Beginner looking for advice on set-up

[Rednecktek]

I was familiar with the expression in its original usage. My high school US history teacher used to roll his own cigarettes during class. He had a stack of rolling papers, a handful of loose filters, and a pile of tobacco, and he would fill 'em, roll 'em, lick 'em and twist while we students looked on. As you might expect, this was in the previous century.

Careful..... your showing your age.

 

[mosesp]

OK, did a first pass at a power audit. Feedback welcome! I did two things, resulting in the two tables below:

• First table: reviewed volt, amp and watt values listed on items and their manuals. Most items did not have a watt value, so I calculated using W = V*A. The garage door opener did not have this info listed on the unit (unless it's on the side facing the ceiling) or the manual.
• Second table: used a Kill-A-Watt device to measure devices in operation.
  • Did not measure the lights as they were hard to get to, and they had watt values listed on them.
  • The method for the dehumidifiers was to measure them when using fan only (three levels) and then also when the compressor kicks on.
  • The method for the batteries was to discharge them completely (lots of edging and leaf blowing) and then test them recharging singly and in tandem.

A few notes:

• I would like to be able to run two battery chargers at the same time, hence the "tandem."
• I expected that the garage door opener would have a surge on startup, then a lower load. I did not see that-- it reached a certain draw (listed below) and stayed at that level during operation. It's a very small garage door that runs for a short amount of time, FWIW.
• A few devices had idle loads that I wasn't expecting: dehumidifier #1, dehum #2, and garage door.
• I recorded the observed watts, and also did the same W = V*A calculation using observed volts and amps. For most devices, observed and calculated were pretty close, but for the battery chargers (marked with "???") they are way off. Not sure what's going on there, might re-test.
• 60 Hz throughout.
• I thought it was interesting that the "idle" volt reading was a little over 121, but with more load drawn, that number crept down a little.
• In reading the manual for the garage door opener I discovered that it has the option to install a backup battery, so I might do that and leave the unit on grid power, which would take that item out of this calculation.

Overall, comparing "label" watts to "observed" watts, the labels (calculated V*A) are consistently higher. If we go with those values to be safe (plus the observed one for the garage door where that info is missing), the sum of all the devices "highest possible load" is 2664W.

LABELS

	V	A	W	W (calc)
Battery charger	120​	2​		240​
Fan 1 (lg)	115​	1.7​		195.5​
Fan 2 (sm)	120​	1​		120​
Dehumidifier 1 (lg)	115​	7.6​		874​
Dehumidifier 2 (sm)	115​	4.2​		483​
CF lightbulb	120​	0.21​	13​	25.2​
Ceiling lights (2) (per) - fluorescent tube			40​	--​
Garage door opener	120	?	?	--​

OBSERVED

	V	A	W	W (calc)
Battery charger - idle	121.8​	0​	0​	0​
Battery charger - single (small batt)	121​	1.67​	128​	202.07 - ???​
Battery charger - single (large batt)	121.1​	1.55​	119​	187.705 - ???​
Battery chargers - tandem	120​	3.1​	252​	372 - ???​
Fan 1 - idle	121​	0​	0​	0​
Fan 1 - level 1	120.7​	1.17​	141​	141.219​
Fan 1 - level 2	120.4​	1.29​	156​	155.316​
Fan 1 - level 3	120.2​	1.42​	162​	170.684​
Fan 2 - idle	121.6​	0​	0​	0​
Fan 2 - level 1	121.3​	0.62​	71.4​	75.206​
Fan 2 - level 2	121.1​	0.75​	90.3​	90.825​
Fan 2 - level 3	120.5​	0.9​	102​	108.45​
Dehumidifier 1 - idle	121​	0.01​	0.9​	1.21​
Dehumidifier 1 - fan level 1	120.5​	0.58​	68.7​	69.89​
Dehumidifier 1 - fan level 2	120.5​	0.61​	74​	73.505​
Dehumidifier 1 - fan level 3	120.5​	0.66​	80.1​	79.53​
Dehumidifier 1 - compressor	118.3​	3.42​	393​	404.586​
Dehumidifier 2 - idle	121​	0.01​	0.9​	1.21​
Dehumidifier 2 - fan level 1	120.5​	0.35​	41.5​	42.175​
Dehumidifier 2 - fan level 2	120.5​	0.35​	42.1​	42.175​
Dehumidifier 2 - fan level 3	120.5​	0.36​	43.7​	43.38​
Dehumidifier 2 - compressor	118.3​	3.06​	311​	361.998​
Garage door opener - idle	121.8​	0.09​	7.5​	10.962​
Garage door opener - run	119​	3.75​	421​	446.25​

 

[Rednecktek]

• I would like to be able to run two battery chargers at the same time, hence the "tandem."

No problem. If you can power the loads of the dehumidifier and garage door you've got plenty to run multiple chargers at once.

• I expected that the garage door opener would have a surge on startup, then a lower load. I did not see that-- it reached a certain draw (listed below) and stayed at that level during operation. It's a very small garage door that runs for a short amount of time, FWIW.

Nice. That helps.

• A few devices had idle loads that I wasn't expecting: dehumidifier #1, dehum #2, and garage door.

That's normal. There's always control voltage running the system so it's awake and ready when you call for it.

• I recorded the observed watts, and also did the same W = V*A calculation using observed volts and amps. For most devices, observed and calculated were pretty close, but for the battery chargers (marked with "???") they are way off. Not sure what's going on there, might re-test.

Close enough, the difference between 150w and 151.12942w is nothing. Rounding is fine.

• 60 Hz throughout.

That's supposed to be that way for American power.

• I thought it was interesting that the "idle" volt reading was a little over 121, but with more load drawn, that number crept down a little.

Again, perfectly normal. Think of Volts like water pressure. There is always water pressure in the pipes in your house but when you flush the toilet the pressure drops a little and shocks whoever is in the shower. That's perfectly normal. 120v, 110v, 115v are all terms used interchangeably.

• In reading the manual for the garage door opener I discovered that it has the option to install a backup battery, so I might do that and leave the unit on grid power, which would take that item out of this calculation.

You could but if it's some super expensive proprietary battery that costs as much as the opener, then don't waste the money since having the rest of the system accommodate for it is almost nothing.

OK, so have you grabbed the Power Audit form from the Resources section? If you plug all the numbers into that form it will automagically calculate your inverter size, battery requirements, and array size. You've got half the math done, now you just need to get time involved. For example, your fan #1 calls for 170w at high speed, so that tells you that you need at least 170w of inverter to power it, but how long are you going to run it? If you only run it 1 hour a day that's 170Wh. But if you want to run it for 10 hours a day that's 1700w which is about 1.5 bog standard LFP batteries. That's where you're going to get the numbers for capacity that's going to determine how much battery bank you need.

I gotta say, that's the most thorough power audit I've seen posted here in a long time. ?

Just napkin mathing here, worst case scenario is that the fans (280w), the dehumidifiers (800w), and the battery chargers (400w) are all plugging along when you open the door (450w) for a total of about 2000w of load. So, a 3Kw inverter gives you plenty of capacity to run anything and still plug in a power tool or two or your MargaritaMaster-5000 without worrying too much.

 

[Pi Curio]

@mosesp

What's your budget?

 

[mosesp]

Thanks @Rednecktek , I will check out that tool in the Resources section with a 3Kw inverter in mind. The time piece is interesting, summer is when I run the dehumidifiers and fans, but we'll also get better panel production. Looking forward to seeing how things go and open to adding more batteries as needed.

 

[mosesp]

@mosesp

What's your budget?

Panel(s), battery(ies), inverter, charge controller, wiring, some kind of way to monitor system status. . . I'd like to spend $1000. Prefer to over-size and willing to pay more for quality. Do-able?

 

[Rednecktek]

Panel(s), battery(ies), inverter, charge controller, wiring, some kind of way to monitor system status. . . I'd like to spend $1500. Do-able?

Only if you scrimp and save and really cut out every spare nickel you can. A bog standard 48v 100Ah battery is $1500-ish.
The inverter is going to be in the $500 range if you stick with a cheaper AIO, and that saves you money on the SCC.
Used panels are going to need to happen.
An AIO can give you basic information on the screen, a proper shunt is going to be $50-$100.
Wiring is going to add up, along with crimping tools and lugs and the like.

 

[Pi Curio]

Panel(s), battery(ies), inverter, charge controller, wiring, some kind of way to monitor system status. . . I'd like to spend $1500. Do-able?

Previously, I've suggested Ecoflow Delta2 or D2 Max and that suggestion is still valid.

However, considering the prices have gone down lately I'll also make an effort and make a DIY setup that you can take into consideration. Others can freely chime in on this setup.

Mind you, I've tried my best to take into consideration only the US stores. Others might know where to get things even cheaper.

- Victron Energy SmartSolar MPPT 100V 30 amp - 129$ (keeping the cost as low as possible here as there are still wiring and fuses to get after the devices, otherwise 100/50 can be also something to consider)

https://www.amazon.com/SmartSolar-MPPT-100-Charge-Controller/dp/B073ZJ3L13/ref=sr_1_2?crid=1TEEW0DNZJGHF&keywords=victron%2B100%2F30&qid=1700250173&sprefix=victron%2B100%2Caps%2C265&sr=8-2&th=1

- Victron Energy SmartShunt IP65 500 amp Battery Monitor (Bluetooth) 130$

https://www.amazon.com/Victron-Energy-SmartShunt-Battery-Bluetooth/dp/B0BF636VBX/ref=sr_1_3?crid=34ZZJFIRRI8YK&keywords=victron+smart+shunt&qid=1700250276&sprefix=victron+smart%2Caps%2C330&sr=8-3

-LiTime 24V 100Ah LiFePO4 Lithium Battery 2.56kWh - 540$ free shipping

LiTime 24V 100Ah LiFePO4 Lithium Battery, Build-in 100A BMS, 2560Wh En

LiTime 24V 100Ah deep cycle lithium battery, assembled by Automotive Grade LiFePO4 Cells with UL certificated. Weights at only 45.59 lbs. 10 years lifespan.

www.litime.com

- Xijia 3000W 3200W (6400W Peak) PSW Inverter DC 24V to AC 120V - 303$ (You can upgrade with another 24V 100Ah down the road to use 2x 24v 100ah in parallel for a total of 200Ah and utilize your inverter to the fullest, though, it will do for now for your power tools etc)

https://www.amazon.com/XIJIA-3000W-Inverter-Converter-40V-60V/dp/B0749JH8W8/ref=sr_1_1?crid=Z29Q9QP5HYQ&keywords=xijia%2B3200w&qid=1700250331&sprefix=xijia%2B3200w%2Caps%2C290&sr=8-1&th=1

So we're at 1.100$ US. 400$ left for the wiring, fuses, at least 1 solar panel(maybe used?) of at least 300W, and a bit for Amazon shipping costs, etc.

- Solar Panel (it depends on how much space you have for solar, and whether you plan to buy brand new panels or not), ideally a 400W Tier1 residential solar panel for starters.

2x 400W would be perfect for a 100/30, an MPPT that can easily fully recharge your 24V 100Ah battery in roughly 3.5-4 hours in good sun with 800W of solar.

Certainly, this is a decent system.

Anyhow, hope it helps a bit.

 

[Rednecktek]

Or you could save some cash and go with a 40a HQST controller or the same money for a Sunthsys 50a version and an Aili shunt and save $90 and have another 10-20a of SCC to play with and money towards wire and more panels.

Around here a 250-ish watt panel is about $100 on Craigslist so $400 could about max out a 40a controller.

The other option would be a 24v AIO for between $450 and $650 depending on brand and capabilities which covers inverter, SCC, AC input (generator or grid) and transfer switch all in one unit. Are they Tier-1-Top-Of-The-Food-Chain? No. Are they cost effective on a budget? Yes.

I don't want to start a Victron or Nothing war, but Value needs to be a factor when working with a budget.

 

[Pi Curio]

Panel(s), battery(ies), inverter, charge controller, wiring, some kind of way to monitor system status. . . I'd like to spend $1000. Prefer to over-size and willing to pay more for quality. Do-able?

Just noticed the edit on the budget.

Honestly, at 1000$ and taking your power needs into consideration, there's no debate, Ecoflow Delta 2 is a winner at 649$. https://us.ecoflow.com/products/delta-2-portable-power-station?variant=40569176326217

That gives you 5-year warranty if I recall correctly, a 1800W AC continues/2200W X-boost, 1kWh battery, AC charging 1200W, Solar 500W max, very portable at 12kg, and with BT APP.

Leaving enough for 2 x 2x100W Ecoflow solar panels(400W total) with usually free shipping(best to check that), nicely protected in the box. https://us.ecoflow.com/products/100w-rigid-solar-panel?variant=40133459640393

Or If you can find a bigger residential Tier1 500W+ panel within Delta2's Voc and Isc limits, plus taking into consideration how cold it gets in your area during winter).


However, keep in mind that, unlike DIY builds, there's a limit to how much you can upgrade the Delta 2 and the cost that comes with it. Other than that, if powering tools on weekends is the goal, it should do the job.

The previous setup of 1500$, is basically at minimum nearly equally powerful as Delta 2 Max, minus the AC charging and other conveniences.

 

[mosesp]

Sorry, let me revise my answer to the previous question. "What's your budget?" prompted a reflex reaction to low-ball everything.

I want a system that is:

• Reliable, low chance of failure (except for user error) over five years.
• Over-sized for my current application, so that I can scale panels / batteries.
• DIY. I see how the EcoFlow and similar would meet my current needs, but I want to learn more about this area, hands-on.

I can't quote a specific bottom-line dollar figure. I would want high quality for each component, but I don't need extra features beyond the application I've described.

 

[Rednecktek]

Growatt 3Kw 24v AIO, LiTime 24v battery, some 250-ish watt used panels. That gets you 50% more inverter overhead, 2Kw of panel support, and both Growatt and LiTime are well regarded brands but you're not forking out extra for the Name Brand Expense.

For decent component options on a budget, HQST controller, LiTime battery, WZRLB inverter, and Aili shunt. Add in some 250w used panels and you'll be ahead of the curve. You can always parallel in more controllers in the future as you expand out the system.

Both should be right around the $1500 budget by the time you get lugs and wires and breakers and pizza and beer all wrapped in.

 

[Pi Curio]

Sorry, let me revise my answer to the previous question. "What's your budget?" prompted a reflex reaction to low-ball everything.

I want a system that is:

• Reliable, low chance of failure (except for user error) over five years.
• Over-sized for my current application, so that I can scale panels / batteries.
• DIY. I see how the EcoFlow and similar would meet my current needs, but I want to learn more about this area, hands-on.

I can't quote a specific bottom-line dollar figure. I would want high quality for each component, but I don't need extra features beyond the application I've described.

In that case, the 1500$ setup. post #48.
Mind you, things are reliable with a low chance of failure until they aren't.

Rednecktek's suggestion looks great too. Perhaps with AIO, even more convenient.

Growatt 3Kw 24v AIO, LiTime 24v battery, some 250-ish watt used panels. That gets you 50% more inverter overhead, 2Kw of panel support, and both Growatt and LiTime are well regarded brands but you're not forking out extra for the Name Brand Expense.

For decent component options on a budget, HQST controller, LiTime battery, WZRLB inverter, and Aili shunt. Add in some 250w used panels and you'll be ahead of the curve. You can always parallel in more controllers in the future as you expand out the system.

Both should be right around the $1500 budget by the time you get lugs and wires and breakers and pizza and beer all wrapped in.

 

[mosesp]

OK, I used the (very helpful!) sizing tool with the wattages above, and my estimates of runtimes. (A little wonky because this is a weekday / weekend situation, not an everyday one.) A 3Kw inverter will handle the load including the garage door surge.

Regarding batteries, I'm wondering about the relationship between W-Hrs and A-Hrs. I see a Li Time battery that has 400 amp hours (just enough) but 5120 watt hours (half of what's needed). Anyway, that battery is $1500 so clearly I'm on the big size of what I'd been looking at. ?

Regarding panels, similar story. Originally I had been thinking a couple of 100-watt panels, but clearly this is a different situation. Now I'm thinking about a semi-permanent mount on the (flat) garage roof, and maybe some additional panels to position at ground level. ?

I just want to start out with something manageable so I can prove to myself that it works, and then add on from there. I may have to work up to powering the whole thing.

I'll look back at the products listed above (thank you!) and come up with a schematic and parts list.

 

[Rednecktek]

That's a 12v battery, you're speccing a 24v system. A 24v 400ah battery is more like 10kwh. All that is for a single day of power usage and a 3000w array to recharge it. If you get a day of cloudy weather your battery is gonna be empty.

Those dehumidifiers are eating your batteries alive but that's the cost of it sadly.

 

[mosesp]

Ah crap, thanks! I plugged in 24V just to see what changed, then forgot to change it back. Going back to 12V, that's:

• min Battery capacity W-Hrs 9552.5
• min Battery capacity A-Hrs 796.0

Which makes more sense-- two of those batteries ($3K ? )

The dehumidifier situation. . . I need to run them in the summer months, but I don't have a good sense of how often the compressor cycles on, and how long it runs each time. I suppose I should test it with the Kill-A-Watt, but the ambient humidity is low right now. The numbers feeding the spreadsheet currently are for "compressor on" level of draw, 6 hours a day. This is a WAG.

 

[Rednecktek]

Better to guess large and have extra capacity than to find out you massively undersized. For a 3Kw inverter I'd stick with 24v at least, 48v if you think you'll want to have a larger system in the future. 3Kw is that sweet spot in the middle where you can go either way. Doing 3kw on a 12v system involved factoring in wires and fuses for 300+ amps of current at 12v which gets large and expensive QUICK!

As far as how long the dehumidifiers run, I've never met one smart enough to shut off and if you really need 2 of them all the time then it'll never hit that sweet 50% that you're after. Plan on those being max load all the time.

 

[12VoltInstalls]

option would be a 24v AIO

For the money!!!!
I’ve been so impressed with the 1012LV-MK from MPPSolar I’d not hesitate to review the idea with watts247.com and buy a 24V MPPSolar unit.
Without meaning or wanting to do the rabbit-hole routine… this is one of those ‘borderline’ projects where if they a 3000W 12V option it might be attractive.

There’s not much for ‘small’ 48V options but I’d almost prefer that versus 24V fwiw but it comes down to $$$

 

[12VoltInstalls]

EDIT to above wouldn’t load
But holy cow I’d buy this right now if I was doin this. That’s the unit I wish was available in 12V for myself!
That would (for me) take care of ‘the house’ beyond anything I can imagine. Down the road the shop will have its own 48V system.

But for the OP wanting the basics of a system at the low budget mentioned, that is absolutely the perfect unit to manage whatever panels and batteries you wanna use or scale into.

Not suggesting this, but cost comparison to 12V of way smaller capacity:

 

[mosesp]

OK, after looking around I'm going with a 24V AIO unit, plus battery and panels. Looking at Growatt and MPPSolar, via Signature Solar and Watts247. Finding it a bit tough to navigate the websites (manufacturer and dealer) to compare units, but thinking one of these might work:

• MPP Solar: 24V 2.7kW ?A
• MPP Solar 24V 2.4kW 80A
• Growatt 24V 3kW 80A at 247 or Signature