Spim08hp 3.7v 8ah 200amp cell build

999zip999

100 TW
Joined
Jan 10, 2010
Messages
11,696
Location
Dana Point So. Cal
I bought 40 cells 36 new and 4 used. One used has a small dent as if a plastic corner made a very small dent. I wonder if this is safe or ask for replacement ?
Ok so the plan was a 10s 2p x 2 big to big so a 20s 1p or 72v 8ah for a bmc 600 hs and em3ev 12fet at 40amp set to 30amp Max.
Or 15s 2p for 60v 16ah battery for same motor set up ? Must make mockup box to see if fits
These cells were under 200.00 usd shipped with holder's
So 72v 8ah or 60v 16ah ?
Haven't unwrapped all the sales I have to make some working space these are very easy to bolt together with the holders I just need a long threaded rod I'm going to alternate with blocks of plastic and blocks of aluminum for the bus bars.
Cells bought from battery hookup USA a family business of selling recycle batteries.
 
I have a RC charger an UaA9 plus + with battery nanny thru the sense wire charger. So it looks like the smallest I can go is 2p on the three pin on the balance board. The battery nanny can handle 6s x 8 groups 3s x 16 groups or 2s ,x 24 groups in secession. I but I never use it and can try and only use charger no nanny. Unless somebody wants to hold my hand for trade ? Bikes , front wheel kit complete or Crystal lyte 3525 rear motor with a bump in it or for part or tires. This could also be for cav3 help
 
Ok I have tested voltage of 20 cells for a 20s1p so to fit my trangle.
1. 3.630v
2. 3.635v
3. 3.635v
4. 3.629v
5. 3.625v
6. 3.631v
7. 3.621v
8. 3.634v
9. 3.632v
10. 3.632v
11. ,3.634v
12. 3.618v
13. 3.615v
14. 3.621v
15. 3.635v
16. 3.634v
17. 3.632v
18. 3.634v
19. 3.635
20. 3.630v
So 3.635v high to 3.618v so all good now these are new with holders and separation blocks for tabs will cut of tab separates that lock cells together strong with 4 insulated holds for 4 through rods in the corners that have nothing to do with the tabs.
So looking good and found out they have plastic interlocking blocks to keep the tabs from touching. I could cut off the fins and still use the blocks to secure the movement and lock it together. The tabs have two u cut in the tabs so going to cut aluminium and plastic insulated blocks with all thread insulated with refrigerator hose on outside of all thread rod with lock nits and 4-5s sesnse be wires. May with tap wires for charging at 41v @ 12amp each with HP 550 -12.6v be and mean well 24v set at 28v or something for 41v. No pics yet. I'm on my phone so working thru it.
 
I have 20 with the shells and 20 without. I've been thinking how to easily attach them together. With the shells, I think a sandwich of aluminum and plastic sheets the proper thickness would work really well then a final buss bar could connect to one side of threaded bars, neg on one side and pos on the other. Of course you would have to be extra careful about what the threaded rod touches. A safer approach would be a tab on the bus bar. The problem there is the bus bar would only rely on a friction connection so I'll have to figure out a way to securely attach the bus bar with bolts. Maybe a two part bus bar with threaded holes on one side.

I was thinking of the same approach for the packs without shells. It may be even easier as the final sandwich can have an extended metal bar that acts as the bus bar. But it would be hard to tighten them all together. I was thinking smaller diameter threaded rod to fit through the notches we would need some means to insulate it. The the last one can act as a buss bar or a plastic insulator. Plastic tube or hose is possible, maybe heat shrink. Hell that may work for the shells too.

I think this would make for easy building because you can configure the pack size by how many metal shims you use. A 3s2p would be BMTMTPTMTMTMTP with M being a metal shim, P being a plastic shim, T being a battery tab and B being the bus either built into the last metal shim or something added. The other side would be PTMTMTMTPTMTMB. You would really have to pay attention making a huge pack like a 14s10p power wall but you would have to do that anyway.
 
Tried twice to post a reply with pics but the pics screwed me up. 512mb upload limit and it erased my reply. I'll try again without photos and post them later.

I've built to packs so far. First is a 3s1p to get my sump pump working so I can finish painting my pool. It runs the pump fine, draws under 25amps, but the cables get hot. I used #12 because that is what I had. With the power supply hooked up I hope it works because we are in rainy season now and I need to get this done.

The other is a 3s2p for an old jump starter I plan to use for general purpose. Jump starting and running small inverters and such. They are currently using grommets but I plan to add aluminum connections with bolts to the jump starter.

For the rest of them I plan a few 12v and 24v for ups's and a 24v mower. For the ones with the shell I plan a 48v solar power pack for offsite construction and camping. I originally thought of making a pack for my bike but I I'll likely go with lifepo for my next bike pack for a little extra safety.
 
I went and bought brass bars for the end thinking that have to be thinner and carry more current but I found out that aluminum carries more current twice as much as brass well I have the aluminum pieces it just didn't think right in my brain and some of the plastic pieces might make it too wide of a battery so I have other pieces of plexiglass to pull them in the separation plates don't need to be that why so we'll see what I get away wiitj.
Gumorder you just live with it you are now in Ennis Spirit archives for the rest of your life sorry for being hard on your phone maybe you should get a different phone plan. Ha ha. Lol.
 
You're overthinking it - use a hand seamer, and bend the tabs over each other to lock in place. You can even add the balance/power leads this way by crimping them in with the tabs. GLHF.

image_12936.jpg
 
Tabs are only 3/8" long......and cell is 1/4" thick.
Any attempt to bend cells over each other will ruin cells.
 
This is what I settled on for connecting cells together for 1P packs. Ive built an 10S, 11S, and 12S pack using this "clam-clip"method.
"clam-clip" method
These packs have been in heavy service (30-amps maximum) for my daily-driver pack for past 6 months:

IMG_0708.JPG
https://www.youtube.com/watch?v=mD_mHqUxeXw&t=102s
I have not tried more than 30-amps. Maybe I'll do a short-test and check voltage drops for next 12S pack I build?
You could use heavier clips and thicker copper (NOT BRASS!!!) strips.
If building packs greater than 1P, you could build parallel 1P packs I suppose to increase amps also. Two 1P parallel packs giving 80 amps.
Building packs using "clam clips" is a very fast, inexpensive and less tedious process than using aluminum screw clamps.
Tools required:
*) Requires heavy copper tape, cut in lengths that cover ALL of the cell tab when the tape is folded in half length-wise.
*) Office Stationery Clam Clip Dispenser Refill packet....I used 3 clamps for each cell junction on first pack I built...picture uses 5.
*) Cells are stacked and held together using thin double-side tape to keep them from sliding around.
*) Cell taps are easy...simply solder wire directly to outside tape surface AFTER each cell junction has clam-clips.

Cut tape to length of tab....must be large enough to cover tabs when tape is folded over.
IMG_0700.JPG
Tape is wrapped around the two tabs STICKY-SIDE facing out and away from tabs. Shiny side touches tabs, NOT sticky side!!
Sticky side SUCKS as a conductor.

IMG_0709.JPG
Done! Took me about 2 minutes to do. Be sure to cover entire junction. I use heavy 2-inch wide duck tape.
I add tap connectors (personal choice: I use voltage monitors....not a BMS) to wire, and shrink entire pack.
Finished pack is enclosed in aluminum box....I also tape all edges of each individual cell....edges can not touch other cells! Bad things will happen (fire).
 
pullin-gs said:
This is what I settled on for connecting cells together for 1P packs. Ive built an 10S, 11S, and 12S pack using this "clam-clip"method.

Nice. I used similar clips on my second pack, a 3s2p. They are clips from the phone line banks you find at an office with many lines. They are a little loose so the copper would help. Maybe copper, not tape so no sticky side, with the hand seamer would work without clips. And the copper will be easier to solder to. I'm not sure it will work with these packs in shells, though.

I was searching for punched aluminum flat bars, 1 inch or 10 mm hole spacing would work. I use to buy them for rack mount equipment but in steel though that would work too. I just want to avoid rust. I still think that is the way to go with these shelled packs.
 
Those clam clips look promising now that I've looked them up. There are several sizes so they may work with the shells. And I don't think you need the copper unless it's to solder to. Ordering them now.
 
Yea I'm been drilling away 20 aluminum and plastic blocks 80 holes plus 20 sense wires and tapped tomorrow. That's a lot of drilling.
 
Oops I just make the buss bars from a cell. And had to open up the holes 40 more holes. Don't piss me off with that clip thing. Hey could you use a 80watt iron to attach the clips or as to make them stay in place ?
Plus you can solder the sense wires to copper ?
 
999zip999 said:
Don't piss off with that clip thing.

Plus you can solder the sense wires to copper ?

I am making my own again today. The buss is nowhere for steel, ( esp. not spring steel)... ( rust? heat? loosening over time?) and I like to overbuild that part. IMO. I found 1mm nickel plated copper in a 1" strip. Folded, on a die, in a press. ... the buss will have the ampacity of well over 600A, the maximum design current for the battery that is being built. Without much temp rise.
Main buss is nowhere to skimp, IMO. Also, in the name of flux cross contamination and longevity, I like to pickle the busses after I press and solder the sense witre to them. Just to make sure everything reactive is gone. Wash, then install. The wrong fluxxes will ruin your day down the line if you let it. I use Phosphoric acid for the pickling operation.

I got a ton of the nickel copper 1mm. 7$/lb. Cut to any length ( up to 6 feet). I will be making these ( folded copper punched busses) specifically for the SPIM08 cells, then, for when I build mine. Quick fast cheap easy reliable.
 

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that's my battery. 20s and bolted a lot of drilling holes and not linking up. So drill and oval we go

Yes mine was very labor intensive took money and took a long time and I had an oval a lot of the holes just to make everything fit because I need it to fit with those tabs as they're half the height of A123 tabs.
So looking forward to more and other easier methods as mine is replaceable but if I took it apart Lowe's plexiglass blocks with probably crack and break at least a few of them. Keep it up gentleman.
 
Ok it's plexiglass - aluminum bar - plexiglass and threaded rod and bolt the tabs together I use a through rod and put it inside a ice machine tube to insulate the tabs ended up using different sizes of plexiglass well take out some of the quarter inch plexiglass out and put three thinner ones in to bring in the bus bar even with the rest of the pack. I wish I would have used a different type of plastic. A stronger one plexiglass is brittle and when cutting with my jigsaw it would melt back together behind the saw.
Hey Dog are those copper rivets ?
 
The positive and negative 8ga and 10ga silicone multi stand wire wrapped in a half of copper pipe half inch copper pipe and filled with solder with torch next time I will use a 80 watt iron then drilled and tapped in to the aluminum buss . Is this good enough for contact ?
 
999zip999 said:
A stronger one plexiglass is brittle and when cutting with my jigsaw it would melt back together behind the saw.
Hey Dog are those copper rivets ?

I splash it with water and cut very slowly with the jigsaw. It is a pain though, you must not let the plastic melt back together right behind the cut .

Yes, copper rivets. Lol. Everyone loves the copper rivets. Lol. Amazon is where they came from. That bus should be fine.
 
999zip999 said:
The positive and negative 8ga and 10ga silicone multi stand wire wrapped in a half of copper pipe half inch copper pipe and filled with solder with torch next time I will use a 80 watt iron then drilled and tapped in to the aluminum buss . Is this good enough for contact ?

You should not attach bare copper to aluminum. When current flows the junction between the two metals will cause the aluminum to corrode. Aluminum corrodes into Aluminum Oxide .. that gray-whitish stuff that is Non-Conductive. The connections develops resistance and starts getting hot under load. Eventually you can end up with a fire there.

A solution to consider is using NO-Ox-ID-A-Special It's a conductive grease that prevents oxidation of the metals and reduces aluminum oxide by chemical reaction. I'd use it between aluminum and copper tabs before clamping or crimping them together as well. Just be careful with it since it is conductive !!
 
Has anyone else had an issue with these cells failing (seemingly random)? I think my issue may have come from not having all of my 22s pack in the holders, as I have not had issues with any other packs I have made with these cells. I am using a 200 amp ANT bms so I know they are not getting overcharged or over discharged(I never charge them past 4.1 volts per cell or discharge the below 2.6 volts). And I live in the states in the southeast, so they haven't ever been cold and the bms keeps them from getting hot. I have had 6 cells fail in the last 3 weeks. No visible damage to the cells(like punctures or crushed cells or tabs blown apart lol). Cells are kapton taped for compression, and to keep the tabs from shorting. They are then surrounded by a layer of foam to prevent any impact or shorting inside my bomber frame. Any ideas, because I am running out of spare cells and ideas myself? Any help would be greatly appreciated. Gonna remove all the cells holders today and somehow install the pack to a secure position in the frame....somehow. still coming up with that plan.
 
If one or more cells die, but not the whole pack, I would first suspect the BMS. On future builds, consider connecting the pack to an RC harness, so that the BMS you use is easily removable when not charging.

BatteryPack10.png
 
PhysicsNerd said:
A solution to consider is using NO-Ox-ID-A-Special
Yes, top stuff!

Most corrosion inhibiting "electric greases" are dielectric, relying on pressure to squeeze it out of the contact areas.

Still want to disengage the bolts (or whatever) and re-apply every once in a while.

 
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