Sad facts
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HELLO?
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HELLO!
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help help
help with battery
Maybe it was a bad solder connection to that main lead and that caused the blowup?
thanks, interesting considerations. Unfortunately I’ve available a 10awg silicon wire for the vesc, and 14awg for charging.
I’ve also a braid wire with a section of roughly 3mm when rounded and 3.5/4 flat, can I use that?
Can I use electrical wire being an internal connection?
I’ve noticed that the core of silicon wires is not copper wire, so I presume have less conductivity?
I found some 1.5mm nickel plates, Is it really better to use wire instead of having just 1 layer of nickel on top of the other nickel layer for the P group?
I found mine on amazon, also nkon have many useful items
I’ve already difficulties sourcing the fuse for charging, I can’t even imagine finding the right one for discharging. The one I found handle 15/20A at a much lower V then 50V for 12S. Any advice of where to buy?
Fuse: Actually on nkon there is a good selection of fuse for discharge at 48V.
Which one should I select considering I’ll use my eMTB mostly uphill and I expect a lot of power drain. I’m unsure now if I’ll use it 2wd or 4wd. What would be an Amp range for discharge?
I reply to myself, maybe is useful for others as well:
To find the total maximum continuous discharge current of your battery pack, multiply the maximum discharge current of a single cell by the number of parallel cells.
So in my case Molicel P42A Maximum Continuous Discharge Current: 45A x 3 = 135A + Safety Margin: 10-20% = 148A/162A
Layering nickel is a bad idea and especially bad if you don’t already have experience doing it. Also your nickel connections are very limiting regarding the current flow if you are going to go the way you pictured.
A 1.5mm nickel sheet wouldn’t work either, there’s zero chance you can weld that.
Go for the 0.2mm 30mm wide nickel strip that I linked for you from nkon.
I wouldn’t buy a fuse from nkon. Well rather I wouldn’t buy a fuse that doesn’t have a datasheet with a chart containing information on time to blow vs current.
If you select the fuse wrong (and it’s very hard to get it right). It’s not going to blow during a short before your wiring blows.
I was talking about my fuse situation above. I found a fuse on mouser that had a proper datasheet and was rated for high enough voltage. If I were to select a fuse that was still uncertain if it blow during a short, that was already below the max current rating where I normally peak using the pack. As I said it’s really hard to get it right… The simplest is making sure to have the weakpoint of your wiring outside the battery.
While you can technically use P42A at 45 amps, you will have a lot of voltage sag doing that. The cell is happier around 30A.
Only if you have a proper nickel connection from the cell to wire. But at that point it’s usually simper to just use nickel. For the connections between the 3 packs use wire.
It’s tinned copper. Doesn’t really affect the conductivity. Nicer to solder.
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sorry I meant 0.15mm nickel strip, I don’t why I wrote that.
What are the main thing to check or be aware when layering nickel? I can make good practice without the cells if I know what should I check for.
I’ve tuned the welder to make the spot not go below the bottom layer and not to powerful to avoid making a hole in the top layer…
Can I use braided 3mm section wire between the 3 packs?
A higher gauge wire isn’t going to help you in the situation of a short. If anything, it will do the opposite as it’ll take longer to burn off. 12awg will do ~90 amps cont. For burst current, you can reasonably double that. Unless @eliSk8 is building a mountainboard or a race board, 12 awg is absolutely sufficient current carrying capacity.
I’m building a mountain board for steep inclines, but with a 3p Molicel I’ll limit the current to 90/100 given that
So I either I do 2x14awg or I have this braided copper wire with a section of roughly 3mm when rounded and 3.5/4mm flat, can I use that?
So then terminate your battery in 10awg for some headroom and you should be good. This looks to be a brick pack. How are you making your Series connections?
yes, I was saying that for series connections, reading your suggestions, I’m planing to use either 2x14awg or that braided 3mm copper wire
If you terminate the main terminals with 10awg you should be using 2 x 12awg or 3 x 14awg for your S connections as a best practice. 2 x 14awg is not sufficient.
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