20A Controller 150V Mod

[Nimbuzz]

Ok, So could you alter the limiter and upgrade the FETs to allow the little controller to handle a 5304 @ 72v? Because the 'big' controller is BIG = VERY big. But Knoxie has a big one on his bmx so I guess it might be necessary -- no?

Thanks,
Al

 

[xyster]

Ok, So could you alter the limiter and upgrade the FETs to allow the little controller to handle a 5304 @ 72v? Because the 'big' controller is BIG = VERY big. But Knoxie has a big one on his bmx so I guess it might be necessary -- no?

The physical problem would be cooling, and how long the modded 72V 20A --> 35+ A controller would live. There's probably many ways to sufficiently improve cooling for the smaller box and sink.
I don't know, but with half the FETs in a smaller box to begin with, there might also be a problem finding correctly-spec'd FETs, and the room to mount them.
There should be plenty of room on the downtube or above or below a back rack to mount the bigger controller -- it's not THAT big.

The 5304 will run OK at 20 amps 72 volts, but acceleration, hill climbing, and top speed will all take a very noticeable hit compared to 72 volts 35+ amps. I wouldn't consider running the x5 with less than ~1500 watts (72v 20a, 48v 35a, etc) -- in that case one might as well get a 4xx series or Puma instead. The x5 simply takes that much power to spin-up in a reasonable amount of time compared to smaller hubmotors. 2500 watts and up (72V 35 A or more) is where this beast outshines the competition....

 

[knoxie]

Hi

The little controller is the size of a pack of cigarettes the other controller is twice the size and a bit! to confuse things further though they do make the big one as a 20A controller as well!

Yes you can make the 20A little controller 30A simply by bridging the busbar, I didnt use one on the BMX as Mark wanted to run the 35A controller on it, it still works ok with the 35A controller but it is a bit too much (wheel spinning and snapping torque arms) so the 20A controller at 72V is perfect for the BMX or the Puma esp at 72V, I still think if your batteries can cope that the big controller is a better unit with the Puma if you are running 37-48V, higher than that then 72V 20A is a better option.

You can use the little controller on an X5 no probs at all, I would upgrade the fets and fet mounting hardware to cope with the increase in load, bridge the busbar and you can pull 30A, on an X5 that will nip you along nicely!

Good luck, still to wet to go riding today what a waste of a day!

Knoxie

 

[deecanio]

Hi Knoxie,

manic weekend mate - just catching up on the thread now
i'm guessing weekend was pretty much a washout? damn british weather - that'll be another week before i can get in the woods again
i'm working on getting my bike clean and my batts mounted but until i know i have a sound setup i cant really get everything mounted in final positions or have the finishing seat/tank combo made.
Unfortunately i will have to tie and duck tape on the second batt until we are happy with it all then i can get stuff done properly.
Hope things are ok mate - busy week again for me and got my mrs birthday at the weekend so no rush this end mate - probably wont get a ride until sunday at the earliest

Cheers


D

 

[Jozzer]

my little controller handles over 2KW (84v@30A) without overheating. It needs to be mounted in the breeze, but then, it always did even at lower power. I have a small fan ready for summer, but I'm not at all sure I'll need it yet. The fact that its small enough to mount anywhere helps keep it in a cool location! (the 35A controller IS that big...it wouldn't find a spot in the breeze on my KMX for sure...its what...4 times the size?)

 

[fechter]

If you upgraded the FETs in the little controller, the amount of heat dissipated should actually be less than the stock configuration. 35 amps would be no problem for 4110's or 4310's (90v max). With 4110's, you could probably push that thing to 60 amps.
A few cooling fins on the side wouldn't hurt either.

It only has 6 FETs, which makes upgrading easier too.

 

[deecanio]

Hi Jozzer,

yes the mounting of the little controller is a big plus for me also - i hope to run it at 30a eventually but may need some bms work done before this can happen so i'm going to run it at 20a to start off with - at least i will get a taster of 72v even if it is only at 1440w.
Knoxie sais he thinks the puma sweetspot is around the 1600-1800 w mark so hopefully i will run 72 x 25a but we will see,i need to run 20a first and check all is ok then maybe do the 30a mod and be happy at that - all depends on the 20a performance.


Cheers


D

 

[knoxie]

Hi

Weekend was a total washout, this week looks the same, we are almost in June and its almost freezing outside tonight, I don't know what's going on any more, still wearing a fleece and tempted to put the heating on!!

Haven't done any more stuff have not had the time, I want to check the 72V controller is going to work, the limit is more to protect your batteries than the controller to be honest, I dont want your BMS burning up like mine did, its expensive and could be quite messy, better to back things off a bit and keep them safe and happy! I will run the BMX with it at 72V#20A and do a movie, I bet it isnt far off the performance of the first video, if the wheels spun less that would be a plus!

I will PM you with the results, forecast looks like water all week there is no end to this

Cheers

P

 

[Jozzer]

Same down here , all wet cold and windy....finaly got my astroflight charger and another 12v added to the pack, and no chance of running the batteries flat
Mudguards are a MUST for wet KMX riding i've found....do you have them Knoxie? I see they sell them for £50 at KMX..must get me some before autumn!

 

[knoxie]

Hi Joz

Yep run a normal MTB on on the back, dont bother on the front, just wear an old jacket and bung it in the wash if I get wet!!

I hope to ride the KMX a lot in the summer, I am so spoiled for choice at the moment!! good news on the extra pack, I still like NIMH batteries no pesky BMS worries, shame the price is flying up on them though, I would like to make my own NIMH pack some time.

Cheers

Knoxie

 

[deecanio]

hi mate,

yes i'd realised the 20a was to protect my point1's no bother with timescales mate, weather is totally crap!!.
i still have to strip my bike anyway so i wont be ready for a while yet.
ill pm you later knoxie - just need to catch up as i didn't get to work until 10.30 today lol, good job my gaffa isn't in


cheers


D

 

[Jozzer]

Lol....you must have a different KMX Knoxie.....my front wheels direct the spray front and centre....and about head height...so I am riding through a selfmade rainstorm!

 

[deecanio]

hey knoxie,

mailed you at nildram mate as my pm's don't seem to be moving.


Cheers,


D

 

[knoxie]

Hi Joz

I generally dont ride the KMX in the rain, the snow was as wet as I have got with it to date, you can get the fenders for the front as well from KMX, they are a little pricey though, but then getting soaked is no fun either.

The KMX do suffer a little with corrosion on some of the bolts, I have found lashings of wd40 or acf50 work really well in keeping it nice and shiny and corrosion free.

Back to you DC went out in the garage and bolted the controller to the bike, the 20A one, will take it for a test run later maybe if the weather holds if not I will try and get out inbetween the showers and try it, I still think 20A would be enough.

Ill try it and see, if it works and doesnt cut out we should be ok, good to go, wish I had a drain brain as my watts up meter wont work at 72V, need to get me a version 2 meter some day.

fingers crossed x I still think your batts will be ok if you keep it to 25A max keep that safe margin in place, we dont want to melt your batteries, mine are easier to get at!!

It more like electric boat weather at the moment though

Cheers

Knoxie

 

[Stevil_Knevil]

Hello Knoxie,

This mod only took you 2 Hours?! Good god.. you're a machine! :wink:

I started some time around 6:00 last night, and finished at about 3:00 this morning. Just got back from the test ride (I felt obligated) with a brand-spankin' new set of 4110 FETs installed in my little C-lyte controller.

Life is good, but I need to go fall down now.


Cheers,

-S

 

[fechter]

Knoxie cheated. The 20 amp controller only has 6 FETs.
Where did you score the 4110's from?

 

[knoxie]

:lol: :lol:

The little controller is much quicker to modify but yes 2 hours or so, I am getting my time right down on the bigger controller as well now!

Glad you done it ok Steve let us know how you get on with it! do you intend to push the current or the volts up?

Cheers

Paul

 

[Stevil_Knevil]

Where did you score the 4110's from?

I bought 12 of them directly from International Rectifier for $4.60 apiece.
Click on-

http://www.irf.com/search/product_line.html

..and enter "IRFB4110PBF" in the search field.

do you intend to push the current or the volts up?

I'm pretty excited about taking the HIGH VOLTAGE route, that - and a DB2 should make for an awesome combo!

Much obliged for the words, pictures and tutorials guys 8)

I look forward to contributing some useful information about implementing this mod. So many options.. the mind boggles.


-S

 

[numberonekiwi]

just done some pricing for the FDP2532 from NZ Farnell sell them for $NZ12.83 ea bringing a total of 6 to $NZ76.98 plus shipping but I have found a US site that sell them for $US4.75 ea for a total of $US28.50 plus shipping have email jameco.com for costs of shipping to NZ as this may be the cheapest option

currently I have the IRF3205 fets x 6 and 63v caps that will need replacing as well

But how many volts can I pump into a xlite 408 @ 20A and 30A looking on ebikes.ca shows when using 96 volts - 1500watts @ 20A and 2200 @ 35A of course with that power I will need torque bars from somewhere

 

[Stevil_Knevil]

let us know how you get on with it!

Ran it in with 36V of 10Ah SLA to a C-lyte 404 in a 16" wheel, no probs. 25 MPH by GPS.

Bumped up to 72V.. the EV grin gets wider.

84V is wired in for tomorrows' run.


Breakin' the law.. breakin' the law!

-S

 

[Doctorbass]

Concerning my last post(controller blown), you'll see that I will need to swap fets too... from the original 4710 (in my 72V 35A start immediate... to.... I dont know exactly... the 4110 seems interesting here right?

Any buy group?

Doc

 

[Doctorbass]

1- Fechter, would you think if my SLA get around 90V few minutes after I disconnected the charger, some 100V rated fets would have no trouble??

2- I wonder if I run 90V in that controller circuit, I can get some 100V + glitch wich can cause controller failure?

3- You said the current seen by a 35A controller can represent around 100A (because of the time integration I think) for the fets.. and if the 4710 are 2x 75A, it's a little bit borderline.. I understant, but i wonder if the voltage can get higher too in this circuit.. hf and inductive circuit usually produce hv glitch noh?

The 4110 fets seems very interesting, but they have lower voltage... the fdp2532 have 150V but less current limit...

4- Wich i could choose? any comment about my questioning?


I hope this subject can help someone else who blowed his controller in the future...

I just try to cover all the subject of blowing controller and risk about that and repairing complexity and sucess... i dot want to miss something!

Thanks

 

[Doctorbass]

found that article on crystalyte website:


http://www.crystalyte.com/72 volt.htm

The 72 volt pack voltage will range from 60 to 87 volts depending on the state of charge.


Doc

 

[fechter]

Use the 4110's, they have a much lower on resistance.

The voltage rating seems to have a bit of safety factor built in, since Lowell hasn't blown his running over the rated voltage.