• Oct 16, 2014|
  • Press |
  • John Dev

Incomplete evaluation of ESYB E4 Intelligent Charger

Support mixed charging. USB output. Can adjust the charging data through Bluetooth and APP function.
It can charge different kinds of batteries, automatic identification of 4.2v li-ion batteries and 1.2v Ni-MH batteries. Manual selection of 3.6v li-po4 batteries and 1.2v Ni-Cd batteries.

Over-charge protection, anti-reversing protection, etc.
Not too many accessories. User manual, adapter, charger body.

Equipped with 9v 2.5A power adapter, max output is 22.5w.

Totally four slots. It can charge 26650(Max) in slot1 and slot4, and 18650(Max) in slot2 and slot3.

The Bluetooth button when first connect the APP and charging status display screen. The buttons on top of the slots can select different modes. When you insert batteries in, you can click them once to select different output current and battery types. But I do suggest you to use APP to control, it is more convenient.

OR code can be scanned by APP to verify authenticity

Each of the four battery slots monitors and charges independently. Capable of charging 4 batteries with different types and different sizes simultaneously.

Max charge current of slot2 and slot3 is 1Amps, max charge current of slot1 and slot6 is 2Amps. But charge current of 1.2v AA battery only can be 0.25Amps in all slots. I am not satisfied with this.

Support USB output function. You need to insert 4.2v battery to use this function.

Specification states that only insert 4 batteries can use the USB function. Actually it can use with only 2 batteries. But output is not stable.
Output voltage is 5.149v, it is really standard.

APP function:
Go to APP store, search “ESYB”, then you can find the official app.
APP displays power and can set charging data.
Can select charging data, like charging current and battery type. At the bottom is the charging curve.
Automatic identification of li-ion batteries and 1.2v batteries. You can switch 3.6v li-po4 batteries and 4.2v li-ion batteries when you use li-ion mode. You can switch Ni-MH and Ni-Cd batteries when you use 1.2v AA mode. That is manual control of the battery type can only be in the limited range. To ensure maximum charge safety.

When batteries are fully charged, you will receive a message.This is convenient.

Charging test of li-ion batteries:
I have no 3.6v li-po4 batteries so I haven’t test them. Following is the charging test of 4.2v 18650 li-ion batteries.

There is about 70% power of the battery.

Slot 1: 4.240v

Slot 2: 4.243v

Slot 3: 4.228v

Slot 4: 4.247v

Max total output current is 4Amps. If you set 2Amps of charging current in slot1 and slot4, and the slot2 and slot3 will not work.


Charging test of AA:
I used 4 AA batteries.

250mAh current is a bit small according to a 2000mAh+ Ni-MH battery. It charges until the next day. And it displays that it charges more than 3000mAh. Until the 18-hour over-charge protection on, that means stop charging.

Test of voltage when you remove the battery:
Slot 1: 1.461v

Slot 2: 1.451v

Slot 3: 1.459v

Slot 4: 1.463v

Another test.
There is no problem to charge eneloop. But I don’t like the 0.25Amps charging current. It is too slow. But this charger is a good charger for li-ion batteries.

Slot 1: 1.469v

Slot 2: 1.460v

Slot 3: 1.456v

Slot 4: 1.460v

Voltage display accuracy:
There is no problem with multimeter accuracy. Regular calibration. Li-ion batteries: 4.224v

Charger displays 4.18v, 0.04v lower.

AA batteries. Voltage: 1.395v

Charger displays 1.37v, 0.025v lower.

Stable, safe.
Bluetooth function is convenient. We can control charging data via APP.
When batteries are fully charged, you will receive a message. This is convenient too.
Charging is fast to meet our general needs. Total output current 4Amps is not my favorite.
If it can support full-power output charge is great.
AA charging current is a bit low. I don’t know why they set the 250mA. If we charge a 2000mAh AA battery, we need at least 10 hours.
Voltage display accuracy is okay. After all, the display accuracy of a charger will not be too high. Most chargers are at this level.