Relay Circuit for Solar and Wind Power Generation

SolarWindBoy

I have 4 DC wind generators (100W - 12V @ 8.3A) and 1 solar panel (200W - Voc = 24V, Isc = 10.67) I want to use to charge a 12V battery pack.

Also, how would the power rating for the resistor be chosen?age of 25V and a current of 16A.

My plan was to use 5 separate relays controlled by a battery charge controller which monitors the voltage of the battery, and outputs 12V when the battery is above the trigger voltage.

For the generators in normal operation, the NC contact is connected to the battery, and then when the battery goes above a certain voltage the relay triggers connecting the NO contacts to a resistor bank dump load.

My plan was to use 5 separate relays controlled by a battery charge controller which monitors the battery's voltage, and outputs 12V when the battery is above the trigger voltage.

I had some questions regarding the choice of components

R1 Value:

I calculated the coil current to be 60mA (Coil Resistance = 200ohms). I then calculated R1 using:

R = (Vin - Vt) / (Ir/gain)

Where:

Vin = 12V

Vt = 0.7V

Ir = 60mA

Gain = 100

Giving R1 = 18.8 kOhms

Is this correct?

D1:

Is 1N4007 a suitable choice for the relay flyback diode?

D2 and F1:

Since the generator is also a motor, D2 was added to prevent the battery powering the motor.

Is sizing them for 20A correct? Would closer to 16A be better? Or the true value instead of the derated value?

Since the generator is also a motor, D2 was added to prevent the battery from powering the motor.

Arc Suppressor:

Is an arc suppressor needed for the terminals? If yes Im not sure how to size the resistor and capacitor as I have seen 2 methods that give drastically different answers.

https://wiki.testguy.net/t/arc-suppression-circuits/39

https://www.nutsvolts.com/questions-and-answers/relay-contact-life

Also how would the power rating for the resistor be chosen?

Thank you in advance for any help you can offer with any part of this, I appreciate I have asked a lot of different things!

Component	Link
K1	https://uk.rs-online.com/web/p/power-relays/1762873?cm_mmc=aff-_-uk-_-findchip-_-1762873-_-instock&utm_source=supplyFrame&utm_medium=buyNow
D1	https://www.lcsc.com/product-detail/Diodes-General-Purpose_TWGMC-1N4007_C727081.html
D2	https://www.lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_YFW-20V80SP_C2988034.html
D3
R1, R2
Q1	https://www.lcsc.com/product-detail/Bipolar-Transistors-BJT_BORN-MMBT2222A_C511875.html
F1	https://www.lcsc.com/product-detail/Fuses_Littelfuse-0501020-WR1_C207007.html

JRHill

Be sure to have plenty of those relays for backups.