What do you guys think of my build?

ESK8 Builds
9

Couple options:

  1. Get 2x 4s batteries for 8s instead
  2. Put your 5s batteries in parallel (not recommended)
  3. Limit your eRPM on the VESC (inefficient)

Best option is to get a more compatible motor though.

10

So should I get a more compatible motor and 2x 4s batteries? Also, what is another hobby online store besides HobbyKing.

11

Nvm, how is a 213kv motor with my current setup?

12

Yea should run fine

13

Do you think a 2x 3000 mAh 30C battery would do better or worse in terms of range?

14

To the best of my knowledge, mAh more or less the range. So if you downsize to 3000mAh (what ‘S’?), you will cut your range by about 40% off of the 5000mAh - Probably something close to 5 miles.

15

My batteries are 5S, 10S in total with two batteries in series. Does the calculation include the C rating as well? For example, my battery is 3 Ah, but with the 20C rating, it would go to 60 Ah. Should I calculate the 60Ah or 3Ah.

16

Just watt hours, nominal voltage x mah. The more you have the more range (approximately 10wh = 1km)

17

Do you mean mah or ah? I don’t belive mah is right

18

right ah, though they’re the same just a lower unit of measurement.

19

cool. One more question: Should I calculate the ah with the 20C rating or not? For example, my battery is 3 Ah, but with the 20C rating, it would go to 60 Ah. 3Ah or 60 Ah?

20

C rating signifies discharge potential. While the rate of discharge plays into the time to depletion, it has no bearing on the watt hours of the pack.

21

Oh I thought it does. I guess I misread this Battery guide: http://www.electric-skateboard.builders/t/what-is-battery-c-rating-is-it-important-for-electric-skateboards/36?source_topic_id=215

22

Is putting 2 batteries in series will make it go further in distance or faster? I am confused whether to put my two batteries in series or parallel.

23

I’d aim for 10s. putting in series directly increases the watt hours of the pack and increases range

24

Series increases voltage but doesn’t add the capacity (you get power at higher voltage but the electrons flow through all cells in series at the same rate Amps, one bucket pouring into another pouring into a pipe). If you put batteries in parallel with the same voltage their voltage doesn’t add but the capacity is increased ( you have twice the buckets at the same height pouring into the same pipe… Twice capacity no change in voltage potential)

C rating has to do with max amperage due to internal resistance and heat build up in the batteries, higher amperage through a fixed resistance creates power loss I^2R higher c rating means higher max amps and less voltage sag under load (when pulling high amps to drive the motor). Power to the ESC and motor is a product of voltage and amperage so 20V at 20A is 400W if you have a 40V battery only need 10A to deliver the 400W. C rating is used in conjunction with the Ah of the pack to determine max amperage so a 5Ah battery with 10C rating can discharge at 510=50A whereas a 20C with same Ah would be 5*20=100A

25

So what would be better? 20C or 30C?

26

The more the better

1 Like
27

Is it better to have a shorter or longer belt? Or does it not matter?

28

You want a belt that fits tight and ideally wider is typically better in terms of power transfer (length shouldn’t make much of a difference there). Another thing to consider is a slightly longer belt will be wrapping around the pulley more which gives you more surface area contact between the belt and the pulley teeth which is always a good thing (see posts on idler bearing usage to improve this further if you’re interested as well).