KU93 36V controller cope with 48V Headway batt?

[alban]

Want to up-power my Tonaro to increase it's good climbing still further. Inspired by Tonaro Bighit Review and Upgrade. Suggests over-volting also increases torque (power).
Thinking of building/getting a Headway LiFePO batt 48V X10AH as it seems straightforward (haha). Also want to be able to use the standard 36V 10AH Li-ion batt as a reserve. 20+ Amps may kill stock Li-ion so thought upping Vs and keeping As at 20 seemed best. Later can up-Amp when Li-ion dies.
I pedal very little so weight not a big issue. Also like the modularity/fixability of the Headways. BMS from cell-man?

So... present controller won't take 48V. Concerned re LVC of 48V version of the KU93 not working with the 36V Li-ion batt. Will the capacitors/mosfets of 36V KU93 deal with 48V battery (?57V hot off the charger)? Presumably if rated 60V, yes?
Also I like the KU93 as I believe it will work even if the Hall sensors get fried!

 

[Scottyf]

60v Caps so yes.
Open it up to check though as well as the Mosfet serial numbers to check their max voltage.

My controller ran at 52.8v max for ages or 12series battery pack.

And yes it also works sensorless.

 

[alban]

60v Caps so yes. Open it up to check though as well as the Mosfet serial numbers to check their max voltage. My controller ran at 52.8v max for ages or 12series battery pack. And yes it also works sensorless.

Cheers Scotty
So as long as the new 48v batt's BMS has its own LVC built in there should be no problems using the 36v ku93. Likely the mosfets are rated for 60v too but I'll check.

 

[aseb]

The hall sensors work at low voltage (3V-24V) not your battery voltage, they should be fed the correct voltage by your controller. They're cheap anyway, but changing them is a bit of a hassle. The Honeywell SS41 are good reliable ones if you do need them, but there are manufacturers and codes for suitable sensors.

 

[Scottyf]

You could go down the booster pack route and get a 3s battery and wire it in with the original battery to up the voltage. But it may be more hassle. But would allow it to be cheaper.

 

[alban]

Thanks guys.
I was concerned re the heat generated in the motor by upping the Watts possibly destroying the Halls and conking out mid-ride, so a controller that works without them would be an insurance policy! However I see the KU93 wiring is different to the stock one so that'll be a bit of a hassle.
Adding 3S idea good but I was going with Headways to reduce voltage sag as they can cope with 5C OK I believe.... certainly 3C... and in case I up Amps more in future. Also just more batt to increase range.
Not sure I'm up to the technicalities but I know help is at hand here!

 

[NRG]

Its not just max FET and cap voltage rating you need to check. The control circuits and chips will be fed 5v typically derived from the battery voltage by a linear 3 pin voltage regulator. Exceed the input / output voltage differential rating (around 40v) and it will blow...so if upping the bat voltage you will need to lower the input voltage to the regulator.

However, some of the newer controllers like the ones from e-crazyman have switch mode power supplies that can take a wide range of voltages IE up to 80v AFAIK....theres some info on ES but I cant find it at the moment...

Edit: Yes, 80v

 

[Deleted member 4366]

Thanks guys.
I was concerned re the heat generated in the motor by upping the Watts possibly destroying the Halls and conking out mid-ride, so a controller that works without them would be an insurance policy! However I see the KU93 wiring is different to the stock one so that'll be a bit of a hassle.
Adding 3S idea good but I was going with Headways to reduce voltage sag as they can cope with 5C OK I believe.... certainly 3C... and in case I up Amps more in future. Also just more batt to increase range.
Not sure I'm up to the technicalities but I know help is at hand here!

The halls won't be destroyed by the battery. There's a voltage regulator in the controler that supplies them with 5v regardless of battery voltage. The most common way they get destroyed is by heat, which depends mainly on how many amps you feed the motor not the battery voltage and whether you run the motor in its efficient range. If you get the KU93 it can run both with and without halls - always better to use the halls if you have them.

i wouldn't worry too much about the connections on the controller being different. If you could post a picture of your controller, which shows the connectors, we can advise on what to do with the connections. You could buy a new pedal sensor and throttle with with connections to match a KU93r: Pedal sensor costs about 75p snd throttle is about £2.50. After that, you only need to connect the battery and motor wires.

 

[wurly]

Why is it better to run motors with hall sensors Dave? i assumed that controllers can work with both bemf and hall pulses.
I fiited a higher value resistor to the 12V regulator in one of my controllers that i intend to run at a higher voltage. Not sure if it was needed, but thought it wouldn't do any harm and could save blowing it and causing further damage.

 

[Deleted member 4366]

Why is it better to run motors with hall sensors Dave? i assumed that controllers can work with both bemf and hall pulses.
I fiited a higher value resistor to the 12V regulator in one of my controllers that i intend to run at a higher voltage. Not sure if it was needed, but thought it wouldn't do any harm and could save blowing it and causing further damage.

Smoother, quieter, better starting and more efficient - but none of them by much, You can tell the difference though.

 

[hech]

Would be interested to see how you intend to fit the new bigger battery and controller. The bike rack monting system on the Tonaro does not lend itself well to conversion and a bigger controller will not fit in the existing compartment..

 

[alban]

Its not just max FET and cap voltage rating you need to check. The control circuits and chips will be fed 5v typically derived from the battery voltage by a linear 3 pin voltage regulator. Exceed the input / output voltage differential rating (around 40v) and it will blow...so if upping the bat voltage you will need to lower the input voltage to the regulator.

So is it in fact impossible to use a 36V and a 48V battery interchangeably with the same controller - unless the ecrazyman version you mention? Is that voltage detection automatic or have to be manually switched each time?

d8veh: Good to know that there are ways round the different connections... you'd mentioned the sensorless capability in prev posts as insurance against Halls failing and conking which I thought was a good plan.

hech: Yes the Tonaro is a bit difficult to mod. I am concerned how much weight it can carry on the rear rack... I was hoping to get a similar sized controller as it is a very tight squeeze in there! However I might have to put it all in a bag attached to the rack on top of the battery which looks reasonably strong. Perhaps the Headways would weigh too much....? I presume the Reviewer I linked to above went RC LiPo.

Anyhow, better to do thought experiments before spending cash!
PS Anyone know the ku93's dimensions?

 

[Scottyf]

You can use the ku93 controller from 30v to 63v.
But you'll loose the low voltage cut out from the controller. It means you'll have to rely on the battery management system to control it.

The controller is not programable. So you cannot change those things.

Sorry I don't have diemensions. D8veh may have them of they may be on bmsbattery website.

I'd be tempted to try the controller first to see if your capable of changing that and then going to a battery that has higher voltage. I'd even be tempted to just get a small lead acid 12v battery to wire in series to see you would like the additional speed.

With it being crank driven I would have thought just uPping the amps in the standard controller would pretty much do what you'd like. As the motor drives through the gears.

Increasing the voltage will allow the max rpm of the motor to increase. Meaning your cadence for any gear will be faster. Bit like fitting race camshafts to internal combustion engines. You increase the available motor spin for any one gear. But unless you can spin your legs super quick you will still need to change gear or not pedal. Just a thought.

 

[banbury frank]

Hi How about buying second matching battery and running at 72 volts


72V/1500W brushless controller for E - bike & scooter | eBay


Frank

 

[alban]

Scottyf: Thanks. So you think that the KU93 can cope with using 48V and 36V batts interchangeably despite the potential 'voltage regulator' problem that NRG mentions? Yes the LVC would need to be controlled by the battery itself.
KU93 is undoubtedly bigger than the stock one so may need a hacksaw and ingenuity!
Increased cadence with 48V may not be a prob as I pedal little.
Another solution may be upping Amps as you say. I could use a Cycleanalyst to dial down the Amps mid-ride if I switch from the new batt to the older Li-ion batt? However that's another £130!

 

[Deleted member 4366]

Another solution may be upping Amps as you say. I could use a Cycleanalyst to dial down the Amps mid-ride if I switch from the new batt to the older Li-ion batt? However that's another £130!

Don't forget the Speedict is only £66 and a lot easier to change parameters mid-ride. You need an Android phone as well - I hope you don't have an iPhone! Also, you can get the CA direct from Ebikes.ca for just over £100, and it's the latest one with big screen.

 

[Scottyf]

I don't think the 9fet will fit at all.
This is the size of a 6fet vs 9fet controller.

You can't hacksaw it either.
I'd look at a basic shunt mod first before doing anything really expensive. That and remove the speed limiter.

 

[alban]

Thanks for the pic. I was thinking of taking the hacksaw to the controller compartment and adjacent battery one to house the KU93. Tricky though to seal it up afterwards....

I'm a Luddite and don't have either phone. I spent my life trying not to be too contactable!

I've removed the limiter and soldered the shunt to 20As but not been fit enough to go out on it. But I think I'm going to 'need more power from the engine room, Scotty'!
Anyhow I'm going to assume the KU93 can allow 36V and 48V batts to be interchangeable.
Reading up about the CA it seems to need a bit of modding to limit current which would test to the limit my nascent electrical 'skills'.

 

[Deleted member 4366]

Alban, Why do you believe that your present controller won't take 48v? Will it take a 44v lipo pack (actually 50v max). The KU 63 is quite small (30x53x97)and can definitely run at 44v, and the shunt can be soldered for about 20 amps. It might be able to fit in your controller compartment. Because your motor goes through the gears, you would get a 30% increase in speed and climbing power just by soldering your present shunt. If you want to go fast all the time, then you might need a bigger controller. I use a KU63 on my Cyclamatic at 44v and 20 amps for moderate runs (one or two miles up medium hill) at 1000w and it seemed ok. If you don't like the idea of Lipos, you could build a 44v Headway pack.

When you do these sort of mods, you need an ammeter or watt-meter. If you get one that shows volts, you can also use it for battery monitoring, which saves weight and complexity. The Speedict is the one I'd recommend.

 

[Scottyf]

I think from reading other posts that the tonaro comes with a max 50v caps in the controller.
Even getting the little 6fet one from Bmsbattery would allow greater flexibility.

Great thing about lipo is the lack of voltage sag vs other battery formats. But there delicate and need care, time and attention.
It would still be cheap though to run another 2x 2s 5000mah in series to make an 8.4v max 10ah battery to run in series with the original battery without the need to change the controller.

This would be pushing your original controller though but would give you 1000w peak hot off the charge.
Those batteries are available
Look at this on eBay:

7.4v 5200mAh 20C LiPo 2S 7.4 Volt RC Akku Battery WF

7.4v 5200mAh 20C LiPo 2S 7.4 Volt RC Akku Battery WF | eBay

So two of them for less than £30 delivered. Then you just need to wire them up and use some form of cell monitoring. But easy enough to do really.

You can use the ku93 at both voltages without damage to the linear voltage regulator. Some times if the voltage is vastly different 36v to say 90v then you need to add a different resistor inline befor it reaches the regulator. The voltage difference is so little in this setup it doesn't matter