Maximize 12FET controller performance

[kZs0lt]

I want to bring out maximum performance from my 12 FET controller.
What would be the max. safe Phase/battery current?
It is a EB212 controller with stock shunt(2 wires, aprox 2.5mOhm), fitted with (12) 4110 FETs.
Battery and Phase traces have been beefed up considerably, battery wires are aprox 4mm2(AWG 11), and Phase are 6mm2(AWG 10).
Generally it is said that 4110 mosfets can take 100a continuously. On the spec it says 120A limited by package. Others say the FET legs are limited to 75a.
Would I be safe with 100a battery and 200a phase? Or should I lower Phase to 2x75A = 150A? Can I crank up battery current even more, or it should not make a lot of difference anyway?

Oh, my battery is a 18s2p a123 M1 cells, so about 58v nominal with 4+Ah. So it will be pretty hard on them, but they can take 30C continuously, or 2x70 = 140amps. I think I'll go for 100a battery for a somewhat conservative max.

And the motor is a 9C 9x7 winding in a 26" wheel. I know this power level can damage it, but the Phase wires are upgraded to what I believe are 12AWG cables, and I would use this power levels only for short periods, for accelerating like 10's of seconds.

I'd like to set up this bike for good accelerations, and wish to have it working reliably at least for some weeks.
What setting would you recommend?
What other needs tuning? Do I really need to lower the shunt value?

P.S.
At the moment I am not sure what are my limits, because I have programmed it as a 209 board with 57a battery / 120a phase because 57a was max in the Parameter designer. CA sees about 70-80a max continually, and 100a max momentary on CA. At these settings however the controller cuts out from a dead stop with full throttle. Maybe lowering the shunt could help?

 

[gwhy!1]

I want to bring out maximum performance from my 12 FET controller.
What would be the max. safe Phase/battery current?
It is a EB212 controller with stock shunt(2 wires, aprox 2.5mOhm), fitted with (12) 4110 FETs.
Battery and Phase traces have been beefed up considerably, battery wires are aprox 4mm2(AWG 11), and Phase are 6mm2(AWG 10).
Generally it is said that 4110 mosfets can take 100a continuously. On the spec it says 120A limited by package. Others say the FET legs are limited to 75a.
Would I be safe with 100a battery and 200a phase? Or should I lower Phase to 2x75A = 150A? Can I crank up battery current even more, or it should not make a lot of difference anyway?

Oh, my battery is a 18s2p a123 M1 cells, so about 58v nominal with 4+Ah. So it will be pretty hard on them, but they can take 30C continuously, or 2x70 = 140amps. I think I'll go for 100a battery for a somewhat conservative max.

And the motor is a 9C 9x7 winding in a 26" wheel. I know this power level can damage it, but the Phase wires are upgraded to what I believe are 12AWG cables, and I would use this power levels only for short periods, for accelerating like 10's of seconds.

I'd like to set up this bike for good accelerations, and wish to have it working reliably at least for some weeks.
What setting would you recommend?
What other needs tuning? Do I really need to lower the shunt value?

P.S.
At the moment I am not sure what are my limits, because I have programmed it as a 209 board with 57a battery / 120a phase because 57a was max in the Parameter designer. CA sees about 70-80a max continually, and 100a max momentary on CA. At these settings however the controller cuts out from a dead stop with full throttle. Maybe lowering the shunt could help?

You need to re-program to a 12fet and lower the shunt value, this should solve your cutting out problem and give you more battery current. I dont know much about hub motors or 12fet controller running 4110's so I cant really tell you what the safe max you can go upto, Im sure someone will chip in soon enough with more info.

 

[ZOMGVTEK]

80/200A is about as high as you would want to take it.

I run my 12 FET Infenion 4110 at 60/150 and its towards the upper limit before you need to start worrying. I ran it at 80/200 for a few WOT runs, and it did get fairly warm. The motors stock phase wires were just about on fire, so I backed it down.

I plan on running it at 80/200 when my 5404 shows up... The worst case is probably just some FET's exploding, which I can handle.

 

[gensem]

Dont forget that when you talk about controllers you have to take care about phase amps and total watts and not battery amps alone.
I

 

[dogman dan]

My idiot 2 cents worth is that the runs better be 10 seconds. That sounds like 75% of the power going to heat. Only so much a 9c can use. Give it more and it gleefully makes heat with it. 3000w seemed to be the practical maximum for my race bike, and it hit that with no mods easily.


Drag race?

 

[John in CR]

I took a 9fet 4110 controller to the point where it was cutting out on acceleration and the controller popped on the 6th or 7th launch. You're not going to get much more out of a 9C anyway, because Justin found the stator started saturating at 90A, and I believe that was even a 9x7, and that's phase amps, so realistically you're already past the limits, and the controller is trying to tell you the same. I don't think shunt mod trickery gets you around that hard wired limit causing the cutouts. FWIW on the batt/phase amp limit ratio, my motors don't sound quite right below a 2.4:1 ration, though YMMV.

Since you really need to turn the controller down a bit, not up, and even if you could go up more it would do little good anyway, then If you want more acceleration you need to put that motor in a smaller wheel. Going to a 20" wheel will give you 23% more torque and a markedly better launch. Other alternatives are to add another motor or install a bigger motor.

Also, note that about the hardest thing on the system is repetitive low speed launches. You mentioned that you wanted to get at least "weeks" of durability, but it doesn't work like that. There's not something really wearing on the system like if you were riding an ICE powered bike hard. It's a matter of whether you exceeded the meltdown limit that session.

If you really want to push the limits then ventilate the motor, including installing some blowers inside to force more flow and increase the turbulent flow at the stator windings. Also put a blower on the controller. I've pushed controllers well past the limit where they otherwise would have blown by ventilating them.

 

[scriewy]

is it some protection that cuts the controllers off ? what is it

 

[gwhy!1]

is it some protection that cuts the controllers off ? what is it

yes it is.

Edit:
Just thought I would mention, I have been running my modded 12fet now at 4.8kW battery and 10kW phase and giving it a very hard time but so far so good.

 

[kZs0lt]

Just thought I would mention, I have been running my modded 12fet now at 4.8kW battery and 10kW phase and giving it a very hard time but so far so good.

Could you please add some detail?
What type of controller do you have, what FETs is using, what are your settings (battery/phase amps), are you using the stock shunt(aprox resistance if you know), what battery and motor are you using?

 

[miuan]

Just thought I would mention, I have been running my modded 12fet now at 4.8kW battery and 10kW phase and giving it a very hard time but so far so good.

How can you make 10kW out of 4.8kW??? Do you have an extra battery in your controller case?

 

[gwhy!1]

Just thought I would mention, I have been running my modded 12fet now at 4.8kW battery and 10kW phase and giving it a very hard time but so far so good.

How can you make 10kW out of 4.8kW??? Do you have an extra battery in your controller case?

Thats what the phase current is set to relative to battery voltage, is far easier to work in Watts rather than amps because this will work with any voltage/current combination ( well I find it easier :wink: but not everyones cup of tea ) .

 

[kZs0lt]

How can you make 10kW out of 4.8kW??? Do you have an extra battery in your controller case?

Thats what the phase current is set to relative to battery voltage, is far easier to work in Watts rather than amps because this will work with any voltage/current combination ( well I find it easier :wink: but not everyones cup of tea ) .

It is more simple, but not as explicit, it could be that you are running 100v with 100amp phase and 48amp battery, or 50v with 200A phase and 96A battery.
For a FET that is limited in current (and voltage) is not the same.
So,

Could you please add some detail?

Thanks,
Zsolt

 

[gwhy!1]

Could you please add some detail?

Thanks,
Zsolt[/quote]

its a moddified ( but not reprogrammed) 12Fet that runs on 48v and a battery current limit of 95A and a phase of 220A I dont know what the shunt value is but it has been reduced quite a bit from stock, the fets are IRFB3077PbF , I run a 3250w rc outrunner have 12s lipo's.

When people just post up there current settings of their controllers it can give the wrong impression i.e some one posts 'I run my controller at 80A' but then fails to say at what voltage , so the next person looks at this and thinks ok I can put my controller upto 80A but in reality the first person is using a 50V and the second is using 100v, so the second person is running twice the power then wonders why the controller blows up. This is why I have started using watts when I talk about my controllers.

 

[kZs0lt]

Thanks for the additional info gwhy!

My understanding is that phase amp is what really matters for FET durability. When a controller is fully loaded set to say 100A phase will generate the same amount of heat in a FET with no regard to battery voltage if it is 24v or 100v.

I'm not sure how phase current is regulated though. Is it precisely calculated from battery current & pwm duty cycle and limited according to the preset value?

its a moddified ( but not reprogrammed) 12Fet that runs on 48v and a battery current limit of 95A and a phase of 220A

If it was not reprogrammed, how can you know phase current limit? Are you measuring battery max current with the soldered up shunt, and assume the ratio between battery/phase current remained the same as original(factory default) and calculate it from the CA or wattmeter detected battery current?

I was also considering to limit my phase current to 220A on my 12 FET controller, but IRFB3077PbF fets are superior to IRFB4110 in current handling ability (but lower voltage) IIRC, so maybe I should consider lowering it. As some say, my 9C 9x7 motor saturates at about 90A phase, so I may not benefit from such a high phase current anyway.

 

[gwhy!1]

Thanks for the additional info gwhy!

My understanding is that phase amp is what really matters for FET durability. When a controller is fully loaded set to say 100A phase will generate the same amount of heat in a FET with no regard to battery voltage if it is 24v or 100v.

Yes, the phase current is not so predicable, in the true sense of the word. There is some relationship between bat voltage and phase current due to the kv of the motor

I'm not sure how phase current is regulated though. Is it precisely calculated from battery current & pwm duty cycle and limited according to the preset value?
I think the controller guestimates from like you say the bat current and pwm, but not totally sure :?

its a moddified ( but not reprogrammed) 12Fet that runs on 48v and a battery current limit of 95A and a phase of 220A

If it was not reprogrammed, how can you know phase current limit? Are you measuring battery max current with the soldered up shunt, and assume the ratio between battery/phase current remained the same as original(factory default) and calculate it from the CA or wattmeter detected battery current?

Yes the phase limit is based on what a stock controller will be set to ( but know one really knows what the actual stock setting are ) with a standard shunt, and Im assuming by reducing the stock shunt this will also increase the phase limit

I was also considering to limit my phase current to 220A on my 12 FET controller, but IRFB3077PbF fets are superior to IRFB4110 in current handling ability (but lower voltage) IIRC, so maybe I should consider lowering it. As some say, my 9C 9x7 motor saturates at about 90A phase, so I may not benefit from such a high phase current anyway.