Solis Inverter / Battery stops discharging at 20%

[Boricio005]

We recently have installed solar panels by Homesmart, a Solis Inverter (RHI 3-6) and 2 Plyontech batteries. Both stored in the loft (bit worried in the summer), but during the evenings when the sun goes down, we obviously draw power from the batteries. When the batteries reaches 20%, it stops and we start using power from the grid. Is this normal? I am assuming this is there to preserve the battery life, but was just thinking that 20% is a lot - seems a little wasted.

Can anyone shed some light to this?

 

[johnb2713]

We recently have installed solar panels by Homesmart, a Solis Inverter (RHI 3-6) and 2 Plyontech batteries. Both stored in the loft (bit worried in the summer), but during the evenings when the sun goes down, we obviously draw power from the batteries. When the batteries reaches 20%, it stops and we start using power from the grid. Is this normal? I am assuming this is there to preserve the battery life, but was just thinking that 20% is a lot - seems a little wasted.

Can anyone shed some light to this?

There will be a parameter in the system somewhere that stops operation at 20%. My system I run between 10% and 95%.

 

[Boricio005]

There will be a parameter in the system somewhere that stops operation at 20%. My system I run between 10% and 95%.

Thanks, do you know where and how I can find and change this setting? I did have a look at the manual, the only thing that looks like it could be is: "Overdischarge Voltage" If so, what should this be? If it's current 20%, should I half the voltage (10%)?

 

[Oldman22]

In the Solis menu will be something like mine which is
The OverDischg SOC can be set from 10% to 40%. This is the one that stops it at 20% in your case.
The ForceCharge SOC can be set from 5% to OverDischg SOC. This is a failsafe backup to start an auto grid recharge if the battery goes below OverDischg SOC setting for some reason.
You should download the manual for your inverter, you will also need the password to alter this setting.

 

[Boricio005]

In the Solis menu will be something like mine which is
The OverDischg SOC can be set from 10% to 40%. This is the one that stops it at 20% in your case.
The ForceCharge SOC can be set from 5% to OverDischg SOC. This is a failsafe backup to start an auto grid recharge if the battery goes below OverDischg SOC setting for some reason.
You should download the manual for your inverter, you will also need the password to alter this setting.

Ah yes! Found it! Thank you so much.

 

[Oldman22]

I set mine at 15% and 5% as if we get a grey day and the battery stays at 15% for longer than 14hrs the battery cell volts drop to a level where the BMS will force a recharge from mains which you don't want. In my case that's 3.4kW for 20mins to top up the cells.
So leaving it at 20% does 2 things, its easier on battery life and means you can go longer before a forced recharge.
Edit: I should explain further for others reading this thread, my Solis inverter is AC coupled and has the ability to run on in a power cut. This means it draws power from the Battery to maintain this state of readiness. Mine draws around 450mA/h from the battery while in standby so 15% with one battery is the lowest I can set and be reasonably sure the battery wont discharge to a Force charge level within the next 15 or so hours. Others set a battery charge period overnight at minimum charge of say 1Amp to keep the battery above Forcecharge SOC.

 

[michael8554]

I have a Pylontech 3000C, and I believe Pylon have set it's built-in BMS to stop discharge at 20%,

 

[Oldman22]

I have a Pylontech 3000C, and I believe Pylon have set it's built-in BMS to stop discharge at 20%,

And yet Pylontech make a point that their 5000 series batteries can be used with a DOD of 95% and your 3000C has a DOD of 90%.
So they must make this adjustable via the BMS? Did you get information on how when you purchased yours?

 

[monkey5]

My dyness (look like pylontech)batteries get to 20% and trickle discharge from then never seen it below 10%

Locked to prevent being resurrected (again)