Still a lot to do, and a long day for sure, but doable and we figured we’d finally be back home late in the day.
As I alluded to in my last post, it would turn out to not be that way at all.
After getting the batteries hooked up, I began the inverter programming-which is pretty quick and simple for such a small basic system- while Denise started packing up all our personal items and tools and parts we were done with.
One thing that makes these inverters and modern lithium batteries fairly easy to program for a simple systems is the fact that the batteries communicate to the inverter via a data cable.
In modern systems, the batteries actually end up driving the inverter instead of vice-versa. The batteries populate the inverter settings for critical parameters such as charging voltages, overall capacity, temperature, etc. Better batteries will also drive their maximum charge and discharge rates based their internal parameters and self-balance individual batteries within a system of batteries, resulting in improved battery life and performance-in fact, good battery/inverter combinations running in communication with each other ( known in the industry as “closed loop communication “)can be up to 30% more efficient than when they are not in communication with each other. This is a significant and important benefit for overall system performance.
Which is great, and we were using a proven battery/inverter combination to leverage all that.
Except right off the bat, the batteries refused to communicate with the inverter. 🙄
I went to do a total system re-boot-which is occasionally needed on a new system on its first power cycle to make everything happy-which is where our problems began to multiply.
The two batteries in this system had been powered up and tested for proper voltage and proper power-up and power-down operation separately and had functioned perfectly before we tied them together.
But once they were put into the system in tandem, the batteries refused to power down. We could kill power to the DC power buss, but the batteries internal BMS ( Battery Management System) wouldn’t fully power down-which in this particular system was a problem because it would need to be powered down for months at a time in the winter, and the stuck-on BMS would prematurely drain the batteries and potentially ruin them.
I spent over an hour in mounting frustration trying everything I could think of to get the batteries to play nice, but everything pointed to a failed BMS or two, and we were running out of time to resolve such an issue.
Luckily, I happened to have that manufactures head US product representative cell phone number, and doubly luckily he answered the phone.
We went through all sorts of trouble shooting procedures and he was coming to the same conclusion as I was. Batteries won’t power down or communicate and it sure looked like a BMS failure-which was highly unusual.
Then we backed up and tried the one thing that I normally try first thing that I normally try in a no-communication type of scenario, but didn’t because of the batteries wouldn’t power down indicating a BMS issue-and that is to try a fresh communication cable to rule out a bad cable. Now, we use only quality pre-terminated data cables, and I’ve never had swapping cables fix a communication issue-it is always something else-but it’s still the first thing one should try because it’s easy and immediately rules out a bad cable.
Well lo and behold-for the first time ever, swapping data cables immediately fixed the communication issues! The batteries still wouldn’t power down, but with proper communication established, it made us realize we had two SEPARATE problems all along that only SEEMED like the same problem, and THAT puts a different spin on our thinking and troubleshooting process.
After several hours, what we discovered was that we needed to add an outboard and additional battery disconnect because the inverters DC buss capacitors were storing residual voltage after the batteries started their shut down process-which in turn would automatically trigger the batteries to power back up. 🙄
This was a perfect storm sort of scenario-these particular batteries with this particular inverter combo produce a unique DC circuit situation not usually an issue with other inverters.
Once we figured that out, the issue was pretty simple to fix, and luckily I happened to have an extra 175 amp DC breaker on the truck, so it was simply a matter of carefully marking out a breaker mounting location and cutting it in.
Here’s the breaker installed.
Yeah, my handwriting sucks. Our label maker is on the fritz, expensive to replace, and I was out of time. Deal with it. 😄😄once we had that all set up, everything with the batteries worked perfectly.
Awesome!
Let’s get out of here!
The only thing left to do was test the little manual backup generator with the inverter to make sure everything there worked as it should, get the batteries charged up enough for seasonal storage, and roll our crap out of here.
Easy-peazey!
Except it wasn’t.
The inverter would NOT connect to the generator at all.
I tried the generator we carry on our work truck , which has proven to connect to these inverters in the past-and that one wouldn’t work either.
Shit.
Meanwhile, Denise was attempting to establish WiFi communications with the inverter with no luck-an unusual situation.
It was beginning to look like we had a bad inverter. 😬
This was bad news, as we were rapidly running out of time to get all this running with it now being Friday afternoon.
I fired off some calls to inverter tech support and our vendor-but by that point in time, we had to stop working on the system, as we were scheduled to be one of three installers selected by a prominent battery manufacturer to be a featured guest speaker in their year-end webinar for installers. A big deal and honor for us for sure!
We had been scheduled to be in our office for this event-but here we were in the middle of nowhere.
Luckily, we had brought our portable Starlink with us, and we frantically deployed it and got a laptop setup just in time to participate.
We did our best to forget about all the problems we were knee deep in, put on our game face, and did our presentation and Q&A session for Pytes Batteries.
The webinar lasted just over an hour, which put us onsite, with a system that wasn’t fully functional, at past 4 pm on a Friday.
We had to face the difficult reality that there was no way we were going home today, and as Denise moved our essential personnel items back into the cabin and scrounged food for a meal that we hadn’t packed for, I went back to fighting with the inverter and generator.
Long story short, I finally got ahold of tech support, and after hours of work, it developed that a particular setting we used for off-grid generators-a setting, I might add, that the manufacturer recommends for our application and that we always use-doesn’t play nice with only this one model of their inverter and a different setting must be used or the inverter will never connect to external AC power.
Seriously. 🙄
Once we changed that setting, everything worked as it should.
But by that time it was dark and another day had passed.
The system was finally done, running properly, and our generator was charging the batteries in preparation to shut the system down for the winter season, but we still had hours of work to get loaded up, and that would have to wait till Saturday morning-and Saturday would prove to be yet another challenging day.