DIY pack 18650 lithium safe

[EMX_USD]

What gives me problem to domyself a pack in 18650 with cells 30A and 3000mah:
If I put two rows of (+) and two rows of (-) in my 16S 5P configuration, does that change anything? instead of having a 16S bms, would you need an 8S bms? Thank you for your information.

I do not know what burns a brushless motor: much more amps than what the manufacturer recommends or much more volts? On the description of a brushless motor it says above all not to exceed the maximum number of volts recommended but for amps is it the same?

[obcd]

The way batteries are normally assembled is that they create several groups of parallel cells (in your case 5) and put those groups in serie. (So that would mean 16 groups) If you don't want to burn your house (bad moment as corona regulations tell you to stay inside), you would choose a quality BMS with bluetooth interface so you can verify the cell voltage of every cell group. Those usually have an option to adjust the number of cell groups that are connected to them. (up to some maximum so less shouldn't be a problem.)

The thing that burns a motor is heat. Motor windings have a resistance, and if current passes trough them, they will produce heat.
The winding losses P = I^2 * R will end up in heat.

Voltage is important for maximum speed. If a motor runs, it works as a generator and will produce voltage. Due to that, you need a higher voltage to make current flow trough the motor windings. If you increase the voltage, you can push more current trough the windings and you have a higher chanche of overheating your motor as well.

[EMX_USD]

The way batteries are normally assembled is that they create several groups of parallel cells (in your case 5) and put those groups in serie. (So that would mean 16 groups) If you don't want to burn your house (bad moment as corona regulations tell you to stay inside), you would choose a quality BMS with bluetooth interface so you can verify the cell voltage of every cell group. Those usually have an option to adjust the number of cell groups that are connected to them. (up to some maximum so less shouldn't be a problem.)

The thing that burns a motor is heat. Motor windings have a resistance, and if current passes trough them, they will produce heat.
The winding losses P = I^2 * R will end up in heat.

Voltage is important for maximum speed. If a motor runs, it works as a generator and will produce voltage. Due to that, you need a higher voltage to make current flow trough the motor windings. If you increase the voltage, you can push more current trough the windings and you have a higher chanche of overheating your motor as well.

ok thanks for your answer.

[EMX_USD]

Hello guys, i have problem with the pen of that spot welder bought on aliexpress. How to assembly that?[/img]

[goatman]

What gives me problem to domyself a pack in 18650 with cells 30A and 3000mah:
If I put two rows of (+) and two rows of (-) in my 16S 5P configuration, does that change anything? instead of having a 16S bms, would you need an 8S bms? Thank you for your information.

I do not know what burns a brushless motor: much more amps than what the manufacturer recommends or much more volts? On the description of a brushless motor it says above all not to exceed the maximum number of volts recommended but for amps is it the same?

16s is 56v and 8s is 28v. what are you trying to build?

[EMX_USD]

Finally, i trying to build 16s. But two 8s in series is 56V too. No problem with that i have the solution but I will post this when it works safely. Trust me.

[EMX_USD]

The spot welder is assembled and battery re

IMG_20200418_083156.jpg (228.67 KiB) Viewed 312 times

charged but it's the pen who don't work!

[goatman]

I know nothing about spot welders but have you checked the trigger to make sure its working

[EMX_USD]

I know nothing about spot welders but have you checked the trigger to make sure its working

Yes, it work

[EMX_USD]

ok it work! one mosfet not welded and one nut out of 6 not tight enough .