Infineon has REGEN BRAKING (and more)

[VanElectric]

I seem to have a similar, but smaller, board than the one in the photos, where I do not have the GND-4 column.
Can I solder BK to GND-3 instead to activate regen?

 

[Takemehome]

I seem to have a similar, but smaller, board than the one in the photos, where I do not have the GND-4 column.
Can I solder BK to GND-3 instead to activate regen?

If you look at your board, you will see that all GND-x are connected together.
GND-3 or GND-8, same thing. :wink:

 

[chet]

If your battery pack has built-in BMS Regen will not work.

 

[edpol]

If your battery pack has built-in BMS Regen will not work.

That's why I'll be using a lead or nickel based pack instead of lithium. Unless of course, there's a reasnonable way of bypassing the batteries to another load.

 

[VanElectric]

I wonder if my regen is reversed, because I do get some light drag when spinning forward (while bike is on the centre stand), but much heavier drag when spinning in reverse. I don't mind the light drag as I think the pressure is perfect, but I'm worried about the motor regenerating charge in the wrong polarity (if that's possible) when I'm regen braking, that may damage the batteries.

So
Question 1: Does polarity of electricity generated by motor change based on direction of spin?
Question 2: Is there any easy wiring/soldering I can do to make spinning forward more "grabby" than spinning backwards?"

Thanks

 

[icecube57]

The GM controller had little drag going forward and alot of drag going backwards. Regen was always on. It kicked in alot harder at higher speeds and was barely noticeable at lower speeds. It was linear with speed. It wouldnt charge my ductape ebay lipo with bms on. It would allow regen with bms bypassed.

 

[tron]

I have a Shenzhen (e-crazyman) 48 volt controller. Is it possible to use regen braking on this model? The board seem different from the pictures in this topic. There is a BK pad but it's miles away from the 4 Ground pad on the board. Did I get an early model? Or can I just jumper it with a long wire? I will send pictures later.

Tron

 

[mwkeefer]

Hello All,

Somthing to think about - Back in the day when we used to build car stereos with 2000-3000 watts of power for Car Audio Competitions we were putting such a drain on the vehicle electrical system (headlights dimming with booming bass, 130+ db) that we turned to stiffining capacitors.

I have read elsewhere's in forums where people have tested stiffining capacitors on their eBikes with mixed results, this is likely due to the choice of brand ("pyramid" was, is and always will be CRAP!).

Though I am awaiting a no-frills but quality low ESR 1/2F Capacitor the electrical theory behind it's series operation with a battery is quite simple and should prove more than effective when combined with ANY BATTERY CHEMISTRY, INCLUDING LIFEPO4!!

The advantages of adding a stiffining capacitor are:

1.) When drawing peak, sudden bursts of AMPS from your power pack... an inline capacitor will provide a good portion of the required power dump at much higher rates of discharge than you can acheive from any battery chemistry including lipo. In essence the capacitor is like having a short term 30C-60C discharge pack.

2.) If used in a regen type ebrake situation... a stiffining capacitor will absorb the power being sent back through the ESC which will be stored (this is how many hybrid cars, trucks and buses work). Since you will in essence be charging the capcitor using your regen, the battery chemistry or function of BMS will not matter and since a capacitor could absorb 20-100A or more it will provide a much more efficient and powerful ebrake clamping effect because it will provide a higher drain on the "generator" hub/wheel. The nice part of this advantage is the flip side.

3.) The flip side of #2 is when launching from the line, after using the regen brake your capacitor will be charged and will exhaust it's own charge before drawing from the battery. This means for between 4-10 seconds (depending on the draw and the capcitor's size) you can draw HUGE AMPS and it will not drain the battery.

Don't misunderstand... you will eventually charge the capacitor fully using regen and then the capacitor will begin trying to pass current to the battery. With BMS protected battery it should not be an issue, with non-BMS it should actually provide longer term regen charging of your pack (works with lipo, sla, etc).

If all you wanted to do was add brakeing power or "clamping power" then just add a load that is switched into the circuit when regen is activated. The first things which come to mind would be a brake light (48v 2A-10A) That would provide a continuous and much more streetable clamping load than a capacitor which may indeed be far too strong of a brake load for a front wheel configuration)

Just some food for thought, I had to chime in,

- Mike

 

[dnmun]

you can't place a capacitor inline in a DC circuit.

the amount of power created by regen is more than a cap can store, imho.

 

[mwkeefer]

You are 100% right on the first count, inline, parallel... what's the difference (I don't need to keep my stinking fingers). JK You really are correct, I can't believe I actually posted that. I will post a wiring diagram this weekend to clarify but you are right, they will not work "inline"

You are 50% right on the second point - It is true a capacitor will hold no where near enough power to provide long and powerful braking, basic electronic theory (unless my math was really off last night, could be possible considering the inline/series/parallel goof above) suggests (again I am being intentionally vague until I test this irl) that a sufficiently large cap (1F) were wired into the configuration it would provide additional load on the ebrake/regen circuit for a short time while it charged which would increase the braking action. The subsequent delivery of it's surplus energy upon restart from dead stop would delay the time before your batteries see the load by a few seconds (give or take a few seconds) and would provide high burst startup current to get you rolling (my testing shows heaviest load in window of 4-7 seconds while reaching top speeds under WOT of 30+ mph) obviously the faster you try to go the faster your CAP will discharge its surplus current so it might be a little like shooting a moving target from a moving target.

And again this is really just food for though, I will test it soon enough and report the results (even if I make a total ass of myself and fail miserably) so I don't encourage anyone else to try this yet (especially if they have pyramid brand caps, or the kind with built in ammeter or any kind of NEONish lights!).

All joking aside dnmun you really are probably right all the way around but the idea seems sound enough (though I admit only in my mind, you have no idea how scary that place is sometimes) that it would bug me for weeks if I didn't do the experiment.

On a side note, this may be posted elsewheres and I may have missed it but. While trying to figure out a method for hacking the values in the Infineon Parameter Designer .asc files and failing, I went old school with a Hex Editor and managed to patch some of the low voltage cutout values to include 36v and 38.5v which is perfect for my lipo pack (12S10AH). I opened the acutal .exe file and made the changes to string variables stored within the binary code (love lazy programmers). I wasn't sure if it would work but much to my joy.. SUCCESS!! Pack cut out at 38.4 hard (had set .5 tolerance). Tested again with 36v cutout and that worked too. Finally I hacked some custom speed % values off 125%, 130% and 150%. When I programmed these the controller took the values without exception. I should warn you I had an odd sync issue running with load at 150% but everything else worked as expected.

Thought I would slip this info into a post nobody will read = )

-Mike

PS: dnmun - thanks for the reality check = )

 

[Takemehome]

Mike,
Do you think these caps will handle the regen voltage ?
Are they not rated at a 20V. max.?

 

[mwkeefer]

Which caps? The ones inside the infineon controllers or the stiffining caps?

I have access to stiffining caps in ranges from 14, 20, 24,36,48, 66, 75 and 100v ranges at 1F... the higher the voltage the more expensive, same with the lower ESR caps.

Please be a bit more specific so I can give you the most accurate information possible.

-Mike

 

[dnmun]

the input power caps and the S/D bus cap are all 63V470uF.

on the goldenmotor regen controller, they added a clamp between the S/D legs to protect the input caps when they invoke regen. they used a 62V zener as a Transient Voltage Suppressor with 1.5kW rating and added a .22R 5W wirewound resistor as the load in series on the zener to absorb the top of the spike above the clamp voltage. they put one clamp on each pair of highside and lowside FETs. 6 clamps for 12 FETs.

i worked on duane's regen controller because all the zeners and the power resistors, almost all that is, had burned open, but the caps which they were installed to protect were still ok. i still decided to add the 100V100uF caps to replace the stock 63V470uF caps.

that also used the p75fn75 FETS.

http://endless-sphere.com/forums/viewtopic.php?f=1&t=9746

 

[mwkeefer]

I see what you mean... I must have missed that somewhere... I know about the 63v 470 for the stock caps... I have already replaced those with higher capacity 100v1000uf caps (following same as HV100, just because it felt right).

Even with the improved caps there I will still need to beef the remaining circuitry (diodes and resistors) to handle the additional voltage and dissappation.

Uggg... it's too late here for me. Brain Mush

Gnite all,
Mike

 

[dnmun]

not really. the high frequency ceramic caps are already likely 100V rated. there is nothing on the power besides the FETs. so just replacing the caps will get you to 72V lifepo4 voltage levels. i would worry a little when the battery is still hot and around 86V or so and the low idle current is pulling the voltage regulator input high and allowing the 12V rail to run on the top of spec. once there is throttle it should be ok. jmho.

 

[mwkeefer]

Couldnt you just slightly undercharge the lifepo4 72v pack so it doesn't come off so hot?

I charge my lipo packs to 4.15 now and 3.2 for cutout voltage. I still get > 5000mah when pulling 20-40 amps

The real point is my 12s lipo pack hot off the charger is only: 49.8v, couldn't the same be done with the LifePo4 72v nominal...

-Mike

 

[dnmun]

i meant that you can use the stock setup except for the caps up to 72V nominal lifepo4. which is about 88V max. but any load on the battery drops it to around 84V immediately.

i guess there is the risk that the charging voltage will break the FETs when hot before there is current sucked out of the pack.

 

[mwkeefer]

Is is possible that the FETs would blow under certain circumstances with a fully charged lifepo4 at 88+v, better to set your per cell cutout just .2 - .4 lower than normal so the hot off the charger V would be slightly lower by 2-3 v minimum and the risk would be reduced by factors.

Considering most of us who are serious have spare controllers / FETs / parts, a blow out might be a no-big-deal or "non-issue" for you.

In either case its good to know the 72v nominal LifePo4 packs will work right off the charger (even if there is a bit of risk).

-Mike

 

[zukster]

Has anyone figured out a way to read the parameters programmed into an Infineon?

I posted here because much of the programming was discussed in this thread, but my main post is here:

http://endless-sphere.com/forums/viewtopic.php?f=2&t=8610&p=216666#p216666

 

[mwkeefer]

Zuk,

As far as I know not yet, I've played with probing the MCU but with no success (thought I had succeeded, I was wrong).

To the best I know the firmware supports one way programming at boot only and in some configurations will output serial data of unknown content via AUX pad durring operation but that's the extent.

That said, if you have a watts up or better an eagletree... and an hour of spare time you can deduce what your infineon stock settings are by working backwards, where did your controller come from with what kit... mayhap I (or someone here like methods) knows the default configuration already.

-Mike

 

[mwkeefer]

Try this: keep some throttle while you brake, you get a good regen back.

Tried that when I first tested. I tried it braking at half throttle, full throttle, no throttle. Results were the same. It turned out to be the LiFePo4 batt doesn't allow regen. It worked great with SLA's, until I installed the switch to get reverse. Now there's no regen, and no reverse. I removed the reverse switch, but still no regen. I don't know where I made the mistake, but I got another controller that has both regen and reverse activated. Turns out to be a GM regen controller, the one they sold before the magic controller. It's also an Infineon, 36v 30a. It should be here shortly.

I have managed to modify the e-bikekit LiFePo4 battery to allow regen... The process is fairly simple and yes I do believe it will be adaptable to other LiFePo4 (and other chemistry) BMSes... There are caveots and actually there are 2 methods, the easy way and the "right" imho way...

[The easy, freeish and potential dangerous to your battery way]

Open the battery up, add a second discharge port (when you see how the first is in place, you will understand how to add perhaps a second anderson or gold 3.5mm plug, whaterver your pack has now.... just add another of the same type...
This plug is not wired to the BMS discharge wiring but directly wired to the battery itself... this is a full BMS bypass...

The only thing which could in theory be dangerous with this setup would be if you programmed the infineon for a higher current or if you soldered the shunt... if you did, you will pull more than the 25A maximum (2.5)c rate of the cells themselves

One other issue, I wouldn't use more than 80% of the capcity in this mannor (8AH) becuase the chance of a cell passing LVC still exists..

[The better way]
Obtain a SPST NC relay with approx 30-60A
Connect an LM317 adjusted for 12v output (the relay will likely consume about 100ma once engaged)
Using a common NPN type transistor with the collector connected to the 12v GND, the gate connected to the fet driver via a high impedance (10k) tap and finally the emitter connected to the GND side of the relay...
Now add that second discharge port but wire it so that when the relay is not engaged, ground is interrupted to that discharge port..

The end result is when the BMS detects LVC on a cell and tries to send the "SWITCH" fets inside off... it also turns off the output at the non BMS protected discharge port.

Without the FET protection, current is free to flow in both directions so regen will again work... the trick here now becomes setting the right regen level... I suppose for a few seconds to a minute a LiFePo4 10AH pack could handle a 1C charge (10A) but really you will want to mess with the regen settings until you get the lowest possible current input to the pack... I believe most LiFePo4 is rated for charging at no more than 1/2C or 5A rate...

In either case, that's the rough cut of how to enable regen using BMS protected LiFePo4 battery systems... there may be mroe complications as in perhaps the gate signal needs to be the trigger of an inverting flip flop to ensure proper disconnect of the non - current limited / directional port... this will eliminate possible overdischarge and when charging through the BMS the same balancing it normally would do will take place.

Hope this helps, sorry so late - and yes I will post a thread on how to do this unless it's already out there...
-Mike

 

[geoff57]

Does anyone know what the pad marked LED does? It's the one near the EB+ and EB- inputs...

The LED pad is used to indicate the chip has power and hopefully is working some of us have bought these controllers from ecrazyman fitted with switches on with either a LED next to them or built in to the switch the wiring of these switches in the controller is as follows.
For the switch the thin red wire(or orange in a very old model) has been removed it is not needed, in it's place is the switch that is connected between the main power positive input to the controller and the Vcc-L pad and the LED indecator is connected to the LED pad and GND no resistor is required with the LED it is on the board.

Hope that explains things.

Geoff

 

[John in CR]

...That said, if you have a watts up or better an eagletree... and an hour of spare time you can deduce what your infineon stock settings are by working backwards, where did your controller come from with what kit... mayhap I (or someone here like methods) knows the default configuration already.

-Mike

What I want of know is the stock settings of the phase current limit for the Infineon boards I have. Is that possible to back into?

 

[mwkeefer]

John,

Only if you can tell me where you sourced (dealer) it and how (individually, part of kit, etc) and approx when you received it.

How many FETS?
Which MCU (846 or the newer 116)
Which model (on the PCB by the caps) EB2XX, 8XX or (hope not) 7XX series?

Even then I can only offer baselines for the units I've tested, upside - I've tested most dealers controllers, even the ones which never make it to market as part of a kit (why do you think they don't make it to market? - lol) or a guess if I know the configuration for one of their competitors kits / controllers which I documented on their behalf.

Regards,
Mike

 

[John in CR]

Mike,

It's an EB715XC with the 846 MCU and 15 sanded face fets. It's part of a 60V motor/controller combo meant for some chinese emotos, with specialty stuff like the ebrake cutoff expects a 12V signal from the lighting system that's input to the controller via a single wire fed to BK. It's not part of any kit, because the motor needs 210mm between the dropouts, so a frame needs significant modification to fit the motor, and the motor needs modification to accept a chain.

The controller is called a 60V30A controller, though I've been running them at 81V off the charger for over a year. I was told by the factory rep that the engineers told him the max off the charger voltage it would take is 83V, so I haven't tried higher even though the caps are 100V caps.

John