Ordered kt 36/48v 17amp controller, how/do i set up lcd3 for 36/48v

it is i footpump

Pedelecer
Jul 6, 2018
102
23
76
Hi all have yosepower 350w rear moter ,36v battery and kt lcd3 display, the controller failed last week.

so i have ordered a. Kt 36/48v 17 amp vertion which suits 250/350w moters. Although i have a kt 17 amp controller it is older type with many wires.

what i am not sure about if in the future i use a 48v battery instead of my 36v one. Do i have to set something in the lcd3 or does it auto detect 36/48 volts



i will have to alter battery lead from bullet to xt 60 though
 

Attachments

  • Like
Reactions: PC2017

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
It's auto-detect, but there is also some sort of memory effect, so when you first connect, make sure your battery can't be mistaken, like when you connect a nearly flat 48v one, it will probably mistake it for a charged 36v one and some people have had difficulty convincing it otherwise. Whatever you've done, you can reset it to factory defaults with one of the settings, so there should be no problem changing voltage later.
 
  • Agree
Reactions: PC2017

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Under what circumstances did the controller fail ?
 

it is i footpump

Pedelecer
Jul 6, 2018
102
23
76
Thanks for info vfr400

nealh. I was doing a bog standard ride about /10mph came to a very slight hill, and lost power, nothing on display, so bike and myself taxi home.
Connecting another battery the battery fuse blew, i assumed lead from battery to controller had a (short). ..
Taking the top of controller and testing the red/black battery wires where they enter the pcb , got error on contunity reading ,appeared to be a short on the circuit board , Although nothing obvious to see ,hence another controller.

i could not remove the pcb board from the case, all screws removed,seemed to be glued in.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Did you do an ohms test on the mosfets to see if one or more was the issue ?
Has it played up before or cut out ?
 

PC2017

Esteemed Pedelecer
Sep 19, 2017
1,319
334
Scunthorpe
like when you connect a nearly flat 48v one, it will probably mistake it for a charged 36v one and some people have had difficulty convincing it otherwise
L settings / L parameters

This could be solved in the L parameters - I have found my L parameters on my KT-LCD3 but have not yet tested my theory - Setting the LVC to the 48V option could eliminate this issue, however for me it is not a viable option as I often switch out 48v battery for 36v

EDIT


The only manual I could find that lists these settings - the principles applies to LCD3
 
Last edited:

it is i footpump

Pedelecer
Jul 6, 2018
102
23
76
Nealh do not know how to test a mosfet re ohms, controller has not given any trouble prior. Trying to get the pcb board out of the case i damaged the pcb board so iv binned the controller. Another should arrive by the 23 aug.

also decided im going to purchase a 48v battery when funds permit.

i seem to recall something on the forum re (L). Settings on lcd3. Thats why i asked re 36/48v. As i might swop between 36v batteries and 48v
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
I use 36v & 48v separately out on rides and change no settings, the lcd3 gives me accurate voltage readout when I swap battery connections.
 

it is i footpump

Pedelecer
Jul 6, 2018
102
23
76
I use 36v & 48v separately out on rides and change no settings, the lcd3 gives me accurate voltage readout when I swap battery connections.
I use 36v & 48v separately out on rides and change no settings, the lcd3 gives me accurate voltage readout when I swap battery connections.
Hi nealh what differance in power do you notice between using a 36v battery against a 48v, i normaly use level 4, and 5 for anything remotly hilly.

I have hit a snag re 48v battery i ordered one of ebay 48v. 13ah. Hailong type, luckily i did not have enough funds in account and purchase was rejected.

i then realised the hailong at 365 mm long, if fitted to my bike will not allow me to. Remove or install the 48v one.

my current 36v one at 360mm just about fits, not to keen on going rear rack type ,because with locks ,shopping etc bike might be a bit top heavy
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
It's very simple. It's a 30% difference in power and torque using the same controller (10S vs 13S). The controller sets a different number of amps in each level, which is the same regardless of voltage. Power = volts x amps. If the amps are the same, power is proportional to volts.
 

harrys

Esteemed Pedelecer
Dec 1, 2016
363
101
73
Chicago, USA
I also swap 36V and 48V batteries into KT controllers. Thanks for mentioning the L1 parameter. Some of my ebikes have the older LCD's without L1. Their autodetect works well enough. Sometimes, when going from 48 to 36. the bar display is stuck low, but that often happens when I power up after a freash charge w/o any battery swapping. In the latter case, riding for 10 seconds clears it up.


My main gripe with the LCD3 is inability to set the wheel diameter to an exact value. Two different bikes with same tire give mileage about 5% apart. I've also been troubled by one of the LCD's suddenly going 40-50% low on speed. A power reset fixes that.
 
  • Informative
Reactions: PC2017