First battery Almost done - Thanks Endless sphere

[barbs00]

Hi All,

After a weekend of involving much head scratching and some truly terrible solder joints I have almost completed my first battery.
It is a 14S 5P made with LG MG1 cells - making it 52v and 14Ah. I have a BBSHD arriving next week

I would like to say a big thanks to all the endless sphere members who have helped get me to this point and for answering my Noob questions. Also, Micah Tolls Ebook and website were an amazing help.(His site is http://www.ebikeschool.com/)

I used an Ardunio spot welder from http://www.malectrics.eu which worked great (once I got a big enough car battery)



The welds are very strong and even difficult to pull apart with pliers.

Pics of almost finished battery



Cheers,

Barbs

 

[barbs00]

Arg...I may have been premature with my last post.

I just measured the voltage and am getting 12.8v from the discharge wires and 12.5 from the charging wires???

I get 50.6 if I measure each end of the battery itself.

Not sure what is going on here - the BMS is wired correctly as far as I can tell.

Here is the BMS i have

https://www.aliexpress.com/item/Hig.../2030986292.html?spm=2114.13010608.0.0.Bu2LgS

Edit....so after playing with multimeter I definately have 50.6v going into the BMS but only 12.8 coming out the other side. I unplug the balancing wires I get around 25v.

 

[zackclark70]

The battery looks good !!! make sure you have all the balance wires the right way around if they are fine you might just be unlucky and have a dead BMS on another note have you made your you have the charge and the output wires the right way as some bms have separate tabs for that

 

[barbs00]

Thanks - Yeah I am beginning to think the BMS is no good

 

[GIGATT]

Impressive. .how long did the build take?

 

[barbs00]

Did it all this weekend - not flat out just plodding along steadily.

Although I have spent ages researching and ordering stuff from overseas