Yea, a lot of (especially cheap) car stereos aren't terribly efficient because well, they're built for a car, which has an engine, and (for all intents and purposes to the stereo designer) an unlimited power supply. :P Most of their inefficiencies comes from heat they give off due to cheap electronics. (That said, if the heat benefits you... hey... no harm there and it's essentially no longer inefficient. XD)

I know the shitty stereo in my truck draws close to freaking 200 Watts if I'm just listening to the radio at a moderate volume. :P Not the peak of what I'd call efficient. :(

A higher end car stereo, or at least a higher build quality one could work, but just verify how much power it's going to use ahead of time. Keep in mind also, that the louder you have the volume, the more power it uses, because well, it takes power to make sound. :P

I take it you'll probably just be using bluetooth or such from your phone to play music a lot of the time, so if you eliminate the CD player and such, you can probably save some cash... All you really need is an amplifier that runs off 12 volts and some speakers. :) Definitely something that can be cobbled together and sound pretty good without shelling out big $$$.

You could use something like this: https://www.amazon.com/Channel-Bluetooth-Amplifier-Wireless-Speakers/dp/B072Q157FY/

It comes with an AC - DC adapter, but if you look at the casing it specifies you can input 9 - 24 volts. So, that means you could run it direct off your battery with no issues I'd venture to say. :)

Whatever you do, try and keep it DC though. Remember, you LOSE power going through the inverter from DC to AC. :( So if you want to run a 10 Watt appliance that uses 10 Watts AC, you'll probably be using about 11 or 12 Watts from the battery. Then you also have the inverter's standby draw (self consumption) of about ~12 - 30 Watts, depending on the inverter.


Let's look at a power budget:

Let's assume you've got a speaker solution that uses ~60 Watts (this is a lot, but probably somewhere in line with what a well built car stereo, or that little thing on Amazon I linked, will use at 'full blast').

Let's say you've got ~25 Watts of LED's as well.

And let's say your inverter has a standby draw (cause we're still going with that you wanna be able to charge your laptop, etc.) of 12 Watts.

If we add all that up, we get 97 Watts consistent draw. If you're out there for 4 hours in a day, that's 97 x 4 = 388 Watt-hours.

We'll say each laptop charge uses (accounting for inverter efficiency losses) about 100 Watt-hours.

So, we'll call it 500 Watt-hours per day (Watt-hours or Wh is a measure of energy. An actual 'amount'. Watts, is a RATE of usage. Thus why 100 Watts for an hour is 100 Watt-hours. :) )


How many panels?

To generate 500 Watt-hours, in the approximate ~3 hours of peak sun of the day (when solar panels work well), you'll need to have at least ~170 Watts of solar panels, not counting that they don't put out their peak in the real world.

When we factor in the ~60% rated output for the panels, we get ~280 Watts of solar panels needed. :) It's not that much. :) But don't go with much less, you'll be disappointed if I had to guess.


How much in battery storage?

Well, 500 Watt-hours isn't a whole lot, but we want to add in a little extra probably because we want to account for less than perfect conditions, and maybe another person charging a laptop or something. We'll smack that up to ~750 Watt-hours of storage, usable.

Since you'll probably use Lead Acid (cheapest) like AGM or such, you'll want to have twice that in RATED capacity, to avoid over-discharging your batteries. (Max 50% Depth of Discharge is recommended.)

So, that's 1500 Wh, or 1.5 KWh of storage needed.

If you divide that by 12 volts, you get 125 Amp-hours. So two 100 Ah batteries would be plenty. :) Just, don't use marine batteries. Get some proper deep cycle AGM ones for ease of use and safety, and longevity in your usage conditions. :)

Uhh. No, it so can't. It has 100Ah capacity. Rule of thumb for 12v DC to AC conversion is 1 hour @ 100w AC draw = about 10A being pulled from the DC battery. 1000w would run it flat in one hour. Likely much less since that would be a very high discharge rate for such a battery and that generally reduces capacity.


While I admit I don't have a solid answer to your original question in my response I do need to express interest in why you're set on the goal zero platform? They are laughably over priced. The Yeti 1250 is 1600 bucks in Canada, and it's not a generator at all. It's a 12v Absorbent Glass Mat battery with 100Ah capacity, with a 1200w pure sinewave inverter and a Maximum Power Point Tracking solar charge controller. It's all stuck in a box with some connections and a nice display. It doesn't come with a solar panel to charge it at all either.

That 100Ah may seem like a lot, but it's not. Especially considering you shouldn't really discharge a lead acid battery more than 50% So 50 amps a day is all you can pull. About 2 an hour. Depending on the duty cycle of your fridge that's it right there. I'm a big fan of 6 volts for dollar/Ah, and you can grab two T105 Trojan batteries most places for 300 bucks. They are good batteries and can take a lot of abuse. I also like USBattery, and have picked these up in Alberta for 100 each. http://usbattery.com/products/6-volt-batteries/us-2200-xc2-lf/ that's 230 Ah for 200 bucks. My last load test on a pair of heavily abused ones that are about 6 years old now still pull just over 100A before 50% discharge. I can't argue with that quality. That leaves us with 1400 bucks to play with, and more capacity to run things from. Since we saved money on storage, I'd spend the money on a good inverter like this. Naturepower and Go Power should be avoided, but might be available a lot cheaper so by all means take the risk if you wish. That's 1500 watts vs the 1200 from the Goal Zero package. So we now have 800 to spend on a charge controller, a box, and 12v output/input options and a box. A box could be simply constructed with plywood and scrap 2x4's and could probably be sourced in any nearby alley. Charge controllers can be had for very cheap or for a little more depending on your requirements. The charge controller in the Yeti appears to be able to handle 20A, so our 13 dollar and change controller above works. Even factoring wire, nuts, bolts, crimping supplies and the time to build it all you're going to be coming out with 600 bucks in your pocket for solar panels. The Yeti doesn't even come with solar panels. They want TWO HUNDRED DOLLARS for 30w in Canada! Unbelievable! Another 30 bucks gets you more than 3x the charging potential. It's also in a nice aluminum frame suitable for reinforcing and adding hinges for portability should you want to pair it with another with all the money you're saving. There is absolutely no way you'd get me to support their over priced gear when it can be done so simply and cheaply on your own, all with better results.


Edit: the specs on the 30w panel say 2A output max, so they're only 24w peak. That extra 30 bucks on a real panel gets you (barely) more than 4x the charging potential. To max out the 20A capabilities of the Yeti 1250 using 30w panels would cost you 2000 dollars for 10 panels. Two of those 100w panels would be 460 dollars and cover just over 80% of that capacity. But why stop there? We saved 600 bucks, lets buy another pair of batteries for 200 to increase our capacity to 460Ah.
With over 4x the reserve you STILL won't be pulling 1000w for a few hours. Just about though, you might get 4.
My favourite part about this is I hate going retail and it's STILL cheaper to piece it together doing it that way. I could find a better inverter used thanks to the used marine market out in BC, for less, I could source a few used batteries after a load test for cheap. I could DIY panels for cheap using epoxy and reclaimed aquarium glass. About 80c a watt materials included. In Canada that's amazing for a single panel.

All Goal Zero prices were from here http://www.goalzerostore.ca/


The only opinion I can give you with pellet stoves is they are VERY expensive and installation is semi permanent, your landlord might even have to get different insurance if there is a stove pipe jammed out his roof. He's probably not going to be happy with having to duct the cold air supply in either. They are also equipped with hoppers for pellet storage, how long you intend to run it and what model of stove you get depends on how often you have to fill it. They are also electronically controlled, so it will need to be constantly plugged in for the auger to feed pellets into the stove to keep the fire going or between a specific range of temperatures. You want to do this for a month and that's a lot of effort for an experiment. You could probably get away with a propane heater of some kind, along with the appropriate detectors for safety. I wouldn't advise on running that unsupervised at all, and it's not going to be appropriate for cooking like a stove would be.

Id say get several good books. (I learned by experience so cant recommend specific titles sorry). Read up on it, timber framing is a way to go about it but probably easier is general '16'' on center' framing. Like I said, there area a lot of aspects to carpentry that seem really complicated but are generally easy to figure out. Books with good physical drawings would be the most helpful. It seems like you dont have a concrete plan as of yet so, to me, the best thing would be to really study up. Id also recommend Lloyd Kahn books as pretty cool inspiration, as far as unique/hippy type buildings go-- https://www.amazon.com/Shelter-Library-Building-Books/dp/0936070110 --they were and are one of the most inspirational building books Ive seen.

Cheap and reliable is best for fire.

• Fire been sorted out for hundreds of thousands of years.
  
  Even more important when you need fire, sometimes you need it NOW! and delays, dead batteries etc are not okay.
  
  
• Get a combination of reusable fire starters like flint and steel or Fresnel lens (only daylight) and anytime fire (matches.)
  
  
• Get fire helpers like Magic biscuits, or saw dust and wax, or accelerates (like ether, gasoline, charcoal lighter fluid)
  
  
• Get an 8'5" x 11" frenzel lens. (for starting with sun light.) https://www.amazon.com/dp/B00IITFX02/
  
  
• Matches
  
  
• birthday candles for kids / make your own fire starters from make-up remover pads and parifin wax. These are the best fire starter helpers you can have. (you can use crayon wax if you don't buy paraffin) https://www.youtube.com/watch?v=uCni8yLXR3w
  
  The only thing the above video fails to do is use a double boiler so what you want is to make a "cup" or the like with some tinfoil, put the wax in that, then set the cup into a pot of boiling water. In this way clean up is a breeze, whatever wax you don't use you can just wait to cool and harden and throw away with the tin foil.
  
  These "magic biscuits" style fire starters will stay dry forever, and you can "crack" them in half to expose cotton fibers for things like flint and steel starters or the focus point of your Fresnel lens, or a match. etc.
  
  

  Make use of the small fire you do start.
  

  
  

• Getting a flame is just the start. One of the VERY BEST things I've ever bought cost about 10 bucks. It was a collapsible tube used like a very long straw to blow air at a fire without having to have your face close enough to suck in a lot of smoke when you take a breath.
  
  Made in america version for $12 from amazon.
  
  Absolute cheapest version $4
  
  

  Skills
  

  
  Fire is great. You don't need to go out int he pouring rain to start a fire, but doing so once in a while will help. Same with the wind. Mostly you need to know how to build a stack of wood so that stuff burns. There are many ways to do this.
  
  

• most of the time building your fire (kindling and med sized wood.) before hand and then covering it with a tarp or plastic. is the best practice. Building on a slight hill or digging a trench around the fire area is also a good "prep" to do before hand.
  
  
• If you are going camping or want a few kits making easy to use fire starter kits from pine cones, dryer lint, wax, pop-sickle sticks, cardboard etc will help. Old pine wood scrap from two by fours or lumber mills or woodworker shops works well too. These are things you can make in your spare time, when it's dry and comfortable.
  
  

  Fire cups!
  

  
  

• Fast food cups that are the wax paper cups (down south and in warmer places use Styrofoam cups) are great for a kit. You can put Popsicle sticks, some matches, some magic biscuits (waxed cotton pads), some black paper (to better start with Fresnel lens / sunlight). Then you put the plastic lid on with a bit of tape over the straw hole and you have a "water proof" cup you can set out, and use when you see fit to start a fire.
  
  Edit corrected spelling.
  

Thanks for taking time to reply. My goal was not to have to mess with solar since my cabin sits in the middle of some pretty dense trees and I've never gotten good direct sunlight. I was hoping for a clean and quiet way to plug in at night and get 3-4 hours of light and maybe enough time to watch a movie off a USB stick.

The idea of charging a small 15lb battery during the week at home and plugging in when I showed up at the cabin vs lugging the 100lb gas generator was really appealing. The gas generator has worked fine but it's just so loud and it sits outside the bedroom window so I worry about even cracking that window in the summer to avoid exhaust.

The lights are off all day as everything else (speakers and phones I charge at home or have simple Anker power bricks) and the cabin is all windows so light isn't an issue until it gets dark. I just need 4 hours of LED lights and 2 hours of LED TV to make me happy.

If the wiring is 110V then it sounds like I'm not going to lose a bunch of efficiency to wire resistance? Are watt-hours the right way to look at this regardless of voltage? I get confused trying to understand if watt-hours are standard regardless of 110v, 12v, or 3.7v systems pulling current. Sorry for the newb questions but the online literature seems really inconsistent in the explanations.

Knowing that any power tools or air conditioner I wanted to run would need the extra juice from the gas generator, would a solution like this or even as small as this get me a couple lights at night and maybe enough power to get through a 2 hour movie off a USB stick in a TV?

If there's a crash course read on this please send it my way, I've been looking for a simple explanation.

I appreciate the help from everyone here. Thanks!

I just ordered the Victron BMV-712 Battery Monitor, it seems to be almost perfect for my use case. I can then configure the DoD (Depth of Discharge) to whatever level I'd like and it'll flip a relay. From there, I can use a switch (and some other jazz) to 3D print an enclosure to contain a simple two position switch:

Low Battery (reached configured DoD). Either start generator, or turn off Inverter.

​

It may be worth using a three position switch instead, which will turn off and keep the inverter off. I have a somewhat small 400Ah bank and I don't know if the fridge (the other large energy consumer) will make it through the night without switching over to propane. It may just be a nice feature to have anyway.

​

Other considerations:

• The generator has a manual push button electric start. It's unclear until it arrives if the button must be held (manual starter actuation), or a single press starts the generator. I'll also need to control pushing the generator off button. That's two momentary switches
  
• The inverter doesn't seem to have an easy external method of controlling the power switch. I'm hoping that it's a low current switch so I can just control it with a relay. The docs state that with the remote panel installed, whichever is used to switch it off and on takes priority. Meaning that, if my system turns off the inverter, I can use the control panel to control it manually. (need to map out the logic there so it behaves as expected)
  
  So in the end, I will need to use some sort of logic such as an Arduino, or a custom circuit to accomplish my goals.
  
  ​
  
  The Victron BMV-712 Battery Monitor just allows me to monitor the DoD (which the inverter doesn't have, it only has a hard 10V low voltage cutoff) and flip a relay. I'll need to do something custom to get the automation I'd like! (I think)
  
  ​
  
  I'll have parts here this week, and the tinkering will begin! I'll have a more solid footing soon.

is it possible to heat with a wood stove using a window stove pipe kit? Something like this would set up really easy and heat really well. https://www.amazon.com/TMS-Portable-Military-Camping-Ice-fishing/dp/B002XNWC8A/ref=pd_sbs_468_4/131-0161893-0365920?_encoding=UTF8&pd_rd_i=B002XNWC8A&pd_rd_r=dfac21e8-10bd-4e5b-8b19-3ef04686d8a6&pd_rd_w=moH1a&pd_rd_wg=VXKVa&pf_rd_p=43281256-7633-49c8-b909-7ffd7d8cb21e&pf_rd_r=3GE8R0MDMX8V0C45T55P&psc=1&refRID=3GE8R0MDMX8V0C45T55P

with all due respect that combo wont work. " EASY RECHARGING : Able to be recharged by Aeiusny 60w solar panel (Sold Separately) within 8-10 hours in full the sun, AC wall outlet (included), or in your car(included).

You will need

1. solar panel
   
2. charge controller
   
3. battery
   
4. power inverter
   
   The panel charges the battery, the battery powers the inverter, the inverter pumps out 120vAC to power the blender, the charge controller ensures the batteries do not overcharge
   
   If you have a 250 watt blender and run it CONTINUOUSLY for 1 hour you will use 250 watts of power.
   
   lets say u buy this battery https://www.amazon.com/Mighty-Max-Battery-Permobil-Wheelchair/dp/B0186FLRHU/ref=sr_1_8?crid=2U42R9CT0BUFB&keywords=golf+cart+battery&qid=1564694821&s=lawn-garden&sprefix=golf+cart+bat%2Clawngarden%2C141&sr=1-8
   
   it has 50amp hours at 12 volts, or 600watts of total power, it can power your blender (through the inverter) for for about 2.2 hours full blast on the blender. you dont want to drain a non Li-Po battery past 50% so you've got 1.1 hrs with the blender
   
   if you have a 100watt solar panel, you wont be able to keep up with the drain BUT you dont need to. if you leave it in the sun for 6 hrs the battery will be fully charged, then it's Margaritavil all night!
   
   your inverter should be 1000watts just to be safe, then u can run a nice boom box off it too.
   
   a few points
   
   you do not need 250 watts of solar panels, you DO need at least 250 watts on the inverter, go with a wiiideee margin, 1000 is very safe
   
   the inverter's watt output can be higher than the battery's watt storage, not a problem, it just means that on full capacity the inverter (1000 watts) will drain the battery (600 watts) in about 30 min, but you wont be using that much power
   
   inverter-https://www.ebay.com/itm/1000W-2000W-Car-Power-Inverter-DC-12V-To-AC-110V-2-AC-Outlets-RV-Solar-Converter/372172069343?hash=item56a72f19df:g:-jUAAOSw88xaQ1X~:sc:USPSFirstClass!07621!US!-1

Effectively, all you have to do is add a thermostatically controlled switch to control the compressor. Some have recommended products like this (though I don't have personal experience with it). You plug the unit into your wall, freezer into the unit, put the thermocouple in the freezer and set the thermometer.

We are using this until our wood stove is installed: https://smile.amazon.com/Mr-Heater-Corporation-Vent-Free-Propane/dp/B01DPZ5B3M/ref=sr_1_6?crid=NCOGX02UHSFL&keywords=mr+heater+propane+heater&qid=1571930761&sprefix=mr+heater%2Caps%2C168&sr=8-6

It has worked great.

So if I understand you correctly I can buy the product you linked as well as a solar panel such as this one

Renogy 100 Watts 12 Volts Monocrystalline Solar Panel https://www.amazon.com/dp/B009Z6CW7O/ref=cm_sw_r_cp_apa_i_B9TqDb33X1GGH

And I should be fine for making let's say 10 margaritas a day for a week (assuming my solar panel is in the sun all day)?

Also does 288kh mean that, on a full charge, it will be able to power anything up to 288 watts for an hour before running out of juice (assuming it's not hooked to the solar panel)?

I’d look into the GoalZero products. We use a Yeti 400 battery for our off grid yurt (https://amzn.to/2IAk0YV), along with 180W of solar to charge it. It takes around 6 hours of direct sun to charge, it seems. If you’re in AK or Canada in summer, sun obviously isn’t hard to come by.

I think our battery is 33ah, so if you’re trying to do big watt draws like a karaoke machine you might want one of their bigger batteries. We only use the 400 to run LED lights and charge computers.

The up front cost might seem intimidating, but it’s lithium and you get the convenience of a plug and play battery-inverter-controller all in one.

Be CAREFUL with Vruzend. Fuse every cell. I destroyed half my garage because I thought my tiny 36 cell packs (4s6p) was safe only being charged to 14v since it should have been safe up to 16.8v. Only takes one bad cell to screw up your life. I've decided it is no longer worth the effort to harvest 18650 batteries. The Renogy 100ah 12v ( https://amzn.to/2NO883u ) for $214 is rated for 1100 cycles at 50% depth of discharge. There's the LifePo4 version for $800 which is rated at 7000 cycles but I ain't made of that kind of money.