Hello everyone,
Yesterday, quite by chance, I watched a YouTube video where someone reviewed their past year with a photovoltaic system and its battery storage. Since I don’t know much about this, and the guy was using exactly the hybrid inverter we are planning to get (KOSTAL PLENTICORE plus), I watched the whole thing.
One detail stood out to me, which he was quite frustrated about because he hadn’t paid attention to it when buying. It was about the maximum charge/discharge current at the battery input. He mentioned that while he made sure the battery itself had a relatively high limit (I think it was 25A), he overlooked the fact that the inverter has only 13A.
I didn’t fully follow his explanation, but he described the problem as the low current limit of the inverter restricting the battery’s output, which means that only about 2.6 kW instead of 5 kW can actually be delivered. This, he said, might lead to situations where if the washing machine and dishwasher run at the same time, grid power would have to be drawn.
This got me thinking, and I searched online for keywords like “what to consider when buying an inverter” and so on. I also skimmed through some forum threads but couldn’t find any advice highlighting this particular specification anywhere.
Am I fundamentally misunderstanding something?
Could someone here explain exactly what this is about? And are there other specs one should pay attention to as well?
I can well imagine that in our case, loads like this will be drawn quite often, and I would be annoyed if such a small detail caused unnecessary grid power consumption.
Best regards
Yesterday, quite by chance, I watched a YouTube video where someone reviewed their past year with a photovoltaic system and its battery storage. Since I don’t know much about this, and the guy was using exactly the hybrid inverter we are planning to get (KOSTAL PLENTICORE plus), I watched the whole thing.
One detail stood out to me, which he was quite frustrated about because he hadn’t paid attention to it when buying. It was about the maximum charge/discharge current at the battery input. He mentioned that while he made sure the battery itself had a relatively high limit (I think it was 25A), he overlooked the fact that the inverter has only 13A.
I didn’t fully follow his explanation, but he described the problem as the low current limit of the inverter restricting the battery’s output, which means that only about 2.6 kW instead of 5 kW can actually be delivered. This, he said, might lead to situations where if the washing machine and dishwasher run at the same time, grid power would have to be drawn.
This got me thinking, and I searched online for keywords like “what to consider when buying an inverter” and so on. I also skimmed through some forum threads but couldn’t find any advice highlighting this particular specification anywhere.
Am I fundamentally misunderstanding something?
Could someone here explain exactly what this is about? And are there other specs one should pay attention to as well?
I can well imagine that in our case, loads like this will be drawn quite often, and I would be annoyed if such a small detail caused unnecessary grid power consumption.
Best regards
I wasn’t planning to get a storage system anytime soon anyway, but this really takes the wind out of the whole storage topic for me even more.
2.6 kW is really not much. 6.5 kW is more reasonable, but how much more does the storage system cost then?
I cook a hot meal almost every evening, and while I don’t always use the highest power setting (which, if I remember correctly, requires over 7 kW), I do often use the second highest setting and several zones at the same time, or the oven and cooktop simultaneously. Of course, the TV is also running – no idea how much power that uses – 250 W? Plus lighting everywhere and the server. Meh...
2.6 kW is really not much. 6.5 kW is more reasonable, but how much more does the storage system cost then?
I cook a hot meal almost every evening, and while I don’t always use the highest power setting (which, if I remember correctly, requires over 7 kW), I do often use the second highest setting and several zones at the same time, or the oven and cooktop simultaneously. Of course, the TV is also running – no idea how much power that uses – 250 W? Plus lighting everywhere and the server. Meh...
I probably should have titled the thread more like: "Inverters – what should be considered in the design?" 😉
No, you’re right, there are surely some people who haven’t yet realized that there are currently significant supply shortages.
I totally agree with Tolentino here, I have the same loads and can already see myself getting annoyed 😕. I’m not even sure, does the heat pump count in here? The mechanical ventilation with heat recovery? (You could also mention the electric car, although that would bring other issues, so let’s leave that out for now 🙂.) What about a possible air conditioning system? Expandable as needed...
Not all of these will run at the same time, but you do start to get a sense of where this could be heading...
No, you’re right, there are surely some people who haven’t yet realized that there are currently significant supply shortages.
I totally agree with Tolentino here, I have the same loads and can already see myself getting annoyed 😕. I’m not even sure, does the heat pump count in here? The mechanical ventilation with heat recovery? (You could also mention the electric car, although that would bring other issues, so let’s leave that out for now 🙂.) What about a possible air conditioning system? Expandable as needed...
Not all of these will run at the same time, but you do start to get a sense of where this could be heading...
All of that, yes. You wouldn’t charge an electric car directly from the battery storage. At least, it should be avoided if possible.
Normally, you charge the car first and then the battery storage. Depending on the distances you need to drive, you can cover five workdays a week on a single battery charge and then fully recharge over the weekend – it depends.
Normally, you charge the car first and then the battery storage. Depending on the distances you need to drive, you can cover five workdays a week on a single battery charge and then fully recharge over the weekend – it depends.
R
RotorMotor24 Aug 2022 15:08Nixwill2 schrieb:
I totally agree with you, Tolentino, I have the same consumers and can already imagine the frustration 😕. I’m not even sure if the heat pump counts in here? What about the controlled residential ventilation system? (You could also mention the electric car, but then there would be other issues, so let’s leave that out 🙂). What about a possible air conditioning system? Expandable as desired…As I said, how often do you use your cooktop in power mode?
Only for a few seconds to minutes.
You don’t charge a car from the home battery storage.
The heat pump and air conditioning usually don’t either (but they rarely, if ever, need more than 1kW).
Of course, it powers controlled ventilation, servers, etc., those run at night as well.
But all that adds up to about 200W total.
As mentioned, a storage system should be designed to cover the basic load; it can also balance peaks occasionally, but shouldn’t primarily serve that purpose.
It’s always like this—the last 10% of self-sufficiency costs 80% more. ;-)
Nixwill2 schrieb:
This is exactly the point—the calculation in the video was done with this inverter, actually 6.5kW, but at 13A. And he somehow implied that this is the bottleneck.
Could the 200V battery voltage have something to do with it?What kind of battery did he have?
Yes, but it is quite disappointing that the amount of electricity stored should actually be enough, yet you can't draw enough power all at once. And P already requires over 7 kW. Levels 7 or 8 (my standard cooking settings) are enough and already push the 2.6 limit quite hard.
I would simply be very disappointed because this is not an edge case at all, but something absolutely everyday.
I would simply be very disappointed because this is not an edge case at all, but something absolutely everyday.
Similar topics