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Lishen 272ah Cells Aluminum Case Positive?

I don't know what BB means because BB is an abbreviation for Battle Born and Big Battery. Battle Born uses cylindrical cells in their batteries.

The cells we are discussing are prismatic cells. If you buy an EVE 280ah cell directly from EVE then it does come with the UL certification. If you buy the same cell from a supplier then it does not.

It's my understanding anything UL Listed must have the UL logo displayed. I have noticed some of the suppliers printing labels with CE Certified on the label, but that is not the same as UL Listed and I question the validity of those labels.

I am attaching the EVE UL Notice.
 

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Apologies, I was referring to Battleborn in that instance but I think you get the theme of the message.
This is the Chinese we are talking about, I don't think printing UL or CE logos is beyond there scope. ?
 
I did some research a while back, I only have a very vague memory of the details, but from what I recall UL and CE are not similar. CE isn't at all comparable to UL. UL is independent third party testing and certification of certain specified criteria. CE is in many cases just a self certification and relates more to broad health, safety, environmental standards compliance, or at least that is my recollection. This article goes into more detail.
 
I am in the process of top balancing my new Lishen cells and thought I would check the leakage from the negative terminal and the cells outer case. I took my meter and measured voltage between the neg terminal and the QR code metal plate , found 3.40 volts. then I took 12 volt landscape light bulbs to see if I could light them with the leakage voltage. The 12 v incandescent bulb would not light, the larger 12 v led bulb would not light, but the small 12 v bulb would light up with it's leads between the neg terminal and the QR code metal plate. Very interesting ????
What’s the leakage current?
 
One of the reasons for BINDING your battery cells is to also reduce or rather eliminate the potential for Friction between the cells. This is particularly important for ANY Mobile Battery Pack be it in a car, truck or boat. Everyone understands & knows that friction over time can wear through things, plastics including ABS and even the aluminium casings.
 
What are good products to put as 'extra' resistor when binding between the cells? I saw somewhere fibreglass plates being used, but they same relative expensive.
Alternatives?
 
I used self adhesive foam sheets.

BENECREAT 10PCS 2mm Thick Self-Adhesive Foam Sheet 8.3x11.8 Insulation Foam for Vase Decor, Containers and Furniture Protection, Black​



they are "compressible and come in various thickness. Cut in half and they cover most of the broad side of the Eve and Lishen 272/280 A cells.

thee have been several discussion regarding the need and/or what to use.......
 
Hi, I'm curious about using thread locker on the bolts/studs. Would the thread locker act as an insulator and keep the connection between the threads on the bolt/stud and and the battery terminal slightly separate? I've never used thread locker on electrical connections, only on bolts or nuts I didn't want to come loose.
 
The bolt/stud/washer/nut are not really the current carriers, its the surface contact between the batterery temrinal and the ring lug that you have to make sure has good contact between each other with as large area contcat as possible, the stud/bolt/nut/washer are used for to make sure the the surface contacts stay tight connection, also there should not be any washer between battery termianal and the ring lug..
 
If I can chime in here. (Months later..sorry) Seems the op was concerned about cells where the exteroir aluminum case might be exposed in spots (possibly due to a lousy wrap or re-wrap job by the seller). I understand cells are shrinkwrapped and capped atop and bottom by some sort of membrane and branded by individual sellers or distributors. In my case, my cells have exposed bare metal from the case. Mostly along the top edge. Not cool! If I meter the pos & neg post, I read 3.33V and when I meter the neg post and the exposed metal on the case, I get the same. 3.33V! I'm shocked at this! My thought at this point is to get a few rolls of electrical tape, and wrap the entire damn cells! And obviously when I assemble my pack, an additional protective something or another between each cell. Those thin plyable kitchen cutting boards are my plan. For just a few bucks too. To think a small ding or scratch on a cell, could expose just a small section of the metal case, that might potentially short out is scary to me. I'm glad I found this thread. And I'll be on the lookout for any future issues like this.
 

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Related to the kitchen cutting boards...
You don't know what their melting or deformation temperature is. As such I would use them. Staying in the kitchen. I rather would use a silicon flexible cooking board.
Or better; there are tapes that have a high temperature rating. I used that.
 
If I can chime in here. (Months later..sorry) Seems the op was concerned about cells where the exteroir aluminum case might be exposed in spots (possibly due to a lousy wrap or re-wrap job by the seller). I understand cells are shrinkwrapped and capped atop and bottom by some sort of membrane and branded by individual sellers or distributors. In my case, my cells have exposed bare metal from the case. Mostly along the top edge. Not cool! If I meter the pos & neg post, I read 3.33V and when I meter the neg post and the exposed metal on the case, I get the same. 3.33V! I'm shocked at this! My thought at this point is to get a few rolls of electrical tape, and wrap the entire damn cells! And obviously when I assemble my pack, an additional protective something or another between each cell. Those thin plyable kitchen cutting boards are my plan. For just a few bucks too. To think a small ding or scratch on a cell, could expose just a small section of the metal case, that might potentially short out is scary to me. I'm glad I found this thread. And I'll be on the lookout for any future issues like this.

It has been measured months before and more tests were done to confirm it was just a ghost voltage, not capable to supply any significant current. Try putting a car lightbulb between the case and the negative terminal (it shouldn't light up) and redo the measurement, you'll see the voltage will be gone ;)

Of course it's not a good idea to have electrical paths on the case in the long term because of things like galvanic corrosion, but at least you'll not have to worry about creating a dead short.
 
If I can chime in here. (Months later..sorry) Seems the op was concerned about cells where the exteroir aluminum case might be exposed in spots (possibly due to a lousy wrap or re-wrap job by the seller). I understand cells are shrinkwrapped and capped atop and bottom by some sort of membrane and branded by individual sellers or distributors. In my case, my cells have exposed bare metal from the case. Mostly along the top edge. Not cool! If I meter the pos & neg post, I read 3.33V and when I meter the neg post and the exposed metal on the case, I get the same. 3.33V! I'm shocked at this! My thought at this point is to get a few rolls of electrical tape, and wrap the entire damn cells! And obviously when I assemble my pack, an additional protective something or another between each cell. Those thin plyable kitchen cutting boards are my plan. For just a few bucks too. To think a small ding or scratch on a cell, could expose just a small section of the metal case, that might potentially short out is scary to me. I'm glad I found this thread. And I'll be on the lookout for any future issues like this.
the amount of leakage current is what is important. it is minuscule and is likely in the mA amount and is insignificant. the NEC code says there should be insulation between the battery and as such, it is a good idea to put an insulating layer between cells if they have exposed metal. the cutting board sheets are very slick (and inexpensive) and thin so do not take up any room when you do the compression fixture. For the cutting board sheets to deform would require a temperature so high that you have other problems with your set up as at a normal .2c charge and discharge rate the LiFePO4 batteries will not likely heat up much at all. yes, the leakage voltage has been documented but is insignificant.

the amperage if you can measure it is tiny.
hope you understand all.
yes, do the electrical tape and insulating materials between cells. I still think this is a good idea to insulate between cells.
the Lishen vendor I bought my second batch of 32 272Ah cells from sent a picture where they used an insulating material between cells.?
 
the amount of leakage current is what is important. it is minuscule and is likely in the mA amount and is insignificant. the NEC code says there should be insulation between the battery and as such, it is a good idea to put an insulating layer between cells if they have exposed metal. the cutting board sheets are very slick (and inexpensive) and thin so do not take up any room when you do the compression fixture. For the cutting board sheets to deform would require a temperature so high that you have other problems with your set up as at a normal .2c charge and discharge rate the LiFePO4 batteries will not likely heat up much at all. yes, the leakage voltage has been documented but is insignificant.

the amperage if you can measure it is tiny.
hope you understand all.
yes, do the electrical tape and insulating materials between cells. I still think this is a good idea to insulate between cells.
the Lishen vendor I bought my second batch of 32 272Ah cells from sent a picture where they used an insulating material between cells.?
I used sheets of teflon between my cells. very slick, heat resistant, and non-conductive.
 
Related to the kitchen cutting boards...
You don't know what their melting or deformation temperature is. As such I would use them. Staying in the kitchen. I rather would use a silicon flexible cooking board.
Or better; there are tapes that have a high temperature rating. I used that.
True..Well, there are those silicone baking mats that I've used in my ovens..and they have a temp rating of 450°F if memory serves me? But really, any of those solutions are just used to provide electrical separation between cells so they don't short against each other if their outer wrap gets worn and exposes a portion of metal can. If cells are in the neighborhood of 160°F these tapes or mats probably won't melt, but I think by that time, you've got bigger problems.
 
It has been measured months before and more tests were done to confirm it was just a ghost voltage, not capable to supply any significant current. Try putting a car lightbulb between the case and the negative terminal (it shouldn't light up) and redo the measurement, you'll see the voltage will be gone ;)

Of course it's not a good idea to have electrical paths on the case in the long term because of things like galvanic corrosion, but at least you'll not have to worry about creating a dead short.
That's funny.. a guy much earlier in this thread did in fact put a few 12v auto bulbs between the terminal and case, and one of them did light up.
 
That light bulb is actully a LED and will light up with only a fraction of a mA.

I should have been more clear and said to use an incandescent light bulb.
 
That light bulb is actully a LED and will light up with only a fraction of a mA.

I should have been more clear and said to use an incandescent light bulb.
Another poster used a 100 ohm resistor and got 10 mA. LEDs typically have a max of 10 or 20 mA. If that was an automotive bulb, it likely has a resistor that limits current at 13V to the desired current to light up the LED.
 
Another poster used a 100 ohm resistor and got 10 mA.

Can you post a link to that post please?


LEDs typically have a max of 10 or 20 mA. If that was an automotive bulb, it likely has a resistor that limits current at 13V to the desired current to light up the LED.

Headlight bulbs use far more powerful LEDs than the typical 5 mm ones that draw 20 mA, and they use electronics to drive the LEDs as a resistor would be very wasteful, big, hot, etc... But I'm not sure what it has to do with what we're talking about initially?
 
If I thought it was fake news I would not have started this thread and posted the information from the Lishen data sheet. ?

There have been two people that have found leakage current with EVE cells. Steve and upnorthandpersonal. And there have been two people that have found leakage current with their Lishen cells. DouglasHHI and Bud Martin as reported in this thread. This is not fake news :)

The reason I started this thread was because when leakage current was first reported with the EVE cells I didn't think it was a big deal. When I read what Bud Martin posted I changed my mind and I felt it appropriate to start this thread since I had also been posting leakage current wasn't a big deal. It was the only way I knew to admit my lack of concern was wrong, and to warn others out of an abundance of caution.
Per wikipedia:



The "current collector" is made of aluminum. There will be leakage, but not severe, it doesn't have the carbon coating. This is why they wrap the cells.
 
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