found a log from i think practice at erl san fran
i’ve found that aside from launches, i don’t use much battery or motor amps especially compared to others but i also only weigh like 160lbs
this is the log from one of the launch practice sessions i had with a little bit of riding on the long “tracks” i usually ride at
More even current distribution. You want to have the copper (wires) as close as possible to the cell itself. So current distribution is kinda like this
instead of this
Copper is 4x as conductive as nickel. Less distance travelled on the nickel is a good way to minimize resistance
Another good way would be to start using the copper - nickel plated steel sandwich weld technique. I think for these new tabless cells the benefits of that will be visible for sure.
That’s a good point. I can’t imagine such a big difference being from battery build alone. I don’t setup my packs unless I’m using lipos, the guy who does it for me uses flat copper braid between series connections and then from memory the little pack had 12awg exit wires. Can’t remember if they were soldered fully across the nickel.
IMHO there’s typically no need to measure each cell. Yea, it would be great to do for possibly helping to detect when a cell is reaching the end of its life but the loss of capacity is usually detected a lot easier.
I think just measuring the temp of the hottest cells in the pack (wedge the thermistor between two cells) is enough. That’s the biggest concern, the hottest cells.
Response time? Nothing for existing ones. But there are smaller bead thermistors and even “flat” ones with faster response times that can be used.
Increasing the thermal coupling is key…
Rounded bead thermistors on a cell = tiny contact patch. Using epoxy to embed the thermistor wedged tightly into the valley between two cells can help. Or you can use a blob of thermal paste on the bead and tape it down tightly with high-temp tape. Anything to increase the surface area that can transfer heat to the bead.
Pretty fucking well established. In the off-grid and full-scale EV world they’re a premier cell manu on par with the likes of Samsung and Molicell, but more known in circles including BAK, Lishen and CATL.
II didn’t know about Saft until recently, I guess EVE pops up in battery liquidator sites frequently.
Hi,
I’m the guy who did this video. I’ve also been into e-skate since 2016. Built 2 packs for my evolve boards.
Although I’m heavily into the Surron world now, I still love e-skate. Have a very rare Hadean Assault, it’s amazing.
Yep the JP40 surpassed even the P50B, and tabless in general is a breakthrough.
Here’s the video:
youtu.be/fpl25iOBzSA?si=hF7mTRulc4qjZf8d
Welcome to the forum!
Anybody have additional info on the Murata VX40, that come in the Makita 40v XGT?
Here’s a tear down video.
Nothing yet. I haven’t seen any separate samples being available yet but I’m happy to test them if anyone can find a couple.
That video is a great reminder to always remember to FULLY discharge a cell if taking it apart. 
That smell he talks about is the electrolyte and is verrrry toxic. The smoke from that thermal runaway (fire) event is stunningly toxic. Look up HF (hydrofluoric acid) to get an idea of the danger from the byproducts of thermal runaway.
I see Liion wholesale carries some BAK cells, but not the 45d.
Hopefully there is a stateside retailer of these soon.
Coolwatts collated all his testing information in a new video. Graphs and such vs the earlier handwritten results.
Spent a lot of time on that. (I’m CoolWatts BTW).
Hope it’s helpful!
I think the charts really help put the results in perspective.
Just watched you video on the tabless, man what a wealth of info. Thanks for sharing!
Welp the 45D has too much sag at the current levels I would run ideally, so they aren’t looking that good for my build anymore. Where do you all buy JP40s and EVE 40PLs? I’m in Europe. I think nkon doesn’t stock either.
Edit: nvm the test data I saw was the wrong cells
Anyone know if the Samsung 45T is tabless? (not a misspelling it’s a new cell)
Nkon will be shipping them from Dec 6 @Dinnye.
I wasn’t going to be sending another batch of new cells to Mooch until late January but I can get those if it’s important.
Sorry to @ you again.
Nkon is going to start shipping 40PL @Dinnye
I mentioned the 45T in case they hold up to their 60A rating well enough to be instead of 40PL.
