Skip to content
View in the app

A better way to browse. Learn more.

Power Forum - Renewable Energy Discussion

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

5x 12KW parallel Sunsynk inverters - battery SOC never decreases even when battery is being used heavily

Featured Replies

Hi All

We have the above at the workplace, and 2x 40KWh FreedomWon LiFEPo batteries for 80KWh total capacity.

For the past three weeks, no matter how heavily we draw on the batteries, their SoC never decreases according to the SoC meter on the units and on the website / app.

The install is about a year old, it was working fine until three weeks ago, e. g. SoC decreases during loadshedding as the loads are serviced using the batteries, then immediate charge-up when grid comes back.

Now you can still see the grid charge occurring after loadshedding ends (so SOMETHING is seeing the batteries are discharged and need recharging) but the actual indicated SoC is always 100% no matter how much the batteries are drained.

We use BMS with CAN bus, no errors indicated on the master inverter or a peer inverter.

This is a problem as SoC is used to turn on the generator if needed at 30% SoC - now, no matter how "flat" the batteries, SoC is ALWAYS 100%.

Any ideas as to what is going on and how it can be corrected?

Thanks!

  • Author
4 minutes ago, PowerUser said:

What does FreedomWon says about this issue?

Haven't referred it yet. I talked to my installer and he will be along tomorrow after hours so we he can try a complete restart of the 5 inverters. I checked the battery indicators themselves, and they appear correct and fine - so it seems to be some kind of interpretation issue with BMS between them and the master inverter itself.

What is strange they stay at 100% on the inverters, but the inverters do know they have discharged (during loadshedding, for example) because the moment mains comes back they start charging. So the "logic" is still ok as regards the inverters knowing when the batteries are full or need a charge, the actual display of SoC and acting on that (like starting the generator at 30% SoC) -that- isn't working... but something else in the inverters seems to know just fine what the ACTUAL charge is as it starts charging and stops just as it normally would.

  • Author
2 minutes ago, madness_za said:

Have you tried a hard reboot of the entire system?

This is the next step. We're dependent on the units for the business, so I arranged with the installer to come by tomorrow after 17h00 and assist with a complete shutdown and restart.

What I do find strange is that charging still works as it should, the inverters stop and start charging when they should if the battery was drained, but it is as if the rest of the SoC mechanism / logic just stopped functioning and got locked into a "SoC is always 100%" mode...

Thanks for the reply!

If you don't come right try a factory reset. Maybe just the master inverter

Had to do so on another install with a similar issue, battery stuck at 100% despite being red on the freedomwon SoC light. Fortunately was just a single inverter. 

  • 1 month later...
  • Author

Just thought I'd get back on this, turns out SunSynk pushed out a non-optional firmware upgrade back then and apparently did not publicize it.

To get it working again, the installer factory-reset the main inverter only, after also completely disconnecting and switching off (via the on-battery breakers) the two Freedom Won batteries.

The sequence was

- Batteries off, master and all slave inverters running on AC
- Factory reset master inverter with AC applied
- Switch off all inverters and turn off AC so master inverter and all slaves go dead completely once master back from its factory reset
- Turn on batteries, -then- switch inverter(s) on so they come back up on DC from batteries only
- Wait a few minutes, then turn on AC to all the inverters

Once this was done the SoC was again correctly displayed and you could see it decrease during loadshedding as the batteries drained from being used.

Generator automatic turn-on is now working again as the master inverter "sees" the batteries reach 30% and then sends the startup signal.
 

Edited by rylan76

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.