10s1p vs 12s1p Comparison

ESK8 Electronics
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I’ve been reading quite a bit in the forums and online, but I can’t seem to answer the question that I currently have.

I haven’t decided if I am gonna do 12s or 10s quite yet, and I currently have basically two options that I;m looking at.

1st option is doing 4x 3s1p 5000mah 20C lipo cells in series to get 12s

2nd, which is the one I have planned for since the beginning, is to do 2x 5s1p 5000mah 25C lipo cells in series to get 10s.

I know that with 12S I will be able to go faster, but will I get more range with that 12s setup since there are more mah’s overall?

1x 190kv motor, approx 145lb rider, VESC

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For a 12s battery you don’t want a motor any higher than 170kv. It makes the ERPM over 60,000 which is bad news.

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Against the comon forum consensus, I run 190kv on 12S and 230kv on 10S, I’ve never exceeded max ERPM, board runs faster and feels amazing!

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That’s because 190kv on 12s and 230kv on 10s is fine. They do not go over erpm limits in real riding scenarios (unless you’re going downhill obviously).

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Wait so if I was going downhill with the throttle off, would I have a problem? I don’t wanna accidentally fry my electronics

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Find out what 60k eRPM translates to in speed on your setup. It should be faster than you’re comfortable going on the board. I don’t believe it’ll fry your VESC as it’s not supplying current to the motors when you’re going downhill like that, but I definitely don’t know for sure.

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Hm alright. Sorry noob question but how would I find out how fast that is? And would the 12s with the 4 5000 packs give me more range overall?

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Plug in your setup to find speed/erpm. Your range is dependent on your watt hours. Ah x voltage = watt hours. So the more the further you’ll go.

http://calc.esk8.it/

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So basically you’re saying that with the 4x 3s packs, since it is a total of 20000mah, or 20ah, 204.212 = total wh?

So for 12s, 20*44.4 = 888 wh?

and for the 10s, 10*36 =720 ?

Any idea how many miles that translates to roughly?

The esk8 calc says my weighted speed with 12s is 30.98mph

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4x 3s packs in series = 12s 5000mah 4x 3 packs in parallel = 3s 20000mah

You don’t get both by putting it in series. 12s x 5000 mah = 222wh. You can estimate 10wh per kilometer for about 22km range.

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I run 12s on 200kv for my personal boards but they a geared to reach well over 40 mph so not a big chance that I will ever overrun the erpm by coasting. It is a different story for a board geared only to reach 25 to 30 mph, you need a little headroom to keep things happy.

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@chaka Oh okay, what’s your gearing ratio and wheel size? I have 16-36 from the TB kit and 83mm wheels.

You mean headroom for the VESC voltage wise?

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@Jinra Ah okay that makes more sense. Thanks!

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You can exceed the Erpm limit on paper and not have a problem during normal operation because you won’t spin the motor fast enough to top it out. Just remember, if you flip your board over on the bench and pull the trigger, it will top out right away And you might fry it that way

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@Namasaki That seems logical, would the VESC stop increasing the speed at the 60,000 Erpm or would it just continue spinning until it blew itself up?

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I think that depends on if you set the limit to 60k in bldc tool. @chaka is more of an expert when it comes to Vescs Mayb he can give a more definitive answer.

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@Namasaki And that limit is just a theoretical one or the limit of the bearings?

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@Namasaki I just found chaka’s post about choosing the right motor for the VESC, that explained it pretty well. I don’t want a dead VESC lol Chaka’s Post

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There is a setting in the bldc tool for max erpm.

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Good point. Going downhill it’s easy to exceed your typical speed = >60k ERPM and kapow dead DRV if unlucky.

Another great way to kill your DRV is on the bench - so don’t full throttle and brake hard. boom dead DRV, then you grab another VESC to re-test because we all like to confirm we’re idiots and kill a second DRV… :facepalm: