From Gearbest :ESYB E4 Bluetooth App LCD Battery Charger-34.37 and Free Shipping| GearBest.com (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 = Shenzhen E-SYB Technology Limited -Shenzhen E-SYB Technology Limited (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 ….
https://www.youtube.com/watch?v=KRq8qnlLqmA (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 …
https://www.youtube.com/watch?v=SftxZkDGzfk (link is external) = Youtube Video by Suki
https://www.youtube.com/watch?v=YvLNCzW6uNk (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.com for making this review possible _..
$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 = Shenzhen E-SYB Technology Limited -Shenzhen E-SYB Technology Limited (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 ….
https://www.youtube.com/watch?v=KRq8qnlLqmA (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 …
https://www.youtube.com/watch?v=SftxZkDGzfk (link is external) = Youtube Video by Suki
https://www.youtube.com/watch?v=YvLNCzW6uNk (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.com for making this review possible _..
