I have read most if not all of the historical posts on the firmware being used on this inverter and I am looking for clarification. The inverter reports U1 as 69.02 and U2 as 112.14. Solar Assistant on the Raspberry Pi also reports Firmware as 69.02.

I am running with SUB as the Output Source Priority and SNU as the Charger Source Priority. I have 4 * 100AH Huawei Lithium batteries with the Absorption and Float Charge both  set to 53.5 volts

I am noticing that when there is no solar generation and mains power is available the voltage flatlines at 53.5 (which is what I would expect) but when the solar starts to kick in the Battery voltage drops to around 49.5 very quickly and then oscillates up and down for the period that Solar generation is available. During this period the Battery SOC is not affected in any material way and is reported by Solar Assistant as 100%. I am just curious to try and understand if this is normal and why it is happening.

The main problem I am having is that sometimes when mains power is restored after a period of load shedding the inverter enters Bypass mode (as it should) but the charger does not start to charge the batteries which have been depleted to around 70% SOC and reporting a voltage of  around 49.2. The only way I can get the inverter to start charging is by setting the Output Source Priority to Utility First via Solar Assistant. As soon as I do this the batteries begin to charge and If I reset the Inverter back to SUB the charging continues until the battery voltage reaches the 53.5 preset value.

I have seen some other posts reporting similar behaviour and wonder if this is a firmware issue? If so where can I get the latest firmware to address this issue?

Any help would be greatfully appreciated

 

13 hours ago, shumbaman said:

The inverter reports U1 as 69.02 and U2 as 112.14.

Those are fairly standard Voltronic version numbers. Some web sites (example) are strongly suggesting that Synapses are now legitimate Voltronic resellers.

If so, you should be able to get a firmware update from your supplier. I have 69.60 and 69.61 here. I would suggest that you try one of those, except that I'm still not convinced that Synapse are genuine, so Voltronic firmware might brick your inverter. And there would be no way to get the original firmware back again. 69.02 sounds very old.

Thank you Coulomb. I am making enquires through the channel from which I recently purchased the Syapse to see if it is a clone or genuine Voltronic. My feeling is that it is genuine but I am not confident enough to go ahead and try a Firmware upgrade. Ironically since my initial post I have had no issues with the inverter not charging when grid power is restored.