What have I done wrong???

[BrandonB]

I have spent all night working on this piece of shit battery, and after getting it done, it reads 4 volts at the outermost two points, where it should read 40V. On the next two innermost points (8s) I get 24V, like it is only 6S! Measured at any 9S, I get 32V, like an 8S pack.. There are no dead cells, I have measured each cell individually and all of them are good. Why am I only getting 4 volts, and these funky readings???

 

[Lessss]

@ work so not seeing the pics. I assume you are hooking this up to a BMS? Might be a DOA BMS, might have run the cables wrong.

 

[only1jake]

Come on guys!!! Please help the poor guy!

 

[BrandonB]

I am tired of messing with these cells. Must have a damn ghost inside them. Every single cell reads good and charged to 2+ Ah. I have already dumped a month into these and will spend no more time with them. Anyone who wants them can have them for the cost of shipping. PM Me.

 

[neptronix]

sheesh. what kind of cells are they?

 

[Lessss]

Put one probe on the end cell and keep it there. Move the other probe to each battery in turn and see if the voltage goes up by the appropriate amount with each cell.

Is there a BMS involved??

 

[Ricky_nz]

Attach one meter probe to one end and then measure step by step along the pack with the other. Stop at the first one that dosn't increment by approx 3.3V.

Also check your meter battery! that can give you funny readings.

Also be careful where you place your probes. flux left over from soldering is an insulator!

Also some of the solder joints don't seem to have been heated enough and have not flowed onto the nickel strips. bottom right of bottom image

 

[NeilP]

My suggestion too.
Connect negative to one end and go along cell by cell...or block of cells till you find where it drops out. probably an 'iffy' solder connection if all cells do give good voltage.

Or a meter range error?

 

[Lessss]

@ home now can see pics
Visually it looks good. Either a crappy connection somewhere or a faulty meter. Try a different meter.

You current flow doesn't look ideal.