Starting Small, would this work?

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George Mason

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https://www.homedepot.com/p/Smartec...-Starter-and-Air-Compressor-JSL-950/309543507        

I'm thinking of pairing something like this with a suitcase charger either 100w or 200 Watts. Any thoughts on how this combo would work? I guess you need to know my plan. I plan to power a laptop a 12in fan that is 12 volts and a couple of LED lights. If you need more information on the laptop let me know but it is basically an HP with a 17-inch screen
 
I saw in the Q&A where it will supply 100 watts for 1.22 hours. How much power does your devices use?
 
telling us about the laptop does no good we need the power consumption.

1. add up your daily usage of power
2. size your battery according to #1
3. size your solar according to #2

of course it the smart thing to do to allow for a few days of no sun.

those jump packs usually do not make a good power source because the battery is small and they aren't made to deep cycle. I can't even find the specs on that page about how many amp hours the battery is capable of.

highdesertranger
 
According to the technical specification portion of the operator manual it is a 12 amp hour battery.  A 100 watt solar panel would be really big for that small a battery.

Amazon sells a 35 amp hour wheel chair battery for $67.  That's 3 times the battery capacity for half the price. 
https://www.amazon.com/ML35-12-Battery-Mighty-Brand-Product/dp/B00K8V2VD0/ 

If you need the air compressor consider getting a more substantial air compressor.  If you need 120 volts AC consider a small inverter suitable for your 120 volt load.  For most laptops you can get a 12 volt power supply.  I searched on amazon for "hp laptop car charger" and the cheapest was $13, most pricey was $50 and would depend on your specific laptop.  A "300 watt pure sine wave" (again, amazon search) is in the $50 neighborhood.

Converting 12 volts to 120 involves about a 20% loss.  Converting 120 volts to 19 volts to feed the laptop will have a similar loss.  A single conversion from 12 to 19, the car charger, only has the loss once.  With a small power system efficiency really matters. 

The laptop will use power depending on what is happening.  A web browsing or text reading will use less power than video watching or a multi-player game.  Battery charging while computing also increases the power level.  The daily energy use depends on what you do with it and how bright the screen is. 

Batteries are not 100% efficient.  The battery in the laptop and an external battery will also have about a 20% loss.  If you can use and charge the laptop while the sun is shining there is less energy wasted going into and back out of the various batteries.
 
Whatever you decide to get remember that the price of your first battery is tuition.  The learning battery will probably die young from being consistently undercharged.  You will believe the solar charge controller when it tells you the battery is full.  You will deplete it too deeply.  If you get a battery bundled in an expensive box, that combination will increase the tuition price when you have to replace it.
 
Average power usage for my laptop is 50 Watts as measured by a kill-a-watt meter for a period of 2 hours
My 12-inch fan is rated at 12 volts 700 milliamps so that equals 8.4 Watts? I have not bought the LED lights yet so I do not know what their power requirements will be I would only need one or two and only at night for short periods of time
 
B and C said:
So it will power your laptop for almost three hours.
 while being charged by 100 watt solar panel? To answer some of the other questions I do not need an air compressor, I have a separate one. I would like to have a jump box just in case my battery goes dead which is why I was thinking about using that as a power source. How would a 100 watt panel pair with 2 100w deep cycle 12-volt batteries? I can get them for $81 a piece from Walmart. It would seem, based on the numbers I've got in my above post, that 100 watts would be enough to run my fan and my laptop continuously while the Sun is up  while still providing some trickle charge to the batteries. Does that seem right?
 
I currently use two fans to keep myself cool when I'm trying to sleep. One fan is a USB rechargeable mini fan that actually does a really good job. The other one is my 12 inch fan that'll run 6 hours on a fully charge external battery. The small fan runs between four and six hours depending on what speed I put it on. I have a separate solar charger for the small fan that was given to me. That charger will also charge my phone and other small things. It will not work on anything that draws more than 2 amps. I don't see how to upload pictures from my hard drive, where do we do that?
 
to upload pics click on the black tab that says "New Reply" not the quick reply. there will be an add attachments tab this is were you do it. there is a tutorial for pics which you should have been given a link to with your intro post. highdesertranger
 
I have a similar, older unit with a 17 ah battery.  If you value that type of battery's life, you don't want to fully discharge it.  (The old rule of thumb is don't use more than half.)  If you use the inverter, it will reduce the available power by about 10%.  Recharging these power packs is a slow process.  The compressor will top off a tire if needed, but will burn up if run for more than a few minutes at a time.

All that being said, it is the only "house" battery we carry, and I like it.  We run a LED strip light on it, but other lighting is battery operated.  Our fans run on D cells or 110, although one does have a 12v plug.

In the past, I didn't see the point is having a complicated battery set-up that would not provide heating, cooling, cooking or refrigeration.  These days, with battery capacity going up, 12v refrigerator prices coming down, and "plug and play" systems emerging, I am considering upgrading (you know...  in five or six years :rolleyes: ).  Truthfully, I am a little uneasy about lithium ion batteries in extreme heat, but I'm a bit of a nervous Nelly.
 
highdesertranger said:
to upload pics click on the black tab that says "New Reply" not the quick reply.  there will be an add attachments tab this is were you do it.  there is a tutorial for pics which you should have been given a link to with your intro post.  highdesertranger
I must be missing you. I see the tips tricks and rules link, but nothing about pictures even when I follow that link. If I'm just being blind I apologize it's not willful blindness
 
George Mason said:
 while being charged by 100 watt solar panel? To answer some of the other questions I do not need an air compressor, I have a separate one. I would like to have a jump box just in case my battery goes dead which is why I was thinking about using that as a power source. How would a 100 watt panel pair with 2 100w deep cycle 12-volt batteries? I can get them for $81 a piece from Walmart. It would seem, based on the numbers I've got in my above post, that 100 watts would be enough to run my fan and my laptop continuously while the Sun is up  while still providing some trickle charge to the batteries. Does that seem right?
My 100 watt panel actually produces 50 to 60 watts mounted flat on the roof not tilting and tracking the sun.  Low elevation and high humidity also make it worse.  A 50 watt laptop would take a lot of your energy supply.  

If you want a jump starter, get that.  A solar electric system can be wired to the vehicle electric system to allow the vehicle to help with house battery charging when necessary and to allow using the solar and the house battery to boost the starter battery.  The low power house system is for the 50 watt computer and 10 watt fan.  The 2000 watt starter motor is best left to the starter battery.

The general rule of thumb is 100 watts of solar for every 100 amp hours of battery.  Those are different things and there is no correct ratio.  If you use a lot of electricity, you need a lot of solar panel.  If you use the electricity mostly after dark you need a bigger battery than if you use the electricity mostly during the day.  If you are not in Arizona like Oregon and Washington, 200 watts of solar might be necessary for a small system.

If you provide a link to the batteries you are considering you might get relevant advice.  Generally "maintenance free" means the lead plates also contain calcium and very little water is used.  Those batteries can be damaged by discharging more than 10% of their capacity.  Industrial deep cycle batteries like golf cart batteries are good for regular 50% discharges and a 75% discharge doesn't cause damage, just slightly reduced cycle life.  I have a 75 amp hour deep cycle trolling motor battery and it seems to be ok with discharging limited to 25%.

Managing your own mobile solar electric utility can be a challenge particularly when funds are limited.  You don't want to buy a lot more than you need.  It helps a lot to be flexible in how much you use.  For example, I have turned off my fridge because it and the battery were getting empty.  If you need the computer every day for work that's different from recreational web browsing.
 
Space is much more a limitation than money at the moment. This is not going to be my permanent van, this is like a prototype. I do not plan to mount solar panels on the roof on this van, I can set the panels out at an angle and let them get the best sunlight exposure possible. That is why I want the suitcase style panels. I can also fold the suitcase panels away and store them under my bed when not in use. I was hoping for a similar solution for the batteries so that I could take the suitcase panels and the batteries out of the van to get charged while parking the van in shade. If I have to use regular size batteries, I probably want to build a battery box with a plug and then an extension cord that will run from the panels to the Box in from the box to whatever I will use to power the computer. Using the suggested car adapter for the laptop, I might not even need an inverter at all. Aside from the computer, my current plan does not require anything to be a hundred and twenty volt AC
 
George Mason said:
I must be missing you. I see the tips tricks and rules link, but nothing about pictures even when I follow that link. If I'm just being blind I apologize it's not willful blindness

About halfway down that post it gives you a clickable link on how to add photos. 
Slow down and read it all.  If you're skimming, you will miss it.
 
Yep definitely skimming, I was expecting an obvious Link in that page. I will go back and check it thanks
 
View attachment 26639
George Mason said:
Yep definitely skimming, I was expecting an obvious Link in that page. I will go back and check it thanks
Click New Reply, then scroll down past the emoticons to "Attachments/Add Attachment".

Click on the Browse button.
 

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George Mason said:
Space is much more a limitation than money at the moment. This is not going to be my permanent van, this is like a prototype. I do not plan to mount solar panels on the roof on this van, I can set the panels out at an angle and let them get the best sunlight exposure possible. That is why I want the suitcase style panels. I can also fold the suitcase panels away and store them under my bed when not in use. I was hoping for a similar solution for the batteries so that I could take the suitcase panels and the batteries out of the van to get charged while parking the van in shade. If I have to use regular size batteries, I probably want to build a battery box with a plug and then an extension cord that will run from the panels to the Box in from the box to whatever I will use to power the computer. Using the suggested car adapter for the laptop, I might not even need an inverter at all. Aside from the computer, my current plan does not require anything to be a hundred and twenty volt AC

Any lead acid battery of a useful capacity is going to be heavy. A 100 AH AGM weighs about 70 pounds, a 100 AH flooded is probably in the 90 pound range. If you can't mount the battery in a permanent location, I'd probably go Lithium, either a Lithium battery or a "solar generator".
 
George Mason said:
 while being charged by 100 watt solar panel? To answer some of the other questions I do not need an air compressor, I have a separate one. I would like to have a jump box just in case my battery goes dead which is why I was thinking about using that as a power source. How would a 100 watt panel pair with 2 100w deep cycle 12-volt batteries? I can get them for $81 a piece from Walmart. It would seem, based on the numbers I've got in my above post, that 100 watts would be enough to run my fan and my laptop continuously while the Sun is up  while still providing some trickle charge to the batteries. Does that seem right?
I must be missing something. Where  does it say you can charge this with  solar?
 
It has a 12V power cord to plug into a vehicle's 12V power port for charging. Just connect that to the controller.
 
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