...and here is the firmware for CPU2 4.10

 

SCCMPPTReflash.zip

My RTC 5KVA inverters came with firmware 72.40 and no CPU2 firmware. I updated the firmware to 72.60A and thought I would add the CPU2 firmware as well to 4.1.  For some reason I cannot flash my inverters with 4.1. I get a Debug Assertion Failed message. Can someone please inform me what the purpose of the CPU2 firmware is and do I really need to install it?

Don are your inverters model MKS or MK. The MKS model has an MPPT charge controller built in while the one on MK models is pulse width modulation. I am guessing you have MK inverters and therefore probably no CPU2.

I have no idea. I cannot find anything inside or on the label with the words MK or MKS.

Perhaps you should ask your supplier whether the inverters have MPPT or pulse width modulation solar charge controllers. MPPT is better and gets maximum power from the solar panels but does cost a bit more.

Mine has MPPT.

Well if it does, scroll upwards through the items on the display U1 is the inverter firmware version and U2 the MPPT controller firmware. I upgraded my Axperts with patched firmware from Coulomb. Look at an explanation and links to the firmware at http://forums.aeva.asn.au/pip4048ms-inverter_topic4332_post63036.html#63036 , it works very well for me. Just understand that it is patched firmware and as with any firmware upgrade there is always the possibility of bricking the inverter. When you run the upgrade for CPU2 as you did, he mains power to the inverter must be switched off. Read the instructions carefully. Batteries must be connected, then switch on the inverter and then the solar panels. Panel volts must be 6V higher than the batteries. I forgot to switch on the panels and my upgrade failed but after turning on the panel breaker, all went well. Good luck.

Ok, that must be the problem. I don't have solar panels connected yet. Thank you for the help ebrsa.

You are welcome. For your information, it is worthwhile reading Coulomb's discussion on what and why he patched the firmware. My chargers finally works as I would expect them to after installing the patched firmware. But that is a change you have to decide whether you will take. Others on the forum however run the Coulomb firmware as well and I have not seen any adverse remarks.

I never read the manual. Manuals are for dummies, lol. Only joking. I somehow missed the part about the solar panels that need to be connected. I am also running the patched firmware. Works fine for me to date. I will only know for sure once I connect up my solar panels.

1 hour ago, Don said:

 Only joking. I somehow missed the part about the solar panels that need to be connected. 

I knew about U2 only being queried whilst being powered  by the panels. This did not stop me trying to reflash the firmware without PV power. When it did not work I thought "Maybe just maybe it needs PV power!". So making that mistake is easy - well that my view and I am sticking to it .

I am feeling better by the minute. When my upgrade of U2 also failed I thought I might have a brick on my hands. The "Don't press stop" message was particularly frightening so I just rebooted the netbook I was using. Thought it might be a good idea to read the instructions carefully which led to realising that I have to turn on the panel's trip switch. Then fortunately the upgrade went swimmingly. Has anyone got it right first time? So far we are 3 guys owning up to making the same mistake.

Chris you want to read the .doc file not the .pdf. The instructions in the .pdf file only lets you load a .ocx file which makes it possible to resize the upgrade GUI applet. After I found out what it does, I did not bother with it as the upgrade gui is big enough.

You also asked about the highest charge voltage on my BMV700 previously and it was 59.2V. My batteries are at 100% at this time and the BMV shows 0AH so I guess that means they really are at 100%. Bulk charge was at 58.3V until it reached 100% and then as soon as the amps dropped the voltage also dropped to 53.95V. Cudos to @Coulomb for this patch. Voltronic should contract with him to fix their firmware.