Cell-King
Member
- Joined
- Sep 23, 2019
- Messages
- 60
>Hi @Cell-King outputting 0W still draws power. Maybe you can have a simple sonoff at the AC output to allow completely disabling the inverter.
Edit: I use a Sonoff POW R2 at the AC output to achieve this. It also measures output power quite accurately.
Thanks @CarlosGS I have a simple timer plug that turns the unit off when it reaches night time rate, just to save a bit of juice. I will look into the sonoff and integrate some control into my python control service so that I have more control over it.
Hi @grundholm After a lot of initial problems i've been able to get these devices working for months at a time. The main problems I was having stemmed from allowing the battery voltage to drop too low. The inverters would start to act erratically so now I keep the cell voltages at about 3.5 volts and it works fine for now. My batteries drift a lot at lower voltages so I think it's probably safer that I keep them at that level anyway. My plan is to double my battery pack shortly and also add a wind turbine so I think that will bring more stability down the road anyway.
Something I will say is that I think it's absolutely necessary to create your own control plane with a raspberry pi and a serial connection, I've been able to add a lot more logic features to the device that I wouldn't be able to have otherwise to the point that I wouldn't use these inverters without it.
Examples of the extra logic I made-
I turn output to 0 watts when electricity is night rate and back on when its morning again.
Increase the AC output watts when I have over 900 watts on the panels, as this maximises power to the house and minimises amps entering the battery (my thinking goes- I might as well use the power from the panels directly and take pressure off the battery charge rate).
When the battery is fully charged output maximum watts, then when I drop to lower battery state of charge reduce output accordingly. I have four stages of output, from maximum to zero output based on state of charge.
To get this working I have a relay board regularly "power cycles" the serial port that's connected to the raspberry pi. I found that the serial would often lock up. This may be due to the RS232 chip that I currently have and I've other models that I'm going to build and try the same with them, so this may not be needed. My CT signals come from a Emonpi over JSON, which I think is a great piece of kit. I preferred having a digital signal sent across my network instead of the supplied external limiter that is shipped.
In summary, to answer your question I think if you can learn from the mistakes of us and get a good control platform running, and avoid the costs of the external limiter, these devices are very cheap and seem to work well once you iron out the kinks.
I think I linked to a version of my python code here in this thread but if you want an updated version let me know.
Edit: I use a Sonoff POW R2 at the AC output to achieve this. It also measures output power quite accurately.
Thanks @CarlosGS I have a simple timer plug that turns the unit off when it reaches night time rate, just to save a bit of juice. I will look into the sonoff and integrate some control into my python control service so that I have more control over it.
Hi @grundholm After a lot of initial problems i've been able to get these devices working for months at a time. The main problems I was having stemmed from allowing the battery voltage to drop too low. The inverters would start to act erratically so now I keep the cell voltages at about 3.5 volts and it works fine for now. My batteries drift a lot at lower voltages so I think it's probably safer that I keep them at that level anyway. My plan is to double my battery pack shortly and also add a wind turbine so I think that will bring more stability down the road anyway.
Something I will say is that I think it's absolutely necessary to create your own control plane with a raspberry pi and a serial connection, I've been able to add a lot more logic features to the device that I wouldn't be able to have otherwise to the point that I wouldn't use these inverters without it.
Examples of the extra logic I made-
I turn output to 0 watts when electricity is night rate and back on when its morning again.
Increase the AC output watts when I have over 900 watts on the panels, as this maximises power to the house and minimises amps entering the battery (my thinking goes- I might as well use the power from the panels directly and take pressure off the battery charge rate).
When the battery is fully charged output maximum watts, then when I drop to lower battery state of charge reduce output accordingly. I have four stages of output, from maximum to zero output based on state of charge.
To get this working I have a relay board regularly "power cycles" the serial port that's connected to the raspberry pi. I found that the serial would often lock up. This may be due to the RS232 chip that I currently have and I've other models that I'm going to build and try the same with them, so this may not be needed. My CT signals come from a Emonpi over JSON, which I think is a great piece of kit. I preferred having a digital signal sent across my network instead of the supplied external limiter that is shipped.
In summary, to answer your question I think if you can learn from the mistakes of us and get a good control platform running, and avoid the costs of the external limiter, these devices are very cheap and seem to work well once you iron out the kinks.
I think I linked to a version of my python code here in this thread but if you want an updated version let me know.