Alban, I only mentioned the regulator as a possible issue not having used one, if the guys say the KU controller is good for 48v then it probably is. If you're still concerned you could measure the voltage going into the regulator and work out what the limit is....or simply buy the e-crazyman controller off ebay which has an in built SMPS and can take 80v...
KU93 36V controller cope with 48V Headway batt?
- Thread starter alban
- Start date
All kinds of possibilities. That's what I like - lateral thinking and unobvious caveats!
I'm looking to create a mountain goat bike - climbing, not speed, being the issue - and also to be able to still use the stock battery without killing it - hence the ability to limit controller to 20A pull. So have a new 48V batt at 20A I thought to allow that... so the KU93 could cope - good.
I like the KU93 for it's sensorless ability also - as to conk out miles from anywhere could be bad for me so reliability/fail safe is key.
I'm nervous of RC lipo and would rather stick with PnP LiFePO TBH at this stage of my development.
Yes I could build a 42V Headway and stick with stock controller or KU63 at 20A but finding a reputable14S BMS might prove tricky?
Hmmm, food for thought.
I'm looking to create a mountain goat bike - climbing, not speed, being the issue - and also to be able to still use the stock battery without killing it - hence the ability to limit controller to 20A pull. So have a new 48V batt at 20A I thought to allow that... so the KU93 could cope - good.
I like the KU93 for it's sensorless ability also - as to conk out miles from anywhere could be bad for me so reliability/fail safe is key.
I'm nervous of RC lipo and would rather stick with PnP LiFePO TBH at this stage of my development.
Yes I could build a 42V Headway and stick with stock controller or KU63 at 20A but finding a reputable14S BMS might prove tricky?
Hmmm, food for thought.
I am currently looking at a number of re-volting options also. Better not push that shunt mod too far on that wee controller. A good alternative is the KU60 which I believe can handle both 36 &48v and is only 20mm longer so may well fit ok. Connections are fairly compatible also exept for the control panel/voltage display and brake wires which need integrated somehow with the controllers 3 speed switch(3 pin) and brake input(2 pin). Would the stock controller with 50v capacitors take 44v nominal lipo? That was a great review on ES eh!
Fully charger lipo at 44.4v nominal is 50.4v so it would be right on the endue of that the caps can take really. With the voltage sag from current though it would be ok.
If lipo os to much of an issue then you could just get a booster pack with the headways and find somewhere to mount it. Like a bottle battery type mount. I'm just trying to think of ways you can get round paying for a complete new battery.
If it's not speed your after then I'd just keep upping the current. That's going to make more of a difference to climbing. I'm sure you can take the controller past the stock 15amp up to 25amp without worrying. Again the only thing that may suffer is the voltage say from that draw. 25x36v = 900w power. Should be plenty to climb at most speeds.
If lipo os to much of an issue then you could just get a booster pack with the headways and find somewhere to mount it. Like a bottle battery type mount. I'm just trying to think of ways you can get round paying for a complete new battery.
If it's not speed your after then I'd just keep upping the current. That's going to make more of a difference to climbing. I'm sure you can take the controller past the stock 15amp up to 25amp without worrying. Again the only thing that may suffer is the voltage say from that draw. 25x36v = 900w power. Should be plenty to climb at most speeds.
Yes, well spotted, the KU60 does look interesting as it's advertised as working at both 36 & 48v and is smaller. Must be new. Would certainly need help with re-wiring it!
I thought about just upping the Amps but 25A draw may ruin the stock 2C max 10AH battery? It does sag under load also. Want increased range too as I use the throttle all the time.
The Review suggested that there was more climbing ability with 48V vis a vis 36V at same current but I take your point Scottyf that upping Amps is the standard way to go for more torque.
I thought about just upping the Amps but 25A draw may ruin the stock 2C max 10AH battery? It does sag under load also. Want increased range too as I use the throttle all the time.
The Review suggested that there was more climbing ability with 48V vis a vis 36V at same current but I take your point Scottyf that upping Amps is the standard way to go for more torque.
There will be more available power at various voltages as it's like the multiplier.
The point is though the bikes motor is driving through the gears meaning you get to decide where the power starts and falls.
It would only be at peak that the batteries would pull over their rated discharge levels. Again I'd still think of doing this before any other major payout.
The reason people buy higher voltage batteries on ebikes is because they want more speed from a single hub unit. They have a fixed gear electric hub. So the only way to get it to go faster is to increase the voltage.
Your motor is not fixed gear. You could increase the torque by adding more solder to the shunt and even if the voltage sag is significant you can compensate this be changing the rear gear ratio on the rear sprocket quite cheaply.
You only need to change on variable to get what you like. I just think you maybe chasing the increased voltage because someone has already done that.
I wouldn't be worried about the current batterry pulling peaks of 25amp. I'd be more worried if it was pulling that all the time but it won't if you keep it high spinning. It will only pull those amps from standstill up untill half the motors top rpm speed. Then it will decrease considerably.
The battery pulling those amps may last less cycle lifes. But it's still far cheaper than a complete new battery.
The point is though the bikes motor is driving through the gears meaning you get to decide where the power starts and falls.
It would only be at peak that the batteries would pull over their rated discharge levels. Again I'd still think of doing this before any other major payout.
The reason people buy higher voltage batteries on ebikes is because they want more speed from a single hub unit. They have a fixed gear electric hub. So the only way to get it to go faster is to increase the voltage.
Your motor is not fixed gear. You could increase the torque by adding more solder to the shunt and even if the voltage sag is significant you can compensate this be changing the rear gear ratio on the rear sprocket quite cheaply.
You only need to change on variable to get what you like. I just think you maybe chasing the increased voltage because someone has already done that.
I wouldn't be worried about the current batterry pulling peaks of 25amp. I'd be more worried if it was pulling that all the time but it won't if you keep it high spinning. It will only pull those amps from standstill up untill half the motors top rpm speed. Then it will decrease considerably.
The battery pulling those amps may last less cycle lifes. But it's still far cheaper than a complete new battery.
Thanks. I will increase Amps by soldering shunt first now to 20 then 25As to see but want more range so will likely get another batt. Yes, the Reviewer's experience, plus that of another, who have said that upping Amps alone didn't seem to give max climbing ability was guiding me. But I'll do it in stages as you are right that I may get what I want by trying the simpler things first.
Don't understand gear ratios so another thing to research!
Don't understand gear ratios so another thing to research!
One other thing I thought of trying was changing the 45 tooth? chainset-wheel thing to 53 tooth. That would give higher speeds but reduce the torque for hill climbing. However that looks like quite a difficult mod on the tonaro unless perhaps the new chainset could be bolted alongside the existing one?
If you guys are serious about tweaking controllers then go for the e-crazyman one, the Lyen is the same but modified version of it. They are programable so you can set a safe battery current limit without hit or miss soldering of the shunt and its possible to tweak the phase amps to suit your application...
You can change the front chain ring to get a higher speed. It will also drop the Motor rpm so it will draw more current for a longer period of time.
Think of how a internal combustion engine delivers power.
A car will deliver most of its power (horse power + torque) at the top of its rev range.
This is why we use a gearbox to keep the engine delivering the max power in a short sweet spot.
Electric motors work differently
They create all their torque and the lowest rpm. They create the highest power pretty much at half the no load speed.
By sticking a larger front chain wheel on you will naturally drop the rotational speed of the motor. Forcing it to draw more current (torque). The only thing that stops the motor accepting more current is the controller.
By upping the chain wheel and increasing the shunt you allow the controller to push through more available amps (current & Torque) and forcing the motor to push you.
You wont know untill you try. It may allow for a higher speed, it may be to higher gearing for the torque to really offer anything extra.
Its a little bit like trail and error. But the point is you have a varible gear system. So even if its to high you can select a lower gear to get it moving again.
Think of how a internal combustion engine delivers power.
A car will deliver most of its power (horse power + torque) at the top of its rev range.
This is why we use a gearbox to keep the engine delivering the max power in a short sweet spot.
Electric motors work differently
They create all their torque and the lowest rpm. They create the highest power pretty much at half the no load speed.
By sticking a larger front chain wheel on you will naturally drop the rotational speed of the motor. Forcing it to draw more current (torque). The only thing that stops the motor accepting more current is the controller.
By upping the chain wheel and increasing the shunt you allow the controller to push through more available amps (current & Torque) and forcing the motor to push you.
You wont know untill you try. It may allow for a higher speed, it may be to higher gearing for the torque to really offer anything extra.
Its a little bit like trail and error. But the point is you have a varible gear system. So even if its to high you can select a lower gear to get it moving again.
D
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Before you solder the shunt, I just had a thought, which might be a simpler solution.
The controller has a connector for a three speed switch. It works by connecting one of the outer wires to the middle one for low speed, the other outer to the middle for high speed and none connected is medium speed. If you don't already have it connected, you may be able to get more power by simply connecting the right pair of wires. I think I'm right in saying that this power control only works on the throttle. The pedal sensor has its own power algorythm, but it's normally too fast to be of any practical use.
OK my latest brain convulsion is to parallel a new Kudos 36V 10AH LiFePO4 batt with my Li-ion 10AH with a 30A 60V dual Schottky diode from Maplins 30A Schottky to prevent reverse charging. This would theoretically give me 20Ah in toto and so a 25A draw would not be harmful as presumably each batt would stay below 20A draw? So I get increased range & torgue without over-stressing either batt n'est-ce pas?
Now the diode would heat up I believe so can I bolt a bit of Alu straight onto the diode using the hole in the body of the diode or is that live?
Seems cheaper, I use the stock Li-ion, I buy British (sort of), keep the stock controller and there's a warranty with the Kudos batt (I presume?). Connect either by Kudos connector or dismantle and fit something else waterproof - what? That may invalidate any warranty tho'!
The only other prob I can foresee is that the Li-ion would drop Voltage quicker and then more current be drawn from the LiFePO4? but if I limit DOD to 80% I should keep it reasonably equal at 12-15A each? Occasionally check performance of Li-ion as it ages too.
Charge each separately.
Who's going to burst my bubble?!
Now the diode would heat up I believe so can I bolt a bit of Alu straight onto the diode using the hole in the body of the diode or is that live?
Seems cheaper, I use the stock Li-ion, I buy British (sort of), keep the stock controller and there's a warranty with the Kudos batt (I presume?). Connect either by Kudos connector or dismantle and fit something else waterproof - what? That may invalidate any warranty tho'!
The only other prob I can foresee is that the Li-ion would drop Voltage quicker and then more current be drawn from the LiFePO4? but if I limit DOD to 80% I should keep it reasonably equal at 12-15A each? Occasionally check performance of Li-ion as it ages too.
Charge each separately.
Who's going to burst my bubble?!
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