DIY ESS - First 5 Arduino Leonardo boards received - First one flashed & ready to ship

5 Arduino Leonardo boards have arrived from Evola.fr website faster than I thought and one of them is already flashed with the DIY ESS program, from the Mac this time

Communication between the Mac and the Arduino Board set up

Choose the first USBModem Port

Program loaded on the board


Now testing the program :

Program log displayed in the Series Monitor of the Arduino IDE:

Working well,

It is now ready to ship !

LifePO4 ESS - Control Board Rebuilding Update #3

Just a quick update on my LiFePO4 ESS Control Board Rebuild started last weekend: Last night wrok

After testing the charge mode for almost 3 hours, eveything is fine (relay heating up a little but nothing abnormal, no heating at all on the wires), so I am charging the whole day today

All 6 grid tie inverters have been plugged in the relay activated outlets

To spread the battery power, each grid tie inverter DC side is connected to its neighbor with a 2.5mm² solid core cupper wire and I may need to double it for the first ones

Also an heavy gauge black cable has been connected from the negative battery pack terminal to the negative DC terminal of the grid tie inverter in the middle of the stack

Testing the inverter mode: I thought everything was going fine, until being under 0W, pushing power outside my home grid, Wattson glowing green and showing - 150W, the grid tie inverters should start to shut off one after the other; But here, nothing for several minutes !? Something was wrong ...

I thought the Blue/Red/Green signal coming from Wattson was affected by the proximity of other live wires and started to move the voltmeter, etc... but nothing changed

It made me think of my Arduino power supply problem 2 weeks ago: Supplying 12V from the battery pack through a ebike.ca 72V to 12V DC-DC converter, I had the same problem

Here I was using a 12V/24V to 5V DC-DC converter (from a car lighter socket USB converter) to power the Arduino board and it looks like it was the source of my problem: 

I then disconnected the USB cable from this USB DC-DC converter, and used the 220V USB hub power supply instead, and everything was back to normal !  Interesting ...

Conclusion: It looks like the Arduino board does not like any DC-DC converter with the battery pack as a power source ! 

LifePO4 ESS - Control Board Rebuilding Update #2

Last night, I continued my LiFePO4 ESS control board building: 

Wiring of the main switch to the programmable dual relay voltmeter and fuse holder & fuse for the 24V command line

I dismounted a car lighter socket 24V to 5V DC-DC converter to use it to power the Arduino board through its micro USB port

Removal of the PCB from the plastic case 

Welding of the positive and negative leads for 24V input

Heaving gauge red cable screwed onto the battery positive terminal

Test with the main switch on charger position : The charger is charging  (good news) and almost no heat is detected on the charger relay power terminal 

From the top: USB cable plugged in at both ends & Charger leads screwed to charger input on the board

Switch on inverter mode, contactor is switching to ON with a big audible "clap" ...

... and 24V to 5V DC-Dc converter is on (blue light on the left)and 24V to 5V DC-Dc converter is on (blue light), ... 

... powering the Arduino board which is starting its relay activation sequence

To be continued, but almost finished ... 

Wattson naked ... So shocking !

Following my first back opening of Wattson, last night I removed the front panel and here is the result:

6V Battery pack on the side

9V DC in on the other side