Change of plans/need info

[user 23166]

Well, my big idea to buy a used conversion van to nomad around in has gone by the wayside for the moment. I have decided I can live in my toyota camry and save a whole lot more money, until the time comes when I've save enough to buy exactly what I want.

I "think" I've figured this out mostly, but I want to ask some of you experts just to be sure.

There are 3 things I HAVE to have in my car...

1. a refrigerator, the one I'm looking at is 55 watts(I'm over averaging at 15 hours running time a day)
2. my cpap, which consumes 2.5 amps
and
3. a max. 5 amp roof vent/fan.

I plan on using solar panels and  Lithium ion batteries, (if i can find them cheap enough) and also a generator.

My question is: how many 100AH batteries and 100 watt solar panels will I need to stay off grid for 3 days assuming full sun for 5 hrs. each day.

I can't really figure out how long 2-100 watt solar panels will take to charge a 100AH battery.

Any help and info. is much appreciated,
thanks everyone

 

[maki2]

companies such as Renogy and other reliable company have calculators on their websites that you should find useful. What is nice about them is you can do several variations of what you want to power and what size of panels you want to try out for size and for capacity. Of course Renogy and many other solar panel system suitable for RV companies also offer some lithium storage battery systems so you can try that into the calculations as well.

You will learn a lot about your needs the easy and painless way by just playing with different combinations of panels, batteries and controllers on the calculators. Plus of course those companies also show the wiring schemes of how things get hooked together.

I do like discussing things in the forum but getting that little bit extra background that has been put together with illustrations sometimes helps make more sense out of what people say in the conversations.

 

[jonyjoe303]

You might get 10 amps out of 200 watts if they are pointed at the sun ( if they are flat on roof and sun is overhead in summer), in winter sun is lower in the horizon, you get less, maybe 7 or 8 amps. 

A completely discharged 100ah lithium might take anywhere from 3 to 5 days to fully charge with 200 watts of solar. I had a 110ah lifepo4 that took about 5 days to fully charge with my 240 watt panel. You have to take into consideration that you might have cloudy days and you will probably be using the battery at night time and maybe even while its charging.

A 12 volt fridge if you set to 40 degrees will use about 26ah per 24 hours. I would instead use 120mm 12 volt case fans (you can find on ebay) they move alot of air and use a little over 1 amp. 120mm fans is all I use on my swampcoolers, no reason you couldnt use these on your roof vent. On hot days even the larger 5 amp fans won't help much, I have one my roof that I never use. If you can lower your amp usage, the longer you can stretch out your batteries.  

For your energy use, definitely get the lithium, at least 100ah, but more is better. Myself I have 220ah lifepo4 (2x110ah connected together) which weighs about 60 pounds total. In comparison the battery it replaced a 102ah agm (51 ah usable power) weighed 70 pounds. Less weight is better for your car.

You keep your power use to the minimum you can remain off-grid indefinitely. I use to run a 12 volt fridge 24/7 plus my swampcooler, and my netbook off of a 75ah agm and a 120 watt solar panel. As long as I had good sun the battery was topped off every day and the 75ah agm got me through the night. I could go months at a time, but all it took was one cloudy/rainy day and the fridge would cut out at night from low voltage. With 75ah agm I had no reserve power for cloudy days. 100 ah lithium will definitely get you at least 2 days of power.

 

[ckelly78z]

This all sounds like alot of equipment to stuff into a mid size sedan, were you planning on traveling lots of miles, or staying for 14 days on BLM lands. I think a good sturdy tent would be a nice home base to live out of.

 

[user 23166]

companies such as Renogy and other reliable company have calculators on their websites that you should find useful. What is nice about them is you can do several variations of what you want to power and what size of panels you want to try out for size and for capacity. Of course Renogy and many other solar panel system suitable for RV companies also offer some lithium storage battery systems so you can try that into the calculations as well.  

You will learn a lot about your needs the easy and painless way by just playing with different combinations of panels, batteries and controllers on the calculators. Plus of course those companies also show the wiring schemes of how things get hooked together.

I do like discussing things in the forum but getting that little bit extra background that has been put together with illustrations sometimes helps make more sense out of what people say in the conversations.

Thx Maki, renogy is a little out of my price range, but I can at least go there and learn some things

 

[user 23166]

You might get 10 amps out of 200 watts if they are pointed at the sun ( if they are flat on roof and sun is overhead in summer), in winter sun is lower in the horizon, you get less, maybe 7 or 8 amps. 

A completely discharged 100ah lithium might take anywhere from 3 to 5 days to fully charge with 200 watts of solar. I had a 110ah lifepo4 that took about 5 days to fully charge with my 240 watt panel. You have to take into consideration that you might have cloudy days and you will probably be using the battery at night time and maybe even while its charging.

A 12 volt fridge if you set to 40 degrees will use about 26ah per 24 hours. I would instead use 120mm 12 volt case fans (you can find on ebay) they move alot of air and use a little over 1 amp. 120mm fans is all I use on my swampcoolers, no reason you couldnt use these on your roof vent. On hot days even the larger 5 amp fans won't help much, I have one my roof that I never use. If you can lower your amp usage, the longer you can stretch out your batteries.  

For your energy use, definitely get the lithium, at least 100ah, but more is better. Myself I have 220ah lifepo4 (2x110ah connected together) which weighs about 60 pounds total. In comparison the battery it replaced a 102ah agm (51 ah usable power) weighed 70 pounds. Less weight is better for your car.

You keep your power use to the minimum you can remain off-grid indefinitely. I use to run a 12 volt fridge 24/7 plus my swampcooler, and my netbook off of a 75ah agm and a 120 watt solar panel. As long as I had good sun the battery was topped off every day and the 75ah agm got me through the night. I could go months at a time, but all it took was one cloudy/rainy day and the fridge would cut out at night from low voltage. With 75ah agm I had no reserve power for cloudy days. 100 ah lithium will definitely get you at least 2 days of power.

Wow, lots of awesome information jony. Thank You :thumbsup:
What 12 volt refrigerator do you use?
Ok, I'll admit it, I have no idea what a swampcooler is.
I figure I can stay a night in an RV park if I have to, to recharge my battery bank.

 

[user 23166]

This all sounds like alot of equipment to stuff into a mid size sedan, were you planning on traveling lots of miles, or staying for 14 days on BLM lands. I think a good sturdy tent would be a nice home base to live out of.

I thought I might buy a little trailer from lowes and have a tow package installed on my car, box it in, complete with a door and lock and have my batteries, Electrical panel, portable solar panel array and generator and some jerry cans of gas, stored in it. I do plan on traveling around a lot, maybe moving every week. I mean the whole point is to go and see the country and see if I feel I want to do this for the rest of my life.

I've already gone through the whole tent scenario in my mind, and frankly, being THAT vulnerable scares the heebie jeebies outta me
At least in my car, if there is trouble, from the four legged OR two legged kind, I can jump right into the drivers seat, start the engine and away I go!