Issue with Battery or Inverter or both?

[Dekkers59]

I had a Solar PV system installed with a Solis RHI5 Inverter and Pylontech US2000 batteries in May 2021, with on-going issues trying to obtain feedback and support from supplier over the last 2-3 months. Once the battery has depleted to less than 7% capacity I receive a  'Battery Communication failure' alarm and notification from the inverter, during the installation the electrician stated that during the winter or daily low light levels the inverter will top up the batteries from the grid to keep the battery charge around 20% which hasn't been the case. As a result as advised by the installer I am now, on a daily basis, having to close down the inverter then reboot the batteries followed by restarting the inverter whilst still awaiting further feedback from the installer( Solis UK have 'apparently' installed all firmware with no effect) My other concern is with this daily rebooting of the system will this impact the performance and potential lifespan of the batteries / inverter? 

 

[Sharpend]

@binky 

Is our resident PV man so will be along soon. 

 

[binky]

the battery shouldn't be discharging that low, but that can happen when there's so much dark overcast weather, as the battery draws a small level of charge to run itself so it drops below the minimum level of around 10%. Once it has done that it becomes a pain to get it going again, as it goes into trickle charge mode, which takes ages to get back above 10%.  If you have the Solis app, then it should be possible to set the battery to charge from the mains by changing the 'work mode'. I forget what the modes are - give the manual a read. Not sure of it can be done via the app, but it should also be possible to set the minimum depth of discharge to a higher level like 15% to avoid any future issues. If this can't be done via the app, it would need to be manually inputted via the menus on the inverter, but you will need a password to do that, and I wouldn't touch that unless talking directly to the tech support team to guide you through the menus, or get your installer to do it.

Not sure why it's registering it as battery coms fail, I've not had that problem - again I woud talk to the tech support guys. The system is suppossed to charge up the batteries occasionally from the grid, but I think that is only once a a week or month. Rebooting won't do anything any harm.

 

[Dekkers59]

Thank you for the clarification I have sent a copy of the relevant page in the Solis instruction manual to the installer regarding the Force Charge SOC which should be preventing the battery going into sleep mode - I checked the menus on the inverter and as you stated it does require a code to be input for access - so its back to the installer to get them to send out the technician to review the settings and change the minimum settings on the Force Charge SOC; the installer has previously informed me that Solis UK have had remote access to my inverter using the Solis app - if it was possible to change remotely you would have expected them to resolve the issue via this route....unless its just another delaying tactic by the installer 

 

[binky]

I've never known any battery supplier to remote change inverter settings, not even SMA. Software updates happen occsionally, and they can sometimes monitor performance, as that is what the portals are for. From memeory the access code is 0010, but it's really down to your installer to change settings, so I wouldn't do that just yet,