R12 mod for high voltage regen

[Hyena]

Hey guys,
I've put together a spreadsheet to make it easy to calculate what resistor changes are necessary to mod your controllers for regen at high voltage (above 75v). It's also handy for hardware changing the LVC and regen limits on non-programmable controllers (I also use it to run stock 36/48v 9C controllers on 15S lipo)

I didn't come up with this concept myself, information about how to do this has been posted in a few threads and knuckles posted the maths a while back and there's more info buried in one of the big infineon controller threads, but this way takes all the hard work out of it.
The pack voltage info I've included is for lipo (largely for my own convenience) but I'm sure you clever folks can put in your own values for lifepo4 or what ever else you're using

A few people have been asking me for this info lately so here it is
(maybe one of the mods can move this to the technical reference area ?)

[dbaker]

What is a 9C controller?

[itchynackers]

Awesome! Now I just need to find the original r12 value for my lyen 12fet.

[Hyena]

What is a 9C controller?

Black infineon controllers as supplied by e-bike kit etc. I got a few bigger 12 fet units direct from 9C with the group order I placed.

Awesome! Now I just need to find the original r12 value for my lyen 12fet.

Easily measured once you open the case to do the mod. I'm too lazy to open a 12 fet lyen I have here right at the moment but if I have cause to open it before you get around to doing yours I'll post up the resistance.

[number1cruncher]

R12 on the 9FET e-bikekit controllers should be around 1200 Ohms. I think all the 846 boards use this same value. Double check though. Good luck!

[auraslip]

Good stuff - just wanted to link to the article where knuckles talks about doing this. http://endless-sphere.com/forums/viewto ... 45#p127913

he says

The stock Infineon R12 value is 1200 ohm.

Is that true for all infineons you reckon?

In any case, thanks for making the spreadsheet

[Hyena]

Not all, no.
The 12 fet infineons from 9C I've used were 2200ohm

[Kingfish]

Hyena,

I think you should post this in the Technical Reference Area:

• Infineon Controller Power Resistor Calculator

Best, KF

[NeilP]

Hyena, can you put a link back up to the calculator spreadsheet..it has gone missing.

Edit: found I had it and have re posted it below


Once the R12 has been modified...can the combined parallel resistance be measured directly across the resistors on the board? or do other components skew the result?

Lyen did my mod for me...and he tells me the overall resistance is now 400 Ohm and to use a 33 % change. From his e-mail

400ohm is the overall resistance value.
Program LVC = real (LVC + 2) x 0.75. For example, real LVC for 24S lipo is 67.2 (24 x 2.8, then program LVC = (67.2+2)x 0.75 = 51.9.
The maximum program regen voltage formula is (real regen x 1.33).

Problem is my controller has died within half a mile of use and it has only just arrived back from repair. It is not the motor, halls, or throttle. I just plugged the other Crystalyte controller back in and it all works fine again.

He has only just returned it after it failed the first time, within a week of building the bike.

it is an 18 FET Infineon Lyen edition 4110 65 amp controller EB218- AS - 1 revision board

I have taken the board out to check for dodgy components...and took an ohm meter to the R12 resistor...and the parallel resistor.
Reading from both R12 and additional resistor ( using three different meters for comparison) is 782 Ω

So can the parallel string be measured while fitted to the board?

[NeilP]

I have found a copy of the xls sheet that I had already downloaded.
And now I am worried

IF the new R12 voltage can be measured while the resistors are in situ...then I think Lyen may have given me the wrong info with regard to the calculation of the new voltages after the mod

From what he told me, I used
Required HVC =83v..so 83 / 1.3333 = Program HVC of 62v
Required LVC =70v..so (70+2) * 0.75 = program LVC of 54v

but going by Hyenas spreadsheet



Looks like my figures are to high.IF the figure can be measured directly

So assuming I have over volted my controller because of too high a HVC figure...what have I damaged and what is the fix ...what components do I need to replace?

[grindz145]

I couldn't manage to download it either, however this is super-useful.

[NeilP]

Hyenas R12 Calc.xls

(24.5 KiB) Downloaded 258 times

well since the original link is broken, and I found it on my machine, I''ll upload it again


I got my bike working again..the figures Lyen had given me were wrong. Maybe he assumed a different standard R12 resistor and did not actually measure it.

I e-mailed him as soon as I had the problem, and he has not got back yet, but he is always a while answering e-mails..I think he has a life other than checking e-mails every five minutes

My board is version EB218 AS -1

so if any one knows what the original R12 value is..and if it can me measured in circuit or not then I will be able to do some meaning calculations

[SamTexas]

... to mod your controllers for regen at high voltage (above 75v)...

Why the 75V threshold? According the ebike.ca, the cutoff voltage for regen is 57V.

One other issue is that the controllers are designed to have a fixed 57V regen cutoff voltage. That means that regen will not work with a higher voltage battery pack unless you trick the controller into thinking everything is running at a lower voltage.

So in theory, this modification needs to be made if one is running 14s (58.8V) or above. Am I missing something?

[NeilP]

... to mod your controllers for regen at high voltage (above 75v)...

Why the 75V threshold? According the ebike.ca, the cutoff voltage for regen is 57V.

Not sure where you go the 75 volt from..I am aiming for 83 volt for my cutoff voltage for Regen

So in theory, this modification needs to be made if one is running 14s (58.8V) or above. Am I missing something?

Exactly ..I am running 20 series..so at 4.15 per cell that is 83 volts.

I am actually wondering if it is an idea to set the regen voltage to something much higher, to give a good current back into the pack...OK so you would have to be careful when the pack is just off charge...but how about setting ( in my case) 90v or greater regen voltage. Unless I was going down a single continuous hill of many miles in length and braking constantly all the way down, even if the regen voltage was set to 100volts..the pack would never reach that or go above even the 83 volts...unless I started braking for a long period immediately after starting riding with a full pack

[number1cruncher]

... to mod your controllers for regen at high voltage (above 75v)...

Why the 75V threshold? According the ebike.ca, the cutoff voltage for regen is 57V.

One other issue is that the controllers are designed to have a fixed 57V regen cutoff voltage. That means that regen will not work with a higher voltage battery pack unless you trick the controller into thinking everything is running at a lower voltage.

So in theory, this modification needs to be made if one is running 14s (58.8V) or above. Am I missing something?

There are two main types of controllers people use on ES: 846 and 116. The 846 has a lower (~57V) regen voltage allowance than the 116 (~75V). Lyen sells the 116s and E-bikekit.com used to sell the 846s.

[NeilP]

There are two main types of controllers people use on ES: 846 and 116. The 846 has a lower (~57V) regen voltage allowance than the 116 (~75V). Lyen sells the 116s and E-bikekit.com used to sell the 846s.

Have not seen those figures on the board at all.. the only reference I have seen on the board is the model number EB218 AS-1

Still, that does not answer my question of wether the overall parallel resistance can be measured on the board or not. that is what I need to know now, that and the original R12 value

EDIT..just had a revelation...846 and 116 refer to the MCU/..I'll have to pop the top off again and have look

[number1cruncher]

Yes, sorry, I meant to mention the numbers I was using referred to the MCU model.

I think your 792ohm is correct as you should be fine reading the resistors in circuit. The original value will be more difficult to find, since the values found around here could be for either MCU. I have a few 116 boards laying around my house, however they are 9 and 12 FETs. I'll see if I can come up with an average value when I get home in about an hour. Hopefully my family does not overwelm me when I walk in the door!

There are two main types of controllers people use on ES: 846 and 116. The 846 has a lower (~57V) regen voltage allowance than the 116 (~75V). Lyen sells the 116s and E-bikekit.com used to sell the 846s.

Have not seen those figures on the board at all.. the only reference I have seen on the board is the model number EB218 AS-1

Still, that does not answer my question of wether the overall parallel resistance can be measured on the board or not. that is what I need to know now, that and the original R12 value

EDIT..just had a revelation...846 and 116 refer to the MCU/..I'll have to pop the top off again and have look

[NeilP]

If reading the resistance with it in series is OK, I could possibly unsolder one end of the new parallel resistor, and measure just that one, and the R12 on the board.

After two days I have only just got the controller fixed back in the bike. and taking it apart again, and doing some unsoldering,,just for he sake of it...just know something will go wrong..it is the usual way...tinker with something enough and soon enough you will F it up.

Back of board

[number1cruncher]

No need to disasemble the resistors I believe.

I just measured mine and they are all 1200ohms. Also the SMD resistor shows 122. I believe this translate to 1 for the first number, 2 for the second, followed by two 0s OR 1200.

Check your original R12 SMD. Does it show 122? If so, use 1200 to calculate your LVC!

If reading the resistance with it in series is OK, I could possibly unsolder one end of the new parallel resistor, and measure just that one, and the R12 on the board.

After two days I have only just got the controller fixed back in the bike. and taking it apart again, and doing some unsoldering,,just for he sake of it...just know something will go wrong..it is the usual way...tinker with something enough and soon enough you will F it up.

Back of board

[NeilP]

I have not got a good enoguh picture to see tonight, so will pop it off tomorrow to get a closer look.
Looking at the last pic I posted...i suppose I could slice a window in the heat shrink of the added resistor, and check its colour code

[miuan]

Guys, have the 112 MCUs the same layout and resistance? Trying to make regen work on a cell_man's 12FET at 74V.

[Hyena]

Sorry for the late reply guys, I've been away from the computer for 2 weeks.

So assuming I have over volted my controller because of too high a HVC figure...what have I damaged and what is the fix ...what components do I need to replace?

The HVC is only for the upper regen voltage really, so like you said unless you started out at the top of a hill on a full charge and regenned all the way down it's unlikely an improperly set HVC has taken your controller out. Infact if anything it would have only damaged your battery. Sounds like something else is wrong.

As for measuring the resistance, yep just put your ohm meter across the original R12 (or the new parallelled one) and read off the value.
Don't rely on the 1200 ohm default value in my calculator, that was just for one particular controller I was using.
You should always measure your R12 value before starting. That's the whole point of the calculator, to work out what additional resistor value you need.

If reading the resistance with it in series is OK, I could possibly unsolder one end of the new parallel resistor, and measure just that one, and the R12 on the board.

Yep that'd probably be the quickest way to check the original R12 value. Just unsolder one leg of the new resistor then measure across the original SMD R12.

... to mod your controllers for regen at high voltage (above 75v)...

Why the 75V threshold? According the ebike.ca, the cutoff voltage for regen is 57V.

Ebikes.ca probably mentions 57v because the controllers and batteries they sell only go up to 48v (last time I checked anyway, apologies Justin if this isnt the case)
75v is fine for up to 18S lipo but for anything higher, ie 20S or 24S lipo (or the lifepo4 equivalent) you need to up the HVC.

Guys, have the 112 MCUs the same layout and resistance? Trying to make regen work on a cell_man's 12FET at 74V.

Probably very similar if not identical but I'd double check to be sure. If the board layout is different using the diode/continuity beeper on your multimeter you can find one where else on the board the back of the R12 resistor goes

[NeilP]

measured mine up, total new is Measueed at 782
Original is marrked 122. so 1200 and measures at 1160
The new resistor measures at 2390. so tha all figures correctly

just so I am 100 % sure I am using the spreadsheet correctly
The Original value figure is the one that goes in the program. and the calculated ' New Value' is the resultant figure that you actually get ? yes?

As an idea. is it ok to set the HVC higher than the final battery voltage. so I have 20 s that I charge to 4.15 per cell to 83 volts.,. So assuming I do not start massive braking with a fresh hot bsttery, ant harm in setting HVC at say 90 or 100 volt?
The pack is never going to reach that voltage, but it will give better braking early on in the discharge cycle

[number1cruncher]

As an idea. is it ok to set the HVC higher than the final battery voltage. so I have 20 s that I charge to 4.15 per cell to 83 volts.,. So assuming I do not start massive braking with a fresh hot bsttery, ant harm in setting HVC at say 90 or 100 volt?
The pack is never going to reach that voltage, but it will give better braking early on in the discharge cycle

Neil,

You lost me here. Are you still working on the LVC? If not, where are you setting an HVC?

[NeilP]

You lost me here. Are you still working on the LVC? If not, where are you setting an HVC?

bot LVC and HVC now sorted with regard to my R12 mod...but

i was wondering about setting the HVC higher than the pack voltage
. I have a 20 s pack...so 4.15/cell = 83 volts
So ideal HVC voltage is ...83 volts

But I was wondering if any harm can come in setting the HVC much higher..say 90 v or 100 v for the same 20s pack.
Although the system will try and push up to what ever limit you set...( the HVC limit) since the pack is below that voltage...hopefully 82 volts or less after a bit of riding. Setting the HVC higher may improve regen braking by ( and recharge current) by allowing a higher potential voltage.