Under discharge 1 cell went low

porrascarlos80

New member
Joined
Oct 3, 2017
Messages
13
Could it be the point in the battery string to which i connected the inverter? Maybe its better to connect it to the middle of the battery bank?

Unable to attach pictures
 
Sure you can attach pictures, unless you don't have them to begin with. Full Edit or post New Reply (not Quick Reply) and either drag the files to the Image section or click the Image section and browse to the image(s) you wish to add.

Without at least an ansii drawing of what your schematic is, we have no way of knowing what happened.
 
apologies for the delay posting the pictures, in other forum i can just attach them , and here the size seems to be limited. I understand the costs associated , no worries.

so here they are

image_cnkxxl.jpg



image_hbtolk.jpg


Now I changed the position of the connections for the inverter , to the middle of the string. I will test tomorrow and see the behavior of my battery .
 
Can't make out how much out of balance the cell is. The host. store. share. logo is over the low cell. The battery is composed of lifepo4 cells?
to attach a photo here drag and drop it in box that saysDrop files here to upload once loaded there click on image, then preview the post to confirm the pic is there.
Later floyd
 
If your images are too large to upload here (hadn't heard that one before), then open them in Paint and resize down to 75% and save them and upload the new size. Please do not use off site photo sharing sites. Examples of reasons is the Host Store Share watermark.



I just checked, 12.15Meg is the largest size allowed to upload. That is a huuuge image (not only file size, but dimensions). Definitely resize by 50% and you'll be good to go, and plenty of clarity will be left.
 
Your drawing shows the cells connected in parallel, but the voltage on your phone app shows the typical generic bms, which needs to be hooked up in series. So either you have your diagram wrong or there's something we're missing here. If you have your cells in parallel as in your diagram, they would have 'balanced' each other out to around .02V
 
As a rule of thumb for pack design, keep your charge and discharge leads connected as far away as possible form eachother. For example if we had a 4S100P square battery pack, you would want to connect the negative lead in the bottom far left corner on the bottom and the positive lead in the far right corner on the top. This way current is forced to travel across all cells, resulting in a more balanced pack.
 
CUDAcores89 said:
As a rule of thumb for pack design, keep your charge and discharge leads connected as far away as possible form eachother. For example if we had a 4S100P square battery pack, you would want to connect the negative lead in the bottom far left corner on the bottom and the positive lead in the far right corner on the top. This way current is forced to travel across all cells, resulting in a more balanced pack.

Interested on your comment, I`m building a 7s120p. Now on soldering process and waiting for my BMS. Is too much if you explain on a diagram?

Thanks,

Gerald
 
You cant connect anything in the middle. Should always be in the far end. If you connect in middle you bypass the bms and you will cause imbalance.
 
Back
Top