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Sixtysix 280ah Cells from Deligreen

@ArthurEld, how long did you make your top balancing cables? I'm still waiting for my cells but got the material to make the cables today.
Drew the cells on a paper to measure, but would like to be 100% sure before I start creating all cables.
 
It probably took an hour or two total. I used 8 AWG wire. Cinergi is making them with much thicker cable for high amps.

I will use 6 AWG wire, but let me clarify my question :)
How long did you make your cables, the length in inches/cm? Want my measurement double checked before I start making 28 cables.
I get it to 11.5 cm center-center when measuring on my paper sketch. I would add I guess 1 cm on top of that for some margin.
 
how long did you make your top balancing cables
If I get that right you are making temporary cables to hook all the cells together in parallel so you can bring them all up to 3.65v Yeh?

I didn't make permanent cables for that . I stripped the insulation off some household electrical wire ,no big amperage, and wrapped a loop round first Pos terminal and put on nut. Then decided which cell next and wrapped the wire around it and did up nut . and so on selecting the highest cell first then next down and so on . If you connect them and notice a large current flow with your clamp meter then connect with a resistor first to reduce or bring up voltage. Graduslly add each cell.

When all connected and left a day or more then start charging with 3.65v power source making sure there is amperage flowing an watch it gradually reduce as the voltage rises.
 
Right, that is the idea. I was attracted by the idea of mounting cells in final serial pack with “fixture” before starting to balance them. Since I also have 4 packs of 16 cells each I will use the cables four times. Cables are done, went pretty quickly.
 
I am still testing my 2nd 48V battery.
So far my tests have produced similar results to others posting about recent EVE 280Ah purchases.
Average capacity is about 275Ah.

I have one cell that is about 270Ah. I will leave open the possibility that I could have caused some capacity loss.
That cell is also set aside as a spare.

My capacity test so far on 48V battery packs have shown that I can get draw over 270Ah without hitting BMS limits.

That is good enough for me.

I accidentally shorted one of my 48V battery packs with a socket/ratchet. It was quite spectacular and I recommend avoiding that.
It caused one stud to burn off and throw jagged stainless steel shards. The aluminum terminal melted away.
Interestingly I can still test 3.3V. That is my second spare.

I am still testing the battery pack with a new cell swapped in. Hopefully I didn't mess up more cells.
 
I ordered hydraulic crimpable cable ends that will crimp to make some battery interconnects for my new 32 cells I received via FedEx on Sunday the 17th of January. all cells are Lishen 272Ah. the busbars supplied by the vendor will only parallel 16 of the 32 at a time. so have to go to plan b.
yes, I arc-ed accidentally on the 1st 32 Lishen cells during connection (about 1.5 months ago), so now all cells get a piece of red tape on the positive end and a Dymo labeled that says positive. woo hoo the 544Ah in 2P8S scared me when it arc-ed and ruined 2 studs like an arc welder. get out the gloves, put on the eye protection.
the plastic tip of the caulk gun let me dislodge the arc-ing busbar. :cool:
 

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I let go of the ratchet because of a spark but it was still sparking so I grabbed it with my bare hand.
I didn't get shocked or burnt. Gloves sound good but I don't know if I could get used to them. I guess I should try.
I taped up the handle on my ratchet but I am going to come up with a way to keep the busbars and terminals covered.
 
I let go of the ratchet because of a spark but it was still sparking so I grabbed it with my bare hand.
I didn't get shocked or burnt. Gloves sound good but I don't know if I could get used to them. I guess I should try.
I taped up the handle on my ratchet but I am going to come up with a way to keep the busbars and terminals covered.
gloves are difficult at times. I use the mechanics gloves, I need to insulate my tools better. I really appreciate your posts. some people think they know too much when in reality they have no hands-on experience with these types of powerful batteries. thanks for your efforts. I kind of wish I had a pair of mechanics gloves with the fingertips removed. eye protection is probably the most important. I put a big shipping blanket on one batch of 16 cells until I can get to them. I use plywood etc to cover some, even when I am the only one there which is essentially all the time as I keep it off-limits to the children via a locked door in my super-insulated off-grid solar shed.
I agree the arc is scary and will give the battery the respect it deserves.
thanks for all your posts! :cool:
 
By the way, I always wear glasses when I am working because I am old and can't see well without them.
Gloves are good, glasses are even more important.
 
By the way, I always wear glasses when I am working because I am old and can't see well without them.
Gloves are good, glasses are even more important.
One tip I learned 40 years ago, take off jewelry on your hands. That wedding ring is an excellent conductor. High current will melt that right on your finger. Unfortunately my glasses are for distance, but safety goggles are a great idea.
 
What BMS are you using? I like how the information is displayed.
I am surprised how well the cells stay together. I top balanced the whole battery to 3.65V this time.
Since they diverge so bad up there I was afraid they would move apart when I got out of the knee.
But that is not the case they came together and stayed together. So far my delta value has been .006 and .004.

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I accidentally shorted one of my 48V battery packs with a socket/ratchet. It was quite spectacular and I recommend avoiding that.
It caused one stud to burn off and throw jagged stainless steel shards. The aluminum terminal melted away.
Interestingly I can still test 3.3V. That is my second spare.

I am still testing the battery pack with a new cell swapped in. Hopefully I didn't mess up more cells.
Here's a picture of the cell I destroyed. The short was from the nut my socket was on and the ratchet handle hitting a nearby busbar.
I'm not sure if the pieces of metal are aluminum or stainless steel.
1611364453235.png
 
Ouch, that sucks. I think there’s a good business opportunity for someone with a 3D printer to make cell covers or terminal covers similar to what Fortune cells do. They make tools with nonconducting coatings on the handles too FYI...
 
This incident already had me thinking of buying a 3D printer.
I put electrical tape on my handle for now.

But I would love to come up with some simple ways to cover everything up.

I've been working with a lot of temporary setups and getting sloppy. I just need to take my time and do it right.
 
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