Energy Draw Issue

ESK8 Electronics
21

Interesting …I don’t find the range off my 12s5p pack to be so great also. Even on a single motor, it’s made from 25r…

22

and the next one arrested :sweat_smile::ok_hand:

3 Likes
23

I do apologize, I do not work with the NESE system. But we do make flat packs for esk8. We have used the 25r 20a before and the reason I ask is that in building this way NESE the resistance must be a lot. We have found a sweet spot in the size of nickel strip to the gage of wire to achieve the most the battery pack can give. Sometimes bigger isn’t better.

24

A resistance of NESE or any other not welded battery packs will be huge compared to normal welding connections. As metals produces oxides which increase resistance and other factors as not hard enough contact and etc, if you point Flir camera to your pack while riding I would guarantee every connection point will shine :slight_smile: Also helical gears are not very efficient compared to plain spur gears :slight_smile:

3 Likes
25

Wow, @Kug3lis did you just kinda agree with me? What’s going on. Am I being pranked??!?!?!??

4 Likes
26

So you are saying that your modules are cutting 30+% of the range from my pack?

27

I think what he is saying is higher resistance means higher heat which means the battery lifetime is less.

28

Well its not cutting the range technically just including more resistance in your power delivery which burns some of the energy as heat :slight_smile:

1 Like
29

The more you draw the more you loose :slight_smile:

30

Is it reasonable for this heat to be the 30% I am missing from the pack?

31

I do understand this principle. Would spot welding the pack fix the range?

32

Well maybe :wink: I can’t measure resistance via internet and tell you exactly whats happening :slight_smile: Also can be your cells are clones, your wiring is bad, your gear mesh is bad, your wheels are too high pressure and many many more variables :slight_smile:

1 Like
33

Looking around I am reading that the difference is negligible.

34

Also how aggressive are you driving.

At low gear ratios helicals are not efficient

35

I purchased them from liionwholesale.com which only sells genuine cells.

The wheels seem to freewheel better than my buddies belt drive so I don’t think this is a mesh issue

Higher pressure would mean better range no?

36

Well like I said I am not mind reader or magician to exactly describe the problem for you :slight_smile:

37

I know. I am just trying to check boxes off to get down to the root of the problem.

38

@Nowind Have you had problems like this with your helical drives before?

39

NESE uses tin coated copper which has much lower resistance when compared to the regularly used nickel tabs. When tightened nicely, it should have negligible resistance.To loose 30% of the energy to heat would mean that the busbar and other contact points would be too hot to touch. If you have a thermal camera, it can give you a nice idea of how hot it gets.

Honestly, I would do the following:

  1. Charge a single cell and see what is the capacity from fully charged to drained to see if your cells are healthy.
  2. Measure the voltage of each parallel group after your VESC/BMS doesn’t work any more. If all the parallel groups are at same voltage then it’s all good, but if one or 2 groups’s voltage is significantly lower than the rest then you have found the parallel group with bad cells. You just replace the cells for that group only.

Also is 40PSI the max you can go on those pnummies? I have heard people using 70PSI to get good range.

40

I can go up to 50psi on my tires.

I have a smart BMS (Not DIEBIEBMS) which Bluetooth. The cells are all within .01V.

Are you recommending using a hobby charger?