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May 30, 2016, 11:25 PM
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E.SYB E4 Charger with Bluetooth

From Gearbest : (link is external)
$34.37 received
Use coupon: ESYBE4GB For a further price reduction

● App control: Check and adjust its charging status at any time
● 2.1 inches LCD screen display charging mode and battery status
● 5V 1A USB output: Can be used as power bank to charge your devices
● Compatible with Li-ion, LiFePO4, Ni-MH and NiCd batteries
● Charges 4 batteries simultaneously, each of the 4 slots monitors and charges independently
● 4 buttons to set the charging current and battery type conveniently
● CC and CV two charging modes
● Automatically stops charging when battery is fully charged
● Activation function for Li-ion batteries with protection board
● Reversed polarity / short-circuit / over-current / over-charge protection

Input: AC 100 – 240V 50 / 60Hz 1A (max)
Output voltage: 4.2V + / – 1pct, 3.6V + / – 1pct, 1.48V + / – 1pct
USB output: 5.0V + / – 5pct, 1A
Output current: Li-ion, LiFePO4: 0.25A / 0.5A / 1A / 2A; Ni-MH, NiCd: 0.25A

E.SYB Website = (link is external)

What we have here is a very interesting charger , that is equipped with Bluetooth allowing the charger to be monitored and adjusted via Android devices ( Phone / tablet ) . ( More later )
I have been charging batteries as quickly as possible to get a feel for this charger . The first thing I noticed is that this charger uses voltage as the cut off ( 4.2v ) , and this means that the batteries will not be 4.2v at completion . So depending on the condition ( internal resistance ) of the battery , termination voltage ( after 30 minutes of rest ) has been from 4.11v to 4.16v ( depending on the battery ) . So it looks like the charger starts with CC and then finishes the charge cycle with CV . It also looks like the charger tries to maintain CC for as long as possible , at 0.25Amp charge rate CC looks to be maintained past 4.19v ( voltage under load = charge load ) . Watching the charger some batteries have dropped charge rate at 4.2v whilst other batteries are maintaining 0.25Amp .

Can one come to the conclusion that this charger is trying very hard to speed up the charge time by minimizing trickle time . In the past a charger would and could trickle on for hours trying to top of a battery trying for the 4.2v . So it could be that this charger is sacrificing a little of the top ( Voltage state of the battery ) to greatly speed up the charge time . Some people may be completely devastated that they can’t get the battery to exactly 4.2v , and yet thousands may rejoice at the greatly decreased time it takes to charge a battery and not worry about a few tenths of a volt . Honestly , I was a little surprised at just how fast this charger charges 18650 . I think the default rate is 0.5Amp if you touch nothing , and just recently I have started to charge at 0.25Amp to see what the difference might be in terminated voltage .
Variable charge rate :

To change the charge rate , insert a battery . Start pushing the button above the battery slot before you get a read out ( I do this as mine is very fast , and if your to slow you can’t adjust the charge rate , once a charge rate is selected ) , keep pushing the button when you get a read out and you will see you are cycling through the charge rates . 0.25A – 0.5A – 1A – 2A Only slots 1 and 4 offer 2Amps as the maximum charge rate , slots 2 and 3 max out at 1Amp . Once charge has begun , you can push the button for the corresponding battery slot to see what is going on , or after completion so how long and how much current went into the battery .

Termination :

As already mentioned , Voltage is used to terminate that charge cycle ( 4.2v ) . Constant Charge rate looks to be maintained for as long as possible to speed up the time it takes to charge that battery . Remember voltage under load works both ways , when you discharge a battery the voltage sags , and when you charge a battery the voltage increases . Once charging or discharging is completed the battery will come to a resting voltage . The price for a faster charger looks to be a few tenths of a volt ( the variable being the quality of the battery charged ) .

Bluetooth :

This is where it gets exciting (?)

Here is a link to a video about QR codes ….

QR Code Reader iPhone App Review (4 min 41 sec)
(link is external)

Now most of you folks wont need to learn anything about QR codes , because your up to date with mobile phone tech and all that ! Well I’m a bit of an old fuddy duddy and so I had to learn something ( it is interesting )

So to get the app , to monitor the charger VIA phone / tablet you need to take a picture of the QR code with a QR reader app ( Back of the box or instruction manual ), this will give you a link to the App for the charger . Hmmmm , perhaps this is something that should be in the instructions .
Here are some video’s made by other people …

ESYB E4 Bluetooth Battery Charger (2 min 38 sec)
(link is external) = Youtube Video by Suki

ESYB E4 Bluetooth Li Ion Charger (21 min 4 sec)
(link is external) = Youtube Video by Z Vaper

Z Vaper has gotten overcharging ( slight ) , but I have gotten nothing but undercharging ( Thats life ) .

My appologies for not testing bluetooth myself and fully , but if I can get monitoring VIA PC working I will update the review .

AA Batteries :

My charger charges at 0.25A ( nimh ) and offers no other options .

Termination voltage is 1.48v , and depending on the state of your AA ( nimh ) resting voltage should be north of 1.4v

The charger takes it’s time starting as it is determining just what battery you have installed , so AA’s are just a little slower to start .

Conclusion :

I have put quite a few batteries through the charger at 0.5A and now 0.25A . It is simply a very fast charger when compared to most other chargers on the market . It offers functionality not dreamed of a few years ago , and quite frankly it works .

2 Slots offer up to 2A charge rate

2 Slots offer up to 1A charge rate

Amazingly keeps relatively cool ( ok winter weather is finally here , so its been very cool even inside ) Haven’t detected any heat at all as yet , this would probably change if charging 4 batteries at maximum rates .. ( At 0.5A and 0.25A ) I have 4 batteries charging right now @ 0.25A and the charger feels cold .

Sliders are very smooth , possibly the smoothest I have ever seen

Feels like a real quality product , ( punching well above its price at time of testing )

I don’t know what everyone else expects from a charger these days , but this charger ticks all the boxes for me . 2 amp charge capability for those larger batteries , 0.25 amp charge for those smaller batteries , true charge termination , CV termination , CC for as long as possible to decrease charge time , and minimal trickle charging .

I still have some 10 or more 18650 to run through this charger , I am currently charging a 18650 @ 0.25A from 3.6v and I am looking forward to seeing how long it takes .. ( Have charged 14 18650 to date )

At this time , the E.SYB E4 charger could possibly be “ The Charger “ to own . I have thrown a few AA ( nimh ) into the charger and I really like the result . This is simply the best charger I have used to date , I really do like it . So far I have nothing negative to report ( Nothing ) . If you need a score out of ten , then it has to be 10 ( Yes 10 out of 10 ) … It is really nice to see companies come out with products that make the flashlight hobby safer and more interesting .

_I would like to thank May from Gearbest (link is external) for making this review possible _..
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