Pushing the IRFB4110's to the limit

[steveo]

Hey everyone,

-I'm looking to push my 36 mosfet controller setup over 100v usage ...

-Everything in controller vr circuit & caps are modified for up to 150v usage/ & cycle analyst is 150v!

-i'm looking to try 32s a123 & 30s turnigy lipo pack

-32s a123 pack at top of charge will be 118.4v; nominal 105.6
-30s turnigy lipo pack top of charge will be 126v; and nominal 111v

Am i crazy? .. should i do it?

forgot to mention about a 250-300amp shunt!

-steveo

 

[rhitee05]

Bad idea. I would be very, very surprised if the 4110 FETs survive voltage 26% above their rating. Even if they do survive, I expect it would dramatically reduce their lifespan. Most likely they will suffer breakdown, lots of current will flow, and there will be magic smoke.

 

[John in CR]

4110's uh no. Just send it to me instead and I'll try to blow it for you at only 20s. Unfortunately I'd probably be successful and still not stress my motors. These controller limits forced upon us really sucks.

 

[zEEz]

Although IR makes and sells very underrated parts, I would not bet they could last very long ...
You can see the experience of Ripperton on diyelectricar forum and his R1 using overvolted KELLY controllers
with plenty IR fets ... They last one or 2 races and then they smoke and be returned to factory ...

My experience using IRF in A-class amplifiers for audio showed you can use them daily for years and years
with the case at 85°C stable and they just rocks ... no failure whatsoever .... but I would not bet on repetitive
spikes administration and continuous overvolting like you plan .... they have to EXPLODE

I will use IRFB3077 parts (75v) with hot packs up to 72v but that's it ... :wink: :wink: :wink:
I don't want to find myself soldering and desoldering FETs day by day ... 8) 8) 8)

STILL, good luck and POST your findings, STEVEO, PLEASE !!!!!! I'm very curious ...

have fun!

 

[steveo]

The idea is that under load say at 200 amps... i don't want my pack dropping below 100v!!!

say for example " 30s turnigy lipo pack top of charge will be 126v; and nominal 111v "

say on a fresh battery; I can expect to see voltage sag of about 5-10v through all connectors; wires .... fuses etc

so lets say 121 - 116v under load ex 200 amps

will the irfb take it ...

I've seen a friend of mine run his controller at 116v unloaded... but his voltage sag bring him down 15-20v

comeon ... where is the doctor?

-steveo..

 

[Doctorbass]

Steveo..

DONT DO THIS

All efforts and complex built like a 36 fets controller will be instantly useless..

It will blow in the first second you turn the throttle .. and will be worst if it's a low turn winding motor

replacing 6 or 12 fets at a time would be a real pain!!!

best i recommand is 24s lipo or 28s A123... and that's with 5304 or 5305 equivalent KV motor.. the 5303 and 5302 or equivalent WILL MAKE IT BLOW with 24s lipo

Please dont make my own shared bad experience become uselless!!... Listen me and dont do that!

I wold say that 22s lipo or 26s A123 is the max SAFE voltage for 4110 to garanty it will not blow..

Personally i use 24s lipo on my 5304 without any problem.. but with 5303 and 5302 it blew too many times!

Cmon Steveo.. follow our advices... we dont really need to have youtube video showing you blowing up your controller.. we preffer that you demonstrate they are tough and real beast when used in their specs!!

Doc

 

[Doctorbass]

On the other hand, an intelligent decision would be to make a 36 fets 150V controller with teh 4115...

that would make a 200A 150v very stable and powerfull controller

Doc

 

[zEEz]

Steveo..

DONT DO THIS
Doc

 

[Doctorbass]

I just hopw the 4 little smily face zEEz posted will not convince you to try that anyway :?

Doc

 

[Arlo1]

The idea is that under load say at 200 amps... i don't want my pack dropping below 100v!!!

say for example " 30s turnigy lipo pack top of charge will be 126v; and nominal 111v "

-steveo..

Then use 4115 fets!

 

[zEEz]

I just hopw the 4 little smily face zEEz posted will not convince you to try that anyway :?

Doc

As I wrote few post upper:

You can see the experience of Ripperton on diyelectricar forum and his R1 using overvolted KELLY controllers
with plenty IR fets ... They last one or 2 races and then they smoke and be returned to factory ...

... any additional empirical proof is welcome ...
BUT my point is that with a 36 mosfet controller it is a pain in the ass to solder new mosfets each day :wink:

have fun!

 

[Doctorbass]

I just hopw the 4 little smily face zEEz posted will not convince you to try that anyway :?

Doc

As I wrote few post upper:

You can see the experience of Ripperton on diyelectricar forum and his R1 using overvolted KELLY controllers
with plenty IR fets ... They last one or 2 races and then they smoke and be returned to factory ...

... any additional empirical proof is welcome ...
BUT my point is that with a 36 mosfet controller it is a pain in the ass to solder new mosfets each day :wink:

have fun!

How Ripperton was able to overvolt a kelly?. they usually dont output any current until the voltage is under the max recommanded ?

Ex: I have the 220A 120V one that can take from 18 to 136VDC.. adn if i try to go over 136vdc it will just not work and the red led will blink...

Doc

 

[zEEz]

How Ripperton was able to overvolt a kelly?. they usually dont output any current until the voltage is under the max recommanded ?

Ex: I have the 220A 120V one that can take from 18 to 136VDC.. adn if i try to go over 136vdc it will just not work and the red led will blink...

Doc

Cannot tell you, but he wrote to use 172v hot battery with KHB14601,24-144V,600A,Opto controller,
so I imagine custom firmware or something .... don't think 172v is within specs ...

http://www.diyelectriccar.com/forum...ric-track-bike-41173p43.html?highlight=ME0913

here it is the link, perhaps you can ask him directly or I can ask myself in the forum, as you prefer 8)

have fun!

 

[liveforphysics]

Do it. Take pictures or the carnage for us to enjoy.

 

[steveo]

fyi, with my experience irfb4115 will not handle x5303 or x5302 motor period. I originally did build my 36fet controller with irfb4115 blew out high side phase 2 times last week with factory 5 wire shunt in 36 mosfet infinion controller!!... I had tempature proble also on high side bus bar and temp never reach over 45 degrees before blowing!! don't get me wrong... i had great success with right motor for the irfb 4115's on my x5306; worked fantastic!!!!!! with my 44s a123 battery...

I will take pictures for sure ...burnt or not burnt... I will try 110v nominal of a123 on drag run... if it blows, it blows.... shit happens hehe

dont hate on me guys... just wana see where the limit is...

i think if under load i'm at like 105v .. i won't blow anything IMO... i will keep clost eye on tempatures of motor & controller

just think of it as another experiment!

-steveo

 

[Arlo1]

fyi, with my experience irfb4115 will not handle x5303 or x5302 motor period. I originally did build my 36fet controller with irfb4115 blew out high side phase 2 times last week with factory 5 wire shunt in 36 mosfet infinion controller!!... I had tempature proble also on high side bus bar and temp never reach over 45 degrees before blowing!! don't get me wrong... i had great success with right motor for the irfb 4115's on my x5306; worked fantastic!!!!!! with my 44s a123 battery...

I will take pictures for sure ...burnt or not burnt... I will try 110v nominal of a123 on drag run... if it blows, it blows.... shit happens hehe

dont hate on me guys... just wana see where the limit is...

i think if under load i'm at like 105v .. i won't blow anything IMO... i will keep clost eye on tempatures of motor & controller
just think of it as another experiment!
-steveo

I belive this is because of how our cheep controllers don't watch phase current they just guess. And the 5303 and 5302 will have to low of inductance combined with lower resistance then the x5304. But thanks for testing that for me I will not bother with a 36 fet with 4115 fets for colossus now that you blew one on a motor about 10x more gental on the controller!
On another note steveo John in CR and I have had great luck adding inductors in series with each phase to save our controllers!!! I started a whole thread on it and did a lot of work with them! I can't take all the credit the idea was given to me by a top secrate member! :wink:

 

[liveforphysics]

IRFB4115 mosfets are simply not suited towards any performance controller.

The IRFB4110 is a good part, but running it outside it's voltage range is really just waiting for the fireworks show. Which is fine, I love some good carnage pictures, but don't be building it as something you're going to trust as a commuter or something. lol

 

[Alan B]

As I recall the inherent body diode in these FETs is a Zener. At some voltage it begins to conduct which is useful to absorb spikes. But if it is continuous current the heat produced will instantly overdissipate and destroy the device.

 

[steveo]

remember this

IRFB4568 mosfets... 150v!!!

kabammm!

(NEVER USE 22 gauge wire for mosfet legs HAHAHA)

I will change out the board with a 12 mosfet infinion; and setup for 150v... I never had any blowing issues with this controller to be honest... it just was so big lol!

should work!

-steveo

 

[zEEz]

Hey, Steveo, if you happen to have too many 4110 that you need to get rid of ...
I offer my postbox as a happy dump for all that disgusting silicon

have fun! (peace and love)

 

[Arlo1]

Steveo what were you running the 36 fet controller with irfb4115 fets at for max voltage?

 

[steveo]

Steveo what were you running the 36 fet controller with irfb4115 fets at for max voltage?

133v & 151v!

 

[Doctorbass]

Steveo.

The most powerfull and safe combo according to my experience would be a 36 fets controller with a 54 or 5303 with 22s lipo. I know 22s is not really common but it will save the fets!!!
fet blow not always due to heat.. in my case the controlelr never got really got when it blew.
if the voltage spikes when mosfet switch on and off are too intense due to the low inductance they will blow.

Using 22s instead of 24s lipo give you 8V margin so the 100V fets work at 92V wich is really tough

using a 04 with 115V and 100A or a 03 with 92V and 125A will give you similar performances but the 4110 controller will survive with the 92V setup :wink:

Now here is my theory of commercial controller tolerance calculations based on known and theorical data:

Let's examine the Kelly controllers:

The 120V model wich is a 120V nominal and 136V max represent fully cahrged battery, is using the 150v fets.

-the nominal is representing 80% of the rating of the mosfet
-the maximum is representing 91% of the rating of the mosfet

What is mean.. is that if you want to keep a safe margin as Kelly do, you should not use max voltage over 91V for a 100v mosfet wich is 22s like i suggested

Anyway.. as we already explained.. the 4110 have half the rds On than the 4115

The 4115 might tolerate 33% more voltage but it tolerate hald the current.. so using the 4115 mean less power

This winter, i will assemble my 36 fets controllers with the 4110 and promiss me that i'll never exceed 91V so i will enjoy the max possible power and still safe configuration.

Do what you want Steveo.. it will still be a real pleasure to watch :wink:

Doc

 

[zombiess]

Please don't, such a waste. It will blow.

It's your stuff though. I run all my 4110 controllers at 99.4V max and so far no issues, but there is very little headroom left. I punished a 9 FET 4310 controller with 24S2P and block time set at 2 for 55amp peaks and a 33A limit. It got warm, but no carnage after 100 miles with a 2806, but the only reason I think I got away with it is the 20" wheel gets it into efficiency range fast.

 

[texaspyro]

Do it. Take pictures or the carnage for us to enjoy.

yes, Yes, YES! Do this... PLEASE! I own stock in some magic smoke factories. They can use the business.

And remember that the FETs will see quite a bit more voltage than just the battery voltage because of switching spikes and inductive kickback. For a 100V battery, you want at least 150V fets.