diy solar

diy solar

Need a little information on my idea.

Solardork

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Jul 25, 2020
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I am going to be off the grid for a year staying in an insulated building, while a cabin is being built for one year, and will be fine without power, im no stranger to being in the wilderness for months on end, but usually just have a phone with me that i charge via a car, but id like to be able to use a tv and charge my phones, and wont have a vehicle on the site. I have think ive formulated a plan, and got alot of help from watching videos and reading posts from this community, but i want to verify a few things that unfortunantly im ignorant of.

so i think i settled on ordering this, and the lowest wattage little LED tv i can find from walmart.


Did some calculations on a 19 inch LED and it came out to 20wH

Found out i can do solar lighting not needing
To run off this, very easily

If i were to plug in my phone to charge while i sleep, roughly 5 to 8 hours the 5 watt charger would take roughly 25 to 40 watts, ill say 50 to be safe.

So my estimated usage would be per day:
20W tv 5 hours a day (over estimating)=100W
5w usb charger to keep my phone on = 20 watts
Total 120W/day

So i figure that the 300 from that battery bank, SHOULD last me roughly 2 days and 2 nights without having to charge it until the third day.

If i got REALLY bored and watched tv 10 hours tv=200W
and charged my phone 2x =roughly 30w
(hey it could happen lol been there before)
id pull 230 watts, and id have to charge the battery up the next morning.

I assume with that in mind, this product should work amazingly for me.

With that being said, i DO have a question that i couldnt find an answer to online.

1. Can i buy a little generator like this one to charge it? Or would that end catostrphicly?


2. This generator says it would burn roughly 1 gallon of fuel to provide 900 continuous watts for 5 hours, and that its fine to run until the fuel runs out, and has a life span of roughly 2000 to 3000 hours, or 400 days running one tank a day. so can theoretically provide 18,000kwH give or take with gasoline, and can power my tv and phone charger while i charge the battery if i REALLY wanted to. I also would like to know of the tv and the phone will charge via the generator without blowing up lol.

4. I was told that a generator like this, will actually even burn alot less fuel if you arent pulling the max load from it, and last longer as well, and on the video from the kind fella who provides us with this amazing forum, he said that the max input for this solar generator was 83 watts. Is this true? How much of a difference is it?

I know even if i had to burn a gallon of gas and run it the entire 5 hours per 2 days to recharge it, my fuel bill per month would only be $30 or so a month which really isnt bad at all. Total cost after both generators, and all the fuel and oil would still cost me under $800 to have power for the entire year.

With that being said,

I do like the idea of using solar panels, but the cost in panels to be able to run this every day for the year ill be off grid without worry (no sun days, having to not use it while im charging it) would i think be more of a hassle during that one year stay, then it would be worth. I dont mind the idea of just running that little gas generator once every day or two to charge it back up.

Not sure how long this solar generator takes to charge up plugged into a regular generator, but if its faster via the 120 adapter, that id like to know...

Thanks for the help guys!!!
 
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The sooner i can get the answer on if i can charge the solar power generator via a regular generator the better, i need to place the order tonight to have it when i need it. Thanks again :)
 
...1. Can i buy a little generator like this one to charge it?
It has the watts, so seems like it... anything it particular worry you about it? You could also recharge it with the car or solar.
Are you concerned about the 2 cycle engine? You could go with a gasoline or propane generator?

.... I was told that a generator like this, will actually even burn alot less fuel if you arent pulling the max load from it, and last longer as well,
True that it uses less, typically the datasheet will provide some information. The work "alot" is subjective and possibly sales hype.

....I know even if i had to burn a gallon of gas and run it the entire 5 hours per 2 days to recharge it, my fuel bill per month would only be $30 or so a month which really isnt bad at all.
I've heard that on santan you can get used panels < $0.40 watt. But, if your insolation is 2 in winter (see calculator), each 100W panel new from altE for $150 would generate 200 watt hours per day. You can also use your stuff while it charges if you have the watts to both run it and charge it. You already have batteries enough for 2 days, so you probably don't need both solar and a generator (the generator noise might help to keep bears away ;-). Perhaps just use the car to recharge it there's more than two days of rain.

Rockpals 300W web page says it only does 500 cycles at > 80% capacity so it'll last you the year.
Recharge times aren't favorable either:
  • 6-7 Hours (AC)
  • 6-7 Hours (12V Car Adapter)
  • 8-9 Hours (optional 18V max Solar Panel)
Have you considered one of Will's DIY solar generators? (See the Blueprints).

Hope that helps!
 
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It has the watts, so seems like it... anything it particular worry you about it? You could also recharge it with the car or solar.
Are you concerned about the 2 cycle engine? You could go with a gasoline or propane generator?


True that it uses less, typically the datasheet will provide some information. The work "alot" is subjective and possibly sales hype.


I've heard that on santan you can get used panels < $0.40 watt. But, if your insolation is 2 in winter (see calculator), each 100W panel new from altE for $150 would generate 200 watt hours per day. You can also use your stuff while it charges if you have the watts to both run it and charge it. You already have batteries enough for 2 days, so you probably don't need both solar and a generator (the generator noise might help to keep bears away ;-). Perhaps just use the car to recharge it there's more than two days of rain.

Rockpals 300W web page says it only does 500 cycles at > 80% capacity so it'll last you the year.
Recharge times aren't favorable either:
  • 6-7 Hours (AC)
  • 6-7 Hours (12V Car Adapter)
  • 8-9 Hours (optional 18V max Solar Panel)
Have you considered one of Will's DIY solar generators? (See the Blueprints).

Hope that helps!

Well, i guess the only concern i had with the generator was if it would damage the unit due to not being sine wave. Other than that, if it was safe for a tv and phone charger and to cool a minifridge or something id just run that dang thing when i wanted to watch tv, get some cool air in the minifridge, or do anything else, and keep a baterry backup just incase....900w is enough for anything id ever need up there, and it isnt like id be using it all day. But the reason i was looking at options for the solar generator is because of the clean energy distribution. Heck i could buy 3 more of those generators for the price of a solar generator lol. But, i do like the idea of never having to deal with fuel!!! And not having that "WAAWAAAAAAAAWAAA" sound of the generator blowing through the woods at the old hippie fella who built a tin roof shack next to there lol.
Ill check out the DIY that you posted, i did contemplate buying the inverter, controler, and such and just building it into a waterproof box but i just cant afford to drop $1500 on it. Ive only got $700 right now, and on fixed income so only have about $800 a mo to live on and work with (hence why 2 years free rent to watch a build site is my cup of tea haha)
 
Okay, checked out
Looks like that $300 unit would be just fine, and i could hook solar panels to it and run a generator to charge the batteries if the sun is low. This seems like a super affordable and viable option. Do you know how many watt hours a battery can hold thats usable without hurting the battery?
 
If I understand you correctly a lead acid battery has 50% of its capacity that is usable and a Lithium battery has 80% usable.
Yeah, that matches up with what ive been told, battery math isnt my strong suit though lol. And if im correct, i heard lithium batteries are the safest bet because they will stop pulling power before they would break? Sounds like a good idea for me lol. I did see a "battery system" as well that stores 3kwh for around $600 with lithium batteries, honestly that might be my best bet, easy setup, that with the $300 1kw system, plug the battery system to the solar controller box, solar panels into it as well, bada boom bada bing all done for about 1k plus a few hundred for the panels. And i plan to be saving up to buy a 1 acre homestead plot so that would be very easy to just throw up an easy cabin and toss that in there and have a cabin and power on day one. Might be what i should do. 3kw would last me a long time, and the ability to connect a generator to it with a auto switch would take care of any worries.
 
... heard lithium batteries are the safest ..."
Depends on the type of lithium battery and there are a few chemistries ... you want LiFePO4 (lithium iron phosphate). Although you'll want a low voltage cutoff on the BMS, that's what prevents them from getting "hurt" by over discharging. Be aware you can do permanent damage charging them at less than 0C. Some BMSes have a low temp cutoff, some say they do but it doesn't work. I'm sure the ones Will lists will work or at least have a warning about it.

... stores 3kwh for around $600 ..."
Take a look on the forums here, some vendors are a lot more reliable then others. The ones Will lists are reliable and well made.
Battery prices are also expected to continue to fall.
 
Depends on the type of lithium battery and there are a few chemistries ... you want LiFePO4 (lithium iron phosphate). Although you'll want a low voltage cutoff on the BMS, that's what prevents them from getting "hurt" by over discharging. Be aware you can do permanent damage charging them at less than 0C. Some BMSes have a low temp cutoff, some say they do but it doesn't work. I'm sure the ones Will lists will work or at least have a warning about it.


Take a look on the forums here, some vendors are a lot more reliable then others. The ones Will lists are reliable and well made.
Battery prices are also expected to continue to fall.
Yeah, the one i saw was from that link you gave me. $699 3kw lifepro battery box. It was in the link that was posted on this thread. I do trust the info from that site.
 
Yeah, the one i saw was from that link you gave me. $699 3kw lifepro battery box. It was in the link that was posted on this thread. I do trust the info from that site.
Where is that link?
 
If i got REALLY bored and watched tv 10 hours tv=200W

I did a quick look at DC 19 inch tv's and found they would use around 10 watts. Something to consider.

Also I just placed an order for 8 200ah lifepo4 batteries. I was quoted $615.00 including the cost for sea shipping DDP. From reading your post it doesn't sound like you would need nearly that much but it gives you and idea of cell cost. Granted this is sea shipping (slow at least 30 days to get them) and DDP meaning all duty fees and taxes are included. You would need to buy a BMS in addition but you would have brand new cells.

As far as the MPP Solar I don't have one but have been seriously considering it. If you get it just make sure you use Will's link and buy from Ian in Utah. The reason is the guy gives great support for the products he sells.
 
I don't know if it's way cheaper now, compared to building your own. Battery Cells have gone down in price and shipping for the Powerwall is $300. Maybe someone who keeps track of this can come up with some prices.
$300 shipping? Wow......... i understand its a battery but.. wow....
 
A little update...... im considering strongly just buying a cheap rv to give me a dry space, and building a solar setup to give me the power id need to live comfortably....

With that being said,


If time constraints didnt matter

And i was able to take a few months and order what i needed.....

Does anybody have good ideas to run a tiny camper or converted trailer???

Id love to hear ideas, see links, etc..... im serious contemplating just buying 5 acres and building me a tiny home....


Invest some cash, and enjoy life bill free..

Mortgage on the 5 acres is $200a mo

honestly if i could build something sustainable to live in, $200 is nothing for a payment on 5 acres..
 
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