The Sunsynk 5 kW is rated for 6500 watts of solar panel power, if I go beyond that ( keeping the voltage range within limits ), will the mppt just clip the excess pv ?
My (limited) understanding is the danger of over voltage for these MPPTs.
So it will be able to handle the excess current and limit it without risk.
One doesn’t want to blow the thing up so I would ask Sunsynk themselves.
It should. It’s easy enough to do it in software, so I would be really surprised if a fairly “large scale” maker like this don’t do it.
There are differences between cheaper and more expensive MPPTs in how they handle overcurrent events. An overcurrent event happens when the software latches onto a power point (which corresponds to switching the buck converter at a certain duty cycle), and then suddenly the insolation changes faster than the software can adjust and that particular point makes more current than the device is rated for. Cheaper devices will simply switch off and restart. More expensive ones can limit the current in hardware.
For this reason, it is usually wise not to over-panel too much on a cheaper MPPT. Not because it will get damaged (it won’t), but because you may lose energy. Rarely a problem in this part of the world.
I have no idea how good the Sunsynk MPPT is. At the price point, I’m going to guess it is probably pretty average.
The mppt’s are rated for 13 amps and the panels are the 9 amp variety
So then we can safely say that the sunsynk is the more expensive type It was previously limited to 9.9A and it did just that. Anything above would just be clipped.
They recently released a firmware that changed this to 13A which I’m a little unhappy about seeing that I had just completed purchasing my panels to accommodate the previous limit.
To @Tariqe original question though, the voltage is the most critical part in this case. The current can be limited. If you are slightly over then you should be fine especially considering that you have got ~91% of the rated panel power in Summer and your panels are also all not facing north. So the different mppt will peak at different times of the day.
Of topic, I decided to clean my panels today, just hosed them down and got around 10% more power. Days are clear and the sun angle is getting better for east-west panels so finally getting above 40kwh now.
Not really. Even the software types can quite effectively limit the MPPT below its maximum power level. What I am referring to is conditions where the PV is constantly fluctuating, perhaps with some cloud flare effect, and maybe even some shading involved (causing multiple local maximae). That’s when the cheaper controllers stop charging and restart, while the more expensive ones can keep going.
Two things you have to understand about this. The first is that even Victron makes both kinds of solar chargers, so this isn’t strictly divided on brand name. And the second is that you’re losing mere seconds of energy and only during very specific conditions.
The point I am trying to make is that you can cause these specific conditions to occur more frequently by grossly oversizing the PV array. So 10% or 20% more… usually not a problem. 50% more… probably not the wisest thing to do. Besides, at some point you will exceed the max PV current capacity of the MPPT anyway.
Yeah. I know. Just couldn’t resist though.
Agree with what you say though and to the end user they need to decide what’s best for them.
Sometimes, we need to decide whether we want the best of the best or we settle for something well suitable for its purpose.