As far as I can tell, the display isn't necessary, and the battery monitor is nice to have as an at-a-glance thing in addition to the system monitoring offered by the Cerbo. If I was to get the display, I would skip the monitor and just get the shunt, but I don't think the extra display cost is worth it.
12v vs 24v
- Thread starter edlittle
- Start date
Vigo
Solar Addict
I can understand at least somewhat. I cant sleep indoors in the temps it would get up to with no ac here for a lot of the year, but i could sleep outdoors with it.. I have very young kids so the thought of sleeping without a lockable hardsided box around us is unnerving to me, but that should subside within a few years.. mine are only 1 and 4 years old. Hopefully when they’re both past 5 or so we can do some camping without mom and dad losing their minds.. ?
I noted that you will be getting the lugs elsewhere.
When I ordered my components, I made a rookie mistake. I ordered lugs based on wire size only. That is on me. Once I started fitting things together I noted that stud sizes were different for different components. When I displayed parts of my build to others they pointed out that the lug hole was too big for the connecting stud.
Ultimately I went back and ordered replacment lugs. There are a number excellent suppliers, I personally chose the Selterm brand because it was highly recommended.
When I ordered my components, I made a rookie mistake. I ordered lugs based on wire size only. That is on me. Once I started fitting things together I noted that stud sizes were different for different components. When I displayed parts of my build to others they pointed out that the lug hole was too big for the connecting stud.
Ultimately I went back and ordered replacment lugs. There are a number excellent suppliers, I personally chose the Selterm brand because it was highly recommended.
Thanks for this call out, I've noticed this on some videos so I'll definitely make sure to quadruple check before ordering lugs!
John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
If you are knew to making compression joinery I suggest you order a few extra to cover practice and mistakes.
HarryN
Solar Enthusiast
Sorry - didn't realize that this thread was older.
midwestsolarnoob
New Member
I don’t know if you’ve already purchased your batteries but watching will’s videos steered me towards using the EG4 ll v2 in our future build. The price is honestly really good and the communication looks amazing. I’m actually in the same predicament with 12v vs 24v vs 48v. We’re running mostly 12v stuff. But running a mini split for a/c . So constantly running an inverter for 120v. Would it allow for significant efficiency to up the battery bank voltage to 24 or even 48v? Or I’m overthinking it. Either way 1500+ watts will be on the roof.
12VoltInstalls
life passes by too quickly to not live in freedom
Well some people have strong feelings about ‘efficiency’ and define it differently.
12V requires bigger cable for heavier inverters. What are the startup and running watts of your (I’m assuming 120V?) minisplit? 12V May support that, and
That is the major consideration for me. If the minisplit is <2500W and 120V (I suspect that it is well under 2500), then I would stay 12V.
These latest and greatest AIO’s, however, are most often for 48V batteries.
In practice, in practical usage, the empirical efficiency of 48V vs 12V does not matter. All that matters is that you have enough power in panels and batteries to accomplish your goals.
That’s my opinion. Ymmv
If one starts with a lower voltage system then the existing wires will easily handle the transition to a higher voltage system. Batteries can be switched from parallel to series. In other words it is easier to move up in voltage versus down in voltage.
midwestsolarnoob
New Member
That’s what I figured. I’m a DC guy anyway as I’m an automotive technician. 12v is what I’m used to and have worked with my whole career.
Mini split is max spec of 800-900w. Reviews say typically runs around 300w to maintain temps. Which that’s all dependent on insulation in our build which it’s getting sheep’s wool and foam board. Should be very well insulated when we’re done.
The only reason I was debating a 48v system was the cost of an AIO. It’s less than a victron SCC or on par in pricing. So same KWs just higher voltage at a more budget friendly start up price. But everything aside from the mini split will be 12v so I think 12v is probably our best bet.
So I guess another question for you, let’s say max the mini split pulls 1000w. We should need more than a 2000w inverter right? Cooking and water heating will be propane. So just device chargers and maybe a coffee maker is all we’ll use for 120v.
So essentially for the entire solar build. I’m at this point.
1500w+ rigid panels on roof
Victron SCC
Victron Inverter charger
Four 400ah EG4 Solar rack batteries 20.5kw
That should be adequate for 2-3 days of power with no charging from panels. Of course panels will be charging but I like the idea of having reserve.
Or should we add another 5kw battery? Thankfully we have til next spring before I install the solar. So plenty of time to plan
Also any other hardware brand suggestions? Maybe similar quality to victron at a better price point?
Thanks for the help!
I full-time in my RV, let me share an overview my system…
1400w of solar, (I have 2 SCC’s but that’s because it built in stages).
Multiplus 12/3000
Smartshunt
544ah of Lithium batteries 12v
CCGX (older version of Cerbo)
BP-65’s to prevent draining of battery by 12v loads.
Items on LP gas… water heater, heat, stovetop, generator for backup.
With this system it provides all the power we usually need. A bigger battery would be nice - but tough to fit in our rig. One day of storms we might be ok - two cloudy days and we run the generator for an hour or so.
We move to nice temps (try to keep in the 70’s year around). Summer is no problem keeping our batteries full - winter in AZ I have to tilt our panels.
On 120v We can run all the small items we want- lights, computers, Starlink, etc.
We can run 2 medium items at once: toaster,etc.
We can run only one heavy item at once, (and no medium items), microwave/convection oven, hair dryer, air conditioner. (On our battery - air conditioner is usually only 1hour if it’s too hot- we have a Micro-Air EZ start on it). If needed longer we start the generator and run both A/C’s.
Because going higher voltage doesn’t cost more, if I were not in a 12v RV I would go 48v.
Also, I would love to have a Multiplus 48/5000 in my rig- the little more spent on the Multiplus would be offset in cheaper mppt’s. (But that would present battery issues (space issues) in my RV). The reason for the 48/5000, is the ability to have two large draw items on at once or one large and one medium.
You have such a large battery - I would wait on the 5th battery until you see if you need it - I doubt you will.
Good Luck with your decision.
1400w of solar, (I have 2 SCC’s but that’s because it built in stages).
Multiplus 12/3000
Smartshunt
544ah of Lithium batteries 12v
CCGX (older version of Cerbo)
BP-65’s to prevent draining of battery by 12v loads.
Items on LP gas… water heater, heat, stovetop, generator for backup.
With this system it provides all the power we usually need. A bigger battery would be nice - but tough to fit in our rig. One day of storms we might be ok - two cloudy days and we run the generator for an hour or so.
We move to nice temps (try to keep in the 70’s year around). Summer is no problem keeping our batteries full - winter in AZ I have to tilt our panels.
On 120v We can run all the small items we want- lights, computers, Starlink, etc.
We can run 2 medium items at once: toaster,etc.
We can run only one heavy item at once, (and no medium items), microwave/convection oven, hair dryer, air conditioner. (On our battery - air conditioner is usually only 1hour if it’s too hot- we have a Micro-Air EZ start on it). If needed longer we start the generator and run both A/C’s.
Because going higher voltage doesn’t cost more, if I were not in a 12v RV I would go 48v.
Also, I would love to have a Multiplus 48/5000 in my rig- the little more spent on the Multiplus would be offset in cheaper mppt’s. (But that would present battery issues (space issues) in my RV). The reason for the 48/5000, is the ability to have two large draw items on at once or one large and one medium.
You have such a large battery - I would wait on the 5th battery until you see if you need it - I doubt you will.
Good Luck with your decision.
12VoltInstalls
life passes by too quickly to not live in freedom
You shouldn’t need more than 2000W (to start the minisplit if 1000W is startup).
However, I personally would go 2500- or 3000W inverter.
I started out with 1200W, run a 2000W right now, and plan to 3000W at some point this fall or maybe over winter. 1200W is enough, but 2000W it seldom works hard. 3000W is 25A will run a few 120V tools without working too hard.
Victron has a 3000W 12V multiplus if you feel spendy. If you don’t feel spendy a QZRELB (Reliable brand) 3000W is < $400
I agree - in your situation. It works for me.
That sounds robust enough. Victron is security. I’d still allocate ~$450 for a cheap QZRELB inverter and maybe a powrMR SCC in case of a need for backups if you have an (unlikely) warranty claim or a lightning strike or something else stupid.
I either forget or am not seeing your locale; I’m uncertain another battery is necessary but 1500 watts of panels… I’d want a floor of 3000W or prefer 5000W of panels minimum depending on your region.
In my situation we get endless cloudy days repeatedly November to January, Feb through March ain’t great either, and this year has been terrible for sun through to today. If you are similar cloudiness 5000 could be marginal. I don’t have A/C here in Vermont and my past typical 800W of panels did better than I’m getting with ~1300W currently. Next week or so I’ll be swapping to six 315W panels, and I when I get my office trailer here at the new property I’ll be onlining ~1200W more, and if I build a ground mount I can add 1300W to that. Because if I’m getting 10% production over a short, dark, cloudy day 500Wh/hr = 2-2.5kWh and that is way more usable than 150 watts a day.
I said all that to influence your thinking. Make what you can get for solar work for you. Your mention of ~3days reserve at ~20kWh batteries means about 6500Wh per day needed; 1500W of panels will barely do that per day with no additional battery replenishment. See what I’m saying?
Victron for what it is is likely your most economically feasible solution at that tier/quality.
My MPPSolar AIO has been fantastic but the don’t have a robust 12V offering. 1000W inverter and is gangable to 9000W, but idle draw is ~26W so it is ~55W with a second unit. Works very very well though. Over 15mos the only issue besides the small inverter was it forgot to start charging the batteries in the AM twice. Power off, back on, it was fine. I recommend this budget brand AIO.
QZRELB and Giandel inverters have not failed on me.
I did have to swap H & N on the Reliable 2000W because it was plugged in wrong internally at the factory- a common issue for them.
With either of those two the open N-G is something to address. Giandel let’s you do it externally, Reliable I haven’t tested yet to see if it smokes out.
I am currently running the MPPSolar for ~800W of panels, one cheap powrMR mppt SCC with 200W, and another powrMR with a 315W panel. I also have a couple windyNation P30L pwm units for backup, as well as several Epever mppt SCC’s if I want to or need to use them.
If you opt for cheapo (powrMR) or even midshelf Epever just buy an extra of each; that’s the beauty of powrMR cheapos: redundancy is $100 not $700 or $400
The Victrons will work great for you. I’ve been saying it nearly five years: if my cheap stuff keeps on going I may never get around to a Victron.
Totally agree.
As far as the 3000W multiplus… I wish MPPSolar made a 12V 3000W AIO unit. The 1012LV-MK has been an awesome machine, just hogtied at 1000W.
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midwestsolarnoob
New Member
Thank you for sharing your build! It gives me some ideas for real world full time mobile living. That’s our plan next year to start full time mobile living.
I haven’t purchased anything yet. We are still building out our rig. We’re converting a low mileage 23’ shuttle bus. Next spring is when I’m thinking we will be making our move into buying our solar components.
I can’t say that I’m sold on the 48v at all. I’m still researching components and such for 12,24, and 48 volts. Using DC is a must imo being mobile and having more mobile intended components vs some people arguing just run all AC from a huge inverter.
What kind of air conditioning do you run? We’re pretty well sold on using a 9k btu mini split. Since we’re using a 23’ platform I don’t believe we will need more. Plus we are going to be comfort chasers with the weather. No reason to rough it out in cold ass winters or blistering heat being mobile.
Also was curious as to how much propane you go through? We will be using propane for cooking and heating water as of now. Not sure I want to add propane for heat yet
That’s 48/5000 victron is a beast! If we decide on 48v that may be our choice. Idk though, EG4 has a couple pretty bad ass AIO’s for 48v.
Thanks again for replying!
midwestsolarnoob
New Member
Okay no more than 2kws. That’s what I meant originally lol. But I’ve already been leaning towards a 3kw. Price isn’t much higher either.
I was already planning on stocking a few backup items for when we hit the road. E.g 12v water pump. Water filters. So a cheap SCC and inverter is a good idea too I’d say as well.
So we currently live in Indiana. But we aren’t leaving for full time mobile living until next year. So in the process of building our rig. Like I mentioned in my other posts, it’s a 23’ shuttle bus conversion. So not alot of sq footage. Do you think 1500w is too little Solar?
We won’t spend time in colder climates. So I’d say most typical days should have 5-6 hours of good sun. But if we do actually spend time in those climates, we won’t be using a mini split. It’ll be heat from combustion of some sorts. Either propane or a diesel heater. Plus we’re going to have a back up generator for emergencies.
I’ll check out those brand and components for sure! So you’re running 3 SCC’s? All to one bank of batteries? How does that work? I’ve thought of the possibly running small 100w’s to fill in space separate from a large panel array. We just don’t have a huge roof space for mounting 2kw+ of panels. Or I haven’t figured out how yet rather
But thanks for all the info!
We don’t use much air conditionings- being high in mountains helps a lot. Our MotorHome has two units - the front one is OEM and we need either generator or shore power for it- it is the standard RV roof unit.(I forget which one).
The bedroom unit we replaced with a Rec-Pro 3800. I could run it on our Multiplus 12/3000 inverter- but the startup surge was often causing the inverter to send our error messages (high ripple- low battery). After I put a MicroAir EZ start on it the startup surge went from 27a (no wonder the inverter was having issues) to 16.5a. We don’t run it a lot - but it is nice knowing if we need to cool down the bedroom- it is there. The mini-splits are more efficient- I wish I could have one - but no place to put the inside unit nor the outside unit.
Also, you can have many solar charge controllers going into one battery- I currently have two - both Victrons mppt’s a 100/50 and a 100/30 - they both have their own solar panel arrays (plus a 30a Dc-Dc charger when the MotorHome’s diesel engine is running).
The bedroom unit we replaced with a Rec-Pro 3800. I could run it on our Multiplus 12/3000 inverter- but the startup surge was often causing the inverter to send our error messages (high ripple- low battery). After I put a MicroAir EZ start on it the startup surge went from 27a (no wonder the inverter was having issues) to 16.5a. We don’t run it a lot - but it is nice knowing if we need to cool down the bedroom- it is there. The mini-splits are more efficient- I wish I could have one - but no place to put the inside unit nor the outside unit.
Also, you can have many solar charge controllers going into one battery- I currently have two - both Victrons mppt’s a 100/50 and a 100/30 - they both have their own solar panel arrays (plus a 30a Dc-Dc charger when the MotorHome’s diesel engine is running).
Here is another reason for 24v
UsbC cannot output much more than 18W on 12V, but can output 100W from 24V…
So, if you have type C devices, that can benefit from high wattage USB, then…
UsbC cannot output much more than 18W on 12V, but can output 100W from 24V…
So, if you have type C devices, that can benefit from high wattage USB, then…
12VoltInstalls
life passes by too quickly to not live in freedom
If flat panels and at your stated needs my wildhat opinion is that it’s marginal.
Yes. Presently.
When I’m “fully set up” on the new property I’ll likely be running two or three cheapo powrMR’s, one or two Epevers, and the AIO.
Not really applicable to your mobile setup, but basically this is my idea:
I’ll have three pairs of series 315W 46VOC panels (fit on a 24-wide SW facing wall) into powrMR’s, 3S2P or 4S2P 100W ~22VOC on a SE facing wall into the 1012LV machine, and a ground mount of I don’t know how many 60W 98VOC parallel thinfilm panels into an Epever 200V 50A SCC that I plan to be way far overpanelled with for cloudy period wattage; keeping not going over .5C total in mind.
I got 39 thinfilms for free; cost me ~5 hours plus some gasoline. I will probably manually switch these in several arrays so in The Dark Months here in Vermont I can total 3kWh+daily. Solar output on these dark days is 5%-10% of nominal power potential- occasionally less- and 5000W potential should do ~3000W total per day most days. I’ll just have to not be stupid and forget to turn them off, or perhaps figure out a contacter/relays to time out in 8 hours.
Again - not really applicable to your situation other than in principle.
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midwestsolarnoob
New Member
Have you ever looked at the 12v roof A/c’s ? They’re a bit more expensive than the 120v’s. That’s what I originally was going to use in my build but we decided the mini split would be the most efficient. We were going to go with the Mabru 12k I believe.
Would I just hook up multiple SCCs nothing special ? They play together fine?
I looked at them out of curiosity… My issues was with a already built MotorHome the 120v wires are already there and if I went with a 12v one I would have to get 1/0(?) awg wires up there. My inverter a Multiplus 12/3000 can handle one air conditioner so it’s all good.
My Victron ones play together fine - a 100/50 and a 100/30. I do have them running DVCC from my CCGX. (The DVCC transmits the voltage, current and temperature from the battery to both of the SCC’s and the Inverter/charger).
