Maybe your brakes are dragging a bit? Your friend is lighter than you?
Help needed with new Scooter
- Thread starter Vasilis69
- Start date
I also mean, where i made a mistake in what i was saying. In order to read about it/correct it and correct also my posts. I do not want to misinform anyone.
He is heavier than me, but i could check also the brakes. Thanks for that!
I think one of the 2 batteries will melt down. It seems dangerous.
Batteries are totally different plus ohm resistance will be different. Its not only Volts and Amperes.
Sure. I use the funniest ones.
You say this just after performing the test that proves it isn't limited. How do you "feel" it can go faster?
What do you mean by this? You're going to open the motor while it’s running?
How is this an upgrade? Please explain the effect on the circuit regarding performance.
I feel like it could go faster because when it hits 58 on the road, it feels like something is limiting it, most likely the controller. It might be due to the controller’s temperature, as the motor hub doesn't have a temperature wire connected to the controller, so I'm not sure.
I plan to check this over the weekend.
No, you can't open the motor while it's running—it's forbidden and you have to be stupid not to know this. I would remove the wheel completely from the scooter and then open the motor, ensuring the battery is not connected. You still need to be careful, as even with the battery disconnected, there could still be some residual voltage. It's not as intense as in electric or hybrid cars, but there can still be a significant current present. To be on the safe side i always were electrical insulated gloves (even when i was opening the controller).
The capacitors originally installed on the controller were low-quality Chinese ones. I replaced them with higher-quality, slightly larger ones.
The key difference is that the 440µF capacitor can store more charge and energy than the 330µF capacitor. For me, its just an upgrade when i removed the low-quality Chinese ones.
Regarding the impact of better soldering plus a better quality fuse and better quality power cables, i do not think i need to explain it.
What else? I am open to ideas/conversation.
chuyskywalker
10 kW
That's the obvious difference, but doesn't explain why. What does 100 extra microfarads get you? If the controller was happy with 330, does 440 help in anyway? What way? "Bigger is better" is a fallacy.
I think you do, because you're likely, well, over-estimating these things. Yes, a very poor soldering job (cold solder, etc), bad fuses, undersized cables, etc can lead to failures, but if the controller/bike was functioning fine and there was no evidence of issues with these components, replacing them for the sake of replacing them was just a waste of time at best.
If you are unmounting the motor to look inside it, that means you are unplugging it from the controller, I'd expect. Since the only thing which would hold voltage after disconnecting a battery would be the caps in the controller, the disconnected motor is 100% safe to touch anything inside of immediately -- it holds no chage.
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More charge and energy, and i believe it means I no longer experience sudden voltage drops when going full throttle, like I did before. However, this could also be due to the soldering improvements, as I made both changes at the same time.
You wouldn’t believe how poorly the soldering was when I first received it. Unfortunately, I don't have any before/after photos to show the difference.
There were no obvious issues - apart from voltage drop i mentioned above - but after replacing the capacitors and improving the soldering, I've noticed better torque and no sudden voltage spikes.
For me, it’s not about whether it works. Of course it was working, but when i see these things, i cannot look the other way. I need to make it better. However, these small improvements you can make can enhance its performance, efficiency, safety, and longevity. It took me more or less 30 mins to fix the whole board (including capacitors), so i am ok with it. I am not planning to just throw it away after 6 months.
FYI:
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Better soldering in a circuit can have several positive effects on its overall performance and reliability. Here are some key aspects:
- Improved Electrical Connections: High-quality soldering ensures strong, consistent electrical connections. Good solder joints minimize the risk of poor conductivity, which can cause intermittent faults or complete circuit failure.
- Reduced Resistance: Properly soldered joints have lower resistance, ensuring that the components in the circuit perform optimally. This is particularly important in high-speed circuits where even small resistance variations can affect signal integrity.
- Longer Lifespan: Well-soldered joints are less likely to develop issues like cracking, corrosion, or poor contact over time. This leads to better durability and longevity of the circuit.
- Reduced Risk of Short Circuits: With proper soldering, there is less chance of excess solder creating unintended bridges between pads or pins, which could lead to short circuits.
- Better Heat Dissipation: Proper soldering also ensures that heat is efficiently dissipated, which can help prevent components from overheating.
- Signal Integrity: In high-frequency circuits, good soldering minimizes the risk of noise or signal degradation. Properly placed soldering can reduce stray inductance and capacitance that can impact the performance of high-speed signals.
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I have personal concerns and fears about voltage, so I always prefer to play it safe. I have also attended some seminars about electric cars, so...
This is a good idea, since your responses sound as ridiculous as your original statements.
I don't think you will have a problem, as long as the 12V lead acid battery is in good condition and rated the same Ah (or higher) than your 72V lithium battery, and the wiring you use can handle the max current your motor requires. A lithium battery won't know or care what chemistry the other battery its in series with. Volts is volts, they add in series. Amps is amps, they add in parallel.
You just need to run it at 84 V long enough to see what top speed your scooter can achieve. If the new top speed meets your needs, then you can look to source a new battery (make or buy).
Well, brother, out of everything I said, this is the part you decided to respond to? I’m curious, are you here to offer help, or just to criticize me?
Last time i checked, we are here to help each other. Even if i am saying something which is totally wrong, you should correct me. I can accept that, i am trying to learn also in the process.
Let me read about it thoroughly, look it up & maybe test it out and i will revert.
Today i placed an order for the below goods. I want to make a battery of ~12v, 20Ah.
First step will be to connect it in series with my current battery (i could use the one i have which is 72v-20Ah) to see if i can get more voltage and if my controller will accept it & second is to have this as a secondary battery for all the 12v things on the scooter (lights/alarm when i remove the 72v battery, etc.)
I will have to mount it to an easy location - not that hard since it has a lot of space under the seat - to make the battery accessible and removable ,so i can charge it at home.
Spot Welder:
14 batteries, type 18650, 2500mAh, 3.6v
Plus this box:
First step will be to connect it in series with my current battery (i could use the one i have which is 72v-20Ah) to see if i can get more voltage and if my controller will accept it & second is to have this as a secondary battery for all the 12v things on the scooter (lights/alarm when i remove the 72v battery, etc.)
I will have to mount it to an easy location - not that hard since it has a lot of space under the seat - to make the battery accessible and removable ,so i can charge it at home.
Spot Welder:
14 batteries, type 18650, 2500mAh, 3.6v
Plus this box:
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What do you think about this one? i ordered it extra.
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3S 60A refers to a lithium battery protection board with a voltage of 12.6V and a current of 60A. It is designed for lithium batteries with a nominal voltage of 3.7V and a maximum charging voltage of 4.2V, including 18650 and 26650 polymer lithium batteries. The dimensions are 41 * 55 * 3.4mm for the enhanced version and 41 * 62 * 3.4mm for the balanced version. The weights are 8.8g for the enhanced version and 9.8g for the balanced version. The charging voltage range is 12.6V-13.6V.
Maximum continuous discharge current: 60A (lower the load current if cooling conditions are inadequate)Voltage for charging: 12.6V-13.6VMaximum continuous charging current: 15AUpgraded model: designed for electric drills with starting current under 120A and power under 260W. (Unbalanced charging feature)
For optimal performance: designed for electric drills with a starting current under 120A and power under 260W. (equipped with a balanced charging feature) Note: To effectively power up the drill, you will need either three 10C-20C power batteries or six 5C-10C power batteries (recommended batteries: SONY VTC4, VTC4A, VTC5A, VTC6). Regular 18650 batteries are not suitable for starting the drill! Use copper wires rated at 0V and 12.6V, with a minimum of 4SQMM (do not use nickel!!).
Please adhere to the wiring diagram when connecting at 2, 4.2V, 8.4V, and 12.6V to avoid short-circuiting. Ensure the '430' resistor heats up during battery charging to confirm proper balance circuit operation. If the '430' resistor heats up but the battery is not charging, verify correct wire connections.
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Attachments
What are you expecting it to do?
Is 14 the number of cells you bought? That'd give you 3S 4P with 2 left over?
My initial plan was to put in series 4 batteries x 3.6v and then in order to get 20Ah capacity i will have to put batteries in parallel. I need a BMS so it can provide 12.6v when fully charged and not 14.4v. But now that i think about it, If i need to put 4 batteries in series to get the 12.6v i need 4S BMS and the voltage when fully charged will be ~16.8v - which is very high. So it cannot work.
Plus. from what i read, BMS is required so it can monitor/balance each series group and provide overvoltage/over discharge and short circuit protection.
Then, lets say that when the 3.6-3.7v batteries are fully charged, each one will give around 4.1-4.2v, which means if i put 3 of them in series i will (almost) have the 12.6volts i want and i can use the 3S BMS, but if this is the case i can use only 12 batteries in total (out of 14 i ordered) and i will get 10ah (3S 4P). Unless i buy 7 more batteries (total 21) to get 17.5ah (3S 7P) - since the cases i find on the internet are max for 21 batteries.
I could try with 10ah then, see how it goes and maybe i can upgrade it later. I just want to connect on this the alarm of the scooter (because when i remove the 72v one to charge it at home, there is no battery, so there is no alarm) plus i was thinking to put there also all the led lights or whatever uses 12v to reduce "some" consumption on the 72v battery. It would reduce the drain and prolong its life.
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