What amp/watt are most people having success with? Are 10a 18650's strong enough?

ESK8 Electronics
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I got a hold of 200 2000mah 18650’s, which are 10a continuous / 20a max, and not certain that’s going to be good enough for my pack. I figure a 12v3p, but not certain if I should go with 4p.

I’m looking at using v4.12 of Vedder’s ESC, which has a continuous 50a and either the 6355 190KV or 6374 190KV 3150W. Both are 80amp max.

With 12s/3p i’m looking at 30a continous / 1152-1512 watt (cutoff at 3.2v to 4.2v x 12) or 60a / 2304 - 3024 max (2664 watt peak at nominal voltage.

The above post mentions people topping out the amperage (meaning they have packs that can handle up to 150amp), so my concerns is I am going to be working with a weak power source? Should I ditch these batteries for this project?

In summary, what are people using? The video walking through how to configure the VESC has a max amp setting of 40 amp (I believe at 12s, but might have been 10s), but

^^ at 27:21 configures the VESC at 30amp, in a dual setup (so 60amp) (12s)

and

^^

Sets his at 25amp (total) 12s.

Does it all really matter that much? I am not a small person. 220lbs. Will going with the higher watt motor be redundant unless I can increase the amperage, or am I way over thinking this since this really only comes into play going up hill and getting up to speed (although acceleration is one of the main points of performance I am concerned about).

I’ve read some details that a larger watt motor pulling the same current will provide more torque (I couldn’t find much detail or proof behind this, so I am not certain whether that’s true), but provide less distance, which isn’t a major concern for me (I can always run another parallel if needed), but in my case, a 3p pack will max out at 2664 peak watts at nominal voltage, so would it even make sense to go with the 3150 watt motor?

Long story short, I am building a battery pack and need to know what motor to buy and what type of pack to build and whether I should get some high C rated batteries to do that. It will also decide what BMS I use. If I need to get closer to the max 50amp continuous the VESC can handle, i’ll just add more batteries and get a more expensive BMS (vs the 30a BMS I am looking at).

What’s everyone else working with? Do we have many lower C rated li-ion packs being used for E-Skates?

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On my dual direct drive i pull 40A in Total. SO 20a each vesc!

On my single I have set the vesc to 40 A aswell! Performance is great. I don’t need more

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Ok this is still fresh… so will try to clarify a few thins before going into more detail…

Are you planning to ride at 40-50kph (25-30mph) mostly?

Are u planning to up hills?

Do you want to experience / enjoy insane acceleration?

Otherwise I think no more than 1000W are needed…

I think @ackmaniack himself could confirm that for ‘general crusing’ no more than 400w might be needed (and perhaps about 800w for ‘decent’ acceleration)…

And yeh… you can always limit max current since you are planning to go with vesc, which is a big plus, I think…

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I use 2900mAh @ 10A cont and 20A burst in a 12s4p configuration. I have my two vescs set at +15a for battery max and it is plenty. Anymore than that and I’d probably have a harder time with fine adjustments.

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Thanks XIII.

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For my single motor build I have my go with a batt max of 40A. For my dual I do 35A on each. However I’ve been tainted by intoxicating power and I weigh about 190lbs. You likely won’t need 70A, especially if you’re not climbing any hills. Both boards are using TBs 190kV 6355 motors and they handle the heat fine.

The amount of power you need is really subjective and comes down to your use case. My dual drive can push me up pretty much anything and accelerates hard enough to knock you on your ass while the single struggles with hills and is much tamer.

A few other notes:

Power/amp ratings on motors are usually complete bullshit and shouldn’t really be considered. Bigger motor = more copper = less heat = higher efficiency. Bigger is always better unless it’s unnecessary for the amount of power your battery/VESC is putting out. With your kind of power you really shouldn’t have to run anything bigger than a 6355.

A 12S3P with 10A cells would only be able to safely output 1332W and even then people always recommend that you set you settings to leave some headroom so you don’t reduce the lifespan of your pack. What kind of cells are they?

Yes, lower C rating lipos are commonly used, however people usually take the C ratings with a grain of salt and assume the packs are only good for roughly half of what their rated for.

Everybody used to use Samsung 25Rs (20A 2500mAh) cause of their high discharge rates, since then people have moved to Samsung 30Qs (15A 3000mAh) because despite them being rated at 15A they actually preform better than 25Rs at 20A.

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(probably 25 to start, and increase to no more than 30)

Not a large amount of them, no. I live in Vegas which is pretty flat, but there are some hills (nothing like S.F. though). I’d say the biggest hill is the one headed West, which is about 450 foot incline over the course of 10 miles, so there aren’t really any steep hills.

Yes, I’m a speed freak for sure. I won’t really rest until I know I’m getting the best bang for my buck in terms of performance. I won’t put a great deal of money to gain 10% performance, but if the return on investment makes sense, I will upgrade. I just don’t want to be sitting at, for example, 30%-50% power while having a weak batter.

That sounds pretty good then. If I can get some good performance out of 1200 watt, then I think this will work, and even then that’s a 3p. I haven’t got my board so not 100% certain how big a 4p will look. It’s a 42" board so I doubt I’ll have an issue going to 4p, but even then that’s only 1500 - 1800 watt max, but from what you’re saying, that should be more than enough?

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There are some videos on youtube with VESC performance readouts overlayed on top of people riding their boards. You could probably watch a few to get an idea of what kind of wattage people are drawing.

These two are pretty crazy boards:

A less intense boards:

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Those are actually what I was just researching too, in terms of what I would upgrade to if the 10a weren’t going to push enough.

The batteries are LGDAMF11865, bought below.

By way of:

^^ Jehu’s got some decent video’s about battery tech that got me interested.

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It’s interesting though, that and

Both state a max continuous discharge of 20a which doesn’t seem to line up with the 10a the seller is advertising.

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Sick, let me check those out. Thank you

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yeh, these sort of videos are good source of info… you should check to find your ‘sweet spot’ for power…

Honestly… I dont have real data about ‘where the real fun starts’’… I just know that 1000W of power should work quite good (for single drive)… for dual you probably would need 1500w minimum I think, to have decent ‘kick’·

Though… I have limited experience but I know that you dont need that many watts to reach these speeds and acceleration should be pretty scary anyways with these smaller (non-pneumatic) wheels anyways.

–

If possible, I would recommend to meet up with someone and test their board… ideally they have the same app to monitor power levels, so that you can see how much power is ‘enough’.

Some might claim 2000w is still not enough for them… and that they ‘feel good’ only with 3000w of power… though I think this would really go for power hungry boards and would probably be a dual system already.

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That’s pretty sick and helps a lot in terms of comparing things I wasn’t able to find answers for. Thank you.

The less intense board still seems to do what i’m hoping it would. It peaks out over what amp I can obtain, but also notice he’s running lower volts. In the end I think I can do a little better peak/continuous watts while running about the same peak amps for a shorter period of time.

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Yeah, that seems crazy now that I am watching the videos. I think I will go with 4p though, to get to that 1500 watt mark. I’m going to start with 1 motor, then add another when I get the cash. I think at this point, though, I will stick with the smaller motor and only consider the bigger motor if I get some higher discharge batteries.

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Thanks a lot all, this helps a lot.

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Thanks for the videos, it was very useful. Actually making me hope to get a good performance at 3200W (2x1600W) despite 50mm size. The calculator already gave out pretty nice numebrs but it is difficult to “comprehend” without seeing it.

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No problem, another good resource for comparing cells is this dude called Mooch from the vaping community that has been testing different cells on the market.

You can see his results here: https://www.e-cigarette-forum.com/forum/blog-entry/18650-battery-ratings-picking-a-safe-battery-to-vape-with.7447/

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Thank you, I would have replied earlier but I am a noob and can only post so many times a day.

I decided, screw it. The packs I bought have 20 batteries each so I might as well just use all 60 of them and do a 12s5p. I don’t have the board yet, so it’s hard for me to determine whether 2 rows of 30 will fit. It’s 24" by length, and I think only 60% of the 42" board is available for the pack (which amounts to 25.5" or so, which leaves no room for the controller unless I put it on the side). With the black battery brackets, going 3 rows across is 8", which only gives me 1.5" of lip and room for screwing the enclosure down, assuming the whole board is 9.5" across.

I’ll create another post and link it here once I start building the pack. I am hoping the 2 rows fit, otherwise I’ll have to figure out how to pack and wire 60 batteries sideways which seems more difficult.

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Actually, if 12s5p and controller/bms doesn’t fit on the board in a 24" length formation, I either have to take the brackets off and glue them or stack them, which I don’t really want to do (but not certain of the clearance yet), or reduce to 12s4p.

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Ok tested my ‘mountainboard’ setup today… pulled about 650W of power going almost max speed, when battery was at about 55%… though it sags a lot,… so with sag included it showed about 15%… which translated to about 1.5-2v sag from total capacity of the pack (if i remember correctly and meter does not lie)… I think it might translate to about 0.3v or so sag per cell group…

Dunno if this matters to you… but yeah… this is with 6s and 4.33 gearing, 9inch tires… dunno how much you might need…