Time for getting help with my electrical

[chiggins]

Hello all!


I'm starting to get to the point were I'm needing to finalize out my electrical plan for my build. I ideally want to get it all figured out beforehand, and then implement in steps so I don't have to drop all the $$$ up front.


The use case for my bus is that it'll mostly be used for long weekend camping trips / multi-day camping music festivals. So no, I will not be living out of it, so I know that changes some things. I do plan to have air conditioning, but only for when I'm connected to shore.


Once the build is finished, I plan on having the following being powered:

• Water pump
• Tankless water heater (probably EcoSmart or something similar)
• Refrigerator (smaller-end, think dorm-sized if not a little bit bigger)
• 7-10 DC puck lights to put in the ceiling
• 3-4 110v outlets for random things including
  • Phones
  • Slow cooker
  • Blender
• Raspberry Pi + amp + speakers
  • Honestly I haven't researched too much into this yet because I don't exactly know what I'm doing here. I want a Pi to be able to send audio to speakers, where the Pi will be running Android Auto from my phone.

I estimate that I'll need around 300-400 amp hours to accomplish this, with 400 being on the generous side of things. But like I said earlier, I want to implement in steps, so I'd like to start out with 100 amp hours worth of battery and add on when $$$ allows. I understand that means I won't be able to power everything I want to right off the bat, which is totally fine with me.


I have to double check my math, but with the rails I have attached to the top of my bus I should have about 240" of space that I can fit solar panels. The solar panels I'm looking at are 26" wide, so I'd be able to fit 8-9 up there.



I don't plan on being on shore all the time, but I do want to have the availability to. I've not decided between 30A or 50A. I lean towards 30A because of cost and how more widely available it is, but I'd hate to build myself into a corner ya know?


I know that I need to size wires appropriately for lengths and power consumption, but I'm not ready to get at that yet since I still need to finalize a floor plan.


What I'd like to get figured out now is just the backbone of the whole system, to make sure what I've figured out so far is appropriate and correct for what I want to do. The items I've pieced together so far are:

• HQST 100 watt monocrystalline 12v solar panels (x8?)
• Victron SmartSolar Charge Controller (150v 45a tr)
• Victron Multiplux 12/3000/120-50 120v VE.Bus
• Victron BMV-712 Battery Monitor
• Battle Born 100 amp hour batteries (4)
• Solar combiner box (suggestions?)

I think that covers the major parts of what I'd like to accomplish so far. I know there's a lot of Victron up there, but I'd like to try and keep to the same manufacturer so that everything "works" well together.


Does that look appropriate? I want to be able to grow into the system and not limit myself right off the bat, minus the batteries. I'll start out with one battery for the bare essentials, then move up as $$$ allows. I want to make sure that my system can accommodate that.


Anyway, I think I've gone on long enough now. I welcome any constructive criticism, I'm sure that I've fudged something up along the way. I appreciate any help and feedback!

[TheHubbardBus]

I'd guess you're not getting a lot of feedback because it sounds like you really have your act together.

One question I have is why you'd go w/ so many 100w solar panels. Are we talking the flexible kind, or rigid? Assuming the latter, I'd think you'd minimize the complication, wiring, & possibly improve your selection of quality components going with fewer/larger.

This recent thread has great insight by @John61 regarding paralleling victron ccs with fewer, larger panels. Might be an option, or at least food for thought.

http://www.skoolie.net/forums/f49/24...lar-30016.html


Assuming you didn't go that route, however, I'd question why you wanted a 12V bank w/ a 3000w system & a lot of panels. In the same thread above there's a discussion of that as well.


I was considering the exact same battery configuration, but feared 4 parallel stand-alone LFPs would not balance correctly w/o an external BMS. I could be wrong. BB certainly has a great warranty, & assuming they honor it and/or are around when / if you need it, probably a safe bet.

[Doktari]

Victron has LFP batteries also. Why not go with all Victron?
That Victron charge controller will handle 24 volt panels. Often the price per watt is better on bigger panels if cost is a factor.

[chiggins]

Originally Posted by TheHubbardBus

I'd guess you're not getting a lot of feedback because it sounds like you really have your act together.

Ha! I hope that is the case, but I definitely out of my element.

Originally Posted by TheHubbardBus

One question I have is why you'd go w/ so many 100w solar panels. Are we talking the flexible kind, or rigid? Assuming the latter, I'd think you'd minimize the complication, wiring, & possibly improve your selection of quality components going with fewer/larger.

I was looking over some other websites and they kinda just spat out 100w solar panels at me. I guess yeah, it would be a lot easier to wire up with higher-watt solar panels. I guess that'd kind of depends on the cost/benefit of more panels vs more charge controllers, if I'm correct?

Originally Posted by TheHubbardBus

This recent thread has great insight by @John61 regarding paralleling victron ccs with fewer, larger panels. Might be an option, or at least food for thought.

http://www.skoolie.net/forums/f49/24...lar-30016.html

Assuming you didn't go that route, however, I'd question why you wanted a 12V bank w/ a 3000w system & a lot of panels. In the same thread above there's a discussion of that as well.

That thread is interesting, it definitely got me curious about going 12v or 24v. If I were to go 24v, would I be able to wire up a 12v battery bank up in parallel to achieve 24v? I'm not entirely sure I follow that.

I just watched the mentioned video by Will Prowse about 12v vs 24v. I imagine I'd like to fit in the category of a medium-sized system, so according to him I'd want to go 24v.


Without knowing a whole lot about either 12v or 24v systems in terms of usability and cost, I don't really have a pull towards either way, ya know?

Originally Posted by TheHubbardBus

I was considering the exact same battery configuration, but feared 4 parallel stand-alone LFPs would not balance correctly w/o an external BMS. I could be wrong. BB certainly has a great warranty, & assuming they honor it and/or are around when / if you need it, probably a safe bet.

I didn't even consider an external BMS, I don't think I've seen a system so far that has made mention of it. The warranty that comes with these batteries is one of the biggest selling points for me, so I'd definitely want to utilize it if the time comes.

[chiggins]

Originally Posted by Doktari

Victron has LFP batteries also. Why not go with all Victron?
That Victron charge controller will handle 24 volt panels. Often the price per watt is better on bigger panels if cost is a factor.

I haven't heard much about the Victron batteries to know either way. I just know that I've seen Battleborn loads more and they seem to be what I'm aiming for.

[Doktari]

Victron Energy prices look high but found a deal on eBay for their Lithium LFP batteries:
https://www.ebay.com/itm/Victron-Lit...UAAOSwPk1eH4o8

[kazetsukai]

I'm just going to give my 0.02c with the stated equipment:

Originally Posted by chiggins

• HQST 100 watt monocrystalline 12v solar panels (x8?)
• Victron SmartSolar Charge Controller (150v 45a tr)
• Victron Multiplux 12/3000/120-50 120v VE.Bus
• Victron BMV-712 Battery Monitor
• Battle Born 100 amp hour batteries (4)
• Solar combiner box (suggestions?)

And the question:

Originally Posted by chiggins

Does that look appropriate? I want to be able to grow into the system and not limit myself right off the bat, minus the batteries. I'll start out with one battery for the bare essentials, then move up as $$$ allows. I want to make sure that my system can accommodate that.

First, my usage:

I have 700W of panels (4x 100W + 1x 300W) at the moment. I have about 50W of sippy loads that run 24/7 (security system, bus computer controlling automation). I see about 500W max power each day, and yesterday my yield was 1.24kWh. The 700W doesn't keep up. I slowly lose voltage until about three-four weeks go by and I'm out. If you have any such load (small but absolutely necessary that it is constant, I'm not talking fridges either), you probably need more panels. I can handle about 30W 24/7, beyond that I'm losing the battle. If you are more of an on/off user, 800W is plenty. I would echo another poster about perhaps going with fewer, bigger panels, but that's just preference in my opinion...




Victron 150V/45A: I have the 150V/100A. These are very nice controllers. Bluetooth management is excellent, and if you have a VE.Direct port, you can monitor it via USB on your Pi. I maintain a Java library that does this, although it should be possible to integrate it with other languages as well.

https://github.com/kazetsukaimiko/victron-java


Metrics are pretty good with VE.Direct, you can watch more or less everything.



Victron Multiplux Inverter/Charger: I've never seen complaints about these Victron units. 3kw is enough to run any single 120V appliance you'll run into and that charging function looks nice...


Victron BMV-712 Battery Monitor: I can't overemphasize the importance of proper monitoring equipment and checking your system multiple times a day. So many people run blindfolded or only with metrics from their charge controllers. Between this and the inverter/mppt you're going to have 100% insight into system performance.


Battle Born: I've heard nothing but great things about these, a bit pricey though. I wonder what the value add is here for you to go with these over, lets say, 4-6 100Ah AGMs, given the use case. If your main electrical usage is during the day, then more panels might better solve your problem? Sounds like you want to start with 4, and maybe add more later. I can't speak for your needs, just consider the strategy perhaps of less/expensive batteries and get a bigger solar array first (~2000W) instead so that the only thing to expand is the battery bank.



Sounds like you did your homework though. Can't point at anything and call it a problem or insufficient given the use case:

Originally Posted by chiggins

• Water pump
• Tankless water heater (probably EcoSmart or something similar)
• Refrigerator (smaller-end, think dorm-sized if not a little bit bigger)
• 7-10 DC puck lights to put in the ceiling
• 3-4 110v outlets for random things including
  • Phones
  • Slow cooker
  • Blender
• Raspberry Pi + amp + speakers
  • Honestly I haven't researched too much into this yet because I don't exactly know what I'm doing here. I want a Pi to be able to send audio to speakers, where the Pi will be running Android Auto from my phone.

[neversayneverbus]

If you could hook up to shore power all the time, then there is no need for any solar setup at all. Or batteries for that matter. That is the cheapest, and the way I'm going to go at first. I'll just plan on the space, attachments, etc... when i do my build so I don't have to backtrack to add it later.

Another idea is a quiet generator. I bought a couple of military diesel generators to try to resell, so I could come up with the money for a nice onan diesel RV generator. But the more they sit in my garage, waiting to sell, the more I think I might take the cabinet off of one of them and repackage it for my bus. The new Onans are 8 to 10 thousand. I bought the military versions for a little over 3k with the same quiet specs and just as good power output. If I decide to do it, I'll put the results on youtube, so others can benefit.

If you can't hook up to shore power, and a generator won't work, then solar is really the only way to go, but a single 100ah battery is not going to get you very far. If money is really tight, you could buy the batteries and not worry about the panels. Then when you can plug into shore power, charge the batteries, and hope they last for what you want for a few days worth, before you have to go charge them again.

[chiggins]

@kazetsukai good to read your post, it was very reassuring and informative. And as much as I hate Java, your library looks fantastic as well


So after some other offline discussions and more research, I think I'm going to go with a 24v system. Seems like a smarter, more efficient, and more economical price. If I size up my usage to require 6000Wh with plenty of reserve, I'd need 1200w of solar to accommodate, along with a 50A solar charge controller.



One thing that I discovered is the Victron EasySolar system, namely the 24/3000/70 model. 24v, 3000w, 70A seems like it'd perfectly accommodate my needs. Are there any big negatives to getting an all-in-one system like that? The price here is just shy of $2,000, which would be a great deal considering buying the devices separate would exceed that cost. Thoughts?

[JDSquared]

Originally Posted by chiggins

One thing that I discovered is the Victron EasySolar system, namely the 24/3000/70 model. 24v, 3000w, 70A seems like it'd perfectly accommodate my needs. Are there any big negatives to getting an all-in-one system like that? The price here is just shy of $2,000, which would be a great deal considering buying the devices separate would exceed that cost. Thoughts?

Im still figuring out my (similar) system, but that price looks good if it's got everything. Especially Victron. Thanks for the link Im going to follow it now.

[chiggins]

Originally Posted by JDSquared

Im still figuring out my (similar) system, but that price looks good if it's got everything. Especially Victron. Thanks for the link Im going to follow it now.

Yeah doesn't that thing look nice? A buddy of mine and I were looking at it last night. If the price is right, why not go that route and save time wiring and everything opposed to it all being done for you.

[kazetsukai]

I'm also a 24V-er.

Originally Posted by chiggins

One thing that I discovered is the Victron EasySolar system, namely the 24/3000/70 model. 24v, 3000w, 70A seems like it'd perfectly accommodate my needs. Are there any big negatives to getting an all-in-one system like that? The price here is just shy of $2,000, which would be a great deal considering buying the devices separate would exceed that cost. Thoughts?

The single point of failure is a pretty big negative in my opinion. That and if you ever wanted to, you couldn't upgrade any single component- you'd just stop using some capabilities at best and now you have a $2000 jack of "2-out-of-3 trades instead of 3 masters of their own domains". The combination has to fit your use case on all three fronts- sounds like it does now, who knows in the future.

Pushing back on my own critique, the single point of failure will not be a _massive_ headache if you do mostly DC infrastructure. If everything is AC and your inverter fails you're in for a world of hurt one way or another so I'd say going DC mostly is probably a good idea in either case.

My setup: I was on a pretty limited budget, and I went down a hardcore/diy path that came with trade offs. My costs and the rationale behind each component:

• Three 24V 5.3kWh Tesla packs - $1100 each.
• Victron Energy MPPT 150V/100A: $800
• 24V PowerJack 8.0 ATS 8000w Split Phase Inverter: $450
• (No charger yet, will probably do a https://www.amazon.com/gp/product/B07TKN76V7 since I don't really need it)
• I already had 800W in panels from another project.
• Infrastructure: $800-$1000

Batteries: Being on a shoestring budget and calculating my capacity needs at around 20kWh, used EV batteries provided the absolute maximum in terms of capacity/dollar. Its near-to-above-AGM cost per watt-hour. A lot of folks reasonably cringe even hearing "used EV battery"- not designed for it, etc. In reality the use case is far tamer than what they were designed for. That being said, A) you're on your own and B) you need to know what you are doing. I started with one pack, and recently bought a couple more. I'll probably have 6-8 in total when done.


MPPT: Given I was charging Tesla packs I needed a reasonably capable and configurable charge controller, so I used a good chunk of cash here. I tuned the voltages and tested everything for months. Last year I brought the (one at the time) Tesla pack into the house for the winter. This year it remains in the bus as A: its heated out there, and B: all my testing indicate its reasonably reliable.

8000W Inverter: This was controversial from the start. I couldn't buy just any inverter, either, I wanted split phase for both 110V and 220V AC service. I have a 220V mini split, which might have two in the future, and I ran 220V to where I planned my laundry to be. The cheapest AIMS I could find was around $1200 for 6000W, but I kept seeing these Power Jack units and their clones pop up, so I did some digging. Ultimately I decided that for the price, if I got 4000W (2000W on each leg) combined out of the claimed 8000w unit I'd be a winner. I held my nose, took a risk. It paid off, the thing works flawlessly. Would I recommend it? If price __really__ matters, you're willing to take a risk, and you absolutely know what you're doing. Otherwise, no.

Infrastructure: The one thing (other than the MPPT) I didn't cheap out on was infrastructure. Fuse boxes, bus bars, thick DC wires, breakers. Neat, organized wiring with a good place to jump from 24V to 12V/48V where needed, and the necessary safety equipment.

I also wanted computer control over everything, so that's also in the infratructure costs but that's another topic.


As soon as my tax rebate hits I'm putting up 2000w-3000w in panels and moving in. I plan to sell property and find land this year.

[Drew Bru]

Originally Posted by kazetsukai

The cheapest AIMS I could find was around $1200 for 6000W, but I kept seeing these Power Jack units and their clones pop up, so I did some digging. Ultimately I decided that for the price, if I got 4000W (2000W on each leg) combined out of the claimed 8000w unit I'd be a winner. I held my nose, took a risk. It paid off, the thing works flawlessly. Would I recommend it? If price __really__ matters, you're willing to take a risk, and you absolutely know what you're doing. Otherwise, no.

Probably a good call on the inverter. Our AIMS crapped out on us after less than a year in service, and the tech support was abysmal. They have a pretty good Social Media Influencer game, but I've heard more than a few horror stories about their Quality Control game.
I ended up getting a Xantrex unit for about the same price as the AIMS unit, and this one is not only smaller and quieter, it's got a 2 year warranty.

[kazetsukai]

Originally Posted by Drew Bru

Probably a good call on the inverter. Our AIMS crapped out on us after less than a year in service, and the tech support was abysmal. They have a pretty good Social Media Influencer game, but I've heard more than a few horror stories about their Quality Control game.

Based on my research, I wouldn't blame AIMS for that, TBH. Its a problem with low frequency inverters in general. These things necessitate very large transformer coils, it is almost impossible to ship them safely. The coil will smash internals moving more than an inch or two


PowerJack as of their V10 units, ship in steel cages, and require you to keep the cage if you intend to ship back on warranty service. I can see why, mine arrived bent and with a dent in the corner of the box courtesy UPS/FedEx.

Originally Posted by Drew Bru

I ended up getting a Xantrex unit for about the same price as the AIMS unit, and this one is not only smaller and quieter, it's got a 2 year warranty.

If its not a monster, its likely high frequency unit. They're easier to ship because the HF design doesn't require a big transformer.