before splitting up and going to the controllers), Grin should carry the shunt you'd need; you can give them the specifics of what you're doing and what you have and they can help you make sure to get the right parts.


In the meantime I will be getting the new controllers as they are provided for free by the seller because they made the mistake to not limit it while that was in our agreement. I need the new controllers because I want my bike to be able to comply with EU laws, PAS to 25kmh and throttle to 6kmh (walk assist) I'm already running 2*1000watt 750watt (I removed the stickers and they're 750 not 1000, the upgrade to 1000 was "free" so that explains why) motors while 250watt is the max so I don't want to push it too much.
Since the CA itself will be able to do the limiting for you, it will keep it legal for you (since the controllers are otherwise identical, right? Meaning, they're still capable of the higher power, just programmed not to use it? So limiting in the CA would be no different...).

This way you can, if necessary for some "offroad" or other situation that requires higher power for a moment, be able to manually change the CA's limit (or use a separate preset for this). Not something you have to do, but could if you wanted to.

(The CA can't increase the limited controllers to make them more powerful, but it can limit the more powerful ones to keep them within any limit you choose).

When I get the CA I will also have to look into running all 3 batteries in parallel as now they are split up between 1 for the front motor and 2 for the rear & system but I will have to do a lot of research before I even try and attempt that.

There are battery paralleling devices made to do this, that prevent problems if you hook up batteries at differnet states of charge / voltage, there are some threads around here discussing htem (at least one or two of them from this summer).

There are ways you could use separate shunts on each system and have the CA read both of them, but it would require designing and building a small circuit to "add" the voltages from each shunt together and feed that to the CA's shunt input.

Also, I saw your ebike creation and it looks amazing. I've wanted a trike ebike originally so I could bring my cats with me but I live in apartments so I sadly don't have the space for it. This is what my bike looks like now if you're interested.

FWIW, you can make (or buy) a folding or removable sidecar to carry cats or cargo, etc.; depending on the design and the space restrictions for parking and moving the bike it might be easy or hard. There's a few threads around here about sidecars, something earlier this year I think where someone was designing and buildng their own based around an off-the-shelf frame kit. This is all hte posts with sidecar in them, but most aren't relevant (or don't have pics)
https://endless-sphere.com/forums/search.php?keywords=sidecar&terms=all&author=&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
a google image search for bicycle sidecars will probably find better results.

Also, the bike I had before this trike is my old CrazyBike2, and I used to use it and a trailer to carry dogs and cargo around; it's very long (almost as long as the trike, not counting the trailer), and it has two large boxes on the side behind the seat for cargo, etc; this is what it looked like (without the trailer) way back then, when I was in an apartment for half a year after a housefire.

. The boxes could, if designed right, carry cats safely. There are many pannier designs that can probably be adapted. (I used a box just like the ones on CB2 on an older more normal bike DayGlo Avenger to carry one dog (Hachi) in.

Again thank you so much for sharing your knowledge it is much appreciated.

Sure; that's what we're all here for.

 

[SlowCo]

Hello,

This is my first post on this forum, I only recently bought an ebike about a week ago.

Please be careful on the road as you are riding an uninsured, illegal moped. FYI, being able to "switch" to 25km/h mode doesn't make it a pedelec/electrically assisted bicycle.