Controller shunt

[70oldsracer]

I have a controller off of my son’s VIvi e-bike. I tried to shunt it and the controller stopped working. My son upgraded to a whole new set up and I was wondering if anyone on here could rebuild the controller so I can use it on another build. I bought all new mosfets for it, looking for someone to solder them in. I’m hoping that will fix the issue. Also wondering if maybe I shunt it wrong, too big of a piece of copper wire, too much solder? Maybe it can be shunted properly for a little more power. I’m attaching a pic of the controller and any help would be greatly appreciated.

 

[70oldsracer]

https://www.amazon.com/Display-Electric-Conversion-Controller-Waterproof/dp/B09VB3QB7J/?_encoding=UTF8&pd_rd_w=Utysr&content-id=amzn1.sym.255b3518-6e7f-495c-8611-30a58648072e%3Aamzn1.symc.a68f4ca3-28dc-4388-a2cf-24672c480d8f&pf_rd_p=255b3518-6e7f-495c-8611-30a58648072e&pf_rd_r=AR6KMCZ72T6G0NTGNP7F&pd_rd_wg=pgWuO&pd_rd_r=42dd5f4d-f18a-4e98-ba89-479213b4f8ea&ref_=pd_hp_d_atf_ci_mcx_mr_ca_hp_atf_d&th=1

I was going to give this a try.

 

[docw009]

It's a KT display. Should work, but it doesn't show the wattage as you ride. Makes it less useful. I use the LCD3 and LCD7 on my bikes. Easier to read the old fashioned monochrome LCD3 and the buttons feel good and can be worked with gloves, Both show power and volts.,.

https://www.aliexpress.us/item/3256802829897972.html?spm=a2g0o.productlist.main.11.555dpTlnpTlnI4&algo_pvid=9b6d5c2e-6f5c-40ea-ab3f-0187575a975b&algo_exp_id=9b6d5c2e-6f5c-40ea-ab3f-0187575a975b-5&pdp_ext_f=%7B%22order%22%3A%224%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21USD%2131.90%2129.67%21%21%2131.90%2129.67%21%402101c5a417396299169621920ea964%2112000024690556561%21sea%21US%21742508029%21X&curPageLogUid=t6JvHokLAA2U&utparam-url=scene%3Asearch%7Cquery_from%3A

 

[70oldsracer]

What display are you using though? Only a KT display works with a KT controller. Other displays may be able to power up the controller, but they can't change PAS levels or read the speed, Throttle and a basic PAS often work though, unless the foreign display gets upset that it cannot understand the data from the KT controller and shuts down,

When I first tried it and nothing worked, I was using the display that came with my sons VIVI bike. I'm thinking about giving this one a try.

https://www.amazon.com/gp/product/B09VB3QB7J/ref=ox_sc_saved_title_1?smid=A38R3YJLU23RON&th=1

 

[70oldsracer]

It's a KT display. Should work, but it doesn't show the wattage as you ride. Makes it less useful. I use the LCD3 and LCD7 on my bikes. Easier to read the old fashioned monochrome LCD3 and the buttons feel good and can be worked with gloves, Both show power and volts.,.

https://www.aliexpress.us/item/3256802829897972.html?spm=a2g0o.productlist.main.11.555dpTlnpTlnI4&algo_pvid=9b6d5c2e-6f5c-40ea-ab3f-0187575a975b&algo_exp_id=9b6d5c2e-6f5c-40ea-ab3f-0187575a975b-5&pdp_ext_f=%7B%22order%22%3A%224%22%2C%22eval%22%3A%221%22%7D&pdp_npi=4%40dis%21USD%2131.90%2129.67%21%21%2131.90%2129.67%21%402101c5a417396299169621920ea964%2112000024690556561%21sea%21US%21742508029%21X&curPageLogUid=t6JvHokLAA2U&utparam-url=scene%3Asearch%7Cquery_from%3A

Do you think that will work with my controller? I'll definitely give it a try, thanks.

 

[E-HP]

Any of the KT displays mention, including the one you linked, will work with the KT controller you linked, but I defer to docw009 on his recommendation for all KT related questions.

 

[70oldsracer]

About to order the display, didn’t realize there were that many to choose from in that link. I think this is the one suggested, but hoping for a confirmation before I order, thanks.

 

[docw009]

Since I have several ebikes with them, I found the LCD3 to be versatile and low cost. Wttas and voltage are important, and I like that it shows the ambient temperature inside the case. If I only had one ebike, I might consider one of the larger color models. The LCD7 is hard for me to see.

 

[70oldsracer]

I’ve been trying to buy the controller, but it keeps switching from the LCD3 to the LCD8H.

 

[docw009]

There are other vendors, Make sure you get the modek with the WP (waterproof) green connector, Bought ny last one here. WP green connector. Did not get the USB add-on,

https://www.aliexpress.us/item/3256803308397060.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.11.2d0d2bpC2bpCPv&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40196.366991.0&scm_id=1007.40196.366991.0&scm-url=1007.40196.366991.0&pvid=92833599-e784-4f66-915a-1e2a1057b622&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40196.366991.0,pvid:92833599-e784-4f66-915a-1e2a1057b622,tpp_buckets:668%232846%238112%231997&pdp_ext_f=%7B%22order%22%3A%2231%22%2C%22eval%22%3A%221%22%2C%22sceneId%22%3A%2230050%22%7D&pdp_npi=4%40dis%21USD%2133.39%2133.39%21%21%2133.39%2133.39%21%402101c5b117398474143018576eac12%2112000026047795447%21rec%21US%21742508029%21X&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_from%3A

 

[70oldsracer]

Here is a pic of my original controller. It says 18 amps, would I see any greater torque using the KT 36 controller? KT says 11amps, but max current 22+/-1amp. If not, maybe it pays to reach out to VIVI and see if I can get a replacement controller and just use all the original cables, display, brakes, throttle and light.

 

[docw009]

KT lists their current by both rated and max. The other guy is listing max.

 

[70oldsracer]

KT lists their current by both rated and max. The other guy is listing max.

Okay, I understand. So 18 max on the VIVI and 22 max on the KT, will I see any difference in the torque? I don't really care about top speed, I want to use the bike for hunting, so a little more torque will be beneficial.

 

[E-HP]

Okay, I understand. So 18 max on the VIVI and 22 max on the KT, will I see any difference in the torque? I don't really care about top speed, I want to use the bike for hunting, so a little more torque will be beneficial.

22/18 = 22% increase in torque.

 

[70oldsracer]

22/18 = 22% increase in torque.

Thank you. Every little bit counts, so I'm going to order the display and try that controller.

 

[MxusMick]

I recently did a few shunt jobs on a few controllers I have. After shunting 4 controllers I discovered it's unsafe because the controller can't protect from overcharge. I did see a decent speed improvement full throttle unloaded but it hardly improves take off, less than 5% acceleration increase and does not improve top speed. You have a controller to practice with replacing Mosfetts so I would buy another controller and write it off as a learning experience.