A very interesting product we have in for reviewing.

A ZeroLemon SlimJuice that is branded as the World’s Slimmest External Battery Pack @ 18600mAh Capacity with dual USB output.

From ZeroLemon


“Home to the World’s Highest Capacity Smartphone Batteries”

Their mission is to provide ultimate smartphone reliability with the world’s highest capacity smartphone batteries & battery packs.

Price when reviewed: 51.99 $ – via Amazon.com

[36 MONTHS WARRANTY]ZeroLemon SlimJuice 18600mAh Ultra-Compact Portable External Battery Backup Charger Power Bank Charger for iPhone 5S, 5C, 5, 4S, 4 (Apple adapters not included), iPod, Samsung Galaxy Note, Galaxy S4, Galaxy S3, Galaxy S2, Galaxy Nexus, HTC One X, One S, Sensation G14, ThunderBolt, Nokia N9 Lumia 920 900, Blackberry Z10, Sony Xperia Z; Google Glass, GoPro and More – White




The SlimJuice line comes in different capacity and physical sizes.

3100, 3500, 6200, 9300, 12400, 15500 and the 18600 mAh (the one we are reviewing today, so that’s a lot of battery capacity reserve !)




Size: 143 x 90 x 19 mm
Output: 2A Fast Charging for Top end Smartphones & Tablets / 1A charging for Smartphones
Input: 1.5A fast charge for External Battery
Capacity: 18600 mAh
Boxed-product Weight: 422 g
Triple LED for charging/discharging status.
It comes in 2 color flavors



Packaging and visual inspection


It comes in a thick and durable zip lock resealable plastic bag.


On the back we have self explanatory details.


Inside we have:

– The external battery itself
– Meshed pouch
– Looped micro USB cable
– Instruction manual and a brochure
– Apple adapter for older interfaces



The instruction manual in detail:



And finally the SlimJuice 18600 mAh external battery.
Here for size references we have the Samsung Galaxy Note 2 and a ball point pen.



And more vs the smartphone.



At the bottom we see the dual USB output, one at 2.1 A and the other at 1 A and on the side the 1.5 A input micro USB charging port.


And on the back extra information.


To conclude the visual inspection:

– Excellent build quality
– Very rugged, feels good and sturdy, no squeaking plastic or movement.
– The USB plugs are very tight and very secure




Out of the box it had 2 active LEDs so that’s roughly ~ 60 % charge left.
First, a small test to see if it worked as is.
That’s an affirmative answer, as you can see.


Then, we did the recommended 12 hours charging cycle.
The LEDs flash when it’s charging.


Test subjects:

Samsung Galaxy S4 – with 2600 mAh battery.
Samsung Galaxy Note 2 – with 3100 mAh.
Samsung External Battery Charger for S4 – with extra S4 2600 mAh battery.
Sony DSC WX50 Digital Camera – with 1300 mAh.


We discharged the phones until 5% battery and then we let them plugged in until the Android said to disconnect.
And for the camera, discharged it until the camera closed automatically when you try to take a picture.

Used both 1A and 2.1A ports.

It automatically regulates the output depending on the maximum value supported by the devices, so there is no worry of overload.

Another very practical feature we discovered is that you can simultaneously charge your devices and charge the external battery itself, as seen below.

Very Nice !




And here are the results:

– To fully charge the SlimJuice – via AC @ 1.5A – takes ~ 8 hours – with the Samsung power cord (it’s rated at 2 A but as mentioned, the SlimJuice will use 1.5 A max).

– To fully charge the SlimJuice – via USB port from a laptop/PC @ 0.5 A – may take ~ 50 hours – so it will be a while.

– Samsung Note 2 – 3100 mAh – charged it from 5 % – took ~ 2.5 Hours @ 2 A – if you only charge this one, we managed more than 5 and a half full charges.

– Samsung S4 – 2600 mAh – charged it from 5 % – took ~ 2 Hours @ 2 A – if you only charge this one, the SlimJuice will last you 7 full charges (the same for the Samsung External Battery Charger for S4 because it also outputs at 2 A)

– Sony DSC-WX50 – 1300 mAh – charged it from completely empty – took ~ 2 Hours @ 1 A – if you only charge this one, it should do more than 14 full cycles !

And here’s a better view:




So you can imagine the many advantages regarding autonomy you get, it will easily last you a whole long trip for anything you have from phones, cameras and tablets.

The Good:

– Premium quality
– Excellent back up advantages
– Excellent customer support and great warranty of 36 months
– It’s compatible with pretty much anything that uses a USB cable and supports any micro USB charger
– the LED indication are very handy
– Self regulated operation, activates and shuts down on its own so no further action required, just plug and play
– Multiple and simultaneous charging the output devices and itself

The Bad:

– Full charge time may take a while but considering that you will plug it in the night also with your phone and by morning everything will be full, so this is a matter of timing.
– Does not come with its own power cord but 99% of the time you will have one from your phone/camera/tablet so that’s completely negligible.
– And maybe weight at around ~ 400 g, but you will always carry this in a luggage, handbag, back pack etc so that shouldn’t be of great concern.
– Needs like 5 or 6 full charging/discharging cycles to get full battery potential, so that’s a few weeks job.


Many thanks to ZeroLemon for supplying us with this sample !


This external battery solution from ZeroLemon made a very good impression and thus it gets our:

Globetrotters Award – 4.5 out of 5


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