Simple circuit to test batery from solar panel
Simple circuit to test batery from solar panel
(OP)
Hi guys,
I have a PLC with solar panel powered, and I want to know the charge of battery (12VDC), and input the signal to PLC (0-5VDC or 4-20mA)
Any suggestion will be wellcome.
Thanks
Melin
I have a PLC with solar panel powered, and I want to know the charge of battery (12VDC), and input the signal to PLC (0-5VDC or 4-20mA)
Any suggestion will be wellcome.
Thanks
Melin





RE: Simple circuit to test batery from solar panel
To get a voltage from battery, you nedd a voltage divider in 0-5V input. For calculate a divider, you nedd know a input impedance from PLC. See in PLC manual.
For top charged battery, voltage is 14V, for mesure this put a resistor between positive battery terminal and PLC input, this resistor have 2x input impedance for 0-15V range.
Regards,
M3
RE: Simple circuit to test batery from solar panel
R2 = R1 / (Vmax/5V - 1)
To be relatively immune to noise and with low power use, I propose to use:
R1 = 100K, 1/4 Watt
Vmax = 20 V
Computation give R2 = 33K, 1/4 Watt
Note that the Wattage must be evaluated if you lower the value of the resistors, else the resistors can become too hot (and can become a fire hazard). On your PLC program, you can scale the input to convert the result in the right voltage scale.
RE: Simple circuit to test batery from solar panel