EVE LF280K cells testing positive between negative pole and the blue body

[guidecca]

Putting a battery together and got some sparks for no known reason. I put my multi meter on the negative pole and my positive lead on the square QR code on top the battery. It tested 3.49 volts. Is this a defect or something common?

 

[timselectric]

Leakage to the case is not that uncommon, from my understanding. This is why the cells are wrapped in plastic.

 

[guidecca]

Every cell I've tested is leaking through at the QR code. Seems strange that I never noticed it before. The blue outside of the case doesn't move at all but some dings and all the QR codes are hot.

 

[guidecca]

These batteries are sparking like crazy. Maybe the compression wasn't such a good idea. I'm thinking that these are the cheapest Chinese product I've ever dealt with and I can't believe no one has this problem. Internals of the cells are trashed.

 

[42OhmsPA]

Please share where you purchased and provide photos. A video would be extra awesome (if safe).
I'll have to check my LF230s tomorrow, I still have a spare in the box.
Sorry to hear you're having issues.

 

[timselectric]

These batteries are sparking like crazy. Maybe the compression wasn't such a good idea. I'm thinking that these are the cheapest Chinese product I've ever dealt with and I can't believe no one has this problem. Internals of the cells are trashed.

How much compression?
And what type of barrier did you use between them?

 

[Bud Martin]

That is why you can buy insulator sheets to put between the cells, and on the bottom of the metal battery case and not relying on that thin blue wrap for insulation.
Video at 6:09

 

[justgary]

It is common. Very few of my cells aren't that way, and those have at least some voltage showing at the case relative to the negative pole.

Kapton tape is cheap, and will help insulate the cells from each other. The PC board fiberglass separators work very well also.

 

[guidecca]

I bought (16) of them from one of the members in this forum who bought them from Docan. I used the same board they make computer boards out of between the cells and they have held up good, no bulging. They have been charged to 3.55 volts. The cells have never been assembled into a battery and can't be assembled into a battery. I don't know how much compression. I used threaded screws and wooden ends pieces. I don't think it is safe to video tape them.

It is common. Very few of my cells aren't that way, and those have at least some voltage showing at the case relative to the negative pole.

Kapton tape is cheap, and will help insulate the cells from each other. The PC board fiberglass separators work very well also.

But is sparking common when adding bus bars?

 

[Ampster]

But is sparking common when adding bus bars?

There should only be sparking when there is a load. That load could be a result of current flowing from the case through the electrolyte to the cathode or anode. I don't believe that either terminals are connected to the case but I did take the above precautions and insulated between cells and I insulated the thread rod and did not place the cells on anything that was conductive.

 

[justgary]

Is the threaded rod touching the cells? Most people use PVC pipe to insulate the rods.

 

[justgary]

Please post a photo of the cells.

 

[400bird]

I bought (16) of them from one of the members in this forum who bought them from Docan. I used the same board they make computer boards out of between the cells and they have held up good, no bulging. They have been charged to 3.55 volts. The cells have never been assembled into a battery and can't be assembled into a battery. I don't know how much compression. I used threaded screws and wooden ends pieces. I don't think it is safe to video tape them.

But is sparking common when adding bus bars?

You bolted the cells together without insulators between them, this creates a connection between cells, because as you found out the case is not isolated from both terminals.

So, when you tried to install the terminals, you created a circuit. Terminal to case to other case to terminal on other battery and then added the bus bar. You created a short circuit.

Add insulation between the cells as recommend above. Also between the cells and any metal of the enclosure.

Also, all these cells are built the same way. The case is connected to one terminal.

 

[guidecca]

I bought (16) of them from one of the members in this forum who bought them from Docan. I used the same board they make computer boards out of between the cells and they have held up good, no bulging. They have been charged to 3.55 volts. The cells have never been assembled into a battery and can't be assembled into a battery. I don't know how much compression. I used threaded screws and wooden ends pieces. I don't think it is safe to video tape them.

Please post a photo of the cells.

 

[guidecca]

You bolted the cells together without insulators between them, this creates a connection between cells, because as you found out the case is not isolated from both terminals.

So, when you tried to install the terminals, you created a circuit. Terminal to case to other case to terminal on other battery and then added the bus bar. You created a short circuit.

Add insulation between the cells as recommend above. Also between the cells and any metal of the enclosure.

Also, all these cells are built the same way. The case is connected to one terminal.

The batteries cells came with terminals. I inserted computer board between the cells before I compressed them. I'll check the video and see if there is a better way to insulate them. The cells are leaking big time. Pictures are attached above.

 

[timselectric]

Where are you getting sparks?

 

[Bud Martin]

"But is sparking common when adding bus bars?"
Can you clarify that about the spark?
It spark when you touch which part to which part?

 

[guidecca]

I

"But is sparking common when adding bus bars?"
Can you clarify that about the spark?
It spark when you touch which part to which part?

I'm putting a bus bar between two cells positive and negative. Of course in parallel no problem but trying to connect them in series and all hell breaks loose. Sometimes it is when I move the pack of cells. I haven't tried to put nuts on the the bus bars. The sparks are flying off the terminals.

 

[timselectric]

Something is definitely wrong with how they are assembled. But can't see what from the pictures.
What's on the bottom of the cells?

 

[guidecca]

The only thing on the bottom of the cells is the covering they came with. I put some plasti-dip on the bus bars to insulate them. Could that be it?