I’m trying to pull as much current as the A123 will allow in a 12s1p config, which should be around 50A. Not trying to go far. This is for a short-range, budget shortboard with hubs. I bought these A123 cells from the batteryhookup
Those are already close to a configuration you are looking for. Please post a pic of the nickel serial and p group connections. I bet u could pretty reasonably get away with breaking down p groups then halfing them and wiring up 2 12s2p packs with copper braid, using the original grey holders.
Thank you! I haven’t had a chance to break them down yet, but would love to be able to re-use the 4s p groups. If I use copper braid, would I solder the copper braid to the thin nickel strips that are already welded to the cells?
For my first pack, I want to build a 12s1p pack. Then will plan to build a second 12s2p or 12s3p pack from the remaining cells.
To the nickel, yes.
I suspect the nickel will look like the blue markings.
I only suggest if you are feeling adventurous. I took apart a pack I soldered back in the day. It was not pretty and would have gotten instantly shamed (rightfully) here for numerous safety reasons.
I’d like to also second the nese packs. Those seem like a great idea that I’ve never actually used myself.
Great, we are in the same damn boat now. I ordered one. Thanks a lot
Sweet! There’s a teardown video for these packs that show more details on the nickel strips:
Also another thread here discussing it:
Would love to be able to re-use as much of the nickel plating as possible (e.g. by reinforcing it with copper braided wire to handle higher discharge rates.
lol, next time record this and put it up on YouTube. People have gotten famous with less, haha
I laugh every time I see this video, does not get old, hahaha
He sounds like a zombie from L4D2 when he shrieks
Do you have the 26650 sized stamped nickel strips for the scaled NESE?
I am making my own. We had a little… Disagreement on this subject
What tool are you using to stamp them?
seeing as its half a mm of copper, I figured I could make/design a divit in a block, 3d print it, and hammer the metal down into that recess in the block. Idk haven’t gotten that far and nor do I have the metals yet. soon tho
something something gallium epoxy something something MesoGlue something something
on my wish list
Has like 3000 times the resistivity of copper, but small amounts to glue nickel strip should be good enough??
This has even lower resistivity, but has a longer cure time, which may make it more difficult to work with.
This looks like the best of both worlds, I don’t fully understand the specifications of epoxies.
Should I take one for the team and test a battery build with these?
There has to be a reason why more people don’t just expoy batteries together (cost???)
Also needs 65° to cure, which runs up close to battery operating temp, maybe that too???
I have a 12s4p nese complete set up sitting on my bench and has been for 4 months.
Haven’t even looked at it. Seemed like a good idea at the time which was 2am and 3/4’s of a bottle of Jack.
Guess now I want to go read the nese thread.
Since 12S LiFePO4 is nearly the same as 10S li-ion I guess this on topic
Seriously though, I use 12S LiFePO4 at 29A (battery) in short-range, non-budget shortboards with satellite motors and they perform great. If you use the cells at less than they are rated for, you will get an increased lifetime. LiFePO4 already has way more lifetime than li-ion anyway though.
I watched a certain EV YouTuber fuck up a vruzend modular pack and it kind of turned me off to the idea.
@Bindings_McGee made a compelling argument for them when he was doing San Diego things.
Hmm, interesting. I’d try the lowest resistance, longest cure one, especially if you can cure it at room temperature.
Forget nickel, if you’re going to use that then just use copper sheet
I answered my own question. So, expoxies before they cure are rather runny, and on some forums they mentioned that it could run under the wrapper. BAD!
There was also the risk of the bond breaking and causing conductive bits to fly around your enclosure. So you would need to otherwise reinforce the cells so other structures absorb the vibration and shock.
Based off an Amazon review, the 24hr cure at room temperature did not make for a strong bond, so sounds like you’d want to blow at it with a hair dryer. Fortunately, 20 minutes at 65°C is well below the thermal stress test used in the datasheets. Although that also might have been because the customer did not rough up the contact surfaces.
This means you need to painstaking sand terminals of the cells before applying the expoy.
It can be done, but I looks like it’s not worth the trouble and cost compared to spot welding or other weldless designs.