Bushwalk Australia

Being a bit of a tight $#%@ and after nearly being ripped off from another seller when buying a Power Traveller Solar Monkey at a price that was too good to be true, I decided to give one of these elcheapo eBay/aliexpress solar power banks a go.

http://www.aliexpress.com/store/product ... 36109.html


Its rating is 50000mah which I knew when I bought it that it wouldn't be any where near that (I read quite a bit about them prior to purchasing). They supposedly get the rating because the solar panels will keep the batteries topped up...which is also not quite the case.

It arrived and it charged several of our Apple products ok, it charged the go pro ok and in fact it charged anything that uses usb.

The solar panel was virtually useless. I left it in the sun for several days and the charge lights didn't change. Eventually (within a couple of weeks) the solar panel stopped working all together. It no longer lights up the charge lights, not that it did anything anyway. The supplier offered to take the product back but for $20 its not worth messing around with.

So that leaves me with a battery bank. I took it on a few hikes that were no more than 2-4 days and it kept mine and a friends phones in charge over that period, so I was pretty happy with it as far as its storage capacity.

I am about to walk the OLT track so I thought id be a little more scientific on measuring its capacity to make sure it will keep my iPhone 6 charged as I am using it to take my photographs.

So here are the results.......

I fully charged the power bank. Well I got it too light up 3 out 4 lights, sometimes when it fully charges it lights up all 4 lights, other times it will only charge until 3 lights are lit up regardless how long its been charging!

So all these tests are using the same iPhone 6.

Day 1 Battery level 18% to 100%
Day 2 Battery level 49% to 100%
Day 3 Battery level 55% to 100%
Day 4 Battery level 30% to 97%
Day 5 Battery level 36% to 100%
Day 6 Battery level 77% to 79% .......battery pack flat.

It charges the phone quite fast. One usb port is supposedly 1 amp and the other side is supposedly 2 amp although I don't see a difference in charge time from one side to the other.

I am not a scientist but I think that gives me around 310% charge. I think an iPhone 6 has around a 1900 mah battery so going by my tiny little brain I figure my 50000mah battery pack is around a 5890mah or there abouts.
Possibly slightly more considering losses etc.

I am going to do the same test again when the battery pack has one of its 4 light charges and see if it makes a difference. But for around $20 id say they are reasonable bang for buck?? Oh and it weighs 205g.

What do you think? Would you buy a cheapo power bank like this?

Danshell - I've had more than a few of these cheapies battery packs over the years. I'll make my reply in two sections - the battery pack, and the solar component:

Battery Pack
The 50000mAh capacity is certainly over-rated. I posted on another forum about these over rated cheap Chinese battery packs. They are false economy for a few reasons including using cheap cells that don't last - so after about 12 months or less you find significantly lower battery capacity, or they may be using mismatched old recycled laptop battery cells which can be dangerous when recharging.

A clue to the fact that they are not the capacity they advertise is to look at the weight of the battery bank. Typically these higher capacity battery banks use a number of 18650 Lithium based cells in series. A good quality Panasonic manufactered 18650 cell weighs about 46-50grams. Looking to the weight and size of the battery bank, now the highest true capacity 18650 cell manufactured by Panasonic is 3400mAh. So to get around about 50,000mAh, you need around 14 x 3400mAh cells (or over 20 x 2200 mAh cells) which would bring the weight of the batteries alone to at least 700grams. With your whole unit being 205grams, it is definitely not near the advertised capacity.

For reference, a good quality (non-solar charging) battery bank like Anker's Astro E7 25600mAh http://www.ianker.com/product/A1210011 weighs 450grams.

If you are interested, this guy does really good tests on batteries (and torches) http://lygte-info.dk/review/batteries20 ... %20UK.html He has a summary on this page about the weights of various li-ion 18650 cells and their capacities.

Also note that sometimes it's been known that dodgy sellers fill the powerbank with packs of sand to make up the weight difference of using fewer cells for example http://says.com/my/tech/cheap-china-pow ... -with-sand and http://life.yinteing.com/wp-content/upl ... eated2.jpg.

Granted, some powerbanks use flat lithium-ion power packs (like those used in tablets and phones), but usually the shape and case will give you an indication of what cells are used inside.

Next, if you look to the price of quality 18650 cells, they can range from about $8-$10 ea for genuine Panasonic cells of about 2400mAh, to upwards of $13-15 for 3400mAh cells. Once you work out the price that would cost, even from a manufacturer's bulk purchasing, it would be difficult to imagine a seller being able to supply a legitimate 50000mAh powerpack at much of a discount.

There are more than a few teardowns of various battery packs on the web. For example, this one by Gough Lui of a supposedly 30000 mAh powerbank:
http://goughlui.com/?p=3930
He also puts it back together with some better quality replacement cells and tests it again:
http://goughlui.com/?p=4321.

Note that with 8 x Genuine 3400mAh cells (27200mAh total), it still takes well over 24 hours to charge. That makes sense if the input charge takes 1A, it would be slower again if it was 0.5A. So if you had a genuine 50,000mAh capacity power bank charging at 5V 1A input, it would take a number of days to fully charge.

Also this is another forums post from the Malaysian forums lowyat.net: https://forum.lowyat.net/topic/2793169 showing the testing of various powerbanks and teardowns of various powerbanks.

With the one you have, you can open it up yourself and have a look inside to see what they have used and work out the actual capacity of the cells.

Solar
I am not a big fan of the combined solar panel/battery banks like the one you linked for a number of reasons:

• As you found, the panel is usually too small with too low an output to adequately and quickly charge the battery (so you tend to use the AC power input to charge more often, and going off grid this can be pointless).
• The battery attached to the solar panel will get really hot during charging especially for a few hours in direct sunlight, and can lead to the battery shutting down and not charging, defeating the purpose.
• The bigger ones with built in batteries tend to be quite heavy for backpacking.

I posted previously about some of my experiences with solar panels when hiking in this thread viewtopic.php?f=21&t=18151#p246900

For reference, my Goal Zero 7w panel charges a 5000mAh battery from empty to full in about 10 hours (over 2 days). Via USB the Goal Zero outputs 5V at about 0.5A (this is for my version bought in 2012/2013 – I think the latest version has upgraded the circuitry and now outputs 5V at up to 1A). My 10w (Instapark Mercury 10) panel cuts that time down to about 5-6 hours as it outputs a higher current, and a 13w panel (Goal Zero 13) brings it down to about 4-5hrs, which can output up to 1A. The 7w panel fully charged a Sony camera battery (1000mAh) directly via USB to the camera in about 2 hours in direct sunlight. Note that the charging times can vary depending on the USB battery packs' charging input current - ie. it would charge slower if it only charging input at 0.5A.

For your battery pack, assuming that it is 50000mAh and that the solar panel component was able to provide a 1A charge, it would still take some 50 hours to charge fully from flat. So you might find that you end up using up the stored power in the battery pack at a much faster rate than you can recharge.

Keithy thanks for a very comprehensive reply.

I wholeheartedly agree with what you have said and your findings on these products.

When I bought the power bank I went with a cheap one because I even though I knew they were no where near their rating, and they wouldn't last the test of time, I didn't want to spend a lot of money on something that was an unknown and end up wasting even more money.
I needed one quickly because I was doing a multiday walk where I wanted to keep my phone charged so I went with the safest option when it comes to wasting the least amount of money.

Even though I knew this unit was rubbish in comparison to some of the really expensive power banks on the market, I also knew I would get 4-5 charges from it and for $20 I wont be disappointed when its batteries start to diminish.

However having said that and now that I have time to research and I am starting to get a bit more knowledge on these items I would like to get a quality power bank at some stage but Im still not willing to spend $200 on one. The Anker Astro you posted a link to looks like it would suit my needs. They appear to be around $150 which is getting up there in price but if they can charge an iPhone 6 10 times as they claim and they are well made then I may be willing to invest that type of money at some stage.
As for solar, its not totally necessary for me. Not when you can get a power bank that has a genuine 25000mah.

Thanks for your advice and reply.

Just out of curiosity I pulled the thing apart to have a look at its batteries.

It has 12 long flat batteries in it that are all bound together with a heavy foil. The unit is all battery though, no sand to weigh this one down. It is cheaply made with out a doubt.

Im now thinking I may be able to make some plug in additional batteries for it! I love tinkering so Im going to have a play with it on the weekend......the power bank that is

Good to know there's no sand in there at least!

I didn't realise your battery pack was one of the thinner ones - couldn't tell from the original pic.

There should be some markings on the flat battery pack inside the USB charger to give you an idea of the actual capacity. Usually they have a model number/voltage/capacity stamped on the pack somewhere, sometimes hidden by some masking tape. Don't open up the foil part though!

For weight comparison, my genuine 5000mAh USB chargers (with flat battery packs inside), weigh around 150grams (case and all). I have an older, cheap and nasty "5000mAh" pack from China, which I have long retired, but that had 2x1400mAh (or smaller) battery packs inside but weighed under 100grams.

That Anker Astro is good, but not worth $150 IMO. It sells on Amazon for USD$60, but doesn't ship to Aust through Amazon unfortunately. They do have an ebay site under the seller AnkerDirect, and occasionally sell battery packs with reasonable shipping. Sometimes they don't list all their battery packs though and don't have the E6 on there now. The biggest one I see on their store now is the 16000mAh one for around AUD$65 shipped http://www.ebay.com.au/itm/Anker-2nd-Ge ... 1597900867

Yes, if you have a big battery pack, you probably don't need the solar charger, depending on how long you are going to be away from AC source, of course. But also note that the charge time would be considerable for bigger battery packs. If you have a genuine 30000mAh pack, it can take over 24 hours to fully charge from a AC source.

Also, with cheap and nasty battery packs, it isn't just the fact you might get short changed on the battery capacity. They can damage the devices you are charging. For example, Gough Lui again does an analysis of the "ripple" in power output quality. http://goughlui.com/2014/06/09/exposed- ... s-at-risk/

The guy Ken Shirrif mentioned in the blog did some really good teardowns of wall chargers a few years back http://www.righto.com/2012/10/a-dozen-u ... le-is.html

Just on the 1A v 2A output. The current is often limited by the software on the device being charged. The iphone probably has a max charging limit of 1A anyway, which is why you aren;t seeing any difference. If you plugged in a tablet (which usually have a 2A charging capacity), you would probably notice the difference.

Secondly, charging a battery from 80% to 100% takes more effort. You will probably get more out of your powerbank if you only charge your iphone to 80% or so. If you are worried about the iphone not lasting the day, then give it 10 minutes charge at lunchtime.

Thirdly, on an extended walk, you may want to look at ways of reducing your phone's power consumption. Airplane mode is the obvious step, but also turn off auto-sync, autoupdate and any 'push' options. Also, uninstall apps that you will not be using while walking or immediately on return back into mobile range. Quite a few apps sit in the background, and periodically wake up to check for updates and the like, which adds to processor overhead. A lot of 'free' apps are quite power hungry, as the ads they use to make money are processor intensive - if it's got ads and you won't be using it, delete it (you can reinstall later).

Thanks for the info macca. I have googled all the battery saving ideas for the iPhone 6 and I am confident I will be saving as much battery power as I can. The iPhone 6 has a very good battery compared to my previous versions so fingers crossed ill keep it running for 6-8 days.

I spent some time yesterday messing around with the cheapy power bank and I have managed to harness power out of standard AA batteries for charging my phone.

I simply disconnected the battery that was built into the power bank and soldered in some temp wires to run 3-4 AA batteries in series and it charged my phone no worries. I need to keep the volts under 6 volts so I didn't damage anything but it worked with 3 AA's (4.5v) or 4 AA's (6v).
The odd thing was that it wouldn't work with my rechargeable AA's regardless how many I ran in series. It just kept turning off.

But I ran some wires out of the side of the battery bank with plugs on them and I made up another set of wires and put some foil in my 'kit' so I can use my AA's if I am desperate and run out of ability to keep the iPhone charged. I carry quite a few quality AA's for my GPS.

Its only an extra 2-3 grams and I carry the AA's anyway but it should give me at least one more full charge!

When I get back and I have more time to tinker and I can risk wrecking my elcheapo power bank I am going to work out a way to do away with the inbuilt battery and use rechargeable AA's or AAA's along with a small solar arrangement that is capable of charging it all in a days walking. Did I mention I love tinkering?

keithy wrote:That Anker Astro is good, but not worth $150 IMO. It sells on Amazon for USD$60, but doesn't ship to Aust through Amazon unfortunately. They do have an ebay site under the seller AnkerDirect, and occasionally sell battery packs with reasonable shipping. Sometimes they don't list all their battery packs though and don't have the E6 on there now. The biggest one I see on their store now is the 16000mAh one for around AUD$65 shipped http://www.ebay.com.au/itm/Anker-2nd-Ge ... 1597900867

I purchased my Anker Astro E5 1500 mah on eBay from a Japanese seller in August 2014 for AU$80 delivered. Has performed well so far. The seller was tokyofreaks23

Andrew

If you are interested in a good, compact solar recharging USB power pack, look at Brunton's Freedom Solar 2200 or Restore 2200 models. http://bruntonoutdoor.com.au/collections/power-level-one

I have an earlier model Restore 2000mAh and it's fanstastic. Leave it open and strapped to your rucksack; it's usually recharged at the end of a sunny day. Very rugged too; mine is 5 years old and still going strong.

Thanks for the info gents. Both those power banks mentioned look pretty good value. I like the idea of the Restore 2200 if they can top up in the sun as you walk.

Has anyone used the non-battery pack ones like these
http://www.ebay.com.au/itm/Mobile-Sourc ... 51bf4c227b
7 watt is said to produce 1300mA which I believe should charge a smart phone and maybe a small tablet. Any feedback from users, I wonder how a phone battery goes accepting charge from a power source that is not consistent like a battery power source is?

I purchased a supposed 5AH pack from Ebay, mine had steel weights in it to make it feel like a decent pack.

I also have a German made Tensai bank which is really good but won't charge my old Nokia E7 or my trusty old Toshiba MP3 player.

Burnsy wrote:Has anyone used the non-battery pack ones like these
http://www.ebay.com.au/itm/Mobile-Sourc ... 51bf4c227b
7 watt is said to produce 1300mA which I believe should charge a smart phone and maybe a small tablet. Any feedback from users, I wonder how a phone battery goes accepting charge from a power source that is not consistent like a battery power source is?

Burnsy
I can't be certain of the answer to your question but when I was messing around with various size and amounts of off the shelf batteries to charge my iPhone 6 it was a simple as the right amount of batteries or watts would make the phone charge but as I reduced the amount of batteries it simply stopped or wouldn't charge.
So Id imagine it would be the same using a solar set up. Lots of sun would charge it but as the light reduced the charge would at some stage turn off. I don't know if it is damaging the phones charging circuit.
What I did notice is that the phone would tolerate quite a range either side of its recommended charging rate.

Can you buy a small solar panel and let me know how it goes?

Burnsy wrote:Has anyone used the non-battery pack ones like these <snip>. 7 watt is said to produce 1300mA which I believe should charge a smart phone and maybe a small tablet. Any feedback from users, I wonder how a phone battery goes accepting charge from a power source that is not consistent like a battery power source is?

They work fine, but your device has to be connected to it to charge, so using the device at the same time can be a PIA. I tend to charge my devices at night when I'm eating / sleeping and there is no sun, so that's why I went with a solar charger with a battery.

Those solar only panels usually have a basic capacitance / bleed circuit to help dampen the over / under voltage a little.

PS. Most solar battery devices also work in pass-though mode when you have a device attached. If there is sufficient sunlight, the device gets the juice, if not the battery gets a trickle charge for later discharge to the device.

the info given in this thread is great... the "Chinese" unit i use (i buy a lot of things on EBay) is pictured below... i have teamed it with a retractable usb cord and a mini multi fit charger (bulldog clip is my addition to stop the battery coming loose while walking... i have found that on a full charge i can get two charges of a 3.7V 2500mAh battery and that it can fully charge one in about 2 hours or about the time i need to replace the one in my mobile (use this plus a "maverick" app as my gps nav) the power bank says it has 10000mAh capacity with 200mA charging in full sun.. i assumed that the capacity was either over optimistic or a miss print but its doing well and almost a year old...
i do also have a solio2 (295g) and a 20W/2amp solar panel (650g).. the solar power bank pictured is 150g..
on day walks i carry the Chinese unit, actually its usually attached to my pack i wear daily.. on overnight walks i carry the solio as well and on longer walks i carry the 20W panel instead of the solio...

on a side note aldi will be selling on 21st march '15 both a hand cranked charger($20) and a 1200mAh solar power bank($10)

Aldi will be selling the Bauhn Solar Charger this Saturday for $10. It has a 1200mAh battery built in:
https://www.aldi.com.au/en/special-buys/special-buys-sat-21-mar/saturday-detail-wk-12/ps/p/solar-charger-1/

That's ten dollars

TEN DOLLARS!