Changing the LVC of a controller

[jerrysimon]

How is it done ?

This is my controller

Its a cheap generic low powered one I think. I got it with my Tongxins when I purchased them directy from China.

It says 31.5v which is too low as my cells would all have to be at 2.6v for that!

I want to raise it so they cut out at around 3.0v ish


Regards

Jerry

 

[NRG]

Hmmm, I don't know that one but looking at the board it could be using a Xiechang 116 chip, what is printed on the chip under the brown capacitor? Also, to the left of the chip there is a row of solder pads with a black line around them, this could be the programming port....

The LVC trigger on these controllers is controlled by a voltage divider feeding a transistor which drives an interrupt line to the chip, the guys on ES have been changing the voltage divider to fool the chip into thinking the voltage is either higher or lower than it really is and so changing the LVC.

The difficulty with yours is its different to the ones shown on ES!

 

[jerrysimon]

Thanks NRG. I am sure dan played around with his after soldering a connector to plug in and re-program the chip.

I need to do a search sigh...

Regards

Jerry

 

[daniel.weck]

Hello, scroll-down this tread to see a few (potentially-interesting) links:

http://www.pedelecs.co.uk/forum/electric-bicycles/5100-can-i-get-more-power-my-36v-250w-bafang-10ah-battery-3.html#post64721

The controllers I use ship with ready-made connectors to configure the onboard chipset, so this is a pretty easy job compared to having to swap physical PCB components. I'm afraid I cannot help much

 

[jerrysimon]

Thanks Dan,

I knew I had remembered seeing your post.

Its complicated lol

Maybe a CA would be easier.....

Regards

Jerry

 

[NRG]

You don't need to faff with USB/TTL converters, e-crazyman can supply a USB cable with program button, all you would then need is the software and a header soldered onto the board...I did this when modifying my Alien and Peugeot.

 

[jerrysimon]

Thanks NRG. Sounds like I would be better ordering an e-crazyman controller with that gizmo.

I wonder which one I should order for my 200w Tongxins ?

PS I have emailed him

Regards

Jerry

 

[NRG]

I think the standard Tongxin controller is rated for 12amps max so just order one of his standard 36v 250w controllers and ask him to pre-program it to 12amps. Then you can mess about with the parameters afterwards....Oh also ask him to get a screen shot of the parameters he uses as theres no way to pull them from the controller to find out....

 

[Deleted member 4366]

It is possible to change the LVC value. There was a thread on ES forum about 3 or 4 months ago. It involves identifying a couple of resistors that make a voltage divider, that the main chip uses to measure the voltage. You have to change a surface mount resistor by soldering another in parallel. IIRC, it was R12 on the controller in question, so do a search on that. The splitter was in the bottom left corner of your first photo, but you'd have to look at ES thread to identify exactly which resistors by following a connection to a particular pin on the main chip.

 

[jerrysimon]

Thanks Dave,

Again sounds complicated

Regards

Jerry

 

[jerrysimon]

I think the standard Tongxin controller is rated for 12amps max so just order one of his standard 36v 250w controllers and ask him to pre-program it to 12amps. Then you can mess about with the parameters afterwards....Oh also ask him to get a screen shot of the parameters he uses as theres no way to pull them from the controller to find out....

Thanks. I have seen the Tongxin pull as much a 18amps peak (Ap on my Watt meter after riding) though on the whole its around 8A ish. Would that matter if it was set at 12 Amps ?

PS I got this off their web site

Tongxin Controller Specifications
Type WZK3610

Voltage V 36

Limit Current A 10 ≥1

Rated Power W 250

I will discuss with him if he emails me thanks.

Regards

Jerry

 

[NRG]

Thanks Dave,

Again sounds complicated

Regards

Jerry

It probably isn't really you've just got to ID the resistor and do the R12 mods but its not as much fun as being able mess about with the other settings via s/w! Buuuut....

I've just checked the Parameter Designer s/w and the LVC settings available may not suit what you want, they jump from 32.5v to 40.5v where I think you would require 36v for your pack?

You may have to modify 'R12' after all...ask Keywin about this as well when you email him....

 

[NRG]

Thanks. I have seen the Tongxin pull as much a 18amps peak (Ap on my Watt meter after riding) though on the whole its around 8A ish. Would that matter if it was set at 12 Amps ?

Regards

Jerry

Not really as the current limit setting is pretty hit or miss being up to +5amps out so 12 would probably be just about the same as you have now....

 

[jerrysimon]

My pack is 39.6 nominal and around 42v fully charged.

Regards

Jerry

 

[Deleted member 4366]

Thanks Dave,

Again sounds complicated

Regards

Jerry

Here's the thread if you're interested. Start from about page 4.
Endless-sphere.com • View topic - Changing the LVC in a 72v generic controller

 

[jerrysimon]

Thanks Dave.

Jerry

 

[daniel.weck]

You don't need to faff with USB/TTL converters, e-crazyman can supply a USB cable with program button, all you would then need is the software and a header soldered onto the board.

I like the handy on/off flash button on this USB/TTL data cable. Did you contact ecrazyman directly? I sent him a message via his eBay outlet, I hope he can supply a unit at reasonable cost. Otherwise I might as well build my own cable. Cheers, Daniel

eBay My World - e-crazyman

 

[NRG]

Yes, just asked him via ebay...

 

[daniel.weck]

I just bought the USB cable + software.
11 USD inc. delivery from e-Crazyman (contacted directly via his eBay account, paid directly using PayPal).
Cheers, Daniel

I like the handy on/off flash button on this USB/TTL data cable. Did you contact ecrazyman directly? I sent him a message via his eBay outlet, I hope he can supply a unit at reasonable cost. Otherwise I might as well build my own cable. Cheers, Daniel

eBay My World - e-crazyman

 

[jerrysimon]

Dan I emailed him but he only sent me info on the controller and over looked my question on the USB cable. I have decided to leave the LVC as it is at the moment anyway and just make sure I don't DOD my packs to zero capacity.

I will watch your update on this though as I am intersted.

Regards

Jerry