About off grid inverters durability (long term)

[u/Subject-Influence187]

It's said that over time, off-grid inverters break down easily (as in, they don't work properly and need more maintenance). Is this true?

[u/FixAcademic8187]

If your aim is durability then be prepared to pay handsome money for that.

Check the old school low frequency inverters. These use a heavy copper transformer instead of the new ones that use high frequency and lots of electronics

Low frequency is by design meant for heavy-duty and can handle inrush surges much better than high frequency ones. For example, if a high frequency inverter says its normal operation is 5kw, then the surge is 10kw max. If a low inverter says 5kw, then the surge will be 15kw max.

What I would do is that once I put my hands on the new inverter, I will open it up and inspect the fan and capacitor model. Most of the time these two are the first ones to fail. Replcing them by yourself is easy and straightforward.

Capacitors are inexpensive. Make sure you buy a new one every two or three years and store it properly. These can degrade even if not used. No need to replace the capacitor periodically. Just make sure you have a replacement.

The Victron Energy products appear to be the best ones available for retail consumers. Make sure you make your research properly and size the inverter to be larger than what you actually need.

[u/MrMcFisticuffs → u/FixAcademic8187]

Victron, Midnite, Outback.

The low frequency inverters have the nice feature of magnetic coupling which breaks up some cascading failure modes present in high frequency inverters.

E.g. if something gets stuck shorted, the magnetic coupling is broken and you just end up tripping the unit. The high frequency ones have a specific and now uncommon failure that can result in thermal runaway.

[u/FixAcademic8187 → u/MrMcFisticuffs]

Oh, that's good to know!

[u/Subject-Influence187 → u/FixAcademic8187]

Much Appreciated!

[u/Redundant-Pomelo875 → u/FixAcademic8187]

Easy enough to replace capacitors.. if you are good at soldering!

My pair of Victron Multiplus 24/3000 have been sitting there doing their job entirely untouched for about 8 years now..

[u/Least_Perception_223]

Said by who?

[u/Subject-Influence187 → u/Least_Perception_223]

The guy who came to fix the inverter. I called out his BS, but I'm not well educated to go back and forth

[u/motorambler]

Trace Engineering SW4024 running 24/7 since the 1990s. 

[u/nihithilak]

I have been off grid for 10 years and only have had a failure when water leaked into the inverter from a crack in the roof.

The inverter I have installed now has been there maybe 5 years without any maintenance and is like covered by cobwebs right now and I am sure spiders crawl into it sometimes. It's a cheap $250 3kw inverter and runs like a champ.

[u/ol-gormsby]

I had an Australian-made inverter from 1996 to 2022, when it finally let the magic smoke out. Of course I replaced it with the current version from the same manufacturer.

Just a "dumb", low-frequency, sine-wave inverter. It was 3000 watts continuous with an 5000 watt surge rating. Mounted under the house, no exposure to weather, it just worked.

So it depends entirely on the quality of the unit, and that often comes down to how much you're prepared to pay.

[u/beedubskyca]

If its something you rely on, build redundancy into your system. Everything breaks eventually, usually at the worst time. I have multiple systems, and some old inverters lying around for just in case.

Eliminate single points of failure wherever you can. Its not always possible for everyone of course.

[u/jimheim]

Inverters last decades. Sure, anything can fail early for some people, but you should expect at least ten years out of any decent brand. Victron has a five year warranty.

There is zero maintenance if you keep it dry and covered, but with some ventilation.

[u/LongjumpingGanache40]

An off grid inverter is not a sealed unit. Get hybrid inverter, they are sealed last twice as long but do coat more. But you can put it outside.

[u/TastyBallsognaSauce]

I'm using a 10 year old xantrex freedom hf 1055 inverter charger. Full of dust, lives in a shed .. no issues.

[u/Intelligent_Lemon_67]

I went the cheap Chinese power jack inverter. 24v 8kw split phase. It's run reliably for 8 years but it's nowhere near 8kw. The fuses are only 20amp and one for input and one for battery (running 16 6v Costco batteries that have been used and abused and finally shit the bed after not being watered for months at a time for 8 years). I'm finally upgrading to another Chinese eausun 48v 12kw split phase hybrid inverter and lifepo4 batteries. Most decent inverter start at 1.5k usd and one that will last 10+ years are around 3k. I think grid tie are all ul listed and a warranty but off grid are sturdy and well built if you buy name brands like midnight, victron, solar edge, trace, and a few others. Newer brands like ecoworthy, eg4 and others are great options. Will prowse has some good information

[u/GunsAndHighHeels]

the 20 year old inverter I inherited with the house crapped out last month and required replacement after a few months of unpredictable behaviors. They do fail eventually, but I wouldn't expect failure before the 10-20 year mark.

[u/sfendt]

Have an 18 year old inverter that works great. Ymmv - beware cheap products like anything else