18 fet controller R115?

[CryB4Die]

Hello,

I have a 18 fet lyen controller that I'm currently using at 36v nominal.
I wan't to use the controller at 74v nominal, I am upgrading my battery pack to a 20s lipo.

My question is if I need to change something in the controller?

there is an resistor that is called R115 on the board and I have seen it more boards (the blue power resistor) . The resistors are both 100ohm on my boards. I have 2 controllers EB218-as-1 and a EB318-XX-X


Do I need to change this resistor to make it work a 74volts nominal?

 

[miuan]

AFAIK the 318 boards work with any voltage. For 218 you want the voltage behind the resistor to remain roughly the same after upping the voltage.
Try measuring the voltage drop across the resistor when the controller is powered. Add another resistor in series. Calculate the value as 3700 ohm / measured voltage drop.
Please note the voltage drop may vary depending on operating conditions.

 

[CryB4Die]

AFAIK the 318 boards work with any voltage. For 218 you want the voltage behind the resistor to remain roughly the same after upping the voltage.
Try measuring the voltage drop across the resistor when the controller is powered. Add another resistor in series. Calculate the value as 3700 ohm / measured voltage drop.
Please note the voltage drop may vary depending on operating conditions.

So you think that I don't have to change anything on the EB318 board, to make it work at 74v?

 

[miuan]

I had a Lyen 9fet, not sure but it was probably eb209 board. It had a switch (2 white wires) which shorted the 2nd power resistor, so with the wires connected, it would work on lower voltages, and disconnected it worked from 60V up.
Then I got some 312 from Cellman and never had to mess with power resistors anymore. I heard the newer models had an advanced voltage supply circuit vs. the old 2XX design with power resistors and LM317 / 7805 TO220 linear regulators.
I ran the stock 312 at 12S and 24S lipo with no problems. Hope your 318 is the same.

 

[CryB4Die]

I have messaged Lyen about this and he said:

Resistor R115 needs to be at least 200ohm to work at 74v, the LVC needs to be set up higher if you don't have a BMS on your battery.

When R115 is 200 Ohm the controller will still work at 36v.