Does this apply to A123 cells as well, or is it the positive anode on those cells?
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Penetration isn’t really something you can look for. You gotta do some tests and see if you can rip the nickel off the cell. If it leaves the weld behind and tears the nickel, it’s great. If not, then that isn’t great.
You want the minimum energy/heat input while still achieving that strength.
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I have been thinking about making a dual tip grinder to touch up easily while welding, hopefully without putting them down.
Bad idea? doing them one at a time with sandpaper good enough?
iirc those are reversed poll compared to standard li-ion, so it maybe the positive. @Battery_Mooch would definitely know better than I would.
I use a small file that’s a pretty fine abrasive. Probably file them every ~120 welds?
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The “button” for the 26650, usually the positive terminal for a Li-ion cell, is the negative terminal for the A123 and Lithium Werks cells. I don’t know if the flatter positive terminal is spot-welded internally but I’m thinking it would be safer to assume so.
There’s nothing in the datasheets about connecting cells and I’ve never seen a cell teardown.
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I might be mistaken I just avoid the very center on both ends and do 6 welds in a circle
As a very general rule of thum I do 1 x 10mm by 0.2 per a cell of q30 in a p group. Depending on how you build your batery this needs to be re assessed
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What is the concern if you don’t mind me asking? I’ve been doing this for years and have never had a problem.
Although I usually fully discharge my lipos to 0 volts on a concrete pad outside, or something along those lines. Everything I’ve ready is that inert lipos are the safest way to dispose of them.
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According to the wise words of Mooch:
“Salt water discharging is incredibly slow and causes electrolysis destruction of the tabs, exposing the inside of the cells and creating toxic sludge water”
Wow I really can’t get this to work on my phone
**there we go
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I recommend you fined proper places to do research sutch as manufactures instructions or recycling businesses. Just because people say carrots help you see in the dark, eating crusts make you hair curly doesn’t make it true. Disharging lipos below there safe limit is dangerus and toxic.
Should I be covering the naked nickel on my pack if shrink wrap is going to be going over the whole pack?
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More insulation is (almost) always better 
That said, you know the use case for your battery better than we do. Sometimes its the best idea to wrap every single square inch of a battery in fish paper. Sometimes thats either not possible, or not necessary. It all depends.
Here’s a battery I am building for a customer right now:
Notice how the only fish paper are the rings on the positive terminal, the strips under the positive nickel fold, and the strips between the sides of the p-groups?
Normally I would wrap the entire p-group all the way around, but that is actually not possible on this pack, as the space in each enclosure segment is wide enough for 8 21700’s, one layer of fish paper, and literally nothing else. Adding one layer of kapton all the way around each group nearly made the battery not fit.
Though in addition to it not fitting, I also deemed a full fish paper wrap unnecessary, as with so little space in the enclosure and each section of the battery being total isolated by the enclosure, the chances os something conductive getting where it shouldnt are slim to none.
So it really all comes down to your application.
To answer your question simply,
A bit of kapton almost never hurts anything, and fish paper is even better 
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To be clear, I wasn’t advocating that people use the salt water method to fully discharge lipo batteries.
Also rather than answering my original question, you instead imply that I didn’t do any research. Just in case I made a mistake, I did another round of research. Everything that I am finding online says that lipo batteries (not lithium-ion) should be fully discharged to 0 volts prior to recycling.
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Thanks for the explanation!
Clearance isn’t an issue at all for my current build right now luckily, and I don’t ever intend on riding it in the rain. But since I did my s-connections with 12awg so there are solder balls on each p-group and I wasn’t sure how I could get kapton tape or fish paper on there and make it stick. I think I have a better idea of how to now though 
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My favorite method for this is to put down a layer of kapton over the nickel, then cut a square with an x-acto knife and solder in that square, then tape over that
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If done carefully and properly that shouldn’t be an issue. But…
Salt water discharging can dissolve the tabs before the cells are discharged, leaving them in a condition that could cause the very problems the discharging was supposed to address. If the LiPo’s are handled like they are inert, instead of partially charged, then that could lead to them being short-circuited.
If the tabs fully dissolve In the salt water, and the internals of the cells are exposed, then you have toxic organic solvents in the water which then get dumped down the drain. It’s a hazard to touch or breathe too.
If discharging to zero volts via a bulb or another method then bottom balancing needs to be done while (slowly!) discharging in order to prevent one or more cells from dropping below zero volts. If this happens it’s the same as those cells being charged with reverse polarity and that’s a great way to start a fire.
Depending on their voltage the amount of energy available to create a fire could be very low but this is not a risk-free procedure.
I am not saying that discharging LiPo’s before disposal is “dangerous”. It’s just not a trouble-free, no-worry thing to do in order to make the pack “safe”. This has to be balanced against just wrapping the pack up to prevent short-circuits and recycling via a dedicated battery recycling bin.
Millions and millions of LiPo’s are disposed of every year without being discharged first. For large packs though that contain huge amounts of energy it could help to get rid of some of that energy first (zero volts is not needed) but the risks should be considered when choosing how.
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Ill save that for next method for my next battery 
I think what I’ll do is get a little square of kapton that covers the solder ball then fishtape or kapton tape down the edges that might come off
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What manufacture tells you to submerge battery’s in water.
What manufacture tells you to deplete lipo battery’s below there fully depleted state?
What should you do when disposal
All from the Samsung Q30 specification of product sheet. If some ones research dose’t include the official paper work of the product then
Yes discharge it if safe to do so and within the safe limits. Going outside destabilises the battery
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Never knew not to discharge batts fully for disposal until a week or two ago. I’ll think twice about using a “lipo killer” led circuit again.
Perhaps they are meant for single cell batteries?
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