Batteries and solar power charging

mickb

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Guys just after a good solar power charger and storage for charging eneloops, 18650 batteries, sat phones, occasionally laptops etc. Not trying to run refrigerators or major appliances etc. A bit in the dark on this subject. Looking at two size ranges, one for backpacking and maybe a mobile system for car camping(unless backpacking versions can do all the above?) preferably durable and longlife items, like the 'malkoff' of solar setups. If anyone has a stickylink to this sort of question posted anywhere on the internet, please feel free to quote it.
 

terjee

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Bad news is that there's no "the one" to get.

Goal Zero is the company/products that others are usually measured against. It's a good place to start looking, to get more familiar with what's out there.

While I don't have a specific product in mind, here's some good things to be aware of:

There are different types of panels, and some can work significantly better than others, especially in less than ideal situations, like overcast weather. Looking for backpacking equipment to use in Norway, this is pretty significant to me. It doesn't take a lot to slowly charge an 18650, and getting some juice can be a major upgrade from getting one.

You'd take a loss storing energy rather than charging directly, but for almost all cases, I think you're in the right path. Being able to spend more time actually capturing the energy, means you'd probably offset the loss.

Foldable panels (or some of them) can have weak parts that'll break with repeated usage. Quality here can vary widely between "flex film" type rollups, and cheaper Chinese foldable.

Some solutions allows you to connect multiple panels. That could give you the option of bringing one panel when backpacking, using two of them when car camping, and letting one be backup for the other.

For car usage, you also have the option of bringing your car battery into the mix. You could charge 18650s off of the car battery, let solar trickle charge it back up, and running your engine then becomes a nice backup energy source. There are panels made specifically for this, including easily connecting through the cigarette lighter type port, but some of those are "smart" these days, which might complicate things.

If you have the budget for it, it'd probably try to have that method as a separate solution, mostly for backup.

Charge controllers are important, although it can be hard to figure out how each one would perform in different situations.

Will it still deliver some juice in less than ideals situations, or would it shut down? Could it even drain the batteries when shut down?

One good sign to look for is MPPT - Maximum Power Point Tracking. Just like with batteries, if you pull too much amperage from a solar panel, the voltage will sag. Go too far, and the voltage would collapse to nothing, giving you zero energy. MPPT is about changing the load that the panel sees, to get the maximum amount of energy, rather than trying to pull too much amperage, and causing such a collapse. It can go "if I reduce the amperage a bit, I'll get higher voltage, and more energy in total, yay!".

There used to be an interesting company here: http://www.aspectsolar.com

But they seem to have gone now. :-/

Oh, and portable solar is often based around either 5V (USB) or 12V (car batteries, 12V accessories). Some support one, some support both well, some support both badly. Worth keeping in mind.
 

Lampas

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If your looking for a broad range of uses, you should check out www.goalzero.com
Although there are so many options, that some reading is recommended (=
 

Keitho

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Anyone have experience with powerfilm? They seem expensive, but high actual wattage for the weight.
 

terjee

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Anyone have experience with powerfilm? They seem expensive, but high actual wattage for the weight.

I have no direct experience, but I've been following them for years. Their reputation is good, they seem more robust and reliable than comparable cheaper products, and at least a few years ago they were said to be among the better in less than optimal conditions.

A lot of their products as "raw" though, providing unregulated output. Some you can connect directly to car batteries for example, but that's often less than optimal.

I really want one, but I haven't (yet) found the perfect thing to pair it with. Ideally I'd want MPPT, efficient storage (think advanced power bank) and also USB and 12V output.

Best use for me at least, would be if I could use it to charge 18650s and phones directly, while excess energy recharged a power bank. All in a very small package offcourse.

Idea could be something like powerfilm panels, but built out to a solution more like this:
https://www.voltaicsystems.com/arc20w-kit
(Might be interesting in it's own right).
 

Lynx_Arc

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I think the issue you will have is that charging lithium ion and eneloops you can use a 5v setup and panel for that purpose but the laptop is going to be a problem as most likely it will desire around 18-20v input from an AC 120v source so you will either have to go with an inverter and a 12v type panel setup or some sort of 12v car charger solution (boost converter) and a 12v panel. A laptop charger usually wants a pretty high current input also don't look to be recharging it off a "backpack" type of setup decently for it.
You will have losses in converting voltage for the laptop that will be substantial for sure.
Basically solar charging usually hinges around 5v or 12v setups and either auto adapters and/or USB solutions. 12v is easier to source but I think USB solutions (5v) is the best all around if you can manage everything with it.
 

Keitho

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A lot of their products as "raw" though, providing unregulated output. Some you can connect directly to car batteries for example, but that's often less than optimal.

I really want one, but I haven't (yet) found the perfect thing to pair it with. Ideally I'd want MPPT, efficient storage (think advanced power bank) and also USB and 12V output.

I was thinking the same thing, terjee; if I could find a little MPPT box or a card that I could put between a powerfilm panel and a USB device (phone, 18650 charger, power bank, whatever), it might be fun to play with as a DIY project for car camping or a teardrop camper. I had a hard time finding one the last time I looked around...
 

Timothybil

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You are really looking at two different scenarios here. One, if by camping you mean going hiking and camping at a different spot every night, then you will want a small portable solar panel with about 10w to 20w output, usually USB only. Some are just solar cells and a USB jack, which is not what you want. Look for one that manages the output so it can handle temporary shading, etc., better. On the other hand, fixed location camping or home power outage use one has more options. One could always use the same type of panels as the mobile option, maybe a little larger for more output. Or, more ideally, several companies offer portable rigid solar panels in a briefcase/suitcase kind of setup. [See GoalZero and Renogy]. The rigid panels are more than likely going to be 18v nominal output, and need a charge controller to charge an attached battery properly. This type of setup will allow one to connect several panels in parallel for more output. The usual setup is a single panel, charge controller, and one or more 12v batteries connected in parallel. The charge controller should use either PWM or MPPT, will usually have one or more USB jacks as well as a 12v output. It is also possible to connect two of such panels in series, in order to charge two 12v batteries also connected in series. Usually, this is only done when one is going to use two or more pairs of panels for increased output and storage, at which point one is rapidly approaching a permanent use setup.

In any case, panels using monocrystalline cells will provide more output than ones using polycrystalline cells. The monocrystalline cells are higher efficiency, but at a higher cost as well. There have been several good threads here on this topic that are very enlightening. My hero is Chris, who has a very nice power outage setup for his home. Living in Florida, his setup is designed to carry him through an outage of several days, as often occurs in hurricanes. He also has a more portable setup as well.
 

ChrisGarrett

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Well, 12vdc vs. 5v USB for starters?

PowerFilm, Goal Zero, Brunton, Global Solar, SunTastics and then the generic type brands.

Then your budget?

I wanted a PowerFilm 30w 12vdc folder back five years ago when I put my 12vdc system into place and just settled for two 30w rigid panels from a decent maker--Soplay. I got a Morningstar SS-10-L PWM digital controller and put my system together. It's a car camping/SHTF hurricane system and is small enough to carry down to the condo grounds if the power goes out.

I got two mother batteries--SLA AGM 12Ah and 22Ah for my 12vdc chargers.

I then got a little 14w Sunkingdom 5v USB charger for my USB chargers and that is portable.

With battery banks, mother batteries, chargers (12vdc/5v USB) I'm covered.

I have a post up with newly installed pictures if you want to search.

Lots of ways to skin a cat, so money/needs are the deciding factor.

Chris
 

StorminMatt

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I was thinking the same thing, terjee; if I could find a little MPPT box or a card that I could put between a powerfilm panel and a USB device (phone, 18650 charger, power bank, whatever), it might be fun to play with as a DIY project for car camping or a teardrop camper. I had a hard time finding one the last time I looked around...

Keep in mind that there are issues with using any kind of MPPT when it comes to charging USB devices or 18650s. MPPT is generally used in residential, commercial, and utility systems, where rather large amounts of power can be dumped back on the grid. This is advantageous, since it improves the return on investment in the system. But charging USB devices and 18650s is different. Neither can simply take all you can dump on them. USB devices (like phones) can generally only take specific amounts of current. And 18650s (and other Li-Ion batteries) have definite limits on charging current. In other words, you DON'T want something that is going to force more current through these devices when the sun gets bright just because the power is now 'there' to do so. That's why even expensive USB chargers don't use MPPT.
 
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ChrisGarrett

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Keep in mind that there are issues with using any kind of MPPT when it comes to charging USB devices or 18650s. MPPT is generally used in residential, commercial, and utility systems, where rather large amounts of power can be dumped back on the grid. This is advantageous, since it improves the return on investment in the system. But charging USB devices and 18650s is different. Neither can simply take all you can dump on them. USB devices (like phones) can generally only take specific amounts of current. And 18650s (and other Li-Ion batteries) have definite limits on charging current. In other words, you DON'T want something that is going to force more current through these devices when the sun gets bright just because the power is now 'there' to do so. That's why even expensive USB chargers don't use MPPT.

And MPPT digital controllers have a microprocessor inside that drains power on its own, so if you're already dealing with small amounts of current, the MPPT controllers might be doing more harm, than good, vis-a-vis useable current going to your devices.

PWM controllers for something like my 60w rigid setup made more sense, especially economical sense.

Chris
 

Timothybil

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I forgot to add that for many, having a USB output solar panel implies using it to charge a power bank rather than via direct connect. There is a problem with some USB devices where if the charging current is lowered or interrupted, the device will stop charging until it is disconnected and reconnected. It is my understanding that some Apple phones do this. Whereas most power banks will just keep charging with whatever they are getting at the time, up to their max input current. Over the years I have acquired three power banks, so I always have one fully charged, one fully charged or charging, and one in use to charge other devices.
 

terjee

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I forgot to add that for many, having a USB output solar panel implies using it to charge a power bank rather than via direct connect. There is a problem with some USB devices where if the charging current is lowered or interrupted, the device will stop charging until it is disconnected and reconnected. It is my understanding that some Apple phones do this. Whereas most power banks will just keep charging with whatever they are getting at the time, up to their max input current. Over the years I have acquired three power banks, so I always have one fully charged, one fully charged or charging, and one in use to charge other devices.

Very good point on the stooping charging. There are some panel controllers that try to sense this, and disconnect/reconnect, in order to trigger it to charge again. Using a powerbank as a go-between makes more sense to me though, allowing it to always capture until full, without the phone having to stay stationary. The reconnect could still be interesting though, if your phone is empty, and you'd want to avoid the losses of going through a power bank.
 

mickb

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Great response to the question thanks. I am still digesting and researching what has been written so I can reply adequately.
 

mickb

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Hi gents I have decided for this project to stick to 5v systems and charging smaller devices, batteries up to 18650's. (Laptops and heavier items off the list, I'll use mini generators and powerpaks for home type SHTF) I'm also not looking for ultralight backpackable version so much now. Chasing something still mobile but heavier duty/more durable would be good. My budget is $1000 so after a decent setup. I don't need lots of power but would pay for the ultimate in durability. Have been checking out the lifetime of solar panels and wondered if its reasonable to assume these panels( and their electronic parts) might make the 10 year mark? I am checking out the links for goalzero etc and will see what I can come up with.
 

terjee

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Have been checking out the lifetime of solar panels and wondered if its reasonable to assume these panels( and their electronic parts) might make the 10 year mark? I am checking out the links for goalzero etc and will see what I can come up with.

Half-jokingly, but with a point; You can't ever assume anything will last 10 years. At the very least it requires some care and tending to.

Beyond that, with the possible exception of electrolytic caps in the electronics, most would last 10 if left on a shelf. If heavily used on the other hand, things becomes much more complicated. How often and how hard will it be used and handles? In what weather? And so on.

A carefully used panel of a good brand, with no joints/foldings, I'd expect functioning in 10 years. A cheap foldable one on the other hand, could fail in one. Personally I've landed on redundant panels probably being the way to go. :)
 

Woods Walker

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One thing I have found is often the simpler the charger the better it works with solar. Solar power can be intermittent. Sometimes a charger can trigger an error during passing clouds which will require it being unplugged then plugged back in. This can be problematic if away from camp or busy around the house. Xtar MC1 plus being evaluated for solar compatibility with both naked and protected lithium ion batteries.

Qnat5hi.jpg



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Notice how I keep the battery behind the panel out of the sun.

MVVztNC.jpg


edit to add. The MC1 Plus appears to be solar compatible per my testing.
 
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terjee

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A lot of power banks refuse charging and usage at the same time. Some even have a mechanical slider to prevent connecting both charger and load at the same time.

Anyone have good experiences with powerbanks that explicitly support it?
 

Woods Walker

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A lot of power banks refuse charging and usage at the same time. Some even have a mechanical slider to prevent connecting both charger and load at the same time.

Anyone have good experiences with powerbanks that explicitly support it?

Some do have pass though charging but that will increase the probability of a charge error with the secondary device. Mycharge Rugged Power and the Nitecore F1 both have pass though charging and solar compatable.

nTwlWm9.jpg
 
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