Newb Controller & FET controller upgrade question

[granolaboy]

Hello,

I've got a cheapie electric scooter with a 48v rated controller. I've opened it up, and it has a 1000uF 63v cap, and 7 mosfets. 6 of the mosfets are clearly identifiable as NEC k4145, and the last one I don't know...

I wanna run this thing at 60v...which in reality with fully charged batteries, is more like 68-69v...

I'm thinking I can replace the Cap with a 100v one, and the fets with some irfb4110's or irfb4410's...then it should handle it no problem.

Problem is, I don't really know what I'm doing :lol: What FETs should I use?

Another issue is the FETs are a bit more expensive than I'd like...

I'm I on the right track? I'm sure most of you will say "just go buy a new controller", but I'm wondering if I can make this one half decent with some cheap higher rated components...

I apologize in advance if all this sounds a bit nutty...

thanks!

 

[Kin]

subscribed, just wondering what kind of responses you will get. Thanks. Sorry I don't have the answer

 

[granolaboy]

Thinking this cap (the highest ripple current on digikey):

http://search.digikey.com/us/en/products/SLPX102M100A3P3/338-1553-ND/1882030

And these fets, chosen for highest current and power:

http://search.digikey.com/us/en/products/IRFB4110GPBF/IRFB4110GPBF-ND/2096587

Hrm....by the time I get the cap and 7 fets I'm already at $40-50...that's a new generic hua tong 72v 1500w controller...

http://www.dhgate.com/72v-1500w-bru...r-for/r-ff80808131bbd38d0131bbda55e40253.html

For the money, it doesn't look like it's worth it...but maybe I'll do it just for the fun...

could go with cheaper fets, like some 4410's:

http://search.digikey.com/us/en/products/IRFB4410ZPBF/IRFB4410ZPBF-ND/1894147

or maybe 4710's:

http://search.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=irfb4710&stock=1

If I got 7 4410's and a cap, that's $35.68 to my door.

hrm.....

perhaps these?

http://www.ebay.com.au/itm/10-x-IRF...509?pt=LH_DefaultDomain_0&hash=item416160323d

If anyone knows anything about mosfets, feel free to chime in!

I guess I'll also need some insulating strip for the fets and some dielectric thermal paste to put it back together right...upgrading the wiring to 12 or 10awg and beefing up the traces would also be a good idea while i'm in there...

Maybe I'll just shunt mod it, go to 60v and wait till it blows...when it does either upgrade the fets/cap, or just get a hua tong...

 

[neptronix]

I'd say go ahead, replace the caps and FETs, but you never know what other components may be lurking around that can't handle the voltage..

You will also need to be pushing higher amps at higher voltage to maintain the higher speed.. fact of life. The question is, could that controller, with it's amount of FETs ( 6?! ), even handle the amperage.

Then down the line, maybe you decide you want even more power, and wonder why you spent ~$40 upgrading a generic, non-programmable controller.

My money is on new controller.

 

[Drunkskunk]

First thing to point out is you have 6 Fets, not 7. the 7th is likely the voltage regulator for the low power side.

What voltage are you planning to use this at? 4110 is a good high voltage FET, but there are some faster switching, more efficent FETS at lower voltages. I think the 4330 is one, but have to verify that.

 

[granolaboy]

I'm going to be running at 60v, so realistically, there could be as much as 69v going through there.

Others have run this controller at 60 without any problems...the odd person bakes it.

Unless I can find the parts for really cheap, I agree, it's not really worth it. Might as well just run it at 60v, and if it fries, get another controller. I'm sure any bottom-of-the-line controller is as good or better than this one.

 

[hjns]

Get some nice 4110 FETs from Methods for 2.50 each (15 total): http://endless-sphere.com/forums/viewtopic.php?f=31&t=36084
And a 100V cap should not be very expensive either, so my guess is you will spend much less than $40.

In the end, it really depends on how much you are willing to spend for pleasure. If you are willing to spend those 40 bucks on a questionable upgrade, then you may actually succeed and have a lot of fun for a couple of months, including the great feeling of having modified a controller. To me, that is worth $40 bucks. Then again, you might just want to save a little bit more money and get a nice Lyen 9 FET 72V controller for $89: http://endless-sphere.com/forums/viewtopic.php?f=31&t=16998

 

[NeilP]

Hell, just get a new one ready made from Lyen

6 fet 4110 ready built programable sensored controller for $79 USD..probably cheaper than upgrading yours once you pay for postage of Caps and FETS and solder

http://lyen.com/


http://endless-sphere.com/forums/viewtopic.php?f=31&t=18744

 

[dnmun]

i agree with neil, if you aren't already up to a high level of soldering skills, do not take on the task of replacing the mosfets.

maybe swap the input caps for 100V and use a little larger input power resistor to drop the voltage to the 12V regulator and then run that until it blows up. maybe it will, maybe not, but by then you will wanna go big anyway. and lyen is the big. skip the mosfets. if they blow and you wanna replace them all then you can decide that then.

 

[wesnewell]

Just buy another controller. For under $40 you can get one that will support up to 100V.

 

[rjoe]

Hi, sorry I know this is late, but I just opened my controller yesterday.

I have a cheap Chinese controller that looks a lot like that with NEC 4145s. However, there are actually only 3 fets, the other 3 are actually barrier diodes for flyback protection.

The flyback diodes in my 36V controller are rated to 100V, so maybe if you can't see them well, you could double check and halve the cost of your proposed FET upgrade

 

[zEEz]

Hi!
if you are willing to solder few components, I can assure you can make the original
controller far more tough just by replacing the mosfets.
In your place I would swap the 6x 2sk4145 (7th one is probably Lm317 voltage regulator)
with 6x irfb3077 <you can get them for 15-20$>. They are great mosfets, they can
double your current capability and because of the RdsON that is 3 times lower also
the produced heat will be reduced. Eventually you will need to put a small blob of solder
around the shunt of your controller in order to increase the current and so the power output
... this will be possible because of the better fets ....

have fun!

 

[jordanjozsef]

You will also need to be pushing higher amps at higher voltage to maintain the higher speed.

That is not true. The higher the voltage, the less amps you need for the same speed. I'm using a 117V battery pack with only 54A controller, but I can reach 90 km/h, and it could still go faster, I just need to increase the battery amps with the shunt mod, I just don't know those IRFB4115 FETs can handle more amps.