a series of early-morning mistakes

Note to self: don’t attempt to troubleshoot or fix stuff until an entire cup of coffee is onboard.

setting the stage

My system makes a healthy amount of power but I rarely charge or discharge the bank at high current.

  • max net solar charge is usually around 30A (after loads are popwered)
  • alternator charging is typically ~30A, when it is being used
  • my background daytime loads are maybe 10A and nighttime 3-4A.
  • my biggest load (3qt instant pot) is theoretically ~54A but I’m usually running it around noon so net current from the bank is maybe 25A.

For all these reasons the POS terminal of my bank is fused at 80A and it’s been in no danger of popping.

Until today.

mistake 1

I was making some potato, bean, and cheese breakfast burritos for breakfast. I’d already brewed coffee then put some potatoes on the 300w hotplate to warm up.

I started drinking the coffee and got out the other ingredients from the fridge. The beans were already in the instant pot where I’d cooked them.

I turned on the Instant Pot to reheat the beans.

At this point both the 54A instant pot load and ~23A load were running, plus the 10A daytlme loads. POP! And it was early enough the solar wasn’t supporting any meaningful part of the load.

Since I’ve never popped that fuse it took me a minute to figure out what had happened. The shunt was still showing some early morning charge so the batteries couldn’t have melted down….. I looked at the POS fuse and saw it was baked, then saw the separate fuse coming from the charge controller. Ah.

I replaced the fuse.

mistake 2

I did not disconnect the loads before restarting the inverter. And I forgot that both loads were auto-on, and that my electric mattress pad would come on at full blast (~15A) when the 120vac came back online.

At this point we are once again over the fuse rating and over the inverter’s 1000w continuous rating.

dodged a bullet

The fuse did not pop.

and got hit by a cannonball

… because the inverter died. My first assumption was that being powered on near the continuous rating injured something. {Edit: I just realized that can’t be it; the inverter powers on with a button press so it could not have powered on with full loads.} Or maybe it died when the fuse popped on its power feed. The manual does not warn that either of these conditions could be destructive. A few years ago I asked about powering on with a load and the consensus was that it was not a problem. Or maybe it is….

I was still half-asleep so I don’t know when the inverter died. I know I didn’t smell the suspecious popped cap aroma until I had replaced the fuse and cranked up everything at once (accidentally).

I opened the case and hoped the user-replaceable blade fuses were popped; no such luck. I also didn’t see anything obiously scorched or leaking. :-\

raiding the parts cabinet

I reached into the parts box and got my old 300w PSW inverter out to hold me over. It will run the small AC loads I have (mainly the heated mattress pad) until I procure a replacement.

I’ll be cooking on propane or crockpot for the forseeable future.

warranty (LOL)

It’s a Chinese inverter so there is little chance they will replace it at 11 months under their 12 month warranty on parts/labor. I didn’t think they’d reply at all but I got an autoresponder asking for details and pics.

The spare inverter was already in place so I popped the hood to get a connection for the inverter. The pic above is my attempt to show that

  • the green power LED is on
  • the USB outlet is live and charging the mini kb
  • but the 120vac outlets show 0v. They actually show a little under 1v for a moment before it goes back to 0v.

I won’t cry if they reject the claim. That kind of thing is baked into the low price of Chinese gear. And it’s conceivable that I did it no favors by powering it up with loads attached.

update March 29th

GoWise responded the next day with an RMA and a UPS call tag. Holy crap.

update April 9th

Thank you for returning the power inverter. It has been tested and declared defective. A replacement PS1002-NP power inverter will be on its way to you. Please note that the warranty does not renew, but this replacement will still be covered in the remainder of your one-year warranty. This ticket will close and a tracking number will be emailed to you separately when available. We anticipate shipping this out in the next week.

It ain’t here yet, but they sure seem to be doing the right things.

update April 15th.

I received the tracked package, installed it, and am back in business. GoWISE even followed up after delivery. Tremendous effort by the customer support team from start to finish. I’ve bought houses and cars where the seller wasn’t this concerned with the experience.

made breakfast, finished coffee

I warmed the ingredients and tortillas over propane and finally polished off that cup of coffee. What a morning.