Power banks - powerbank - avoid or not?

[hifihifi]

How to know when you buy powerbank with good electronics that not damage Phone at all?

I want to go on holiday and buy a cheap powerbank.
But I know cheap powerbank is cheap electronics. Unstable 5V or spikes are bad for smartphone. I read on the phones that some powerbank generates even 8V at startup.

I don't want to distroy my smartphone, expecialy on holiday.
Some people do not distroy smartphone but damage charging circuit inside smartphone and getting draining battery (this people already change battery and still high draining battery).

Any advice? or test from bad/good electronics in powerbanks?

[Rerouter]

To my knowledge, smartphones are pretty solid, as just about all the cheap chinese wall chargers pull the same, so once your phone is charged its sitting there at 8V, (This is part of why the whole finished charging please unplug message appears)

In short most of them will be a single lithium cell and a boost converter with the absolute minimum in the way of parts, a larger capacity one will be 2 or 3 lithium cells, with resistors strapped on the data lines to show they are a 2A charger or similar even if they can only handle 300ma (one i got in France)

The only good ones i have gotten where a promotional item from Australia telecom telstra, the even have a 2 way rocker switch, rather than the generic soft power switch that gets bumped in your bag and runs flat,

I think dave's catchphrase holds truest with these, dont turn it on, take it apart (or atleast measure it yourself)

[chrism2010]

Martin over at mjlorton.com did a comparative review of some power banks last year - might me helpful?

http://www.mjlorton.com/forum/index.php?topic=808.0

[dannyf]

"Any advice? or test from bad/good electronics in powerbanks?"

Way over thinking it.

Buying a reputable brands and you should be mostly OK. Unless you are rich, don't buy cheap.

[edy]

The cheap power banks are mostly lying about the mAh capacity. They may claim 4000 mAh and be only 2400 mAh or worse. Also, some may be fakes of reputable brands. Many will add sand inside to increase weight to also trick you into thinking that it has more batteries.

Bottom line: whatever you buy, make sure you can return it after testing it yourself on your phone.

I bought a power bank from a local store, brand supposedly "reputable". For one, rated at same mAh as my wife's power bank that was charging my phone 3x to full capacity from 0%. The one I bought barely charge my phone once to 70%... and the USB port and cable was getting so hot, I measured measured measured with a thermocouple and got close to 80 degrees Celsius! I complained to the company and they sent me a new one. Also I returned the old one for a refund. The new one was still garbage. So I wouldn't trust ANYTHING unless you have a way of returning once you test it. If the place doesn't allow refunds, don't buy it!

[tszaboo]

If you want a high quality power bank to charge your phone, buy a Xiaomi power bank. I know, it is chinese, but they are really top shelf. Samsung cells, protection, durable case, proper everything. Make sure it is original.
I dont know why people bother with these no-name brands.

[SteveyG]

I've found the RavPower battery banks to be pretty solid. The output looks great on the scope and capacity is not far off advertised.

[Iwanushka]

Try samsung power banks they have panda edition version which is best PB to my knowledge, you can also replace 18650 cells, it has integrated microusb cable and regular usb A socket so you can connect any usb device to charge, only problem with that PB it takes all night to charge it

[hans]

If you want some mainstream information, here it is:



In short: don't buy cheap crap. Buy a decent power bank from a reputable manufacturer, they will never dare to touch garbage lithium cells or dodgy charging circuits.

I've bought a Xiaomi power bank and can recommended them. They also function nicely as an UPS for e.g. an RPi (although not the most ideal scenario); i.e. they won't disable their output when charging.

[System Error Message]

i suggest avoiding cheap generic/fake stuff as its not just the capacity but i've also seen them tested.  The generic ones all have that white case with solar panel and a fake power rating, the 1A port outputs 500mA and the 2A port outputs 1A when charging your phone.

Instead of just buying for a one time occasion why not spend a bit more and buy something that would last you for at least 2 years. There are many decent power banks but go with the one that provides an accurate description that doesnt try to lie or miss out details. Linustechtips did a review on waterproof powerbanks and the reasoning for their choice was more that the description of accurate (resistant rather than proof in wording).

Cheap/generic stuff tend to have fake lithium batteries meaning batteries that have varying capacities that dont match their rated capacities. Ultrafire batteries are a prime example as people have opened them and shown what exactly is inside. You can if you want to save money go for basic power banks like amazon branded power banks for example but whether or not they would be good for your stuff depends on what you use them for as they dont exactly provide much benefit if you want to charge your tablet or thin laptop.

[retiredcaps]

I have nothing to contribute towards the powerbank discussion, but if you want to make your smartphone last the entire day while you are on vacation, you can

- turn off wifi when not needed
- set your phone to go into standby after 30 seconds of non activity/touch/use
- turn off all background checks for software/syncing info, etc
- turn on low battery use mode (or maximize battery life mode)
- turn off bluetooth if not needed
- bring a dedicated separate camera for your photos, videos
- recharge your phone to 100% during night time when you are sleeping using your original charger
- turn down the brightness setting

[encryptededdy]

If you want a high quality power bank to charge your phone, buy a Xiaomi power bank. I know, it is chinese, but they are really top shelf. Samsung cells, protection, durable case, proper everything. Make sure it is original.
I dont know why people bother with these no-name brands.

From my experience trying to buy a Xiaomi power bank, it's rather difficult to find a genuine one when buying off ebay, aliexpress etc. especially if you've never seen a genuine one in real life before to compare to. There are some very good fakes out there.

[amyk]

Get the ones that have replaceable 18650s and then put your choice of quality cells in them.

[bitslice]

I've found the RavPower battery banks to be pretty solid. The output looks great on the scope and capacity is not far off advertised.

Really happy with my Ravpower too, huge capacity.
I've got other unrelated stuff by Xiaomi, top quality manufacturer.

[depeje]

I've got a couple of power banks and when I measure the capacity they've only got a bit over half their rating. It might be correct if I multiply the result by 5/3,7. Do they all specify the capacity at the cells, and not at the USB port? Or is it just mine which do that?

[Kilrah]

Do they all specify the capacity at the cells, and not at the USB port?

Yep. One of these things that one manufcturer started doing to have bigger numbers to boast, and everybody of course had to follow for obvious marketing reasons 

[dannyf]

"but if you want to make your smartphone last the entire day while you are on vacation, you can..."

Sounds easier to just turn off the phone.

[depeje]

Do they all specify the capacity at the cells, and not at the USB port?

Yep. One of these things that one manufcturer started doing to have bigger numbers to boast, and everybody of course had to follow for obvious marketing reasons 

I'm already looking forward to the days when a new battery chemistry with different voltage is going to be used in these things... If we make these with NiMH cells, couldn't we boast even bigger numbers?