Off Grid Customer Story: Saving Our Customer $24K in Batteries

Brad & Nikki Burnett Heads House and Shed House Off Grid System

We were initially contacted by Brad & Nikki who were experiencing a range of issues with their rural off grid property systems at Burnett heads, just East of Bundaberg in Queensland. They were extremely frustrated by the lack of support and service and couldn't find anyone available or knowledgeable. They also wanted to add more air conditioning units to the main house and wanted to know if the system could handle the extra load. The problem was, the system was in such a poor state we needed to get it sorted first. So, we initially went out and had a good look over the main house system and made a list. We basically started by working through each item until we had it resolved before moving onto the next.  

This system was your classic case of "all the gear and no idea". Now I don't like to bag out other people's work but seriously...this wasn't great. The Victron Cerbo GX wasn't connecting to the internet (so no logs) and the Fronius grid tie inverter had not been set in "off-grid mode" and was constantly dropping out during the day (Victron inverters Hertz move around a bit and the Fronius needs to be told to look at a wider window of Hertz), it also needed a firmware update which stopped all the lights flickering...I swear these guys must have thought the house was haunted. But it's a known issue with the older Fronius Primo inverters and easily rectified with a firmware and settings update. 

Then we turned our attention to the Cerbo GX and it's constant WIFI dropouts. Again, easily fixed with the addition of a USB WIFI extender. This gave us the ability to remotely monitor the system from our base in Childers. Then to all the settings...which were bad.  So bad that the 5 x Power+ batteries had NEVER in 4 years had an active balance and we well down in capacity.  They were set at 52V and not the required 57.6V.  Doesn't seem much but in lithium land...it's a massive gap. We rectified this. 

Now to the 15Kw 3 phase diesel generator. I mean...seriously, you couldn't have chosen a more inappropriate generator if you tried. For starters, the house is single phase (not 3-phase). So a 15Kw generator is 5Kw per phase. When you run a 3-phase generator off a single phase, you shouldn't run more than 47% of load on that single phase, or it's not good for the generator. This massive 3-phase generator had to be dialled back to around 2.5Kw. Effectively a small campsite generator would have done the same job. 

Now we needed to sort all the generator start and stop time settings to make it kick in if the system was ever in overload or if the batteries got too low. We are getting there!!  But the batteries are just not giving us the power they should. Not even after several months at the correct settings. The next step is to test each battery with a fixed load to determine the state of charge (SOC). In pairs the batteries were ferried to Childers batteries for extensive charge and discharge tests. Using a Victron SmartShunt we logged and recorded each charge and discharge. At the end of the testing, we determined that the 4 year old Power+ batteries were only outputting around 40% of their capacity.  

Now the real challenge began. And that was convincing Power+ why they should warranty all 8 of the property's batteries (5 in the main house and 3 in the shed house).  We provided all the evidence, built a case on behalf of our client and presented it to Power+. I am happy to say that the team at Power+ reviewed the case and kindly warrantied the batteries....all 8 of them.  $24,000 worth of batteries.  Hats off to Power+ and a huge shout out for standing by their customers.  

From here we turned our attention to the vacant shed house. Again, a system review and the addition of a WIFI expander so we could remote monitor the system. We soon discovered that the Victron SmartShunt was only measuring discharge loads and no charging? So another trip out to site only to discover that the installer had installed the shunt in the negative cable going from the Lynx buss bar to the Victron inverter and not in the negative from the batteries to the buss bar.  The system has also been installed with NO CIRCUIT BREAKERS...seriously bad!!! Some relocating, rewiring and upgrading the system to the current standards by adding a waterproof circuit breaker to the batteries, fusing to the DC side of the Victron inverter charger and the solar regs. We also updated the labels to meet the code.