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[Lucifer]

Yeah they are a more realistic price the one in the diag I found cost a staggering amount.

Thank you. Not sure of the controller spec, like the other 24v folding bike the controller is built into the frame, and TBH I thought I would leave well alone, as they are a real pain to get out, but I would have guessed at 10A, certainly wouldn't expect it to be over 20A

As just making the two packs into one battery appears so simple, (And as I have 4 of these working) I think that will be an easy relatively risk free option, I only really started thinking of // as an afterthought to save swapping batteries for range, and hoped it might give more current on steep hills. but it has turned out to be a lot more complicated than I expected, And even now I think I have worked out how to do it, there are still grey areas, and its a fair bit of work compared with the one battery approach. I'm not too bothered about losing the ability to use them separately, and in fact cannot see why I would want to. And even if I did the same with another two I would still have two separate batteries (both double the mah they original had). I mention that as that's the only way I could see having two separate batteries as an advantage. one could be at home on charge, while I'm out using the other one.

On the heating issue, I was thinking that the nice looking carrier might trap heat (like wrapping the fin batteries all up in a towel), heat that would otherwise normally be naturally conducted to the ally case, then convected away by passing air. So it was this outer case or pillion box that I was thinking of ventilating. Might be overkill, but I have already ordered the controller in the picture, complete with remote probe £2.70 inc post , and I have loads of old pc fans to choose from, and was actually thinking of small one from video graphics card.

As I got the bits I'll do it anyway, peace of mind. Besides in a worse case scenario, if the battery should burst into flames, at least I should get a jet of flame out the back so the bike will look rocket propelled LOL

K

Hi again (Sorry)

Spent literally hours, trying to find a suitable 36v controller, not given up, but like everything else e-bike related, it's always ends up a bit more problematic than expected.

I did put the controller back in the bike and try with a 2x 12v SLA batteries, and it wasn't too bad, but still felt underpowered.

But that gave me another idea (OH NO! he says)..... LOL. Because its almost useable as a spare bike....... Almost

Well everyone appears to jump straight to 36v from 24v when overvolting, well that's 50%, so you can guess where this is going, As I have now sussed how to build batteries, I thought without modifying the controller or motor, I could go to 28v or even 32v. Try 28 first so build 28v 8S battery pack, well it would come out more than 28v but let's not split hairs. That might well be enough to give the bike that bit more get up and go, and thus make it useable. Found this BMS See Image (2), which will do various configurations (8 cell BMS)

For charging this non standard cell config, I thought I could mod the existing 24v charger (which gives out 29v) to output a bit more to deal with the extra cells. It happens to be in a much bigger plastic box than it needs (so lots of room), So I could fit one of these boosters inside (see photo)

Called "150W DC-DC Boost Converter 10-32V To 12-35V Step Up Voltage Charger Module UK" from the listing).

As the required increase would only be small, even if it's not as good as it claims it should do the trick.

Q1 What do you think, think the controller would take 28v or 32v without mods?

Q2 What about the charger mod, see any problem?

Q3 If nothing else is modified, but an 8S 28v battery is used, that would increase the power, bit more ability to deliver current, and a bit more speed due to motor RPM increase, wouldn't it?

That might be enough to make the bike useable, as a spare, not much work so dont mind from the time point of view trying it, long as it doesn't look like it will burn it out. LOL

Keith

 

[amberwolf]

Q1 What do you think, think the controller would take 28v or 32v without mods?

Still depends on exactly the same things (that we don't know yet) as any other voltage you'd want to use with it besides the original, and still has the same gotchas.

Q2 What about the charger mod, see any problem?

See this thread for how that may work out

Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Using the Wangdd22 1500W 30A DC Boost Converter on an ebike. Background: Why bother? Short answer - economy, versatility and fun to try. Longer answer: This is my first e-bike and I'm trying to keep costs down. I bought a used donor mountain bike ($180) and a $225 rear wheel kit (48V...

endless-sphere.com

Q3 If nothing else is modified, but an 8S 28v battery is used, that would increase the power, bit more ability to deliver current, and a bit more speed due to motor RPM increase, wouldn't it?

Battery current is still limited by the controller to the same thing it was before. Phase curren't isn't measured by these controllers, whether it will increase (probably a tiny bit) or not and how much depends on how it's designed and it's firmware, neither of which we can know enough about to say anything useful.

If the controller is not speed limited, it will increase the motor RPM proportionallly to the voltage increase..

 

[Lucifer]

Re Booster.
See this thread for how that may work out

Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Using the Wangdd22 1500W 30A DC Boost Converter on an ebike. Background: Why bother? Short answer - economy, versatility and fun to try. Longer answer: This is my first e-bike and I'm trying to keep costs down. I bought a used donor mountain bike ($180) and a $225 rear wheel kit (48V...

endless-sphere.com

Great thread, very interesting. Obviously if I replace the controller I wouldn't need this, but clearly it would work fine. He is actually using it for the output to the bike, (and getting by), I was only going to use it to modify the charger to charge a battery that was non standard from a voltage POV. I can see no reason other than tradition that these batteries go up in multiples of 12v (prob a hangover from 12v lead acid batteries). But I only considered making a non standard number of // groups, because so many people just say "Oh it will be ok just stick the 36v battery on the 24v controller...... It will be fine". Well I wasn't going to go down that route, but I was tempted to think that there must be some built in leeway so a smaller voltage increase "Probably" will be fine, and at least we know all the caps in the present controller ( Big ones 63v some small ones 50v) can clearly take the extra voltage, but if that not the case there isn't much point in experimenting with intermediate voltages, either stay with 24v (build a new battery and sell the bike) or upgrade to 36v, using standard readily available components....... So back to finding a new 36v controller.

I found one controller that looks promising, will need some more thought, this one actually has a wiring diagram (most on e-bay don't appear to..... LOL). I put the diag below together with the previous picture of the original controllers pinouts (004.jpg). I notice it has a 6 wire hall plug (but one is empty) my old one had 5 wires, (so just change the plug).

This one doesn't have power assist? (which I don't want or need), but not quite sure (No IDEA how it works) so.....

NOT SURE HOW TO PHRASE THIS QUESTION as I no idea how the power assist bit actually is supposed to work.
Is there something in the motor that will require a signal from "power assist" ?

Because the original controller had it (even though it no longer works and does not appear to do anything)

I got as far as rigging up some SLA batteries and putting the controller back, and going round the block a few times. And then it poured down with rain, so I have not got as far as seeing what happens if I disconnect the Power Assist Plug yet. But I assume that if the bike continues to work with the plug disconnected then I don't need it on the new controller, If it doesn't the I do need it?

In which case this controller will be no use I assume?

I think 'Ill do some more looking for a perfect match before I try the disconnect PA plug, ( It's raining again) the right one must be out there somewhere.

Shame because so far it was the only one I found that looked close and actually had a wiring diagram !!!!!!! (novel idea LOL)

That aside if that issue was resolved (one way or another), am I on the right track I assume that this 36 - 48v business is irrelevant from my point of view, just means that the controller will take either battery, I'm not even considering 48V don't think the motor would like that at all.

If the controller is not speed limited, it will increase the motor RPM proportionallly to the voltage increase..

Well that at least that's some good news, I don't actually need FAST, but this thing is just painfully slow. As in IF a five year old with stabilisers on his bike said "Race you Mister" You would not have to make out to let him win...... LOL (Well Almost .......)

 

[Lucifer]

Still depends on exactly the same things (that we don't know yet) as any other voltage you'd want to use with it besides the original, and still has the same gotchas.

I had asked the bike manufacturer for some information on the controller and motor. Well, basically they misunderstood and thought I wanted them to convert it to 36v (like their newer MK3 model). But in the process of saying its not cost effective with labour, I picked up this snippet.

"As your mk2 is the older one (than the 36v MK3) we would also need to re-wire the front end to a compatible throttle."

So I take it the original controller is totally dif to the newer controllers in some way? Possibly analogue instead of digital, or something? Even if that's the case it doesn't sound insurmountable, I assume it's just changing the throttle itself, can prob use all the same wiring that runs through the frame to the controller, even if I had to re run a wire that doesn't sound like a big deal, especially if forewarned about it.

Keith.

 

[amberwolf]

"As your mk2 is the older one (than the 36v MK3) we would also need to re-wire the front end to a compatible throttle."

So I take it the original controller is totally dif to the newer controllers in some way? Possibly analogue instead of digital, or something? Even if that's the case it doesn't sound insurmountable, I assume it's just changing the throttle itself, can prob use all the same wiring that runs through the frame to the controller, even if I had to re run a wire that doesn't sound like a big deal, especially if forewarned about it.

Does the throttle have a battery meter on it? If so, that's the only normal reason to need to change it. But you can just leave the battery meter wire disconnected and ignore it, rather than changing the throttle. And if you are really DIYing it you can look at the comparators/voltage references in the little board inside for each light, and recalculate/change the resistors in the voltage dividers so they turn on at the appropriate voltages for the higher voltage pack. (or change teh whole board out for one from a throttle that already does what you want...but then you mgiht as well change the whole throttle)


It's unlikely that they actually used an incompatible throttle (like a potentiometer vs hall), as the board in their existing 24v controller clearly has the places for the LVPS input resistor/etc that are required for the higher voltages.

 

[Lucifer]

Does the throttle have a battery meter on it? If so, that's the only normal reason to need to change it. But you can just leave the battery meter wire disconnected and ignore it, rather than changing the throttle. And if you are really DIYing it you can look at the comparators/voltage references in the little board inside for each light, and recalculate/change the resistors in the voltage dividers so they turn on at the appropriate voltages for the higher voltage pack. (or change teh whole board out for one from a throttle that already does what you want...but then you mgiht as well change the whole throttle)


It's unlikely that they actually used an incompatible throttle (like a potentiometer vs hall), as the board in their existing 24v controller clearly has the places for the LVPS input resistor/etc that are required for the higher voltages.

Thank you..... I suspected this was basically crap, but was not sure ( I mean it's probably 10 years old, but I doubt even bikes of that age would be using analogue potentiometers as throttles..,..... But I could of been wrong). The throttle does not have any meter of any kind on it, in fact none on the handlebars at all, and in fact the only meter on this bike is on the battery. Of course the newer model may well have meter(s) on the throttle. But for this one all I want to do is get it going as a spare, I can live without meters. will probably only ever use it as a stand by if I break the other one, so no frills for this is more than acceptable..... as long as it goes, if and when I need it to.

If at all possible..... as this is my first upgrade project, I would very much prefer to simply replace component parts rather than do board level mods, (though I have the kinda mind that wants to know how to do them). But if I can buy a ready to go controller replacement like the one doc advised me to fit , which was about $16, and you only "NEED" to connect a few wires and can let the rest float, (see his post 2nd link below) well bearing in mind that this is a spare bike, that I kinda need, but also don't intend using.... that sounds good. Trouble is the supplier wont ship it to the uk, found others that will, but charge more for it, then want $30 to post it, and I will have to pay an unknown amount of extra tax once it gets here....... so trying to find one in the uk.

The controller Doc recommended

In this thread

Simple by the look of it

Now if that works as expected, even I can fit that and have the bike working in a couple of hours max. Any comments on it... Good or bad, or how to get one here wo quadrupling the price LOL

You know why the Chinese will end up owning this world.....Its not because they rip of everyone ideas......... or because they use effectively slave labour......... and get massive state investment to mass produce products........ No it's because the have a state subsidised postal system that can ship something to the other side of the world for 3c instead or $30. And then blatantly under declare its value, so no tax is payable. The west all need to wake up to this before it's too late.

I do have a couple of other "MUCH BETTER" bikes covered up in the garden, newer, higher spec, obviously more powerful, (but broken). Now when I get to looking at them, and assuming I have one fully working bike, (and a spare), and most important of all..... I have understood the basics of all this (getting there)...... Well that will probably be a totally different story, and quite looking forward to it... LOL

K

 

[amberwolf]

But I only considered making a non standard number of // groups, because so many people just say "Oh it will be ok just stick the 36v battery on the 24v controller...... It will be fine". Well I wasn't going to go down that route, but I was tempted to think that there must be some built in leeway so a smaller voltage increase "Probably" will be fine, and at least we know all the caps in the present controller ( Big ones 63v some small ones 50v) can clearly take the extra voltage,

While the extra effort and time is probably not worth it: As I noted before, it's likely to need that LVPS input resistor (because even one extra series cell group could push it over the limit for the LVPS regulator input at full charge; these are usually an LM317 variant, many but not all of which can take 40v max input, some of which only take 30v max), and you'd have to get those pics of the FETs to find out their specs, to find out what they can handle. My bet is the FETs would be fine but the LVPS is not, wihtout that resistor.

I found one controller that looks promising, will need some more thought, this one actually has a wiring diagram (most on e-bay don't appear to..... LOL). I put the diag below together with the previous picture of the original controllers pinouts (004.jpg). I notice it has a 6 wire hall plug (but one is empty) my old one had 5 wires, (so just change the plug).

6 wire plugs (or 9 wire incl phases) are often used because motor-casing-installed speed sensors are commonly using the 6th wire, referenced to the same ground as the halls, and supplied with the same 5v. Even if you find one that does use that 6th wire and your motor dosen't have it, you can wire that out to a separate wheel speed sensor as is used on any old cycle computer / speedometer. (most just use ground and signal).

This one doesn't have power assist? (which I don't want or need), but not quite sure (No IDEA how it works) so.....

Most "power assist" or PAS (pedal assist sensor or system) just read a hall or reed sensor at a bracket near the pedals that detects a ring of magnets (on the chainrings or a plastic ring on the crankshaft) passing it.

The results of detection vary, but most controllers just use it as an on/off switch--you are pedalling, or you are not.

Some use this to enable a throttle, or disable it. Those are usually made that way because in some areas of the world it's illegal to have a throttle that works without pedalling. (someplaces it's illegal to have a throttle at all).

Most use it to turn on the full amount of whatever assist level you have chosen at the display (or if no display, to turn on the full amount of whatever power the controller can provide).

Many but not all have at least one assist mode where the throttle completely overrides the PAS at any time to give the max amount of assist possible (sometimes limited by the assist level chosen, but usually that only affects the PAS, not the throttle).

Most use the assist level to determine the max speed the PAS assist goes to, so you get about the same startup power out of them all, but you only go to a certain speed.

Some use the assist level to determine the max battery current the PAS goes to, as a "torque simulation", and the only speed limit is whatever max speed that will get you on your specific riding conditions, or whatever speed limit the controller itself has programmed in.

A *very few* (most no longer made AFAICT, or only used on OEM bikes, not sold separately) use the sensor to actually determine cadence, and control the speed (or power, torque, etc) of the bike based on how fast you are pedalling. There is zero reason that all controllers can't do this, except that their internal software simply wasn't written to do it. If they can read a PAS sensor they *can* count it's pulses over time and provide output based on it, but they simply don't.

BUT: the Cycle Analyst v3.x from ebikes.ca , a completely separate ebike computer (not a controller or display for one) will provide that mode (which I use to control my SB Cruiser trike) for any throttle-controllable controller.

And there are some DIY projects here on ES and elsewhere that convert the pulses from a common PAS output into a variable voltage based on cadence, to use as a throttle input to a controller that doesn't need the PAS signal to work. They're generally not as configurable as the CA, but better than most PAS-only controllers.

And there is open source OSFW for Lishui and KT controllers that should be able to do it (or could be rewritten to since the code is freely available).

But I assume that if the bike continues to work with the plug disconnected then I don't need it on the new controller, If it doesn't the I do need it?

Correct. Almost certainly it does not need it if it doesn't work now.

Whether the pictured new controller needs it or not, you'd have to test.

That aside if that issue was resolved (one way or another), am I on the right track I assume that this 36 - 48v business is irrelevant from my point of view, just means that the controller will take either battery, I'm not even considering 48V don't think the motor would like that at all.

The motor itself doesn't care; it spins faster for higher average voltage, and may have higher current across it's resistance (but resistance is so tiny vs even the original voltage that currents can be so high it doesn't really matter). You could probalby use a couple hundred volts on it before it would start to matter.

(brushed motors, two-wire, are an exception for several reasons but you're not likely to have any of those on ebikes)


Many controllers for 36-48v are autodetecting, so since the ranges of those votlages cross, sometimes a fully charged 36v gets detected as a 48v and the system thinks it's empty and won't run, or an empty 48v gets detected as a full 36v and the system would let you overdischarge and damage it if it's BMS doesn't stop you.

 

[amberwolf]

( I mean it's probably 10 years old, but I doubt even bikes of that age would be using analogue potentiometers as throttles..,..... But I could of been wrong).

They are used on higher end stuff, like the expensive Domino throttle, for a number of reasons, but to make a good pot throttle it's not as cheap as a hall throttle, so....

I don't have any good suggestions on getting a (good) controller cheaply....aliexpress has plenty of cheap ones probably including the one(s) you're already looking at, but you never know what you are are going to actually receive vs what you ordered (or if it will function), and you may still have the VAT/etc problem. I try to only use Ali* for "dollar" items, and only things that won't matter much to me if they work as advertised...that if I get them anywhere else they'll cost 10-30x (or more) as much, for the exact same item (that may also not work as advertised).

 

[Lucifer]

As the power assist wasn't working and I wasn't bothered about that. I asked (in short) If I disconnect the power assist and the bike still works atm then basically the bike doesn't need it?

Correct. Almost certainly it does not need it if it doesn't work now.

Whether the pictured new controller needs it or not, you'd have to test.

Well I unplugged the power assist cables from the existing controller, and it did not make any difference at all. So obviously power assist still did not work, but twist and go throttle still worked perfectly. So the bike itself doesn't need this feature. And therefore if this is not even on the replacement controller, that will not need it either.... I assume.

So having simplified the issue (I hope). I have searched e-bay again and found plenty of cheap controllers on e-bay for about £10, that don't have power assist, (that appears to make them much more expensive.... at least over here), but wo power assist these cheap controllers look like they will work, and are cheap enough to buy one and try it. Not the end of the world if it doesn't work. (and I have another potential use for it anyway).

And I also finally found an exceptional brilliant and practical video on You tube one how to fit one, it is over 20 mins long, but no waffle or padding at all, crystal clear from beginning to end. I know you know how to do this, but this is worth a look, so that you could recommend it to people (like me LOL) in future.

Brilliant video on how to replace the motor controller without instructions.

So for the moment forgetting everything previously discussed for the moment.

If I buy and fit a new one of these 36v controllers, and put a 36v battery on the bike. then (apart from keeping an eye on the motor temperature which makes ice cubes atm). I can more or less not worry about all the other previous concerns, which were really to do with modifying the old controller to handle 36v, (which while very interesting and probably doable, is prob not worth the time it will take if I can buy one off the shelf for £10... OR EVEN LESS! ready to plug in and go.

As there are no gauges or indicators of any kind on this bike (ex the 24v battery which would be going anyway). So there is no instrumentation of any kind to be out of calibration (I will prob buy a handlebar display for it, to match the controller, once the thing works and is a useful bit of kit). I do have a spare throttle of my daughters 36v e-scooter, so if the existing throttle for any reason does not work, (which I doubt TBH), I can use that to test the bike and buy a new throttle, but from our previous chat, I dont think thats an issue.

So I think given this scenario it's just a question of whether the motor will handle 36v isn't it?

It's a pretty big hub motor, that only rotates painfully slowly atm which IMHO is due to lack of power i.e it desperately wants some more volts LOL. But with all the previous discussion and considerations about this it would be easy for a newbie to e-bikes like me to miss something.

SO did I miss anything that should still be taken into account if the bike gets both a new 36v battery (that I now have several of ready to go) and matching new 36v controller, other than keeping an eye on the motor temp?

Keith

I'm hoping and preying for basically, that sounds ok, but you would have to test it. In which case I finally understand the basics of this.......LOL