Hi there! I’ve been entertaining the idea of building a board and I’ve been trying to plan out the wiring. I made a (very crude) schematic of what I was thinking. Please let me know if it’ll work or needs any improvement.
Additionally, I’m planning on having a 12s setup with a SK3 168kv motor. All XT90 connectors are going to be anti-spark also.
Looks all fine to me not showing your receiver though. Also good to keep in mind board flex and how you will hold the cables to the board, also best to keep them as short as possible from what I’m told and what I understand.
They worked okay for me for a short time but I pulled a cell too low and basically never properly recovered the pack after that (it could never fully bring that cell up to 4.2). The amperage didn’t seem to be a problem but they were also hefty and I didn’t need the top speed it gives really.
I never tried them but people who have been on this forum longer I have, said that they are not good.
The thing about C ratings (and this has been discussed in earlier threads) is that it is not a real number.
And though I am a strong supporter of the use of Lipos for e-skate, I have to admit the C rating are not realistic. However, they do serve as a relative value when comparing similar Lipos to each other.
Here is a prime example:
I use 5ah Lipos that are rated 60/120C
That’s 300a continuous and 600 amp peak.
That is just ridiculous. The main wires coming from those batteries are only rated for 75a
And when I go up a 10% grade, I still get a little voltage sag.
So don’t count on those multi rotor packs to be capable of 100a cuz you can bet they won’t be anywhere near that
Yeah thing is I weigh like 120lbs or so and no hills here and with a 149kv motor my ammeter never showed above 20A draw even when I punch it so it still has plenty of headroom for pulling more power, that said they are huge and they probably don’t dissipate heat that well especially from the cells in the center of the pack.
Even if the motor got the full rated power delivered at 40V to get around 2500W you’d have to be drawing about 80A I’m sure this has never happened.
Schematic looks good - i’d move the anti-spark XT90 to the end so it’s what you plug in to power the VESC - instead of two anti-spark XT90’s on each battery (though that works too, but you only need the last one you connect). And if you connect those, then plug in the final single plug to power the ESC/VESC it will spark since the resistor to slow the inrush is bypassed when the plug is fully seated…
As for the Multistar 10Ah 10C packs - like almost all lipo’s made - the C rating is usually MARKETING and should be questioned. One of the reason i shoot for higher C packs so that the actual real-world performance is sufficient.
The difference with li-ion vs lipo is i trust the actual tests of the 18650 cells done by Mooch and others on the candlepower and vape forums. Heavy load tests around the 15-25+ Amps are great indicators for our use.
And on the flats and only 120lbs - i think the multistars will work fine for you. I’d still watch out for over-discharging them, or under heavy use feel them to see if getting hot. Inspect frequently when you charge and look for puffed cells and any that sag early. Signs of a failing pack - stop using and charging!
Going higher voltage will definitely help because you will draw less amps.
The main thing as mentioned in another similar thread is to be careful to not discharge these batteries too low.
Don’t go below 3.6v per cell and if possible, you would do better to not go below 3.8v per cell.
With 12s and 10ah your max range would be apx 20 miles.
If you can limit your ride to 15 miles it would be good.