Solis 5kw hybrid inverter paired with 16.1k fogstar battery not depleting it's charge

Hi ​@H22a7 , that sounds like there’s a setting on your system to prevent power draw from the battery - can you tell if the battery provided power previously?

Ours is a different manufacturer but I have a setting called ‘Charge Priority’ which makes sure the battery is topped up but can also stop power being drawn from the battery.

A few things to check - You might have 

• Set Reserve SOC high (e.g. 80–100%) - keeps battery charge high
• Use Feed-in Priority mode - designed to make most use of export 
• Or configure TOU with no discharge window - depending on your tariff, can restrict battery discharge at certain times

Hey ​@H22a7 

I’m glad to see BPLightlog has already stopped by with some helpful advice here, if you’ve not had a chance to check that out, please do and let us know if that helps.

We have some slightly similar topics on the Forum, I wonder if those could be helpful too, I’ve linked to a couple of those below:

Do let us know how you get on, I hope some of the above is helpful to you. 

Hi BP, I thank you for the reply.. 

The battery came prey charged at 30% it charged to 66 % and depleted to 20% that night so was working as it should

The problem came when it changed to 100 % the next day, after that it never departed it's charge.

I have tried all your suggestions but still no luck unfortunately.. I believe the inverter has a failsafe or something that won't release the charge? 

Hi Abby, thank you for your reply.. 

Still no luck unfortunately 

The ‘fail safe’ is generally to prevent the battery going too low or to stop discharge during a power cut (there needs to be extra protection for engineers) rather than when full so I’m not sure what else to suggest if you’ve checked your timings (sometimes used to prevent discharge during the day or at any off-peak times).

There should also be a forced discharge setting which might help if you want to get the battery below 100% although this does export power rather than powering the home.

I contacted Solis and they were rude and unhelpful.. They said the fogstar battery was not compatible with the solis inverters. 

Fogstar are telling me the battery is fully functional and it is the inverter at fault so I don't know what to do now 

Who did the install ? At this point I would get the installer back to rectify.

Or you could ask Fogstar how to ensure it’s set properly. Some inverters have a setting for which batteries are connected (which adjust levels for voltage, current etc)

I am not having any luck with Solis they said the fogstar battery is not compatible and may void the warranty and Fogstar just uses the pylon protocol that doesn't work so I am between a rock and a hard place. Thanks for your help BP.. Much appreciated 

I’ve found a few more details that might be worth checking:

1. The set up must be for a 48v Solis inverter
2. You should have the batteries connected via 50mm^2 cables
3. You need to use the CAN connection from the inverter CAN port to the battery
4. Set the battery protocol to CAN>Pylontech
5. The inverter needs the battery type set to Pylontech>Lithium (CAN)

The CAN connection and set up is critical otherwise the inverter cannot read the SOC (state of charge) which might explain why your battery won’t discharge.

If you have multiple batteries, only the master links via CAN, the others via RS485.

Of course, you may have already covered these points - the other thing to check is that firmware is up to date

You are a legend BP.. I will give that a go and let you know the out.. Thanks again