If restarting from scratch knowing what you know now, how would you build your system differently?

[Zwy]

for a ground based system DIY batteries can be a valid choice, however, for an RV not so much. i've not done a deep dive into DIY batteries recently but a quick cursorily scan showed me that the batteries i would want to use for a DIY are the same price or more than a pre-built system. in this case i would want compact light weight batteries which usually cost more.

Compact and lightweight are probably pouch cells. I would be a little leery in an RV application, the Up In Smoke forum here had an RV fire with pouch cells.

I use prismatic in my truck camper 24V system. I do use a compression fixture.

 

[PunchySunshine]

I definitely would have used a wire trough! (if I knew they existed when I installed). I would probably use the Sinclair racking instead of the Iron Ridge for ease of install and material cost. I would definitely have used metal conduit instead of PVC from the array into the house and back out to the transfer switch. I would have also ran the ground conductor from the array to the house. But we're happy because it just works and I don't want to mess with any of this!

 

[OM617YOTA]

I am so torn on this. I have been thinking about and procrastinating on my system for years and have thus far avoided 1 and 2 only by being so slow to take any steps at all.

A battery is my next step, and on one hand I am not sure that I really want to get deeper into batteries themselves as a hobby, but on the other hand I think it might be nicer to have huge 15kwh batteries, rather than a rack full of 3x more 5kwh's to pay attention to. And I don't know if SOC comm to the inverter/sc will be important to me or not.

I went DIY for cost savings, but I'm a special case, with severe health issues, and very limited functional time. I'd have been very far ahead to just pay the extra and buy prebuilt. It seriously slowed me down by months, but wouldn't for normal people. We've all watched Will top balance and add a BMS to individual cells in a couple days.

I'm glad I did it, I don't resent the time taken or education and experience gained, but I'd have been much better off just writing a check and devoting the time to other things.

DIY or prebuilt are both good options. Just flip a coin and keep moving forward.

 

[42OhmsPA]

I'd start by oversizing panels and battery bank by at least 25%.
I'm torn between AIO and modular.
Idle consumption depends on quality / cost of the equipment, from what I've learned.
I'd definitely DIY batteries again but I'd use an industrial cabinet to hold them.
I'd add an E array and increase size of W array..

 

[Rednecktek]

What would I do different?

Plan for 48v right out the gate.
Buy the panels AFTER I've got the rest of the infrastructure (conduit, wires, mounting spaces, etc) in place. (I could have had 275w panels for what my 190w panels cost me that I haven't been able to put up yet.)
Build steel frames instead of PT wood.
Bought the EG4 3Kw unit instead of the Growatt 24v 3kw unit.

 

[JJJJ]

Part of me would have a house in the remote country. On the other hand have terrific neighbors who have been very supportive and we help each other out.

There will always be room for improvement, however life is short.

Regarding solar there will always be the next best product. Having more is intriguing, however I think the best thing is to be content with where you are and with what you have.

Still love the creative process however and that is why I stay with this.

 

[EastTexCowboy]

There are a few minor things I would have done differently but with the technology and products that were available at the time not really a lot. Parroting @timselectric, I did a lot of research then I found this forum and did a lot more research and asked a lot of questions. One of the reasons I say I wouldn't have done a lot different is that, even with some of the things I'm not crazy about on my system, it has worked flawlessly since I first fired it up back in November. Don't mess with something that works. I'd like more output and more batteries but that's because of this accursed addiction.

 

[OffGridForGood]

If somehow I could have had the knowledge, experience and understanding I have now, back in Jan 2021, I would:
1. Pick an inverter with high voltage DC solar string input capability.
2. Bought all the PV panels at once, full skid price/ship rather than a few at a time.
3. DIY all the rack batteries (instead of getting two factory server racks, then switching to DIY)
4. Use the 304Ah cells instead of the 280K's
5. Use the JK BMS from the start instead of the Daly and switching.
6. Bought two Iotawatt units while they were still available! LOL.

But then I would have missed out on so much of the learning experience with you all!
No regrets.

 

[Crowz]

Well this question depends on how you look at it.

Doing it all today I would use all of the money I spent on the 24 volt system and lead acid batteries to a 48 volt hybrid like I have now and lifepo4 batteries and larger panels.

But that means no solar back all of those years ago and no knowledge that I gained from it or the fun and experience I gained from it. Is it worth erasing all of those memories? Building the system with my kids. Learning what worked and didn't from tinkering. The celebrations with the family when we achieved success after toiling to get it all wired up.

Nah I'd do it all the same

 

[1201]

Married into a wealthy family.

How do you make a small fortune with solar?
Start with a large fortune

 

[1201]

If somehow I could have had the knowledge, experience and understanding I have now, back in Jan 2021, I would:
1. Pick an inverter with high voltage DC solar string input capability.

Why?

6. Bought two Iotawatt units while they were still available! LOL.

Lol. I heard you can get the emporia vue and flash it with a better firmware and integrate with home assistant.

I love my iotawatt by the way. But sometimes it makes my head hurt when I glance at it just to see what the house is using and I see 20kw!!!

 

[nc73]

Would've kept my lvx, EG4 does not like my heat pump. For folks that think diy battery costs almost the same as prebuilt...you suck at math. I saved 50% with DIY.

 

[Shimmy]

Lol. I heard you can get the emporia vue and flash it with a better firmware and integrate with home assistant.

I am so happy my IoTaWatt uploads to InfluxDB directly. I have some equipment that HomeAssistant brokers to InfluxDB and it seems so much more flakey.

Mental note: cache the Graph+ remote resources locally. That has to be one of the best features of the IoTaWatt; sad that I like the graphs there better than Grafana (for things that can be graphed based on just local data).

 

[Tomthumb62]

For context, my use case is for a small camp trailer that we use usually a few weeks of the year. This year we're using it a few months. Propane for heat and cooking. What I did end up doing differently, after learning from mistakes:

• Added 200W more solar to the 200W already there and added another 200W for portable on the ground.
• Added a Victron 12/1200VA (1000W) inverter to replace a Renogy 2000W. Idle draw savings is HUGE in the upgrade.
• Replaced 2x100Ah 12v AGMs that are a major PITA to try to charge with only 200W solar with a single 12v 200Ah LiFePO4, which can charge from 100W or 600W just the same, albeit faster with more watts.
• Replaced the monster NOCO Gen2 20A 2-bank lead-acid charger with a slightly smaller Victron IP22 30A multi-chemistry charger. Probably the best value upgrade I made as the NOCO was $200 new and the Victron was $150 "like new open box". The Victron ecosystem with the stellar (free) phone app Victron Connect is really really good (and good looking).
• Re-wired almost everything. PV cable is now 10AWG (overkill until 100Wx4 in 4p combines for a possible max 34A). 8AWG from where the 4p+2p could give me almost 40A. Other wires upgraded too and added a 50A breaker between panels and SCC to use as a switch for maintenance work.
• Added a "box" between the wood stud legs that supports the 120v fridge and below where the Victron inverter is mounted. In the "box" is a 2x2.1A 12v USB charger, 20A AC breaker (12AWG marine grade wire for the trailer house AC wiring) and a Baomain 20A manual transfer switch, to switch AC power from the inverter to shore power.
• Added an extension cord outlet (leftover from another project) to the Victron IP22 30A charger so that every time I plug into shore power, the AC charger is powered on and starts charging the battery.

The difference is we now have a system that WORKS and is RELIABLE and doesn't need shore power charging every couple of days to charge up those pesky and picky-of-charge AGMs! It hums along perfectly unless we get more than 2-3 days of clouds/rain.

Much of the equipment that I originally bought was before I learned of this forum. After being a sponge and asking questions for about 2 years, I made the above upgrades. It's not our most absolute dream version (a 300Ah battery that takes half the space of the current 200Ah one would be a dream, like one of the 280Ah SunFunKits), but it's close to it and was within our budget. We made smart purchases this time, such as finding the Victron gear as "like new open box" for about 12% off new...the best price I could find anywhere. Another smart buy (multiple times) was learning about and buying all my 8AWG down to 1/0AWG cables from batterycablesusa.com as they have the best price and selection and customization of anyone else out there...lower price because they only sell direct and don't have the overhead fees of AMZ or ebay. I also bought more of my gear through Will Prowse's affiliate links, because my purchases were far more thought out this time and not driven by my internal consumerism/getting sucked into Amazon and buying stuff before I really know that it's what I need. Glad to support Will in a small way like that because this forum exists largely because of him.

 

[toms]

For completely off-grid systems the biggest thing i do differently now to what i did ten years ago is to use a primary and secondary system.

 

[JJJJ]

For completely off-grid systems the biggest thing i do differently now to what i did ten years ago is to use a primary and secondary system.

I have debated something like this for my freezer. It sips the power. I have debated setting up a UPS type system dedicated to it only. It could run for days or possibly longer if the power went out.

 

[1201]

Can you expound a little on this? Thanks

 

[JJJJ]

A UPS is basically a battery pack with a charger/ inverter . When the power goes out it throws a switch to pull power from the battery.

A battery attached to a properly sized inverter preferably pure sign wave would power the freezer. A proper designed charger eg. Victron makes a smaller one that could potentially keep the battery topped off.

Technically this is not a true UPS but a battery buffer to ensure constant power with the grid on or off.

Of course the real world can bring up concerns not seen on paper so this might be an over simplification.

My apologies. Not trying to get this thread off track.

 

[Crowz]

That's one thing that is different from my old stuff besides the actual equipment is now its being divided up.

The primary system runs the "required" things and will have batteries. The secondary stuff gets a hybrid but no batteries and just solar panels.

This way the secondary stuff aka washing machine, dryer, stove, some of the non required heat pumps and ac units, etc is run by the sun only very cheaply. So clothes washing and stuff gets done during the day.

The primary system has 90% of the power bill worth of stuff which includes the refrigerators, freezers, house heatpumps, computer room, bedroom and two of the family type rooms. This eliminates most of the power bill and will work with power outages too.

 

[Rocketman]

The big thing for my full-time RV is Victron has come out with new stuff that would have been better! I want the new stuff…

The other thing is I have expanded one array- when installed it was the right size 400w of solar on a 100/30 mppt, but then I needed more power when conditions weren’t perfect so I added another 200w to that array- so now very overpaneled.