duwdu
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duwdu reacted to PaulF007 in Axpert MPPT vs Victron MPPTKeep in mind that was done by me and I tried to be as impartial as possible. I asked @Chris Hobson just to verify that what I wrote was what I meant (Thanks Chris for the help) Also it should be noted that @The Terrible Triplett arranged through Victron SA for the SCC and we should give that man a Bells for his bravesness. Lastly the guys from SP Powerunits who was kind enough to give the SCC for testing. If you are in the Pretoria area it will be well worth your time to go by them. In the short time that I spoke with them I realised that there is still a massive amount if info that I don't know and I could have saved a fair amount of money have I took the time to chat to them beforehand.
As for the report here is what I came up with:
The System:
My current setup consists of the following:
· 12 x 260 w solar panels set in 3 panels per array
· 8 x 6-GFM-170F batteries
· Victron BMV 702 Battery Monitor
· 1 Axpert 5000 VA – Firmware 72.80 Loaded
· Victron 150/35 SCC (Test Unit)
First Method:
I have been testing the two SCC’s over a period days alternating between them to see how they perform under my day to day conditions. Now the consumption on a day to day basis does not stay consistent as this is a running household, but it does give you a reasonable idea as to the performance of the different SCCs.
First is the Axpert on a normal day starting from a 89 % SOC
By the end of the day the the battery monitor showed that the batteries was charged to 99 % and overall there was no real problems that I could see.
Second was the Victron SCC also starting on 89 % SOC
By the end of the day the the battery monitor showed again that the batteries was charged to 99 % and overall there was no apparent difference that I could see bet tween the two days.
Second Method:
I then decided to put the two SCCs next to each other and see how they would perform in exactly the same conditions. This meant that I would need to split the system in half having 6 panels on each SCC, and 4 batteries that was discharged to the same level. As my batteries do not get discharged very low at night I also decided to push them lower than what they have ever been discharged in order to give the SCC enough time charge. The batteries were discharged overnight to 70 % SOC and then the whole system was switched off, split and wired to the two SCC. As I only have one BMV I decided that I would not use it for any comparisons as it would only be able to measure the Axpert’s output.
Both the Axpert and the Victron do report battery Volts solar Amps and solar Watts and these readings were compared.
(As a side note when I tested the Victron SCC I did notice that there was a slight difference between the Victron SCC battery volt reading and that of the BMV so there would be some deviation between the two SCC’s , the Axpert’s readings were very close to the BMV)
EmonCMS was used to log the data from the two SCC and there was no other load on the Axpert.
First graph is the Panels watts outputs from the two SCC.
Panel amp output
Battery Volts
Linear comparison between the Watt output of the two SCC’s
Personal Notes on the tests :
Apart from the one battery bank that took a bit more charge than the other I could not see any real apparent difference between the two SCC’s outputs. It was also noted that the Axpert’s data is not as refined as the Victron’s. The step pattern of the Axpert’s Amp feed indicates reporting of Amps in whole numbers oppose to Victron more accurate readings in decimals. There was also a small variation in voltage reported by the Axpert and this can either be ascribed to again the coarser scale of its voltage readings or an inability to perfectly maintain absorb or float. Since there is a small amount of variation in the Victron voltage feed and the Axpert Voltage line is nearly linear I suspect that the case is the former and the scale is too coarse to truly record the voltage. Occasionally it is rounded up or down resulting in peaks and troughs. In my opinion there is no real difference between the two SCC’s outputs as the data confirms it.
Some Extra notes:
Now there could be a host of other tests that one could do to compare the two SCC’s, but I attempted to run them in normal and side by side tests. The only thing that I would like to see is how they would compare under a cloudy day where the SCC would need to adjust as clouds passes over the system but then I would need to run the system in parallel over a time or hope that you time the weather perfectly and then split the system again. As this is a running household and not a test bench site it would be impractical to do so.
One last comment, when you handle the Victron SCC you do feel that there is a big difference between the two units. The Victron feels solid and well built and I would say the Victron would be able to handle a lot more hammering than would the Axpert but considering the price tag I am not prepared to push either one of them but my money would definitely be on the Victron to be on top of that one .
The Victron gives you a host of options so that you could configure your system to be as automated as possible but it comes at a price. The Axpert is more of an off grid “Inverter/UPS with a SCC” that does not give you many options so you would need to build your own setup to make it work fairly well within a grid system. In my case I have a remote triggered switch on the Axpert that will switch to grid under certain conditions and the family needs to be constantly aware as to what the system is currently doing before something is switched on or off. Where as if you have a Victron you could setup it up as a grid tie and then there would be no need for checking the system all the time.
Also to consider is the future value of your property. If you have an Axpert, you have had to grow with the system and learnt as you went on. In my case I had to setup up all sorts of things to make the system work. Now if I would like to sell the system with the property will I be able to get a buyer that will be able to understand the system and will he be able to get every thing going again if the R-Pi were to fall over? If not the system would become a liability and not an asset.
All in all money talks and the Axpert gives real good value for money as long as you know what you get and you are happy to live with it else consider saving a bit longer get your baseload lower and maybe consider getting a smaller Victron system.
Best Regards
Paul