New here looking for advise

1Dude

Finding my (electric) wheels
May 23, 2020
17
1
Hello what a great site full of information
Anyway I have just bought an Ebike off a friend as it does not work, the battery (36v) is very good but the controller is burnt out the controller was part of the battery mount and not much information on it, i have removed the board and left the connection for the battery so i can fit a replacement controller the motor fitted to the rear wheel is a Bafang BFSWX02 36v 250W (13)
so after reading some other posts on here i think i am going to go for a KT controller and display i like the look of display KT LCD3
After spending many hours on ebay and amazon I am dot sure what controller to buy and what wattage / amps.
can you please recommend one and where to purchase it from? , i am quite handy with a soldering iron and a meter so i don't think i will have much of a problem wiring it up to the existing wires, i will also need to purchase a thumb throttle as the bike never had one before.
 
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Benjahmin

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Nov 10, 2014
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Before spending your hard earned, are you sure the controller is duff? What's happening or not happening?
What's the battery voltage measuring at?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Dependant on your answer to Ben's post, you can buy replacement battery mount controllers if it is dead/blown. You will need to show us a pic of the battery.
 

1Dude

Finding my (electric) wheels
May 23, 2020
17
1
Thank you for your reply, its defiantly the controller that has gone its burnt out, I have taken the cover off and its black, a couple of resister blown, i would imagine that on of the 6 fets have shorted, i would have tried a repair but the board is set in a resin.
The battery is virtually brand new only 4 months old showing fully charged, I have also tried it on my neighbours bike and its fine.
As you can see in the pics i have remove the old controller from the mount, you can also see that the negative wire has got hot in pic 4.
the old controller look like the one in the attached pic available from ali express (this has more fets), but i rather replace with a decent separate controller and display.

So what do i buy to get this back working, from what i see on posts on here the KT controllers and displays are good but dont know what to get and where from ?

Regards
 

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Benjahmin

Esteemed Pedelecer
Nov 10, 2014
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Fair cop, it does look fairly mullered !
Neal knows more about specific controllers than me. However almost any 36v matching controller and disply will do it, it's a matter of trying to match plugs if you want to avoid a lot of soldering.
 

1Dude

Finding my (electric) wheels
May 23, 2020
17
1
Thanks for the reply
I know from reading that the motor Bafang BFSWX02 36v 250W (13) (9wires) is capable of more power so do i go for the 250W controller or a 500w turning the power down in the settings a little ? i am also going for KT-LCD8H Display on whatever controller i go for due to ease of setting it up.


So i have been looking at the following
I am very tempted to get this controller i know it is 500w and over the top ' So would it be ok ? or could i turn the power down in the settings ?
KT36/48ZWSRM-NBP03 500W 11 amp 22 amp max with the KT-LCD8H display ? What do you think ?
the total price will be about £97


Others i have looked at
36v-48 250w
KT36/48ZWSR-NBP01
controller 7amp 15amp max this one i think would be ok.


Sensored Brushless Motor Controller 36V/48V 500W 6-FET 20A KT Sine Wave

KT36 36/48V 250W/350W with Waterproof/SM (HiGo) Connectors

ensored Brushless Motor Controller DC 24V/36V 250W 6-FET 15A KT Sine Wave



Thanks for all your help
 
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1Dude

Finding my (electric) wheels
May 23, 2020
17
1
Question 1:
if i purchased the T36/48ZWSRM-NBP03 500W 11 amp 22 amp max with the KT-LCD8H display
Can i turn the power down using the display ?

Question 2
is the display KT-LCD8H waterproof ?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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I would opt for the 22a model as you can reduce the amps using C5 setting.
Be governed by the connectors you already have if re using throttle, PAS and brakes.
The higo isn't compatible with Julet as the wire/pin sequence is different, though they do connect fine they won't work mixing and matching. Higo is Bafangs waterproof system. The hub will use a standard Julet 8 or 9 pin connector.

Ignore the rating 250,350 or 500w with controllers it is a better to be guided by the current that can be supplied and whether your battery can deliver that current continuously if needed to.
 
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1Dude

Finding my (electric) wheels
May 23, 2020
17
1
Hello Thank you for the reply I have now ordered the controller and display
the hub is a 9 pin / wire see pics, the rest of the connections on the bike are Julet.
When i removed the old controller i cut the wires off at the pcb, as you can see in the pics so I can either solder or fit new connectors, I will mount the controller on the rear carrier the cables from the motor will reach but i will have to extend the cables from the brakes and the p.a.s, I have also ordered a thumb throttle that comes with a cable but may need extending..
 

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1Dude

Finding my (electric) wheels
May 23, 2020
17
1
I have to say I ordered my parts from Modds E Bikes, I gave them a call first and they are very helpful.
is there any standard colour coded for the Julet connectors , or do i have to use my meter to identify the brake wires etc ?
 
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Nealh

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Aug 7, 2014
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The Julet pin outs/wire colours are standard but can't tell you the sequence off hand.
Use a metre on continuity/buzz mode on you cut wire/julet connectors to identify the pin and wire colour sequence.

Look at the julet end on and draw it on paper including the alignment mark, mark the pin positions and then when you check continuity for the each pin note the wire colour on the drawing/diagram for each pin.
 

1Dude

Finding my (electric) wheels
May 23, 2020
17
1
ok all the parts arrived today, so i have connected it all up allot of soldering it seems to be working off the throttle but not he pas i may have the wires on the pas the wrong way around as the colours did not match the wires on the controller are yellow black brown and the wires from the pas are blue yellow red !

next i will need so help setting up the KT-LCD8H
not sure what P1 or P2 should be on
I have left p1 at its default and P2 set to one as this seems more the correct mph ?
I dont know what i need to set on the C setting ?

Can someone help ?

Motor Bafang BFSWX02 36v 250W (13)

thanks in advance
 

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Nealh

Esteemed Pedelecer
Aug 7, 2014
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KT controller PAS Brown 5v, Black Gnd & Yellow Sig.
PAS connection Red 5v, Yellow Gnd & Blue sig.
One thing to remember with China colours Red or Brown can be 5v.
Black or Yellow can be Gnd but Black takes precedence over the latter when both are used.

For P1 set the speed cut off 25km/h and then ride first to see what the motor actually cuts out at allowing for inaccuracy 15.7 mph will be about right, if the read out is too slow then adjust P1 value up if too fast adjust it down. Once set or close use a GPS to verify the speed the after that you can adjust the speed cut off to suit knowing it will quite accurate.
 
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Nealh

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Aug 7, 2014
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For C settings leave then as they are and list all 14 for us to see, only a few make much difference.
 

1Dude

Finding my (electric) wheels
May 23, 2020
17
1
Thanks for the reply
i will give the PAS as try I have definitely got the wires wrong on the pas I had red to brown yellow to yellow black to blue so hopefully no damage done.
Ref the P and C Settings i have read on here someone else has the same motor and they say its 6 magnets but when I set P1 to 6 the speed is way out shows about 3 mph when it is flat out ? if i set to 1 or 0 its about right.

Thanks again
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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For PAS you have connected Gnd & Sig incorrectly together.

P1 setting is about setting the correct or near value for the internal motor gear ratio so that the near correct odo speed is about right.
P2 affects the odo on the road reading It will be value 1 or 6, it is dependent on internal speed sensing magnets. Most hub use 1 magnet hence P2/1 but d8veh did mention that he thought the SWX02 had 6 instead.
 

1Dude

Finding my (electric) wheels
May 23, 2020
17
1
I have been out and changed the wires on the pas and I also had to change C1 to 5 reverse signal 12 (12 magnets) as the sensor is on the right side next to the crank drive cog, not sure what it means by 07 standard 06 higher and 05 highest ?
it seems to be working but cant go fare as it is bucketing it down here

I need to have a look for a box for the controller to fit in now any idea where i can get one from ?
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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I have been out and changed the wires on the pas and I also had to change C1 to 5 reverse signal 12 (12 magnets) as the sensor is on the right side next to the crank drive cog, not sure what it means by 07 standard 06 higher and 05 highest ?
it seems to be working but cant go fare as it is bucketing it down here

I need to have a look for a box for the controller to fit in now any idea where i can get one from ?

For the C1 05 - 07, I think might be down to the signal strength input. if it works leave it .
 

1Dude

Finding my (electric) wheels
May 23, 2020
17
1
I have been around the block now and all seems fine Thank you Nealh for your help
I also got a a bag from Aldi, a little modification to it and the controller fits perfectly inside 'see pic' jut need to put a hole in the bottom of it to allow for the wires 'i will have some more soldering and soldering up again lol' that's tomorrows job.
 

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1Dude

Finding my (electric) wheels
May 23, 2020
17
1
Ok i have spent all afternoon cleaning up the wiring and the bag from Aldi was made for the controller it looks good,
I have one problem that i have just noticed the power bar meter on the display is not showing how full the battery is! do you have any idea ?
it was working half an hour earlier not sure what gone on as it showing the voltage?
 

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