Rogue cell? Or not? Lifepo4

[Seabhac]

I have a 16s Lifepo4 bank. Overkill Solar B.M.S. Sunny day with clouds, battery bank is full so I turned on a 2kw blow heater to use the free energy from the sun. One of the cells (On the app), the one that seems to go up and down more in voltage than the others generally and is always the one subject to most of the balancing, was well in the red (high volts and balancing) when I checked before turning on the heater. So I turned on the heater and everything seemed fine until a cloud appeared. It plunged to 2.9v and was see sawing up and down. I manually checked the cell voltage with a multimeter and it is fine but the BMS thinks otherwise. I wonder whats up? Anyone see this kind of thing before? I'll try to post a video of the screen.

 

[Seabhac]

Here's a vid. When the clouds come over it drops as the battery bank is under load. But why this poor little lifepo4 cell is suffering so much? Or should I say appears to be.

 

[hwy17]

Check the bus bars and voltage taps are tight. That means checking 4 connections, the two on the positive bus bar to that cell and the two on the negative.

 

[upnorthandpersonal]

I manually checked the cell voltage with a multimeter and it is fine but the BMS thinks otherwise.

Connection issue. Maybe a bad crimp on the connector.

 

[Daddy Tanuki]

i vote for bad connection as well.

 

[Seabhac]

Check the bus bars and voltage taps are tight. That means checking 4 connections, the two on the positive bus bar to that cell and the two on the negative.

I hadn't thought of the 2. Mmmm

 

[Seabhac]

Connection issue. Maybe a bad crimp on the connector.

Will do thanks.