Latelly, I've been playing arround with the idea to add some storage capability to our solar system.
We have netmetering in one hour intervals - So I don't need anything too crazy. 200-500W Injection with a 2.5 - 5KW Battery pack would be great.
I'm thinking I could go two ways:
I have a growatt SP1000 that could be quickly deployed to our system - The only thing missing is a 48V battery to couple to it.
This seems to be rather inneficient, drawing about 60W idle, to keep a DC output for the main inverter, which itself would draw another 20-30W to start injecting anything into the mains.
Another option is to keep a DC only / Offgrid system for lights and general electronics. These would easily make it to the 2KW mark every day. With a small 500W inverter, I could have standling losses of about 10-15W - Plus all the gear would be capable of continued operation should the grid go down. I could probably use the SP1000 for battery charging duties from the main array. If the battery goes too low - a transfer switch would bring back that circuit to mains.
Are you guys using any of the chinese batteries? If so what has your experience been so far? I wanted the BMS to cut down at 3.1V and 3.4V (LiFePo4). Years ago I did an EV conversion using those voltages and never during the few years I've owed it I had to do any sort of balancing. They would put out 80% of their rated capacity and the EV would push them up to 2-5C. Most chinese BMS's however seem to leave the cells cooking at nominal 3.65, while only cutting out closer to 3.9V. I know smart BMS's seem to have more features available - but, judging by the ammount of forum posts with faulty batteries after a while, I'm wondering how reliable these things are...
Any advice or experience sharing apreciated.
We have netmetering in one hour intervals - So I don't need anything too crazy. 200-500W Injection with a 2.5 - 5KW Battery pack would be great.
I'm thinking I could go two ways:
I have a growatt SP1000 that could be quickly deployed to our system - The only thing missing is a 48V battery to couple to it.
This seems to be rather inneficient, drawing about 60W idle, to keep a DC output for the main inverter, which itself would draw another 20-30W to start injecting anything into the mains.
Another option is to keep a DC only / Offgrid system for lights and general electronics. These would easily make it to the 2KW mark every day. With a small 500W inverter, I could have standling losses of about 10-15W - Plus all the gear would be capable of continued operation should the grid go down. I could probably use the SP1000 for battery charging duties from the main array. If the battery goes too low - a transfer switch would bring back that circuit to mains.
Are you guys using any of the chinese batteries? If so what has your experience been so far? I wanted the BMS to cut down at 3.1V and 3.4V (LiFePo4). Years ago I did an EV conversion using those voltages and never during the few years I've owed it I had to do any sort of balancing. They would put out 80% of their rated capacity and the EV would push them up to 2-5C. Most chinese BMS's however seem to leave the cells cooking at nominal 3.65, while only cutting out closer to 3.9V. I know smart BMS's seem to have more features available - but, judging by the ammount of forum posts with faulty batteries after a while, I'm wondering how reliable these things are...
Any advice or experience sharing apreciated.
