Bushwalk Australia

Yes, certainly a bargain ! The only issue I have found is that when charging my phone, any shadows or clouds that pass over the panel stop the phone from charging and it won't restart without unplugging and plugging it back in.

I found the same but it is true of all panels without some form of built in storage. To use it on the move where there are regular shading events it is best to use it to charge up a battery pack and then use that to charge phones etc.

Turfa wrote:Yes, certainly a bargain ! The only issue I have found is that when charging my phone, any shadows or clouds that pass over the panel stop the phone from charging and it won't restart without unplugging and plugging it back in.

Apparently there's small module for some solar chargers to fix that issue... for the life of me I can't find it...
One of the US brands were sprouting on about it... Anker maybe?

That's about all I can find quickly!

Now the question is - does anyone make a third party version to fit between your phone and your choice of solar panel...?

The problem is mainly with phones as they have their own fairly fancy charger built in so the restart feature doesn't work properly. It is a great benefit for devices with simpler charging electronics. There is a auto restart built in to the Anker panels which are excellent when more power is needed - discussed at the start of this thread. From what I have read all the Goal Zero stuff, while reliable, is totally over engineered and thus remarkably heavy.

That is correct. Most smart phones and some powerbanks do not like the variable voltage coming out of a temporarily obscured solar charger like on a cloudy day or under tree cover. The voltage drop for phones like iPhones mean that it starts when the voltage is over 5V but when voltage drops due to clouds or tree cover the iPhone stops and does not resume charging at full power even after the solar panel is exposed to direct sun again.

Some panels have included some charging restart capabilities in the controller circuit. This sometimes detects a drop in voltage/current and cuts power to the usb port or sometimes they will cycle the power when it voltage/current hits a set lower limit.

This cheaper 6.5W panel does not appear to have an auto reset feature in the controller. A few of my other panels have an auto reset controller.

Another issue to be wary of when you are trying to direct charge phones using USB solar panels is that even if your panel has a auto reset circuit, is that in low sunlight conditions, the phone might appear to be charging, and it might charge at a slow trickle charge rate and the recharge icon might appear on your phone. However, even if then exposed to full sunlight conditions, the phone will not leave the slow trickle rate as the phone is charging although not slow enough to trigger the auto reset circuit. This means that your phone might display the charging icon, however the battery may decrease due to the charging rate being locked in at a very low current until the phone is unplugged and replugged in to the panel in full sunlight conditions.

This is why it is preferable to add a battery pack between the solar panel charger and a smartphone, as Mark suggests. Most USB battery banks can take a very low charge current and still charge the batteries satisfactorily.

I have had success in directly charging non-smartphones, and cameras - my old Goal Zero 7w panel fully charged a Sony camera battery (1000mAh) directly via USB in about 2 hours in direct sunlight on a sunny snow covered mountainside. But typically for smartphones and tablets, I will use a powerbank charged by the solar panel.

So for light and cheap panels, charge via a power bank and then use that to charge your phone. Is there something you need to lookout for when buying a power bank, to avoid having the same problem people are having with charging directly to phone?

A quick update on the single panel 6.5w solar panel mentioned here viewtopic.php?f=21&t=24317#p324947

I just did the Great Ocean Walk last week, and in between the wet days had some very hot sunny days. I'm happy with the performance of the panel for its weight.

It performed quite well in non-ideal sunlight, and would restart charging when exposed to sunlight. I had it attached to my pack and while walking and did not always have it facing the sun, nor at an ideal angle and occasionally under tree cover. Despite this, it managed to charge up my fully flat 10000mAh Xiaomi battery bank almost halfway in around 5-6 hours walking. I then used the battery bank to fully charge the 4100mAh battery in my phone (from 15% to 100%) in the evening, with some charge to spare. I forgot to bring my USB power logging monitor along to record the charge capacity from the panel to the battery bank and will try that on day walk soon.

Note that I was using a USB cable that can charge at higher currents (>0.5A) connected between the solar panel and the battery bank.

There’s a difference to the USB cable?

GPSGuided wrote:There’s a difference to the USB cable?

Cable type can have quite the impact on charging time. USB cables are not all equal. The cheaper ones (or free ones that come with some devices) usually have thinner wire thickness. Thinner wires have greater resistance and this can cause voltage drops and slower charging. This can be further exacerbated by longer cables or USB cable extensions.

I have separated most of my micro USB cables into rubbish/slow charging/fast charging. The rubbish ones are in a pile of cables for recycling. I use the slow charging cables for dumb USB devices that do not require >0.5A power, like some LED lamps that I have that are powered by USB.

Some cables have markings referring to the AWG (American Wire Gauge). This can be helpful in selecting a faster charging USB cable. The lower the AWG number, the thicker the wire. The higher the AWG number, the thinner the wire.

The typical AWG numbers are 20, 22, 24, 26, 28. Most of the cheap/free USB cables out there are AWG28. This includes older cables like those micro USBs from my pre-2009 Nokia phones. These would only charge at <0.5A even when connected to power supplies that can output higher currents.

Note that some cables have two sets of numbers for AWG like 28/24AWG. This is to differentiate the data line gauge and the power line gauge. So in this example (28/24 AWG), it is 28AWG data/ 24 AWG power. For charging purposes, only the second AWG number for power is of concern.

Also note that many cables do not display the AWG.

My first forays into solar USB charging were when the USB standard was only 0.5A for charging. These were when devices did not need the faster charging, but even then using longer cables or cable extensions led to slower charging due to the voltage drop.

As a comparison, to my example above where charging the 10000mAh batttery bank with the 6.5W panel to around half (say 5000mAh) in around 5 hours. In Nepal three years back, it took me around two full days to charge up a 5000mAh battery bank using a 6.5W panel with output at <0.5A.

Thanks Keithy for the explanation. Never thought about that in past and more to learn and remember. The gauge restriction made sense, at least it's not due to some electronic circuitry that I wasn't aware of. So apart from the gauge labelling, how do you tell the difference? I don't think I have ever seen a charge cable with their gauge marking, need to check. Do you have some other device to test? I assume that with higher current, those thinner cable would just act as a resistor and heat up, right?

Yes, a 'low current' cable will get warm, or warmer than a when charging a lower current device. These were built for 0.5 amps, the older standard.

A search on fleebay for "USB cable hi current" gets a few hits .. some for 2 amps. Some include a digital display of current and voltage, that would reduce the charging power a little compared to a cable without a display.

GPSGuided wrote:Do you have some other device to test?

Around 2013/2014 I used to use a spliced USB cable (stripped open with the +ve wire cut) combined with a multimeter and use it to test my USB gadgets and devices while charging, to see what the current draw the devices are pulling.

But this was unwieldy when using it with my various solar panels as initially intended to test. It was during this investigation that I discovered the discrepancies between my various USB cables and investigated further.

I have now got a small collection of various USB current/voltage meter testers, some of which were very cheap. The cheap ones do work out ok, but they do not read very low currents (usually not a problem for testing solar panels and cables).

Gough Lui who does interesting electronics and gadgetry reviews did a teardown of two types of these, both of which I have now got – http://goughlui.com/2014/10/27/review-t ... nt-meters/.

He also did a reverse engineer of it http://goughlui.com/2014/10/28/reverse- ... er-doctor/ and you can see more info there

I also have an Xtar one, and a Keweisi KWS-V20 which includes a memory log of the cumulative capacity in mAh passing through. The OLED screen ones are difficult to read in direct sunlight however.

There are other various meters out there, HKJ does good reviews on them http://www.lygte-info.dk/info/indexUSB%20UK.html. Search the page for "meters". I also picked up a more expensive model called the "YZXstudio". These are more precise, with upgradable firmware and output logging but are quite a bit more expensive and to me a little more delicate compared to the cheaper ones.

Alternatively, another way I found to sort through my cables are to take a high current USB wall socket charger (eg one capable of charging >2A) and a device that accepts a charging current of >2A (my newer smartphones/tablets), and an app that will read the voltage/current from the phone/tablet's charging controller. I use an android app called Ampere, however it is not compatible with all phones due to the chipsets used in each phone. It is not as accurate as the usb meters or a multimeter, but as long as everything else is the same (USB wall socket and device) is a good way to separate fast and slow charging cables.

For example, when my tablet is down to <25% charge, I will run the Ampere app and using various cables plugged into a 2.4A USB power socket. Fast charging cables will show a charging amps of around 1.6A, and slow charging cables will show a charging current of 0.5A or less.

brilliant!

Those 6.5W Solar Panels are now down to AUD$14.78 on eBay with free shipping.

Stew63 wrote:Those 6.5W Solar Panels are now down to AUD$14.78 on eBay with free shipping.

Stew63 - do you mean the ones that look like this?

While at first glance they appear similar, they are a different panel and have different characteristics.

These have the "handle" notch at one end. Their panel has 10 panel segments vs 12 segments on the other 6.5W panel.

How do I know? Well... I also got that one to test out earlier in the year. I think I still have it in my box of tricks somewhere. I will take a pic to compare a bit later.

Hiking apps and music tend to suck my apple and android phones dry pretty quick.

So I bought an Anker solar recharger cheap off ebay:

https://www.anker.com/products/variant/ ... s/A2421011

Overall it's been great. It is not very good, however, during a 4 day blizzard when I really really needed it to work!

A dude showed how he tortured his on youtube so it's tough too...

cheers

LBC

Crieky I thought $159 was OK. Got the 21w Anker for chrissy and am happy with it so far. I was told you can charge a phone and battery pack in about 4hrs full sun which suits me.
For vehicle lighting I use a Luci 2.0 and it's great, only use it on low.

Lord Backcountry wrote:Hiking apps and music tend to suck my apple and android phones dry pretty quick.

Extending battery life;
Put the phone into 'aeroplane mode' - particularly if you are getting away from the cell phone towers - say 2 or less bars.

Music/podcasts should be plaid over earphones. Not all ear phones are equivalent, some are louder than others .. I have not tied them for how quickly they flatten batteries, do the louder ones flatten the batteries even a lower volumes than quieter earphones plaid at a higher volume? Don't know.

A spare battery for my android phone cost $10 off ebay. Think I'll keep that one for essential or near essential use.

The Authentic SUNWALK 6.5W Outdoor High-effect Solar Charger Panel 5V/1.3A USB output arrived from Fasttech this week!

Plugged it onto the Nitecore Fujifilm charger and it is working.

Is there any way of getting a good quality Fullsize USB extension cable?

Jaycar has a testing cable, anyone found it working well?
https://www.jaycar.com.au/usb-power-met ... y/p/XC5073



And also available a short 0.5m $5.95 extension:
https://www.jaycar.com.au/0-5m-usb-2-0- ... e/p/WC7708
(also longer lengths available)

Neo wrote:Crieky I thought $159 was OK. Got the 21w Anker for chrissy and am happy with it so far. I was told you can charge a phone and battery pack in about 4hrs full sun which suits me.
For vehicle lighting I use a Luci 2.0 and it's great, only use it on low.

Update post: The Anker has served me well, travelling around by vehicle.
Gets some charge on a cloudy day, quite good if there is full sun.
Still working fine no issues.
Haven't carried it on a trip as my phone battery is cactus anyway.
Good for topping up battery packs and Bluetooth speaker when parked or have the panel on the dashboard.

Recently got a new battery charger with a USB input cable, yet to test the timeframe for two AAAs in it with the panel.

photohiker - I suggest you check that the cable you linked to will display both voltage (as shown) and also amperage - voltage alone is not very useful. I got a couple of USB-micro USB cables from Banggood (https://www.banggood.com/Bakeey-2-in-1- ... rehouse=CN) which have a volt & amp readout built into the USB plug itself. I also have a pass though type version (https://www.banggood.com/0A-3A-3_5V-7V-USB-Charger-Voltage-Current-Meter-Mobile-Tester-Amper-Voltmeter-Power-Detector-p-1133173.html?rmmds=search&cur_warehouse=CN) but I don't find this a useful as the USB plug can be too big to fit slightly recessed sockets.

Ok, will see what it does.

The charger is working through the window:

Mark F wrote:photohiker - I suggest you check that the cable you linked to will display both voltage (as shown) and also amperage - voltage alone is not very useful.

Hi Mark, found the info of that Jaycar device: "The easy to read LCD display alternates between voltage and current passing through"

https://www.jaycar.com.au/usb-power-met ... y/p/XC5073

Will pick one up tomorrow and see how well it works.

Just be careful where you put the spaces when you write “21W Anker”!

Hi, I know this thread is a few years old now, but hoping for an update. On the basis of the information you all provided here I spent up big on a 6 watt 5 volt solar panel from Fastech, exactly the same model discussed in this thread. Happy to say, that after what seems to be the usual wait time and very polite offers of a refund, a change in model (colour) by Fastech, I'd held out until last week, and just as I gave up it finally arrived. I've been charging a few devices to see what it can do. I am keen to get an update on your own experiences with this panel, especially now its been a couple of years, hear about any trips, your successes or challenges with the solar panel and charging devices? I am walking the AAWT next year, never owned a hiking panel, and want some reassurance that my $10.40 solar panel (including postage!) is up to it. Thanks in advance - Marc

I haven't had any issues with my setup. The key thing to determine is your power requirements. You also need to consider how you will deploy the panel. If you walk all day from sunrise to sun set then a panel is unlikely to work for you - they really don't work hung from the back of your pack; too much shading and varying light levels. If hanging from your pack then only charge a battery pack. The more sophisticated charger circuits in phones keep restarting and little if any energy is added.

You also need to consider carrying a battery pack to cover you for cloudy days. The size of the pack is determined by your needs. I allow for three days of capacity in the battery pack and you also have about that in the internal batteries in the devices you want to charge - so 5 to 6 days capacity all up. I usually rely on a single battery (3400 mAh) but if I expected cloudier conditions I might take two. I don't bother with solar for trips of 4 days or less.

To give you some idea how it works for me I get a bit under 3 days out of my phone battery (gps, maps etc in flight mode and turned off at night). My headlamp (Petzl Bindi 680mAh) needs recharging once a week on average and the Steripen (850mAh) the same. I now have to factor in my inReach mini (1250mAh 1-2 messages and a weather report per day, no tracking) but I haven't got a handle on that yet but I expect about once a week. While I can run the devices for the length of time mentioned I try to recharge them when they get to 40-50% and charge them up to 80-85% for efficiency. I will charge them further once my battery pack is full and conditions permit. My first aim is to keep the battery pack fully charged (this provides flexibility); once that is done I will then charge the phone, then the inReach, then the other devices as I can live without them if needed.

I tend to be a slow starter so I get some charging time in the morning while I eat breakfast and pack up and then an hour for lunch and hopefully a period in the late afternoon when I have finished for the day.

Thanks for getting back. Very helpful. I have been doing some guess work on how much power the panel is delivering. I estimate that it has produced well over a 1000 mAh on two partly sunny days in October. Good to know that I am not to expect that on top of my pack. While catching the light around the backyard that hadn't yet sunken in. I am happy to adopt your long breakfast and lunch strategy – I can live with that!

I had a further question. When you refer to use of a battery pack, are you using a standard power bank, or is it something with protections (like for overcharging, or do you find you can keep a close eye on it)?