Well I mean obviously it’s good to build your pack to be able to output its full potential but I can tell you right now that it will probably be difficult to get those to pull 100a each continuously lol
Probably 2 10s is fine
*YMMV if you are very heavy or you ride only hills
My (admittedly limited) understanding is that when you discharge a cell, you take the area under the discharge curve and find the midpoint, and that’s the nominal voltage.
It could also be based on capacity not energy, but the concept is the same.
Like Mooch said, that point will shift around significantly depending on the current draw, which is probably why RC lipo packs have a higher nominal voltage than li-ion.
The maximum and minimum voltages also affect things obviously. Since cylindrical cells are usually rated down to 2.5v, that pushes the nominal down as well. Since lipo RC packs really don’t like being drained that low (for best cycle life), that also pushes up their nominal voltage.
Same with “high voltage” cells with a 4.3 or 4.35 maximum, that raises the nominal a bit (to 3.65 usually).
Yeah I know, but it gets hot in the summer nowadays (yay climate change) so having extra copper and cooling while limiting amp output will tremendously help with temp performance.
If the nickle is as Joey shows, you’d be able to draw up to about 30 amps per cell (5A/weld with a 50A/cell max) so if you collected 100% of the current on both ends, the pack would be capable of probably 100% of the cell’s continous rating. But its almost impossible to use that many battery amps and I think those are 10A cells anyway, in which case you’re 100% fine.
I am building a non-staggered 12p pack (can’t be staggered don’t have more sideways space). It is better to glue groups of 3 instead of groups of 4 right (red)? So that I have 6 instead of 4 connections to group the single layers together (with the outside edges - green).
Or do I smother hot glue/silicone in between the layers like pb+j so I have glue connecting the layers (green in the middle too)- instead of just outsides? The reason I was just going to do outside is because this isnt staggered so there would be a lot more glue needed and might get too messy?
Nother question for you lads i got a friend whos soon gonna setup a 10s18p for his board and he wanted to know a good charge amps to use for the triple paralleled 10s6p setup.
Now i suggested each packs safe charge would be about 5amps per pack so about 15amps total for all three using a beefy lp-20 charge port fused of course and using 12awg wires on both the lp-20 port as well as to the bmses what do yall think of this plan, is it a good idea or no?
Edit: this was his idea on the wiring setup
Would I be better of with not using cell holders for an E moto/ E motocross, I’m using 26650 so finding that size in the honeycomb option with a fast delivery is a pain in the butt. Using black hotglue or high temp silicone for vibration resistence would be as good right? High temp foam/ rubber mat for series insulation and dampening AND for outside layer protection under heat shrink? Sounds like a good plan, just need a good layout for a 20s12p
I’ve built one like this, a 12S5P 21700 for a subsonic enclosure.
Those vertical P groups are not only challenging to wire, they are challenging to wire in a way that evenly distributes the load coming through. It is do-able, but needs to be done really well
I would recommend re-evaluating your layout vs the size available. Not sure why those groups couldn’t be 6 cells wide. 6x21mm= 126 vs 140 the way they are now.
Either way, that’s getting really really messy with the P groups split like that. Especially with such a high amp battery, you risk having unequal amounts of energy flowing through separate part of the same P group.
Even doing it to support the same amps, this is gonna take more wire, more connections, increase failure points and resistance and add weight.
Nickel series connections aren’t all bad. And that battery should definitely definitely not flex
Building a 10s4p for a friend’s evolve without the evolve guts. Figured a neat way to route the balance cables for this configuration.
I might be concerned that eventually the tape part of the filament tape might wear down leaving your balance wires sitting on nylon strands? Pretty pack anyway, just nitpicking
Both seem pretty similar to me; I’d probably go with 3 groups of 4 just so that the cells are more level + less groups to work with.
I don’t really see why this would cause a problem, is it a structural thing or an electrical thing?
Both? The tape part maybe isn’t as slick/soft/unabrasive and heat resistant as kapton tape and the fibre part is abrasive(or not ) (I can’t tell how abrasive it is as I don’t have any) so with vibration and time could become an electrical problem if the wires wear out and short themselves.
Edit: structurally it will hold for sure
Pretty neat pack non the less
I think there is so much surface area there that abrasion won’t be a problem. Even if the fibre starts to wear into the insulation of the wire, its only ~0.1mm thick vs the 0.5+mm thick insulation. I don’t think it would wear away to the conductor. If there is so much pressure on the pack that the balance wires wear through fibre tape you have bigger problems…
If you’re gonna cross balance wires, that’s the way to do it 
nice work Linford
You can peel the fibers off and rub them between your fingers without any grit or itchy feeling. I don’t think it’s really that abrasive but definitely not purpose designed for electrical situations as kapton is.
Ooh okay noted, thought it would be like any other fiberglass and be somewhat itchy. I don’t have any so can’t test it out. Thanks for the info!
