Author Topic: A year "unplugged"  (Read 2265 times)

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Offline MadScientist267

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A year "unplugged"
« on: January 15, 2017, 06:27:19 am »
Today marks the 1 year mark for the official day the truck officially was unplugged and things got real.

There's a lot of things to say about the adventure, but I'll save some of it for later posting...

I'm calling it a success, with some gotchas. Overall it has done what it was intended to do, despite a few shortcomings that I simply either couldn't put more resources into, or couldn't simulate accurately before it went live.

It hasn't spent the *entire* year doing it all on its own, I've utilized opportunity to plug in a couple of times both helping deal with the extremes at either end of the seasons and as part of certain aspects of designing the new charger.

It's done stretches of every scenario ever really encountered since all of this was considered so long ago, to the point that I know how to make it handle what it can, and learned how to workaround what it can't when things get too far out of bounds.

The most notable shortcoming in capability has turned out to be the fridge, despite its excellent performance. This wasn't too great of a surprise, because it was so difficult to determine exactly what it would need vs what would be available. That said, the couple months or so it has spent basically offline were relatively easy to workaround since they line up with the coldest months of the year.

Basic rundown of the externally used energy resources in the course of a year to do something like this are approximately as follows:

About 20 gallons of propane for heat

About 125 hours of genset run time (some of which was purely about testing for the new charger)

Somewhere between 300 and 500 hours plugged in (again, some of that for charger development and testing, another chunk of it was to help determine some minimum requirements needed for peak cooling when the A/C unit was brought into the picture, and as of this winter, some newer experimental heating methods involving the wax)

At no point after the genset was brought back online in mid-late summer did the Wh/hr usage exceed 700W (either for genset or grid), as the system operated in "Live UPS" mode after continuing issues associated with the genset dictated that it could not always be relied upon to provide continuous clean power that avoided interruptions with things like fridge operation. While these issues with the generator have been largely resolved, the plug inevitably fouls, and even a single stumble can (and does) easily cause overload conditions when it tries to recover. Live UPS mode resolved this.

At only 1 point (other than a single mock up scenario test a short time later) was "plugging in" used as an emergency measure to prevent damage to the battery bank. During the ~4 month stretch where the generator was completely unavailable (approx April to July as memory serves), the system relied on extreme conservation and the overkill presence of PV during extended periods of reduced solar input to prevent damage to the battery bank.

To date there only stands 3 critical system failures once going live that left the system in a compromised state.

1. The aforementioned genset problems. This has ultimately been determined to be mostly the PCV valve sticking closed, causing massive amounts of oil blow by and consumption, resulting in extreme amounts of smoke at the exhaust. The issue was slowly resolved in time using a rather extreme but carefully concocted, tested, and refined cocktail of additives and cleaning processes to free up the sticky valve. Once cleared, a very light synthetic (0W20) oil with small amounts of the main cleaning agent used in the original cocktail has helped keep it clear. Spare plugs are kept on hand, but the frequency of the need to replace it is much less now and it consumes much less oil. The engine will be rebuilt as soon as it is practical and/or viable to do so.

2. The disconnect switch originally in place between the main DC bus and the classic output. This switch (despite the lack of actual apparent cause other than cheap construction) was developing significant resistance, causing charging problems. It was removed and bypassed, and never replaced.

3. The original charger intended for use while plugged in or on generator suffered from many many design issues that were mostly a result of cheap selection of base components,  hasty construction, and had a "it at least works and there are still bigger issues to resolve before launch". The rebuild is still in the process of reaching completion but still has a few minor details to be worked out. Of the many failures that plagued the original, the inrush NTCs were the final points of failure that prompted the complete redesign from near scratch. The standard doubler used on its original front end was replaced with an active PFC section "borrowed" from a PC computer supply that had lost its main low voltage section, and the silicon in the original "grunt" board replaced with much more robust components for the job. The result is a rock solid charger that efficiently loads the genset, and is in the process of having its new arduino based control system finished up, replacing an operable but very feature limited pure analog control system. The new design has multiple layers of protection built in, in addition to being able to either run integrated with the original control, or run standalone, not only as a smart battery charger but also can be used as a high power bench power supply independent of the main battery bank should something come up that needs it.

There are MANY other aspects to doing all of this that simply fall outside the scope of a single post, but this covers a good percentage of the technical aspects that pertain to the energy related concepts. The main one I've left out  (other than brief mention) here is the never ending game that thermodynamics plays, which in itself is a whole world unto itself. A close second is all of the master control that without things like Raspberry Pi, Arduino, and other microcontroller based technologies, the entire project would be much more difficult if not nearly impossible to have managed without.

So, to the few that have helped in making things possible, clearer, and more viable as time has gone on, I'm eternally grateful. Your donations, help, and input has been invaluable from the beginning, and will never be forgotten.

To those that have considered attempting something like this, but aren't sure of where to begin...

I simply warn that it's a lot of work and presents a seemingly endless set of challenges, but is entirely doable. If things are well thought out, one is determined enough, and prepared to continuously adapt to all the issues that go along with the entire concept, it's very rewarding to see it all come together, in spite of all the mistakes and apparent "dead ends" that regularly crawl out of the woodwork. It requires a LOT of thinking outside the box.

Steve

Wanted: Schrödinger's cat, dead and alive.

Offline rossw

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Re: A year "unplugged"
« Reply #1 on: January 15, 2017, 01:42:40 pm »
Interesting distillation of 12 months into a few paragraphs!
I remember many of the trials and tribulations from IRC. All in all, a project well done, Steve, regardless of the reasons!

Offline MadScientist267

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Re: A year "unplugged"
« Reply #2 on: January 15, 2017, 07:46:21 pm »
Indeed very condensed, and thank you Ross.

There are *so* many things that have run full spectrum, each one going all the way from simple thought exercises all the way to craters in the bench from facedesking. Technical, logistical, spatial, safety, security, emotional & physical demands... just to name a few. The list is seemingly endless.

I had to find at least a starting point to lay down the marker that represented a full round trip with nature... Seemed the technical aspects and pitfalls were the simplest place to begin, but certainly only represent a sliver of what the endeavor as a whole brings to the table.

It's difficult to single out any one aspect that's been more difficult than any other, but I suppose there's one that stands out above the others simply because it complicates all of the rest. That would be the mobility factor. Being able to pick up the whole show and take it with me is a double edge sword. It causes many things that otherwise wouldn't necessarily be an issue, to become diametrically opposed to one another.

Not only is there the whole "mode change" thing when it comes time to pick up and go somewhere, but there are things like protection that I built in to shut down the fridge for transit... To reduce the chance of damage to the compressor (it's a recip type, which has vulnerabilities that gyro forces and vibration threaten during operation, and scroll types generally aren't susceptible to)... this has repeatedly caused issues when the need to go somewhere coincides with a needed visit from the sun.

Likewise, I avoid the abuse the open road provides when the batteries are below a certain level to reduce shedding and plate damage. Can't say for everywhere, but the road system here isn't exactly all nice and smooth, curvy, and gentle with pristine landscaping all around... and the truck ain't exactly a golf cart... things shake, rattle, and roll... and if it ain't just about bolted slam down, slide all over the place too (while I'm mentioning it lol).

Ventilation and operation of the heater are interrupted, one inherently, the other for safety, respectively. This of course leads to thermal annoyances (at best), as it's repeatedly been proven that at both ends, it's much easier to maintain temps than to let heat content run very far in either direction and try to bring it back into line after the run.

Projects in play on the bench, in a fragile state... All I can say there is "Gorilla tape and I are no stranger to one another"...

Then there's also the idea that if something happens involving the drivetrain, the entire thing may get threatened as a whole.

Again, just to name a few.

All part of the game as it must be played when everything is in a single basket like this... It's... challenging, to say the least.
Wanted: Schrödinger's cat, dead and alive.

Offline bj

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Re: A year "unplugged"
« Reply #3 on: January 16, 2017, 05:21:53 am »
  Been reading, not saying much, because it's hard to type with your fingers crossed. ;)
  But, you did it. 
  Congratulations Steve
"Even a blind squirrel will find an acorn once in a while"
bj

Offline MadScientist267

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Re: A year "unplugged"
« Reply #4 on: January 17, 2017, 02:19:21 am »
Thanks BJ

It is one thing if it's nothing else... very rewarding to see the composite of 40 years worth of curiosity, imagination, theory, questioning, failures, successes, beat downs and victories all come together in a non trivial manner, and be able to call it successful as a single entity.

Not sure if I mentioned it elsewhere, but 5 years ago, the closest thing to what I have in hand today didn't extend beyond "a cell phone, an 8W solar panel, and a tent". At that, only on paper. No joke, wanted to try "this", only... like that.

I would have been unable to stop laughing if someone had said "5 years from now you'll be celebrating a year off grid in a solar powered Uhaul RV conversion". Pffft. Yeah right.  ::)

I simply ran with what just happened to be the right set of circumstances in disguise... I guess the joke is on me hahaha - Nobody stepped forward at the time to give me someone to laugh at... but here I am anyway  ;D

Wanted: Schrödinger's cat, dead and alive.