Help get me started in solar charging

I really just got into the charging game a month ago picking up a Nitecore D4 charger. However, I've wondered about solar solutions for charging my eneloops and Li-ions for my lights.

I've seen the foldable and portable solar panels with the USB connection going to the little AA chargers. But with no battery pack, no energy could be stored for night charging.

So my question is what is a straightforward and simple solution for getting set up to charge my batteries with solar? Is the USB the way to go but requiring buying 2 separate USB chargers for NiMh and Li-ions?

Is this intended as a portable solution? Car? Camper? on foot? at home?

Where weight and size counts, you actually don't really want a middle-man battery bank. The idea would be to charge the devices you intend to use directly, OR, use the cells you intend to charge anyway, as your power bank for other devices.

I have been testing a "SUNKINGDOM™ 5W 5V Portable Ultra-thin Solar Panel Charger USB Output" from amazon, in conjunction with an Xtar MC1+, as well as my cell phone (GPS), and it seems to work pretty well. This combination is going back-backing with us this week for the first time. A bit bigger panel would be better but this is an acceptable compromise for performance vs weight for my intended use. You could swap out for a Klarus CH1 charger instead to get NIMH charging capability while maintaining the variable input power tolerance.

This would be a portable solution. If I could avoid purchasing separate chargers, it'd be ideal to use the Nitecore D4 I already have.

I was pondering the foldable panels with USB output going into a DC to DC 5 to 12v boost converter cable that is able to plug directly into the D4. Not sure if this is possible.

I have seen the Cottonpicker setups particularly the one that has a female 12v port allowing me to use the 12v cigarette lighter plug with my D4 to connect and run it if it can provide the 1A of current it needs. Again, not sure if it's possible but see he offers an 1100mA panel that includes both a Li-ion and NiMh charger. Maybe that'd be easier.

That Sunkingdom with the MC1+ might be the ticket. Fairly cheap setup. Do you have a good recommendation for eneloop charging with this setup?

I have both the 5v USB output folding panels and a 12v & 5v panel.
I am planning to use the D4 directly on the 12v output and see how it goes.

I know that to charge 12v batteries directly you really need an 18v panel usually but I am hoping the panel might run the charger as it is,I will let you know.

I wonder how the size and weight of a solar setup, charger, etc. compares to that of just bringing along enough extra charged Eneloops?

1DaveN said:

I wonder how the size and weight of a solar setup, charger, etc. compares to that of just bringing along enough extra charged Eneloops?

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What if you're in a power outage for weeks or bugging out and only so many eneloops?

uofaengr said:

What if you're in a power outage for weeks or bugging out and only so many eneloops?

Click to expand...

Plus, there's something to be said about not having to be super conservative because you know you have limited battery power. Especially when you're actually trying to enjoy yourself.

I wouldn't bother trying to boost from 5V to 12V. It would be better to buck from an 18V panel (common for laptops) to a 12V output, or just see if the D4 would support a 16-20V input without bucking. (sounds like AVservice is going to try that).

The D4 is probably not going to be very tolerance to variable input power from solar, so the panel will either need to be oversized, or connected to a middle-man power bank.

This is the sort of panel I would be considering to run the D4 directly: http://www.amazon.com/dp/B00W67GF5O/?tag=cpf0b6-20

Unfortunately, there aren't as many good value 12V "portable" panels out there as there are ~18V and 5V.

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If you want to be able to charge multiple cells at once, I think that you would be money ahead to pick up this instead: http://www.amazon.com/dp/B00TEQJEC6/?tag=cpf0b6-20
And then just pick up a few Klarus CH1 chargers. Use a USB charging splitter cable on the 2A output to connect 2 X CH1's to that port, and connect a single CH1 to the 1A port.

uofaengr said:

What if you're in a power outage for weeks or bugging out and only so many eneloops?

Click to expand...

Of course - someone mentioned backpacking and I somehow got the idea that was your purpose. My mistake

A basic Li-Ion setup is very simple: all you need is a solar panel with a USB output, and a simple Li-Ion charger to plug into it (such as one of the XTAR MC series). This works because the Li-Ion chemistries are very tolerant of intermittent charging at highly variable currents, such as when clouds pass in front of the sun.

The charger needs to be simple, though, because complex chargers with displays and multiple charging options tend to get confused and reset themselves when supplied from such a variable power source. These resets can render the system inefficient and may even be dangerous if the reset charger defaults to a high current while you're charging a small cell.

When choosing your charger, you'll also want to try and get one that can still put some charge into your cell even at low power when your solar panel is poorly lit, but has the capacity to take full advantage when the panel is collecting lots of energy in good conditions.

If you want to maintain a steady power supply for a more complex charger, store surplus power for later use, or charge NiMH cells, you'll need a buffer battery. The nice thing about USB-based systems is that you can use a USB powerbank for that.

In this arrangement, your solar panel charges the powerbank and the powerbank powers the charger. This is less efficient, because of the extra power conversion step that the powerbank represents - you'll lose about a third of your solar energy - but will be much more reliable in terms of maintaining constant power as clouds pass in front of the sun.

It also means that spare energy not immediately used by the charger will be stored by the powerbank for later use. You can even charge the powerbank by itself and charge your cells later, instead of being forced to do everything while the sun's shining. If you have a USB-chargeable mobile phone or similar device, the powerbank will charge that as well.

Be warned that not all powerbanks can simultaneously charge up (in this case, from your solar panel) whilst powering a device (your Li-Ion or NiMH charger). Some powerbanks can only do one or the other at a time.

When it comes to charging NiMH cells, I strongly recommend that you use a buffer battery, because the -dV/dt algorithm generally used by smart chargers is not very tolerant of interruptions in power, especially when a NiMH cell is approaching full charge.

If a cloud passes in front of the sun, you don't have a buffer battery and the NiMH charger resets, it can lose track of the recorded voltage it needs to spot the -dV/dt endpoint. This can cause your cells to be overcharged, reducing their capacity and service life.

mdocod said:

I wouldn't bother trying to boost from 5V to 12V. It would be better to buck from an 18V panel (common for laptops) to a 12V output, or just see if the D4 would support a 16-20V input without bucking. (sounds like AVservice is going to try that).

The D4 is probably not going to be very tolerance to variable input power from solar, so the panel will either need to be oversized, or connected to a middle-man power bank.

This is the sort of panel I would be considering to run the D4 directly: http://www.amazon.com/dp/B00W67GF5O/?tag=cpf0b6-20

Unfortunately, there aren't as many good value 12V "portable" panels out there as there are ~18V and 5V.

--------

If you want to be able to charge multiple cells at once, I think that you would be money ahead to pick up this instead: http://www.amazon.com/dp/B00TEQJEC6/?tag=cpf0b6-20
And then just pick up a few Klarus CH1 chargers. Use a USB charging splitter cable on the 2A output to connect 2 X CH1's to that port, and connect a single CH1 to the 1A port.

Click to expand...

This looks about exactly what I'm looking for. I wonder if I should use a powerbank in between as mentioned below. With the Klarus chargers at about $10 apiece. Having basically unlimited charging capability for 2 cells at a time with roughly $75 invested isn't too bad.

1DaveN said:

Of course - someone mentioned backpacking and I somehow got the idea that was your purpose. My mistake

Click to expand...

No worries.

Phlogiston said:

A basic Li-Ion setup is very simple: all you need is a solar panel with a USB output and a simple Li-Ion charger (such as one of the XTAR MC series). This works because the Li-Ion chemistries are very tolerant of intermittent charging at highly variable currents, such as when clouds pass in front of the sun.

The charger needs to be simple, though, because complex chargers with displays and multiple charging options tend to get confused and reset themselves when supplied from such a variable power source. These resets can render the system inefficient and may even be dangerous if the reset charger defaults to a high current while you're charging a small cell.

When choosing your charger, you'll also want to try and get one that can still put some charge into your cell even at low power when your solar panel is poorly lit, but has the capacity to take full advantage when the panel is collecting lots of energy in good conditions.

If you want to maintain a steady power supply for a more complex charger, store surplus power for later use, or charge NiMH cells, you'll need a buffer battery. The nice thing about USB-based systems is that you can use a USB powerbank for that.

In this arrangement, your solar panel charges the powerbank and the powerbank powers the charger. This is less efficient, because of the extra power conversion step that the powerbank represents - you'll lose about a third of your solar energy - but will be much more reliable in terms of maintaining constant power as clouds pass in front of the sun.

It also means that spare energy not immediately used by the charger will be stored by the powerbank for later use. You can even charge the powerbank by itself and charge your cells later, instead of being forced to do everything while the sun's shining. If you have a USB-chargeable mobile phone or similar device, the powerbank will charge that as well.

Be warned that not all powerbanks can simultaneously charge up (in this case, from your solar panel) whilst powering a device (your Li-Ion or NiMH charger). Some powerbanks can only do one or the other at a time.

When it comes to charging NiMH cells, I strongly recommend that you use a buffer battery, because the -dV/dt algorithm generally used by smart chargers is not very tolerant of interruptions in power, especially when a NiMH cell is approaching full charge.

If a cloud passes in front of the sun, you don't have a buffer battery and the NiMH charger resets, it can lose track of the recorded voltage it needs to spot the -dV/dt endpoint. This can cause your cells to be overcharged, reducing their capacity and service life.

Click to expand...

That's a very good point regarding the powerbank. What's a very highly regarded powerbank around here? High quality and capacity without breaking the bank. I know they're a dime a dozen these days. Thanks a lot for your detailed post. [emoji106]

You could use a CH1 with an 18650 in it as a buffer-bank for a NIMH charger

(assuming it supports simultaneous charging and USB output, not sure).

If you only plan on 2 X CH1's, not 3, then I would advise a step smaller, something in the ~13W size, usually comes with a 2A USB output. Use with a splitter cable. Look for units with sunpower brand solar cells. Stin, ECEEN, Poweradd, Sunkingdom, kingsolar, allpower, Choe, Anker, and more, all seem to be "branding" pretty similar technology and solar cells, which in most cases are "decent" quality units for the money.

uofaengr said:

That's a very good point regarding the powerbank. What's a very highly regarded powerbank around here? High quality and capacity without breaking the bank. I know they're a dime a dozen these days. Thanks a lot for your detailed post. [emoji106]

Click to expand...

You're very welcome

Unfortunately, I'm away from home at the moment, so I don't have access to most of my equipment in order to recommend a powerbank. Perhaps someone else here can help?

mdocod said:

You could use a CH1 with an 18650 in it as a buffer-bank for a NIMH charger

(assuming it supports simultaneous charging and USB output, not sure).

If you only plan on 2 X CH1's, not 3, then I would advise a step smaller, something in the ~13W size, usually comes with a 2A USB output. Use with a splitter cable. Look for units with sunpower brand solar cells. Stin, ECEEN, Poweradd, Sunkingdom, kingsolar, allpower, Choe, Anker, and more, all seem to be "branding" pretty similar technology and solar cells, which in most cases are "decent" quality units for the money.

Click to expand...

I can vouch for the Anker IQ 14W foldable solar panel - you can find my thoughts on it here:

http://www.candlepowerforums.com/vb...ghts-on-the-Anker-IQ-14W-foldable-solar-panel

My 5v panels are the Anker which seemed like a pretty good choice for the price at the time and also an Anker power pack,I have a 16,000mah model and it seems crazy small for the output compared to others that I have?

My 12v Panel is the Ultrapark 27 watt and I have a bunch of SLA batteries that I can charge with that from 4ah to 36ah to 75ah if I decide to go that way.
Again it seemed the best quality for the money but many similar models and brands sell for about the same price. It also seems many are identical or at least similar and I would bet they are made in the same factories too.

The ML-102 charger that I have is a pass-through charger but uses only the shorter unprotected 18650's. CPF member HKJ recently reviewed the latest model. It can be used as a powerbank for charging at night, my understanding.

My older NiteCore i2 charger did not like my solar panel...

Soshine makes a 'universal' charger that can do NiMh. HKJ reviewed one sometime ago.

If you're going the USB route, I strongly recommend the Xtar USB Detector in order to check voltage and amperage. CPF member mdocod talked about using a USB plug, stripping the wires, to use as a lightweight volt meter to check your batteries in the field. It reads about .02A (if I remember) less than my DMM but is VERY handy. I used a salvaged USB charging cord from a cheap toy that had broken.

You should also remember to have your device that is being charged, kept cool as practical when charging from the sun. I have slowed down my outside charging when the days are really hot. Of course, you do what you need to do.

Perhaps you will consider using rechargeable lithium batteries as well (if you are not already). Their ability to sustain output is nice for high performing flashlights.

Good Luck and hope you have fun.

Here is my setup, cheap(ish) and very capable.


I find that charging your rechargables from the powerbank is much easier and faster than charging from the panel directly, specially on partly cloudy days. Both these items are from good reliable companys and both come with a warranty. The anker power bank i got came with an 18 month warranty and the panel came with a one year.

Also the panel is much smaller than it appears, about the size of an ipad mini, very portable.

Im using 2 xtar mc1 chargers

Edit: it just occurred to me that also having a powerbank in conjunction with the solar panel allows you to charge 4 things at once in a pinch. 2 off the panel and 2 off the bank. Very useful imo

Rider57 said:

Here is my setup, cheap(ish) and very capable.


I find that charging your rechargables from the powerbank is much easier and faster than charging from the panel directly, specially on partly cloudy days. Both these items are from good reliable companys and both come with a warranty. The anker power bank i got came with an 18 month warranty and the panel came with a one year.

Click to expand...

What charger are you using?

Xstar mc1's, all my batterys charge just as if they were plugged in to the wall outlets both off the power bank and straight off the panel.

uofaengr said:

I really just got into the charging game a month ago picking up a Nitecore D4 charger. However, I've wondered about solar solutions for charging my eneloops and Li-ions for my lights.

I've seen the foldable and portable solar panels with the USB connection going to the little AA chargers. But with no battery pack, no energy could be stored for night charging.

So my question is what is a straightforward and simple solution for getting set up to charge my batteries with solar? Is the USB the way to go but requiring buying 2 separate USB chargers for NiMh and Li-ions?

Click to expand...

There's an adage with solar charging and much like 'fish tanks,' simply put, it's:

'Get the biggest you can afford, space/convenience allowing.'

Here's my 12v system that I put together 3 summers ago. It's not back-packable, but it's easy enough to manage:

http://www.candlepowerforums.com/vb/showthread.php?342073-Portable-solar-charging-setup-I-just-built

With any panel above 20w, it's suggested that you get a digital solar controller to regulate panel voltage, which can be up to 20+ volts.

Secondly, get a mother battery and stick that into the chain. You can charge that up by day and then charge your batteries/cells up by night. You can use the mother battery to run a 12v fan, if like me, you're in a hot place like Miami when the power goes out.

12v AGM/SLA mother batteries really aren't all that expensive and you'll get 3-5 years out of them, if you take care.

With a 12v system, I can run my Xtar VP2 and WP2 II chargers and my NiteCore i4 v2 charger.

After I put that system together, I decided on a 5v USB 'portable' system and bought a SunKingdom 14w USB folding panel and a couple of Xtar 5v USB chargers for li-ion (MP1+) and NiMH/li-ion (XP1.)

I also bought a Ruinovo 4x18650 power bank that came with 4 Sanyo UR18650FM 2600mAh 18650 cells. I can use the power bank, much like the 'mother batteries' and charge the bank up with the panel and then charge stuff up off of the Ruinovo and things are peachy.

The Ruinovo power bank has a 2A 5v input, so with the Sunkingdom 14w panel's two 2A+ outputs, I get a faster charge on the bank.

Small USB panels will charge small, so keep that in mind. A 12v system, one of 60w like mine, can deliver 3.5A and get those mother batteries charged up more quickly than smaller panels. My two mother batteries are 12Ah and 22Ah, so plenty of juice to take care of a bunch of Eneloops, li-ion cells and my fan.

I'm covered in any event--say if I have to bolt out the door to the beach, or out in the woods, or if my power has gone out in the event of a hurricane blowing through Miami, cutting power along the way.

Chris

I think the finest solar charger is the Energy Bar which you will find at www.aspectsolar.com. There are Energy Bars of various capacities.

You can choose a solar panel at that site to go with the Energy Bar you select.

So your batteries will recharge from the charger you plug into your Energy Bar.