Photovoltaic Generation Systems

Custom Controller Board

Testing the Battery

The SolarKing Battery Setup ready for Testing. I was hoping for better results, after the dismal results from the Optimum branded lithium based battery. See: Optimum-Ion-Lithium-Battery-SCAM

I wanted to be sure that the Battery I purchases was capable of delivering something close to the advertised capacity. I set up a roughy constant load test with a small ups powering a 40 watt incandescent globe and discarded automotive headlamp. They each drew about four and a half amps giving a total of around nine amps. Firstly, I fully charged the battery until the internal controller cut in and stopped the charge process, and then started the constant load discharge noting the times and current draw.

09.259.313.02Start Test
16.404.8412.88Reduced Load
19.419.0912.59Increase Load
21.208.6011.60UPS Alarm Sounded and Stopped
21.304.5011.33Reduced Load
21.404.1710.80Stop Test

Two Photovoltaic Panels Setup for Testing

The objective is to see how well two household solar panel and a 100AHr LiFePO4 Battery could run a domestic fridge and freezer. The Freezer is a Kelvinator KTM56200WB with a Volume of 520 Litres and rated power consumption of 375 Watts. According to my cheap inline watt meter it actually draws about 130 Watts with a power factor of approximatgly 90% when the compressor is running.

The Freezer is a FD213S with a volume of 200 liters. The same cheap watt meter indicates a draw of 50 Watts with a power factor of approximatly 30%. This seem a low power factor but that is what the cheap power meter reads.

The two panel system consists of two 190 watt 36.5 volt (Pmax) PV panels in series, a Victron Energy Blue power Smart MPPT Controller and an Low Energy Developments LiFePo4 12 Volt 100Ahr battery.

The no brand inverter is 12 volt DC to 240 VAC with a peak ratting of 1300 watts.

JULI-PV-Panels JULI-PV-Label


JULI Energy Company - JLS72M190W

Open Circuit Voltage(Voc)43.80 V
Short Circuit Current(Isc)5.83 A
Maximum Power Voltage(Vmp)36.50 V
Maximum Power Current(Imp)5.20 A
Maximum System Voltage1000 VDC
Cell Type125mm x 125mm
Number of Cells6 x 12pcs
Dimensions 1580 x 808 x 40mm(62.20 x 31.81 x 1.57 inch)
Peak Power(Pmax)190W
Module Efficiency14.88%
Practical Module Efficiency17.76%
Power Tolerance±3%
Operating Temperature-40℃~85℃
Nominal Operating Cell Temp.45±2℃
Temp.Coefficient Isc(TK Isc)0.05%/℃
Temp.Coefficient Voc(TK Voc)-0.33%/℃
Temp.Coefficient Power(TK Pmax)-0.4%/℃
Series Fuse Rating 10A
Number of Bypass Diode3

Note:the specifications are obtained under the Standard Test Conditions(STCs):1000W/㎡ solar irradiance,1.5 Air Mass,and cell temperature of 25℃.

The NOCT is obtained under the Test Conditions:800W/㎡,20℃ ambient temperature,1m/s wind speed,AM 1.5 spectrum.



Smart Solar MPPT 100/30 Controller



MPPT Solar Charger Error Codes


Example PV Setup

Example PV Setup


PV Cables

MC4 Female Connector
MC4 Male Connector

MC4 Connectors:

The MC in MC4 stands for Multi-Contact and the 4 for the 4mm diameter contact pin.
mc4 connectors

Maintaing Polarity of DC Connections:
Maintaing Polarity of DC Connections


Venus OS

Venus is short for Victron Unix like distro with a linux kernel

Github Archive

Sales Pitch



Glenn Lyons VK4PK
Ver:gnl20190916 - pre published v0.9