# 18650 power bank



## bella-headlight (Jan 8, 2016)

So having got into 18650"s this year & getting some decent cells, chargers & DMM I am now thinking of buying an 18650 power bank enclosure to put my own cells in.
Any recommendations ?
I am thinking of getting this one by Soshine http://www.ebay.co.uk/itm/151752857352?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
It takes 4 x 18650"s & has 5v USB outlets of 1A & 2.1A.


----------



## kreisl (Jan 8, 2016)

i have Tomo V8-4 coming in, looks like a nice plasticky one with on/off switch. i can't recommend it yet, still need to test it. there are lots of reviews on the WWW, mostly positive.

http://club.dx.com/reviews/285415/656941


----------



## bella-headlight (Jan 8, 2016)

The Soshine looks very very similar to this Tomo power bank http://www.ebay.co.uk/itm/Tomo-Port...109147?hash=item25b0451c1b:g:EiMAAOSwo0JWJyxi but a bit cheaper & white not black ?


----------



## Timothybil (Jan 8, 2016)

Looks nice. Be aware that the total output of the power bank is 2A per the documentation, so that if you are charging an iPad on the 2.4A jack, that is all that is available. I don't know if that means the 1A jack would just be dead, or if whatever was being drawn from the 1A jack would be subtracted from the 2.4A jack. Also, that is my interpretation, you might want to ask the seller to make sure.

For any power bank, keep in mind that there is an approximate 10%-20% power loss due to the voltage conversion circuitry in the power bank. Then there will be a similar power loss in the device being charged as well. It means a big hit on the available charging capacity, but for the most part that is made up by the ability to have a portable source of power not tied to anything.

At that price, if I was buying it, I would buy one and put a single cell into it just to check how well it works and holds up. If it seems okay, I would buy a second, and fill both of them with 2300 mAh or 2600 mAh cells. That way I would cut down on the cost of cells compared to the more expensive 3400-3600 mAh cells, and have two power banks available. Just like with lights - "One is None and Two is One!"


----------



## CuriousOne (Jan 9, 2016)

These "1A" and "2.1A" jacks in reality, are just wired to same supply. They just difer by resistor dividers on DATA pins, so apple devices will know how much current to consume, that's all.


----------



## TinderBox (UK) (Jan 9, 2016)

As has been said there is an Soshine and an Tomo version of the charger, I have the Soshine version, I have we think a newer version that shows the ma being used while charging a phone/tablet ect, the older version only shows the battery levels.

John.









bella-headlight said:


> So having got into 18650"s this year & getting some decent cells, chargers & DMM I am now thinking of buying an 18650 power bank enclosure to put my own cells in.
> Any recommendations ?
> I am thinking of getting this one by Soshine http://www.ebay.co.uk/itm/151752857352?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
> It takes 4 x 18650"s & has 5v USB outlets of 1A & 2.1A.


----------



## bella-headlight (Jan 9, 2016)

TinderBox (UK) said:


> As has been said there is an Soshine and an Tomo version of the charger, I have the Soshine version, I have we think a newer version that shows the ma being used while charging a phone/tablet ect, the older version only shows the battery levels.
> 
> John.


 Hi John, do you have a link to the Soshine one in your pic as I can only find the one I have already linked to, a Soshine E3 or the Tomo equivalent ?


----------



## bella-headlight (Jan 9, 2016)

kreisl said:


> i have Tomo V8-4 coming in, looks like a nice plasticky one with on/off switch. i can't recommend it yet, still need to test it. there are lots of reviews on the WWW, mostly positive.
> 
> http://club.dx.com/reviews/285415/656941



From what I can tell the Soshine E4 & Tomo V8-4 are the same power bank.
From what I have read they are not bad as far as 18650 power banks go.
It would be nice to have the digital read outs as on Tinderbox"s version though.


----------



## TinderBox (UK) (Jan 9, 2016)

Hi.

This is the the guy i bough my Soshine from, but it`s been a couple of months and he only had two left, so this could be new stock, but is it the new version with the charging ma or the old version with just the battery gauge, maybe you can ask him to check.

My Sohine does not have an model or version number to help identify an new ma gauge version.

*eBay item number: 151752857352*



John


----------



## bella-headlight (Jan 9, 2016)

Thanks John, that is actually the seller & item number of the one I am looking at, I will message the seller & ask if he has them with the ma readouts as opposed to voltage bars.
Either way I think I will buy 2 as I have 18 laptop pulls & should get 8 serviceable cells from them hopefully.
12 are showing good voltage but I am waiting for a Liitokala Engineer 500 analysing charger to arrive so that I can find out their actaul ma capacities.


----------



## TinderBox (UK) (Jan 9, 2016)

Yeah, That is the Guy i bought mine from, my listing is below, I got mine for £6.99 it was an auction and i was the only bidder.

As i said dont assume he is selling the newer version that show the charging ma, he might have the old version now, send him a message and ask, but speaking to an non English speaker can be fun.

One negative with the version that shows the "charging ma" is you cannot see how much power is left in the power bank, until the charge is finished or the power bank runs empty.

It is an *Soshine E3*

http://www.ebay.co.uk/itm/161876759354?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

John.








bella-headlight said:


> Thanks John, that is actually the seller & item number of the one I am looking at, I will message the seller & ask if he has them with the ma readouts as opposed to voltage bars.
> Either way I think I will buy 2 as I have 18 laptop pulls & should get 8 serviceable cells from them hopefully.
> 12 are showing good voltage but I am waiting for a Liitokala Engineer 500 analysing charger to arrive so that I can find out their actaul ma capacities.


----------



## bella-headlight (Jan 9, 2016)

That listing you have put 
http://www.ebay.co.uk/itm/1618767593...%3AMEBIDX%3AIT
shows the model with charge bars so maybe the one with the charge bars as opposed to ma readout is the newer version ?
The model with charge bars is an E3 model also & is exactly the same as the Tomo V8-4.
I have searched everywhere I can think & can only find the Soshine E3/Tomo V8-4 with charge bars not ma readout.


----------



## TinderBox (UK) (Jan 9, 2016)

I did not know i was getting the newer version with the ma, I was just expecting to get the one with the bars.

Most seller are likely using the old photo`s, keep looking or ask the seller.

John.


----------



## bella-headlight (Jan 9, 2016)

Ok understood, I have messaged the seller asking him which version he is selling.
Thanks for all your help.


----------



## Lynx_Arc (Jan 9, 2016)

Interesting this box has pictures of the battery gauge and the digital output readout in the description
I wonder if you can switch between the displays.
http://www.aliexpress.com/item-img/Original-Brand-Soshine-E3-Mobile-Power-Boxes-4-Slot-18650-Charger-Free-Shipping/1666482914.html#


----------



## TinderBox (UK) (Jan 9, 2016)

The Soshine shows the battery level bars until you connect a device you want to charge then the display changes to show the charging ma on the two usb ports.

John.



Lynx_Arc said:


> Interesting this box has pictures of the battery gauge and the digital output readout in the description
> I wonder if you can switch between the displays.
> http://www.aliexpress.com/item-img/...-18650-Charger-Free-Shipping/1666482914.html#


----------



## bella-headlight (Jan 9, 2016)

Right so the Soshine E3 shows both battery level bars & charging ma depending on whether a device is being charged from it ?
In that case I will order the one in my earlier link


----------



## TinderBox (UK) (Jan 9, 2016)

It only switches to the charging ma on the newer version, so ask the seller before buying.

John.



bella-headlight said:


> Right so the Soshine E3 shows both battery level bars & charging ma depending on whether a device is being charged from it ?
> In that case I will order the one in my earlier link


----------



## bella-headlight (Jan 9, 2016)

Ok I will wait for a reply from the seller before buying, although I will probably buy the item whether it shows charging ma or not.
Thanks again for the help.


----------



## TinderBox (UK) (Jan 9, 2016)

Did you see the teardown of the tomo version, this one does NOT show the charging ma.

http://powercartel.com/teardowns/tomo-v8-4-soshine-e3-diy-usb-power-bank-teardown/

John.


----------



## bella-headlight (Jan 9, 2016)

Yes I have seen that John.
As I said earlier I have not been able to find one advertised that shows the charging ma although Lynx Arc has now linked to one on Aliexpress that does.


----------



## Lynx_Arc (Jan 9, 2016)

bella-headlight said:


> Yes I have seen that John.
> As I said earlier I have not been able to find one advertised that shows the charging ma although Lynx Arc has now linked to one on Aliexpress that does.


The problem is that one says out of stock which doesn't help.


----------



## kreisl (Jan 16, 2016)

kreisl said:


> i have Tomo V8-4 coming in, looks like a nice plasticky one with on/off switch. i can't recommend it yet, still need to test it.



I got mine today, on a Saturday :twothumbs
FYI it's the one with current/voltage display when connected to smartphone ("5.13V 0.79A"). My USB meter shows at the same time '4.97V 0.74A xxxxmAh'.
It is smaller than i had expected. The plastic feels cheap, well it is plastic lol. The pixelated LCD is pretty cool and my overall first impression is 'i like the product despite the el cheapo material'.

What i also like about it: it has 2 patent numbers on the back, not 'Patent pending'. And apparently the product has been evolved from years back.

I won't test it for the sake of testing, there are many technical and customer reviews on the www, blogs, forums, amazon, and youtube, but i'll use it a few times on the go in conjunction with my USB meter and USB charger(s), just to play with it. No serious or systematic testing. I am not that bored in life.

Protected 18650's. Unprotected 18650's are an easy, almost loose fit. I got a 69.10mm long Protected 18650 which fits soo, i wouldn't try to insert anything longer than that. All Protected Eagletac 18650's (blue label, red label, green label) for example fit, they are shorter than 69.1mm.


----------



## TinderBox (UK) (Jan 16, 2016)

I am glad you got the version with the ma reading, though mine does not seem to be made of cheap plastic (good quality in my opinion) and does not have an patent number on the back either.

John.


----------



## kreisl (Jan 16, 2016)

Here a photo ..


----------



## TinderBox (UK) (Jan 16, 2016)

I have the white Soshine version, no label like that on mine.

John.


----------



## bella-headlight (Jan 16, 2016)

Well the seller didn"t reply to me so I ordered one of the white Soshine E3"s anyway instead of the 2 I intended to get.
I will find out whether it has the digital ma readout when it arrives.


----------



## bella-headlight (Jan 19, 2016)

Power bank arrived today & I loaded it up with 4 x 1800mah 18650 lap top pulls.
It shows the charging bars when the unit is being charged & voltage & mah when it is being used to charge an item.


----------



## TinderBox (UK) (Jan 19, 2016)

Glad you got the ma version, what do you think of the build quality?

John.



bella-headlight said:


> Power bank arrived today & I loaded it up with 4 x 1800mah 18650 lap top pulls.
> It shows the charging bars when the unit is being charged & voltage & mah when it is being used to charge an item.


----------



## bella-headlight (Jan 19, 2016)

TinderBox (UK) said:


> Glad you got the ma version, what do you think of the build quality?
> 
> John.



TBH considering it cost less than £9 delivered I think the build quality is pretty good.
I have compared some voltage readings on the power bank with my DMM readings & they are very close to what it shows & charge termination seems ok although according to my DMM it terminates at 4.17v & not 4.20v ( not that that is necessarily a bad thing) but it is not a problem as I do not intend to charge cells with it as I will use my D4 or Liitokala Engineer 500 for that.
All in all pretty pleased with it & at the money I think I will buy another as from my 18 laptop pull cells I have 12 that appear good so I can have 2 power banks loaded up with cells & carry 4 spare charged cells for trips away for charging phones & a tablet.


----------



## PapaLumen (Jan 19, 2016)

What phone are you charging with it? Does it give charge at more than 0.5A when using it? ie it will say, "usb" (0.5A) and not "ac" (1A+) when you plug it in to most android phones, or you can check with current monitoring app. I have a powerbank that can do 2A but it wouldn't until I bridged the data pins on the usb connector.


----------



## bella-headlight (Jan 20, 2016)

PapaLumen said:


> What phone are you charging with it? Does it give charge at more than 0.5A when using it? ie it will say, "usb" (0.5A) and not "ac" (1A+) when you plug it in to most android phones, or you can check with current monitoring app. I have a powerbank that can do 2A but it wouldn't until I bridged the data pins on the usb connector.



Yes it does.
My phone is a Samsung Galaxy A3 which came with a 1 amp wall charger so I am guessing that it only wants to draw a max of about 1 amp when charging ?
When charging the phone off either the 1 amp or 2 amp outlets it initially showed .98-.99 mah (checked with a KCX-017 inline tester/meter).
The phone was already 65% charged when I tried this & the mah slowly dropped from there down to .20 mah when the phone was fully charged up.
I tried charging a Samsung Tablet & the 2 amp outlet initially showed 1.60-1.61 mah, (the Tablet was already 85% charged when I did this) & again the amps slowly dropped from there as it charged.
I don"t know if it would have drawn more if the Tablet had been more depleted (guess it would ?) but I am guessing from this that the 2 amp outlet probably will give around 2 amps if the demand was put on it.
Hope this helps & I will try charging the tablet when it is about 30% (which is when I usually charge it) & see what amperage the power bank gives then & report back.


----------



## Lynx_Arc (Jan 20, 2016)

I bought a few cheap ebay power banks, a 1 cell and a 3 cell model and they seem ok, I like the single cell version I got as you can easily remove the cells by unscrewing the bottom and pulling out the plastic shell which has the guts in it.


----------



## TinderBox (UK) (Jan 21, 2016)

I bought a 18650 flashlight (the beam is very tight), that is a power bank as well (0.5A) from AliExpress for $12 it`s a little tight for protected cells but mine just about fit.

John.


----------



## PapaLumen (Jan 21, 2016)

bella-headlight said:


> Yes it does.
> My phone is a Samsung Galaxy A3 which came with a 1 amp wall charger so I am guessing that it only wants to draw a max of about 1 amp when charging ?
> When charging the phone off either the 1 amp or 2 amp outlets it initially showed .98-.99 mah (checked with a KCX-017 inline tester/meter).
> The phone was already 65% charged when I tried this & the mah slowly dropped from there down to .20 mah when the phone was fully charged up.
> ...



Yep if it's quite charged already then the current will keep reducing. From 30% I would think the tablet would take the full 2A. I assume you mean .98A or 980ma (not mah) and 1.6-1.61A. I need to get me one of those inline current/voltage checkers. The one you have looks fancy..


----------



## bella-headlight (Jan 22, 2016)

Yes sorry I meant ma & A"s oops.
I have now charged a depleted tablet (35%) with the Power bank using the 2A outlet & it initially showed 1.98A (again checked with a KCX-017) so that is close enough to 2A for me :twothumbs
The KCX-017 was bought after reading HKJ"s review of it http://lygte-info.dk/review/USBmeter KCX-017 UK.html
It only cost £3.70 delivered off ebay http://www.ebay.co.uk/itm/151924189378?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
I have used it to check what some of my USB chargers are really putting out compared to what is claimed for them !


----------



## bella-headlight (Jan 28, 2016)

Well 6 days on & I am not so happy with the Soshine E4 power bank.
A few hours after making the above post one of the bays stopped working.
I contacted the seller immediately who replied yesterday asking for photographs & details of the batteries I was using.
His site now says that he is away until 18th February but this morning I got a message from him saying that he is away till 6th March for the "Chinese Spring Festival" ?


----------



## TinderBox (UK) (Jan 28, 2016)

That`s bad luck, but faults happen, my Maha C9000 developed a faulty channel so it happens to the best manufactures.

If you got it from china/hong-kong it would cost me twice as much to return it, royal mail so expensive so sellers have not asked for return after i tell them the cost and usually send me a replacement on seeing a video of it not working correctly.

Chinese holiday is messing with your replacement, 30+ day holiday :thinking: i wonder what eBay/PayPal think of that.

John.


----------



## bella-headlight (Jan 28, 2016)

Yes don"t think I will have a problem getting a replacement (hopefully) as I have sent him what he has asked for, just a bit of pain that he is away for nearly 6 weeks ?


----------



## bella-headlight (Mar 10, 2016)

Well still no contact from the seller despite me seeing that his shop was in fact back up & running over 3 weeks ago & not on the 6th of this month as he claimed & me sending him several more messages over the last 3 weeks so I have now involved paypal.
I first contacted the seller on January 27th & ebay contacted him on 2nd March so he has had more than enough time to at least contact me & tell me what is happening.


----------



## bella-headlight (Mar 11, 2016)

Paypal has refunded me in full.


----------



## TinderBox (UK) (Mar 11, 2016)

Great result, now what are you going to buy to replace it.

John.



bella-headlight said:


> Paypal has refunded me in full.


----------



## bella-headlight (Mar 11, 2016)

TinderBox (UK) said:


> Great result, now what are you going to buy to replace it.
> 
> John.



Believe it or not another one the same from a different seller or the black Tomo version.
I really liked this power bank.


----------



## TinderBox (UK) (Mar 11, 2016)

Do the new 2 cell versions show the ma being draw from the usb ports like the new 4 cell version do?

I have the 4 cell Soshine that shows the ma.

EDIT: Also have a look at the Soshine E4S

John.


----------



## bella-headlight (Mar 11, 2016)

I have already just ordered a Tomo V8.
I like the capacity of the 4 x 18650 form power bank.


----------



## TinderBox (UK) (Jul 9, 2016)

I put 4 x 18650 3400mah (NCR18650B) in my Soshine E3, that`s 13600mah and put an connected an usb power meter, and then connected an 1amp resistor load.

Once the Soshine E3 shut down due to low battery i checked the usb power meter, It only showed 7750mah had been pulled from the power band, that has a capacity of 13600mah, that means only 57% of the power banks capacity is available with an 1amp load, that`s not very good.

I checked the no-load voltage of the 4x18650 when i removed them from the power bank, 3.25v, 3.22v, 3.24v, 3.26v , I will charge the 18650 back up in the Soshine E3 and see what the full termination voltage is.


John.


----------



## kreisl (Jul 9, 2016)

thanks for the 1amp load test.

i had several v8 4 tomos for testing, great price , white, black 

~*10h30min* for charging 4x NCR18650B from 2.858V each, 
total "13791mAh" (usb doctor) transferred between USB adapter output 5V (mains) and USB port input 5V (tomo),
termination voltage on my current unit is like:
slot1 4.205V (after overnight and with older cell: 4.197V)
slot2 4.216v (after overnight and with older cell: 4.214V)
slot3 4.184V (after overnight and with older cell: 4.180V)
slot4 4.214v (after overnight and with older cell: 4.210V)
measured removed from tray, with ut61e

initial tomo USB input current was "1.65A" (usb doctor) and this number decreased slowly during the CC-phase and decreased faster, as expected, during the CV-phase. basically the tomo USB input current did not exhibit perfect CC-CV behavior, since the CC-phase was not constant 1.65A.

edit: single cell 18650 powerbank 1.56us$ rofl
http://m.gearbest.com/chargers/pp_187287.html


----------



## HKJ (Jul 9, 2016)

TinderBox (UK) said:


> Once the Soshine E3 shut down due to low battery i checked the usb power meter, It only showed 7750mah had been pulled from the power band, that has a capacity of 13600mah, that means only 57% of the power banks capacity is available with an 1amp load, that`s not very good.



That means about 80% efficiency in the boost converter, not bad and not not very good either.


----------



## TinderBox (UK) (Jul 9, 2016)

Well that termination voltage looks good, so the E3 must be really inefficient, My Nitecore F1 specs say it`s 90% efficient, I will have to put this to the test next.

John.



kreisl said:


> thanks for the 1amp load test.
> 
> i had several v8 4 tomos for testing, great price , white, black
> 
> ...


----------



## kreisl (Jul 9, 2016)

TinderBox (UK) said:


> Well that termination voltage looks good, so the E3 must be really inefficient,


tomo technical details were reviewed years ago, for example on a blog. i like the concept of exchangeable 18650's. but the technology inside is outdated, of course. there are now a bunch of QC3.0, Qualcomm's QuickCharge v3.0 technology, enabled powerbanks on the market. already tons of them on taobao/alibaba, and a few better of them like BlitzWolf also available for the Western market.

HKJ reviewed the massive Ravpower QC3.0 enabled 18650 powerbank not long ago. And afaik TOMO is developing a QC3.0 powerbank, maybe similar in function to the V8-4, these days too. For the most compact portable QC3.0 powerbanks i'd choose BlitzWolf or Xiaomi or alike, for 18650 exchangeability i'd hope for the new TOMO which is hopefully more efficient than our old unit.

Btw, for fair comparison or evaluation of efficiency, in my opinion imo one should refer to the energy (stored energy in 18650's vs. delivered energy to 1amp load), not to the capacity.

If you take the capacity as point of reference, then yes, the Tomo has efficiency of ~50%. A number which is typical for 18650 powerbanks.


----------



## TinderBox (UK) (Jul 9, 2016)

Ok, I just tested the Nitecore F1, I fully charged an new 18650 an 3400mah (NCR18650B) different cell to last test, I connected my usb power meter, and added an 1amp resistor load, my usb meter only showed 1630mah when the battery power died.

So from an 3400mah cell, you only get approx 1630mah of power, and then the device you are charging has an charging efficiency as well, so there is a lot of wasted energy.

John.


----------



## kreisl (Jul 9, 2016)

see? again around 50%
really typical number because you reference capacity instead of energy.


----------



## TinderBox (UK) (Jul 9, 2016)

Nitecore rate the F1 with an 90% efficiency in the specs, but i suppose that`s at 500ma load or lower??

John.



kreisl said:


> see? again around 50%
> really typical number because you reference capacity instead of energy.


----------



## HKJ (Jul 9, 2016)

TinderBox (UK) said:


> So from an 3400mah cell, you only get approx 1630mah of power, and then the device you are charging has an charging efficiency as well, so there is a lot of wasted energy.



Not that much, efficiency is about 80% at 1A if you do the match correctly (Based on my measurements).


----------



## kreisl (Jul 9, 2016)

i just did a quick simple test myself with a single 1x Sanyo NCR18650GA *3500mAh* nonimal (fully charged, condition Like New) in the tomo. i don't have a 1amp load, so i simply charged my depleted cr*ppy phone battery. what matters is that the system (=tomo+1xNCR18650GA) refused to continue charging after "1540mAh" (USB meter) had been transferred. I could restart the tomo with its ON/OFF switch and there'd be a ~0.9A current at the USB port, but after a few seconds the system would turn off automatically again. After taking out the warm Sanyo cell and letting it rest for a while, its offline voltage was ~3.40V. As we know from energy balance, the actual battery current draw must have been higher than the 0.9A, and at that high current draw the actual capacity of the Sanyo may be *3300mAh*, not 3500mAh. Rough calculation, the Sanyo delivered ~*3100mAh* capacity (~200mAh difference because at 3.40V the Sanyo isn't fully depleted!) but only *1540mAh *got delivered at the USB port. That's a capacitive efficiency of 49.7%, or 50% (rounded).

My USB meter does not measure energy, too bad, hmm. :thinking:

One could do the same simple test with other "powerbanks" like the USB chargers by Nietcore, Littokaala, Obus, Xstar, and you'd get about the same result, a capacitive efficiency of *~50%*.

EDIT:
*1670mAh* at 0.65A USB port 3.4V offline battery
*1720mAh *at 0.16A CCCV USB port 3.2V offline battery
*1410mAh* at 1.05A USB port 3.5V offline battery


----------



## sidecross (Jul 9, 2016)

Some of the confusion maybe because some people may be using an analogy of a 'power-bank' as a spare fuel tank in an automotive paradigm. 

In the automotive paradigm, fuel can be taken from a fuel tank or reserve vessel until empty; this is not the same with current from a battery cell. 

I plan on using 50% of the 'power-bank' capacity as my usable current.


----------



## Lynx_Arc (Jul 9, 2016)

kreisl said:


> i just did a quick simple test myself with a single 1x Sanyo NCR18650GA *3500mAh* nonimal (fully charged, condition Like New) in the tomo. i don't have a 1amp load, so i simply charged my depleted cr*ppy phone battery. what matters is that the system (=tomo+1xNCR18650GA) refused to continue charging after "1540mAh" (USB meter) had been transferred. I could restart the tomo with its ON/OFF switch and there'd be a ~0.9A current at the USB port, but after a few seconds the system would turn off automatically again. After taking out the warm Sanyo cell and letting it rest for a while, its offline voltage was ~3.40V. As we know from energy balance, the actual battery current draw must have been higher than the 0.9A, and at that high current draw the actual capacity of the Sanyo may be *3300mAh*, not 3500mAh. Rough calculation, the Sanyo delivered ~*3100mAh* capacity (~200mAh difference because at 3.40V the Sanyo isn't fully depleted!) but only *1540mAh *got delivered at the USB port. That's a capacitive efficiency of 49.7%, or 50% (rounded).
> 
> My USB meter does not measure energy, too bad, hmm. :thinking:
> 
> One could do the same simple test with other "powerbanks" like the USB chargers by Nietcore, Littokaala, Obus, Xstar, and you'd get about the same result, a capacitive efficiency of *~50%*.



And if you calculate the actual energy at 3.7v nominal in 5.0v out you get 11470mw in 7700mw out or about 67% efficiency which is pretty close to the 70% figure I estimate power banks do that number probably goes down as current increases and goes up as it decreases.


----------



## Gauss163 (Jul 9, 2016)

TinderBox (UK) said:


> I put 4 x 18650 3400mah (NCR18650B) in my Soshine E3, that`s 13600mah and put an connected an usb power meter, and then connected an 1amp resistor load.
> 
> Once the Soshine E3 shut down due to low battery i checked the usb power meter, It only showed 7750mah had been pulled from the power band, that has a capacity of 13600mah, that means only 57% of the power banks capacity is available with an 1amp load, that`s not very good... .


 
It's 82% efficient, not 57%. You were comparing apples and oranges since the cell's capacity is rated at 3.7V but the USB meter is reporting capacity at 5V. To compare you should compare the total _energy_. The meter measured 5V*7.75Ah = 38.75Wh. HKJ's discharge test shows the NCR18650B deliver about 11.856Wh at 0.5A. So 38.75/(4*11.856) = 0.817, so you got about 82% efficiency. That's typical for a cheap powerbank. Try it at 5V/0.5A to see if it gets much better.

Note that when you use the powerbank to charge a device that also includes another typically 80% efficient buck/boost regulator then they combine by multiplying to yield 66% efficiency in total, i.e. about 1/3 of the powerbank's energy is lost in the combined inefficiency of the step up/down voltage regulators on both ends. 

For example, if you use the powerbank to charge a cellphone or tablet battery then typically at most 2/3 of the powerbank's energy can be transferred to the target battery. This double loss - combined with the above voltage mismatch in capacity ratings - are the source of much confusion.


----------



## TinderBox (UK) (Jul 10, 2016)

Thanks, Gauss163 you are full of knowledge :bow:, There should be a better way for the average consumer to pick a power bank, The mah rating seems to be of little use as it is based on 3.7v, But that only 2/3 of the mah rating of an power bank will actually be transferred to the battery of your device is handy to know.

John.


----------



## kreisl (Jul 11, 2016)

kreisl said:


> For the most compact portable QC3.0 powerbanks i'd choose *BlitzWolf *or *Xiaomi *or alike, for 18650 exchangeability i'd hope for the new *TOMO *which is hopefully more efficient than our old unit.


I checked amazon, looks like *Anker *has updated their flagship model of the powercore+ powerbank series from QC2.0 to QC3.0, good for them! Soon enough all other powerbank manufacturers will offer their products with QC3.0 compatibility, no doubt. As mentioned earlier, on toabao and alipapa there are already lots of noname powerbanks with QC3.0 technology. Maybe not certified by Qualcomm, i dunno.

Qualcomm has published a PDF list with all official QC3.0 certified products by trade names and makers all over the world. But Qualcomm isnt able to keep the list uptodate since every week there are more new QC3.0 powerbanks popping up on the market, especially those made in the Chinas.

As with flashlights, i stick with brand name products. Gives me a better feeling :duh2:


----------



## TinderBox (UK) (Jul 11, 2016)

Does fast charging your phone/tablet battery not decrease it`s cycle life? not a problem if it`s easy to replace the battery but most phones have the battery built in these days.

Most owners don't realise this and are most likely happy with the quick charge speed.

These quick chargers should offer a slow charging option for when you are not in a hurry, like a overnight charge.

Unless they are using some new type of fast charging battery?

John.


----------



## recDNA (Jul 11, 2016)

I got lost in the physics somewhere.... Did we come up with the best solution for a single 18650 powerbank? I don't have room in my pocket for a charger bigger than a deck of cards along with my cell phone. If I can get 1500mAh out of the charger I can get an extra 2.5 hours of sot. That's all I care about. Well actually safety is my primary concern.


----------



## TinderBox (UK) (Jul 11, 2016)

It`s the "Nitecore F1" for me, I put both securing bands black and yellow to make sure the 18650 does not move.

John.


----------



## Lynx_Arc (Jul 11, 2016)

TinderBox (UK) said:


> Does fast charging your phone/tablet battery not decrease it`s cycle life? not a problem if it`s easy to replace the battery but most phones have the battery built in these days.
> 
> Most owners don't realise this and are most likely happy with the quick charge speed.
> 
> ...


I think fast charging probably decreases battery life a little but in reality it may actually increase usable battery life as people will be getting a better charge on their battery that will last longer and have them charging less often partially. I've read about the quick charging and even if you have a power bank that supports it your device also needs to support it and your power cable too and I'm guessing the power bank probably needs to have higher amp output rating as the technology has charging at higher voltage than 5v with probably as much current.


----------



## Gauss163 (Jul 11, 2016)

Lynx_Arc said:


> I think fast charging probably decreases battery life a little but in reality it may actually increase usable battery life as people will be getting a better charge on their battery that will last longer and have them charging less often partially...



Not true. Fast charging is always less healthy (in extreme cases you can decrease lifetime by a factor of 10 or more). Further partial charge/discharge cycles are healthier too as long as they are not always restricted to very low or very high voltage ranges, i.e. the more they are balanced around the 50% point, and the smaller the capacity (dis)charged, the healthier it will be. 

For example, if you only used the region between 45-55% capacity then you might get 10x the cumulative lifetime compared to normal usage. Of course that's just to illustrate a point, since that would be far too inconvenient in practice. But you will also gain significant lifetime by using only the region between 80-20%, or 90-10%, both of which are not too inconvenient, assuming you have enough control of the charger/device to restrict cell usage to those regions (e.g. "battery saver" software for laptops often expose such functionality to the user).


----------



## Lynx_Arc (Jul 12, 2016)

Gauss163 said:


> Not true. Fast charging is always less healthy (in extreme cases you can decrease lifetime by a factor of 10 or more). Further partial charge/discharge cycles are healthier too as long as they are not always restricted to very low or very high voltage ranges, i.e. the more they are balanced around the 50% point, and the smaller the capacity (dis)charged, the healthier it will be.
> 
> For example, if you only used the region between 45-55% capacity then you might get 10x the cumulative lifetime compared to normal usage. Of course that's just to illustrate a point, since that would be far too inconvenient in practice. But you will also gain significant lifetime by using only the region between 80-20%, or 90-10%, both of which are not too inconvenient, assuming you have enough control of the charger/device to restrict cell usage to those regions (e.g. "battery saver" software for laptops often expose such functionality to the user).


This is an interesting article
http://insideevs.com/rapid-chargingdraining-lithium-ion-batteries-damaging-previously-thought/


----------



## TinderBox (UK) (Jul 12, 2016)

Heat is the enemy of battery`s (that`s why Tesla and others controls the temperature of their battery`s) the only way the average user can avoid heat, is to do a normal slow charge and keep discharge currents as low as possible, so if you phone/tablet get`s hot while it`s charging the battery is getting damaged (as we know there are many other variables in battery health)

When rechargeable thulium battery are made, the manufacture can add several (highly secret) additives to the mix and this can considerably extend the cycle life of the cell, but we do not know how our battery`s were made in general and what additives were used.

So i would like to see fast chargers for (phone/tablets) have a slow charge option for when you are not in a hurry.

John.


----------



## Gauss163 (Jul 13, 2016)

Lynx_Arc said:


> This is an interesting article
> http://insideevs.com/rapid-chargingdraining-lithium-ion-batteries-damaging-previously-thought/




It's about LiFePo4 coin cells so not clear how it applies (if at all). Many tests on 18650 Li-ion cells have shown much degradation at high charge rates.

There are various mult-stage fast charging algorithms that are devised to minimize health impact, but these aren't typically available in consumer-level chargers (yet)


----------



## Lynx_Arc (Jul 13, 2016)

Gauss163 said:


> It's about LiFePo4 coin cells so not clear how it applies (if at all). Many tests on 18650 Li-ion cells have shown much degradation at high charge rates.
> 
> There are various mult-stage fast charging algorithms that are devised to minimize health impact, but these aren't typically available in consumer-level chargers (yet)


I think it will be interesting in that if you create fast chargers that degrade batteries a little faster then you can sell more phones when the non replaceable batteries wear out faster.


----------



## IonicBond (Dec 8, 2016)

Picked up the latest version of the Tomo V8-4, along with the latest 3-cell version, but have some funny observations:

At first, I thought they were both broken. Of course, I threw the included little usb jumpers in the trash, and used some nice Anker charge cables. That lead to no more than 0.05A charge current! Say what?

Ok, pull the oem cables from the trash, and now the unit will charge my smaller devices at about 1.5A max on the 2A port. Small tablets, average android smartphone - all came originally with only 1A ac chargers anyway. I forgot where I saw it, but somewhere in the Tomo material online, they go on to state that the included cables are "not resistance decoded", whatever that means.

Ah, so a trip to the past. From what I can tell, the ports are influenced by the apple-like method of using/looking for resistance on the data lines, rather than a total short to signify a charge-only cable? I'm not a cable expert.

Get this - when I used my Abovetek inline usb volt and ammeter, it does not always agree with the display:

When using a beefy short Anker charge-only cable, the inline meter shows about 1.4A, but the Tomo display only shows 0.05A flowing! What?

Switch to the oem Tomo cables, and now the inline meter agrees with the display, at about 1.4A each - about max that I've observed with my stuff.

I've gotten spoiled with all the "smart port" usb outputs from Anker battery packs and the like, but the Tomo output seems fussy about the specific cabling, yielding wildly different results depending.

I'm having fun with the Tomo's but lack of a smart-port to automatically figure out the proper cabling was driving me nutty.


----------

