Is that possible to run the MPP without solar panels connected to it, but batteries get charged only from solar from Fronius inverter (without importing from the grid)It could work but will not.
The main reason is that you need a BMS for the 48V packs like 2 x 48V or 4 x 48V (2s 96V or 4s 192V).
They are in series and you would need a very strong balancer to equalize them.
I never ever saw such a beast. There is a reason why high V packs are so expensive.
The cheap (and really cheap) solution is to buy an MPP Solar ($700) or Growatt off-grid inverter (5kW), and use your 48V pack with that.
Everything connected to this inverters has UPS power. The grid-tie inverter produces power to you and to sell.
Only one function is missing : no backfeed from battery to grid.
Like here:
This is pretty much the set up I have except my grid tied inverter powers the house directly.The cheap (and really cheap) solution is to buy an MPP Solar ($700) or Growatt off-grid inverter (5kW), and use your 48V pack with that.
Everything connected to this inverters has UPS power. The grid-tie inverter produces power to you and to sell.
Only one function is missing : no backfeed from battery to grid.
Like here:
Yes. This is exactly how mine is set up now, just batteries and no solar PV input. The off grid inverter's AC input comes from a circuit that gets its power from the grid and/or the grid tied solar PV system. This keeps the batteries topped up ready for action in case of an outage.Is that possible to run the MPP without solar panels connected to it, but batteries get charged only from solar from Fronius inverter (without importing from the grid)
Is that possible to run the MPP without solar panels connected to it, but batteries get charged only from solar from Fronius inverter (without importing from the grid)
I have a 10kw solar array with 2x5kw Fronius grid-tie inverters, I want to minimize the grid use while providing backup power for any outage, any recommended configuration to have a DIY battery bank.
Currently, I'm thinking of installing a Victron mulitiplus 2 -10kw inverter with a DIY battery bank, but the Victron inverter is quite expensive (around 5k AUD)
Have a read of what I did in this thread:I have a 10kw solar array with 2x5kw Fronius grid-tie inverters, I want to minimize the grid use while providing backup power for any outage, any recommended configuration to have a DIY battery bank.
Currently, I'm thinking of installing a Victron mulitiplus 2 -10kw inverter with a DIY battery bank, but the Victron inverter is quite expensive (around 5k AUD)
Hi, I just got a Fronius Gen24 Symo 5.0 inverter. I am going to start looking into reverse engineering the communication between the battery and inverter so that we can get a DIY solution available. I'll post more about this in a build thread.
EDIT: Here's the build thread: https://diysolarforum.com/threads/dalas-solar-powered-workshop-diy-powerwall-coming.23732/
So to start with the Fronius inverter reverse engineering, is there some user on this forum that has batteries hooked up to a Fronius inverter? It would make it so much easier if we could get a log file from a working system!
Looking forward to hear about it. As I understand from my Fronius hybrid 5.0.3S is that it can give 5kW AC to the grid (240V system here in Sweden), and 3kW to a battery pack so 8KW at maximum load. We are 3 weeks from the summer soltice so we got power from 4:00 to 22:00 and my panels are not tilted.Hi, I just got a Fronius Gen24 Symo 5.0 inverter. I am going to start looking into reverse engineering the communication between the battery and inverter so that we can get a DIY solution available. I'll post more about this in a build thread.
EDIT: Here's the build thread: https://diysolarforum.com/threads/dalas-solar-powered-workshop-diy-powerwall-coming.23732/
So to start with the Fronius inverter reverse engineering, is there some user on this forum that has batteries hooked up to a Fronius inverter? It would make it so much easier if we could get a log file from a working system!
Hi, I just got a Fronius Gen24 Symo 5.0 inverter. I am going to start looking into reverse engineering the communication between the battery and inverter so that we can get a DIY solution available. I'll post more about this in a build thread.
EDIT: Here's the build thread: https://diysolarforum.com/threads/dalas-solar-powered-workshop-diy-powerwall-coming.23732/
So to start with the Fronius inverter reverse engineering, is there some user on this forum that has batteries hooked up to a Fronius inverter? It would make it so much easier if we could get a log file from a working system!
Yes you are (Output data PV point = 3000VA), but AC nominal output (Pac,r) = 5000W ?
Here's the Sunspec Modbus specification, to get the discussion started on how to make a compatible DIY battery: https://sunspec.org/sunspec-modbus/
Looking forward to hear about it. As I understand from my Fronius hybrid 5.0.3S is that it can give 5kW AC to the grid (240V system here in Sweden), and 3kW to a battery pack so 8KW at maximum load. We are 3 weeks from the summer soltice so we got power from 4:00 to 22:00 and my panels are not tilted.
The battery packs I have are Nissan LEAF ones (400VDC with BMS), but if the voltage is not matching what the inverter needs it's pretty easy to re-arrange the layout. My only concern with using the LEAF pack BMS is that the shunts are so tiny that it takes forever to balance a pack. If I need to change BMS I will most likely opt for Batrium or something similar. The missing link is an arduino/raspberry linking the Battery pack to the inverter by acting as a middle-man (which we will figure out in this thread )How do you want to solve the high Vdc battery and BMS problem DIY ? Did you find a 3-400Vdc BMS? Or with equalizer ?
Ok good to know and I dont have any battery now so 5kW is maximum. Actually get 5.2kW since the inverter is under rated I guess. Now I just need to find out what electric components are used from 20:00, thought I turned off the floor heating we have during winter months in the bathrooms.How do you want to solve the high Vdc battery and BMS problem DIY ? Did you find a 3-400Vdc BMS? Or with equalizer ?
Jep 3kVA that means mostly 2,4kW (pf 0,8)
I am not sure but I do not think that it gives 5+3(2,4?)kW.
Possible when there is a blackout 5kW part stops and 3kW starts.
So when not a blackout it is in bypass mode for the protected load (and can give more power than 3kW because it comes directly from grid)
The battery packs I have are Nissan LEAF ones (400VDC with BMS), but if the voltage is not matching what the inverter needs it's pretty easy to re-arrange the layout. My only concern with using the LEAF pack BMS is that the shunts are so tiny that it takes forever to balance a pack. If I need to change BMS I will most likely opt for Batrium or something similar. The missing link is an arduino/raspberry linking the Battery pack to the inverter by acting as a middle-man (which we will figure out in this thread )