Hi,

 

I had my system installed 3 weeks ago and have noticed that there is a 113watt difference in what the battery is supplying and what the actual load is. The battery is supplying more power than what the load needs, is this what the inverter uses to run ?

Also, I have a 8.8kw sunsynk inverter

18 x 460w Canadian solar panels

3 x 6,4kw BSL batteries on my system.

Can I add more batteries?

 

Hope I'm making sense 🤪

Hi Jaco, yes it is normal that you will have losses due to inefficiencies, however whether Sunsynk machines are actually achieving their advertised efficiency values remains a big question mark for me.  I have raised this question with their support and am still waiting for an answer 4 weeks later.  Also note that the machine uses 50W to operate.

Sunsynk advertise a euro efficiency of 96,5%.  Euro efficiency is a weighted average of DC to AC conversion at various loads.  My machine is very inefficient at converting solar dc to ac.  I have done some tests and calculated my euro efficiency at more like 90%.

Edited May 17, 20224 yr by Halcyon

That's a huge difference,  thank you for the reply 🙏 

39 minutes ago, Jaco Vorster said:

That's a huge difference,  thank you for the reply 🙏 

I doubt that the own use is huge. The value of 50W just to be on is perhaps a lot better than some other inverters. Some are running at 90%. Yes we all tend to want 100% but due to the losses in conversion of power one just has to accept it. Just look how much of a ICE fuel heat value is actually converted into power.

My small 2.4kw Axpert uses 25W while the inverter is switched off and this is just to use the PV to charge the batteries. Using 50W for a machine capable of 8kW is how I see it as great. Many highly efficient transformer battery chargers can easily use 40W just to provide 80W in charging. Thus total draw of 120W.

Yes you can add more batteries but bear in mind the maximum current that the MPPT's can use to charge them. You have quite a bit of unused PV power as it is.

Edited May 17, 20224 yr by Scorp007

Thank you 🙏

18 hours ago, Jaco Vorster said:

Can I add more batteries?

Yes, you should be able to add more batteries in parallel, haven't found a mention from BSL about how many, usually 7 to 8, but could even be more, 7  should be more than plenty for most of us, though, I'd imagine...

Thank you,

Was thinking 5 max , budget won't allow more 😕