# Mewyeah BMS



## Yabert (Feb 7, 2010)

nedrapr said:


> In one wiring diagram (the simple EV wiring diagram) it appears the N1 contactor shuts off power to the speed controller (in my case a Zilla) if the system senses the batteries are being discharged unsafely. Not sure I like that idea while I'm driving the car.


Yes, save your live is WAY more inportant than save a cell. My BMS don't act on my controller, only on the charger. But, is your bms cut the power or reduce the power?



> I imagine the 12 volt battery will be charged by the DC/DC from the battery pack.


 Yes, the big battery charge the tiny 12v. BMS shouldn't be an important load.
My BMS systems work like that since many years without problem.


----------



## nedrapr (Mar 9, 2011)

Thanks Yabert,

Do you have a Mewyeah BMS system? 

It appears the BMS N1 or N2 contactor cuts the power rather than reduces the power. I emailed Jack asking for clarification on that. 

I may just use the N1 contactor on the charger only and rig up the N2 connector to operate a overdischarge warning light rather than cutting off the power if the BMS senses an unsafe discharge.

It sounds like from the manual you can use the contactors however you choose depending on the application.

So I'll take your advice and just use it to switch on/off the charger.


----------



## nedrapr (Mar 9, 2011)

I think I'll wire up that N1 contactor to the Valet Mode on the Zilla and set the parameters to run on low current. And also wire up a light on the dash to indicate when the Valet mode turns on. I need to study the manual a bit more.


----------



## evmetro (Apr 9, 2012)

If it cuts power to the controller and you don't want that to happen, you could just wire in a dash light or led to that circuit so that you can know to reduce the power via your accelerator pedal.


----------



## nedrapr (Mar 9, 2011)

Great idea. I was considering that and it may be the easiest thing to do. I just did some research on the forum and some people have also rigged up the contactor to put their Zilla into Valet Mode. 

But the warning light is probably the easiest. Less intrusive to the controller.


----------



## evmetro (Apr 9, 2012)

That looks like a pretty cool bms. I checked out the manual on the internet. It looks like it still needs further interpretation from the "English Chinese" to plain English, but a lot of products that are made in the USA still need interpretation from engineer dialect to plain English as well. It looks like it has a lot of features and canbus, etc. Do you have the dash board on yours?


----------



## nedrapr (Mar 9, 2011)

I don't have the dashboard. It looks really cool though. I have the small display monitor for mine.

The system seems to be very well made and organized. Before I ordered it, I gave Jack Winston the car measurements and he made up some really nice wiring harnesses for it with every wire labeled. I have most of it installed in the car. Everything snapped together easily. Just need to bolt the collect wires to the batteries and get the N1 and N2 contactors figured out.

The manual is in Chinese English but I can pretty much translate and easily read it. 

I think I'm the first one in the US to use this system. I'm not an EE. But I'm sure an EE or experienced BMS installer can easily connect everything up with no problems.

I just received an email from an engineer from MewYeah and he answered alot of my questions.


----------



## evmetro (Apr 9, 2012)

I tend to go pretty deep when I do a conversion, so that dash sure looks cool with the turn signal indicators and all the other stuff all built in.

I can't wait to see how this BMS works out, so keep us posted!


----------



## glyndwr1998 (Apr 27, 2013)

Hi, i have tried finding info on this bms but am struggling to find anything on it.

Any link to the manual download, or the company or distributor website, be interested to see what it does and how much it costs.

Many thanks, anthony.


----------

