I am planning to check what type of battery cell I have by cutting and peeling back the shrink wrap and fish paper covering the pack. Once I have done this, can I just tape the shrink wrap and fish paper back together using gorilla tape?
I took the board out for the fist time today and it ran really well. It pulled away effortlessly and climbed hills easily. The only thing I need to change are the breaks, as when going down a relatively small hill, the breaks are not stronge enough to slow the board down without me having to bail. Has anyone got any recommendations as to what Vesc setting I can change to beef up the breaks without damaging the battery, or am I at the limit until I determine what cells are in the battery pack.
@Tonkatron @Yungdaff @professor_shartsis @Kingdom421 @mynamesmatt
I have removed the shrink wrap and some of the fish paper from the pack, and the cells are labelled:
BFN ICR18650 2000 2000mAh 3.7V
MH60385 17F19
Based on this info, do you know if I can safely change any of the Vesc setting to improve brakes?
I don’t know 100% shure but i guess it’s battery from China.
The “Bigger brands” Like Samsung,Lg,Sanyo, and Sony always mark the battery’s like
Sony- Vtc6 Samsung-30Q etc etc.
Send that pic to APS and ask. u got i free so hey thats better then nothing.
Yep, its a Chinese company called Shenzhen Bofuneng Co. and the closest battery I could find to it online was:
Key Specifications/Special Features:
Model: 18650MP-2000mAh
Manufacturer: BFN
Size: 18.5 X 65.2mm
Nominal Capcity: 2000mAh
Cycle life: ≥300 times
Type: Li-ion Cylindrical Battery
Certfication: UL:√ CB:√
Initial Impedance: Max:35mΩ
Weight: 41±2g
Head: Flat/High
Warranty: 12 Months
Nominal voltage: 3.7V
Standard Charge: CC/CV,0.2C5A,4.20V
Standard Discharge: CC,0.2C5A, 3.00V
End-of-charge Voltage: 4.20V±0.05V
End-of-charge Current: 0.02C5A (At CV mode)
End-of-discharge Voltage: 3.00 V
Charging Time: 8.0hours(standard charge)
Quick Charge Current: 2000mAh @1.0C
Quick Discharge Current: 4000mAh@2.0C
Max Discharge Current: 10000mAh@5.0C
I agree APS was extremely generous to send me a spare battery for free, and I know Bruno is always very busy. As such I’m trying not to annoy him with 101 questions, and instead looking to the forum for guidance.
I was messing with switching motor reg between-20 &-40 i found they were breaking much harder at -40. Im not suggesting going that high on those batteries but maybe something better it would be fine.
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I am planning to change the Motor Min from -12 to -25. Hopefully that will improve that brakes without stressing the battery.
@Kingdom421 what was reason for initially recommending -12? I am guessing for street wheels this setting will give gentle braking, however for AT it’s not strong enough to adquitely slow the board down hill.
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Most cells are 4ah fast charge 4*3p is 12 so a bat regent max of -12 would stay in most manufacture good quality fast charge rating.
That’s if you play it safe some cells are rated lower some higher.
Most of us are willing to play a bit on the dangerous side and justify higher ratings on the bases we don’t use the brakes on 100% duty load for any length of time. Braking at full duty cycle produces (from max speed max brake level applied) will generate almost the full motor min amps
The thing is when braking your very unlikely to matain that full duty cycle because the point of braking is to slow down and as soon as that happenes so dose the duty cycle.
From experience I use aprox 20% of the curent that you max motor- to what gose back in the battery on average when braking (these numbered are all very aprox) and take no responcability as every ones builds and ridding style and train is different so this aprox will very depending on that.
Say I use motor- 50a I want at least battery min 20% is -10a but I also want head room for hard braking peeks that’s normally another 10-20% of the motor -
So if yor still following that’s 15-20a battery- to avoid my VESC from reducing my brakes notisably
The best 18650 cell I’m using Sony VTC5a is rated to 6a charge so in my 3p config that’s a total of 18a charge all good if I was useing a single drive.
The issue is I’m useing dule drive
So both are set to
Motor 45a
Motor min 35a
Bat 50a
Bat -14a
That’s a combined bat regen if 28a. 10a over the battery rating. As long as I’m awar of this and watch I don’t over do it braking on hills it’s working fine for me
The General rule of them seems to be double the cells charge rating use good quality genuine cells from a well known and trusted manufacture and supply we don’t abuse them to much and test cells looking to see if any start failing regular and the over exseeding the manufactures rating seems to work all at your own risk. This dose reduce the life span of the cells a little but there’s a lot of us out there doing it.
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So it’s a 3p 10s?
So dule VESC settings I’d be useing
Bat max 15a each
Bat min 3a each
Personally this batty is not suitable for esk8 need much better quality cells or add more cells make it in to a 8s10p. as curtly i would want a lot more power out of a battery and think you will fined that one lacking and with a hell of a volt drop.
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Thanks a mil for your detailed explanation.
To summaries what I have gathered so far:
-
Motor Max (Motor Current Max): Set to 30A
This is the MAX amps you want inside your motor (i.e. it controls low end acceleration).
This setting needs to be below the max current of the motors (i.e. 46A).
It also needs to take into consideration the limit of the VESC (i.e. 50A).
With my 4.12 HW VESC (with no heat sink), I should set motor max between 30 and 40A.
Hence I should start with a low setting of 30A, and depending on how the acceleration is I can later increase it up to 40A, and if I am feeling really adventurous I could even set it as high as 60a or 80A. -
Motor Min (Motor Current Max Brake): Set to -20A
This is the max amps I want inside the motor during braking (i.e. it controls break force at mid to low speeds).
This setting should be approx. 10A below motor max. -
Battery Max (Battery Current Max): Set to 15A
This is the max current draw from the battery.
This setting is based on the limit of the battery, however for VESC HW 4.12, this setting should be no more than 35A regardless of the battery type.
Also, motor amps should always be greater than battery amps.
For my battery cells, the ‘max constant current’ is 10A.
10A x 3P = 30A. For a dual setup 30A / 2 = 15A. -
Battery Min (Battery Current Max Regen): Set to -9A
This is the max regen-charging current I want to flow into the battery whilst braking (i.e. controls break force at high speeds).
This setting is based on the limit of the battery.
For my battery cells, the ‘Quick charge current’ is 2Ah.
2Ah x 3P = -6. For Duel setup -6/2 = -3A.
However, at this setting the “Battery Current Max Regen” will limit the brake power at nearly all speeds because it is too low.
Max charge current ratings are only for continuous charge and not for short bursts, which take mostly not longer than 5 seconds.
Therefore it can be set to 20% of Motor Max setpoint which is -6A, plus a 10% buffer = -9A.
Would you be able to confirm if the settings above makes sense, in particular the motor min. setpoint?
Also, would I be right to assume that the settings above are conservative enough that I need not worry about the what type of BMS is installed?
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Almost got it the charge curent is related to battery not motor. I’d take this as a % of the max battery charge if you willing to exceed manufacture rating.
Quick charge 2a a battery times 3 battery’s is 6a as you said + 100% is 12a then split that over the 2 VESC.
Max battery - 6a per VESC.
I don’t know of any one that exceeding double the manufacture quick charge rating but some people do run at it. There’s no guarantee the battery can take that much abuse but I defiantly wouldn’t go any higher.
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Motor min should not exceed motor rating from manufacture
Set it to a level that feels right for you when braking on average it’s about 50-75% of what people set the motor max to
Say manufacture rate the motor at 50a
You can have
Motor max 40a
Motor max -50a
That makes the - 120% of the + but you have not exceeded manufacture rating.
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Irrelevant and the VESC creator says the opasit battery max should preferably be larger than motor max if the battery rating allows it.
If the motor max is 100 and battery max is 10 be VESC will only provide 10 amps to the motor (there will be a small blip at the start we’re the capacitors empty say 12a for a couple of seconds then drop down to 10a again.
If the motor max is 10 and battery max is 100 then the VESC will only pull 10a from the battery and give 10a to the motor (excluding any electrical losses in the circuitry)
There is a thing to consider with widely in balance values of acceleration curve
Say motor max max is 50 but bat max is 37.5the VESC will hit duty cycle max of the PWM at 75% throttle basikly the last 25% of the throttle won’t do any thing as there’s no more power to give
So the VESC will at 1/2 throttle the VESC will 1/2 the input value past 1/2 throttle then restrict the rest according to the max battery value
Eg
1/4 throttle is 12.5a
1/2 throttle is 25a
3/4 throttle is 31.25a
1 throttle is 37.5a
Same apples for brakes
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I agree im using -40 now stops real fast for a big guy like me
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Whats good settings for a fat guy running 10s3p 30q. Single 4.12 and 190kv 6374 tb .
Well off the top of my head you VESC is limited to 50amp
moto to 75a
Battery 45-60amp
Batt 50a
Batt regen -15 to start. keep upping it untill brakes feel right at high speed max -24amp (this is double the fast recharge rate of you battery so bare that In mined when braking down hills)
Moto Max 60 (any thing over bat max but less than manufacture motor max rating)
Motor min -20 keep uping it untill you fined brakes you like at slow speeds
ERPM limit 60000
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Use the new VESC-Tool is my advice.
If you like you can reduce the battery drain to sufficient values for the pack.
There is a advanced tab in the wizard to manipulate that.
Motor regen should be same as motor max, Batt Regen should never be set low since that are your high speed brakes!
Don’t put the pack life over your own life!
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I am using an old version of the Vesc tool for the Mac. The only reason I haven’t upgrade to the new Vesc tool is it took me a while to find a Mac version for the old one.
Has the new Vesc tool been ported over to the Mac?
You can use a Android smartphone.
Simply get a Bluetooth dongle.
If you have no android phone, get a cheap used one for some bucks. Android 7 or later.
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