solar – TheCampfireCanAlwaysBeBigger.com

Compact 20W Folding Solar Panel (min. 20W)

Given a choice, you ALWAYS want to charge your device off a Portable USB Power Bank. Use solar panels to trickle charge your device only as a last resort.

Power Banks provide the fastest and most consistent charge to your device, because of their built-in charge monitoring circuitry. Re-charge the Power Bank with a solar panel only if you don’t have ready access to a wall outlet or vehicle cigarette lighter port. If the Power Bank is completely discharged, then you could use the solar panel directly to trickle charge your device, but it is best to have the solar panel trickle charge the Power Bank first, instead of the device directly. The primary reasoning is that most (99%) portable folding solar panels do not have a voltage regulatory built-in, which means that the charge varies, relative to the sunlight. This variance, over time, puts a stress on the battery chemistry.

The combination of a solar panel directly attached to a power bank is a great idea in theory, but if either the power bank or solar panel fail, then you basically need to discard the entire unit. So, it is better to keep the two components separate and modular. Also, a power bank is much more compact to move and carry around, without the attached solar panels (the exception to the rule is the Powerfilm LightSaver Max Portable Solar Charger, which costs around $380USD and is difficult to find).

Based on my testing of a variety of crystalline style portable folding solar panels from Amazon, the Anker has a very good quality 21W portable solar charger which has a better-than-average voltage regulator built-in. It’s this small circuit that separates many of the made-in-China fold-able solar panels found on Amazon, from the USA designed versions. More on this below.

PowerFilm‘s thin film F15-1800 30w is the solar panel I’ve settled on for my solar charging needs. PowerFilm panels use amorphous silicon (a-Si) thin-film solar modules (like on a solar powered calculator), versus crystalline solar cells. The efficiency of amorphous solar panels is not as high as those made from crystalline solar cells, so the amorphous panels are larger, but cost quite a bit more. The advantages of amorphous panels in a bug out situation though, far out weight the higher efficiency of the smaller crystalline panels. The advantages include:

they charge better in overcast conditions — which is a more realistic scenario than expecting full sunlight each and every day
they are bullet proof (literally!); Powerfilm panels stand up to abuse and will continue to produce a charge, unlike crystalline panels, which when damaged, pretty much make the entire folding solar panel set, toast
they are flexible; they can be rolled up or folded up into a much thinner profile
because amorphous panels are thin, they are much lighter to carry
Powerfilm’s version of the solar cells are designed to output 12V; this allows for charging vehicle batteries; in addition to using cigarette lighter accessories such as a 5V 2.A USB charger to charge your mobile phone

In terms of reasonable performance, you want at least a 20W panel to charge a mobile phone in a reasonable amount of time (4-6 hours). 30W or 60W folding solar panels are preferable, but much more expensive and larger when folded.

To calculate the actual amperage (which is what determines how quickly something can be recharged), divide the rated watts of the panel by the voltage. For example, a 20W panel will theoretically produced 4A at peak performance given that USB devices operate at 5V (20W / 5V = 4A). Based on this theoretical value, I usually take 60% of it to get an ACTUAL operating value you would get in the field (4A x 60% = 2.4A real-world expected charging capabilities). Then, if the panel offers up 2 or more USB connections, I divide the real-world result by that many ports (solar panel with 2 USB plug-in ports = 2.4A / 2 = 1.2A typical output).

The listed wattage rating for a folding solar panel, is the optimal output during ideal sunny conditions between 11am-4pm, with the panel perfectly angled towards the sun. Unfortunately, you will rarely get this kind of output on a consistent basis. In theory, when trickle charging a device directly off a solar panel, and some clouds roll in and block the sun, the solar panel’s voltage regulator is supposed to compensate and properly lower (step-down) the output amperage while continuing to trickle charge the device. In reality, when clouds appear, the less expensive folding solar panels from China, simply shut down the solar panel output, producing NO charge. This means you have to be very conscience of any clouds, and need to continually monitor if the solar panel is still working or not, which sort of defeats the purpose of having a solar panel automatically and continuously charge a device back to full capacity. If this happens to you (clouds appear), then you will need to manually unplug the device from the solar panel, wait a few seconds, then re-plug it back in, in order to restart/reset the trickle charge coming out of the solar panel. You’ll assume that because the sun is back out, that the solar panel is automatically going to start charging your device again, but this will most likely not be the case.

After much testing of several Amazon folding solar panels, it appears Anker’s solar panel circuitry is one of the few that adjusts for cloudy conditions and continues to produce output through a wide range of sunlight conditions, whereas the lesser brand solar panels do not. One last important note: If you are going to trickle charge a device or re-charge a Power Bank with the solar panel, leave the solar panel exposed to the sun for at least 1-2 minutes first, BEFORE you plug anything in. This allows the capacitors in the voltage regulator circuitry to “charge up” or create/fill-up a buffer so that the trickle charge is more consistent. Otherwise, plugging in the device or Power Bank immediately after setting up the solar panel, will not give you the best trickle charge, because the device will be immediately draining these capacitors and not letting them establish their full capacitance.

With all that technical detail behind us, the bottom line is that typically, a 20W solar panel will produce about 1.2A to 1.8A consistently at around 5V while the sun is out with no clouds. Compare that to the quick charge wall warts that operate at 2.4A or even 3.0A now-a-days.

A very useful tool to pair with a solar panel is a USB Multimeter, which measures the voltage and amperage being sent to your device. I definitely pack one of these at all times with my solar panel kit to help troubleshoot, test, and estimate how long it will take me to charge my mobile phone and other USB chargeable devices.

There are primarily two mass-market brands that dominate the LED headlamp market in the big-box camping stores (REI, MEC, MooseJaw.com, Backcountry.com, Amazon, etc): Petzl and Black Diamond, although any brand of headlamp will outlast you, unless you really abuse your equipment. I have a Tikka XP from 1992, that is still going strong. The three key areas where headlamps have improved in recent years, beyond the typical weight reduction attempts, are:

1) dimming technologies (that improve battery life), and advances in

2) LED brightness, along with

3) weather/water-resistance

MARCH 2017: I’ve also started considering the Fenix brand of headlamps as they are offered in 1 x AA and 2 x AAA form factors — using fewer batteries and weight less.

Of course, the primary purpose behind a headlamp is to free up your hands. Pretty much all the mass-market headlamps now use 3 x AAA batteries. The newest craze is USB-rechargeable (but that assumes you now bring a USB charger or a folding solar charger PLUS the cable with you — for longer trips).

Instead, I prefer to stick with readily replaceable batteries. I use the very convenient Store-A-Cell battery holder/carrier/caddy by PowerPax and simply bring spares. The 6 x AAA glow-in-the dark version is what I carry for all my camping trips. Recently they’ve introduced a 4 x AAA version if you don’t need to carry as many batteries. You should try to standardize on AA or AAA size batteries for all your electronics.

I’ve been partial to the Zipka Plus over the years, because it is so light weight, and by using the re-tractable head strap, you can strap it to your wrist. Recently, I’ve switched to the Black Diamond SPOT headlamp (shown in the featured picture above), simply because the newer LED in the SPOT is much brighter than my Zipka Plus (from 2007). The SPOT also has a red LED for night vision, is very simple to operate, even with gloves on. It is currently the best rated headlamp on the market for the under $40 price-point.

MAY 2019: In my foray of looking for the best headlamp, I believe I’ve come across the best priced solution for my purposes — the single AA powered ThruNite TH20 (in neutral white), for under $30USD/$40CAD. I absolutely love this headlamp compared to all previous headlamps I’ve owned primarily because it runs on a single AA battery in an unbreakable aircraft-grade machined aluminum shell, and is super-simple to operate. The headlamp is easily removable from the head strap to become a flashlight and has a very nice big on/off button that controls an “infinite” brightness adjustment (moonlight=0.5lumens to 250 lumens in turbo mode) which produces an excellent flood/beam pattern for camping purposes. The headlamp uses a well designed reflector with a 2014-engineered Cree XP-L (V6) diode. The headlamp comes with replaceable o-rings and is waterproof to 2 meters. If you want more brightness, you can swap the AA battery for a 14500 750mA Li-ion rechargeable battery to produce up to a 520 lumen blast of light in turbo mode, so you can see that 1/2 mile ahead of you on your midnight walk down the trail, blind other campers across the lake, or send SOS signals to the moon. It does not have a red LED for night vision, but I’ve always found this option under-used during camping, unless you are star-gazing. I do have the small Nite Ize Moonlit LED Micro Swivel Lantern in Red, that I use inside my hammock or tent, if I need red light.

Practically speaking, at a campsite you only really need about 25-30 lumens (think 30 birthday candles worth) of brightness to do most tasks — like washing up, reading in a tent, and visiting the thunderbox during the night. So any of today’s headlamps (or flashlights) are over-kill in terms of the brightness you need. This means any light you choose will last a very very long time (upwards of almost 2 weeks on a fresh set of batteries) if you operate the flashlight on the more practical lower brightness settings. Too much light is harsh on your eyes during the evening, and is annoying as heck to everyone else you decide to face head on. By using only a single AA battery to power your primary light needs, you’ve reduced the need to carry so many spare batteries, and you know that you cannot mix up a used battery with a new one. Just remember to unscrew the cap by 1/4 turn when you pack the TH20 away in your pack, so the push button doesn’t accidentally get turned on.

JAN 2019: On the topic of lighting — I was on a camping trip recently where there was a fire ban, so we used a general purpose lantern to mimic a campfire at night.

I’ve used my fair-share of lanterns over of the years, and by far the best lantern I’ve used to date which impressed me and I now recommend to everyone, is the $20 Goal Zero Crush Light Solar Powered Lantern (available from pretty much any outdoor retailer, or Amazon). Not only is it compact (about 6″ in diameter) and solar/USB rechargeable, but it has a flicker mode that emulates a candle (and in this case a campfire). Its even sufficiently waterproof to be used upside down as an emergency bowl if you forgot yours, or need a spare at the site.

But by far the biggest selling feature for me was the quality of light. Unlike many LED lanterns out there that produce a cheap and harsh blue-tinged light, this Goal Zero product uses a very nice LED that is yellow tinged, like an incandescent light bulb, which is easier on the eyes in the evening. Expect a solid 4-5 hours of light in medium mode, and more than 10+ hours in low mode — more than enough for the evening. Also, the lantern crushes down or or folds flat to a very portable form factor when packing up, and can be recharged from a Portable Power Bank over-night, if necessary. Keep in mind that you only need about 5 lumens of light (low power mode on most flashlights/headlamps/lanterns) to see sufficiently in a 10 foot radius, when performing tasks. At 5 lumens, all lighting devices running on a battery will last at least 10 to 12 hours to get you through the night.

In general, you want to pack two forms of light in a bugout bag; one for general purpose AREA lighting, and another that you can carry with you and is localized to the task you are performing.

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