What size battery do I need for a portable solar panel?
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highdesertranger
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You size the battery according to your needs, you size your solar to your battery. 3 steps,
1. determine daily usage of power
2. Size your battery according to #1
3. Size your solar to #2
We can help with the details.
Highdesertranger
1. determine daily usage of power
2. Size your battery according to #1
3. Size your solar to #2
We can help with the details.
Highdesertranger
Um, the heart of your electric system is your battery. Your battery isn't an accessory to your solar panel, it's the single most important element of your personal power company. A solar panel is just one of the several ways available to keep your battery(s) charged.
Don't get any battery until you know how much battery capacity YOU need to power the things that YOU want to power. And then you can talk about which batteries are best for YOU to meet that need. Only then is it time to think about the best ways to keep that battery charged.
Don't get any battery until you know how much battery capacity YOU need to power the things that YOU want to power. And then you can talk about which batteries are best for YOU to meet that need. Only then is it time to think about the best ways to keep that battery charged.
MrNoodly
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Solar panels come rated in watts.
Deep cycle batteries (the kind you want) come rated in amp hours (Ah). (If it's rated in cold cranking amps [CCA] it's not a deep cycle battery.)
General rule of thumb: the number of amp hours and watts should be close to the same.
Like jacqueg said, first figure out how much battery you'll need. And remember, with a lead-acid battery you should never use more than half the wattage. And, because science is weird, half of a 12V battery charge isn't 6V, it's like 12.2 or 12.4, because a full charge is 12.7 or 12.8. Lithium batteries are different in several ways, but also very expensive. I'm guessing someone will be along shortly to make the argument for them.
Deep cycle batteries (the kind you want) come rated in amp hours (Ah). (If it's rated in cold cranking amps [CCA] it's not a deep cycle battery.)
General rule of thumb: the number of amp hours and watts should be close to the same.
Like jacqueg said, first figure out how much battery you'll need. And remember, with a lead-acid battery you should never use more than half the wattage. And, because science is weird, half of a 12V battery charge isn't 6V, it's like 12.2 or 12.4, because a full charge is 12.7 or 12.8. Lithium batteries are different in several ways, but also very expensive. I'm guessing someone will be along shortly to make the argument for them.
Ok. Let me rephrase my question.
I am going to get a 100 watt solar battery for very light use in my van.
I will just use it to run a few strands of LED lights and charge my cell phone and computer. I don't want a fridge or anything else that takes up a lot of energy.
If I am only going to have portable 100 watt solar panel, what size battery should I pair it with?
I am going to get a 100 watt solar battery for very light use in my van.
I will just use it to run a few strands of LED lights and charge my cell phone and computer. I don't want a fridge or anything else that takes up a lot of energy.
If I am only going to have portable 100 watt solar panel, what size battery should I pair it with?
How much room do you have for batteries? If you are just using 30 watts while the sun is out just hook the portable solar wires with alligator clamps to your vehicle’s battery and use it. Just carry a cheap charged up jumper pack in case the car fails to start. If that happens then buy two wet cell 6 volt golf cart batteries (be sure they are enclosed and vented to the out side air as they do create fumes) and wire them in series for 12 volts. They are the cheapest and best beginner batteries so if you do ruin them by running them too low too often or not maintaining them it will only cost you a couple hundred bucks and they may even be covered by warranty depending on where you get them. Be sure to keep them charged up to full charge daily. If you drive a lot you may want to consider a charge wire you can hook up to them while driving and grounding them to the chassis but just remember to disconnect the charge wire when you are done driving so you don’t run down your vehicle battery again.
AuricTech
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For your stated power needs, Giggles, you probably will find that a 300 Wh to 500 Wh portable power station (often misleadingly called a "solar generator"), mated to your planned 100W solar panel, will do what you need it to do. Depending on the output options on the solar panel you plan to buy, look for one that already comes with adapters (e.g., if your solar panel uses MC4 connectors, look for a power station that comes with an MC4 adapter). Ideally, a portable power station has pass-through capability (i.e., you can draw power from it while you're also charging it).
The downsides of portable power stations include relatively high price for a given battery capacity and an all-or-nothing mode (i.e., if any component fails, you might not be able to use the thing at all).
The upsides of portable power stations include ease of use (the battery, charge controller, DC-to-AC inverter, USB ports and other accessories are built in) and portability (the whole power station is in one package).
For more robust power needs (trust me, your power needs will expand over time), Bullfrog's reply will come in handy.
ETA: "Wh" means "Watt-hours," the gold standard for comparing power system capacity. Don't use Amp-hours without referring to the voltage of a system.
The downsides of portable power stations include relatively high price for a given battery capacity and an all-or-nothing mode (i.e., if any component fails, you might not be able to use the thing at all).
The upsides of portable power stations include ease of use (the battery, charge controller, DC-to-AC inverter, USB ports and other accessories are built in) and portability (the whole power station is in one package).
For more robust power needs (trust me, your power needs will expand over time), Bullfrog's reply will come in handy.
ETA: "Wh" means "Watt-hours," the gold standard for comparing power system capacity. Don't use Amp-hours without referring to the voltage of a system.
Here's a little info on the group 31 battery. I have two in my van and they are way more power than I need. In fact, one would work fine but I like a backup when out in the sticks.
https://batterysavvy.com/best-group-31-batteries/
https://batterysavvy.com/best-group-31-batteries/
RoamerRV428
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poster asked such a simple question for her needs 
just go to Autozone or some other place for a battery. walk in and say you are buying a 100 watt solar portable panel and charging a laptop and some fairy lights. The person behind the counter will not steer you wrong.....done deal and easy without all the crazy extra info on this thread you don't really need.
best of luck and let us know how your new set up goes
just go to Autozone or some other place for a battery. walk in and say you are buying a 100 watt solar portable panel and charging a laptop and some fairy lights. The person behind the counter will not steer you wrong.....done deal and easy without all the crazy extra info on this thread you don't really need.
best of luck and let us know how your new set up goes
highdesertranger
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" The person behind the counter will not steer you wrong."
That's very funny. More than likely an auto parts store doesn't even have the right type of battery.
Giggles you are putting the cart before the horse.
Highdesertranger
That's very funny. More than likely an auto parts store doesn't even have the right type of battery.
Giggles you are putting the cart before the horse.
Highdesertranger
RoamerRV428
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a place that has batteries can't steer someone to buy just a good quality battery for some fairy lights, little solar panel and some charging a laptop and phone?
come on LOL
ya'll make life 'out there' seem like nothing can be easy and simple....yea it can be just that. Talking super simple solar set up here...not solar to run a household. Poster said simple, simple can be done, well-- simply.
come on LOL
ya'll make life 'out there' seem like nothing can be easy and simple....yea it can be just that. Talking super simple solar set up here...not solar to run a household. Poster said simple, simple can be done, well-- simply.
The deal is most end up wasting quite a lot of money getting a system that is way less than their needs because they underestimated or didn’t have the money to get a good working system. Most of us have learned building up a system a little at a time makes for an expensive education. You are better off to accept and do the proven steps to understand and correctly estimate your needs first. If that laptop is going to be playing games 24 hours a day and the lights are on continuously and they decide to add just one more thing someone will destroy a battery quickly without some way to monitor the state of charge when just starting out. Lots of people just can’t afford to waste their money learning. “You can never have enough solar.” has become a pretty regular statement on this forum for that reason.
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