If you are looking for a good 18650 li-ion charger, please see M4 from TOMO , Compared to other chargers, has the advantage of being able to work as a power-bankHere is my review that tells you everything important:
The high-value charger combines the features of the PowerBank and the 18650 Li-ion battery charge. If you need 18650 battery cell removed from charger and insert into light or or headlamp … I tested one piece TOMO M4 p and here is pros and cons :
- 4x 18650 charger slots (Is better than two)
- Each 18650 slot has its own charging circuit can charge different capacities of 18650
- Has overvoltage and under voltage protection.
- USB has always above 5V
- Good price 12-16 usd
Here is cons
- Charging via USB is slow
TOMO M4 charger has good ratio price/value for about 15 usd you will get a 2in1 good charger of 18650 cels and powerbank at the same time. It has all the necessary protection.
Detailed description and test in my LABS
The charger has 4 charging slots and each has its own charging circuit can charge different capacities of 18650 cells from different manufacturers. PowerBank capacity depends on brand for example Panasonic Samsung, Samsung, Sanyo products have the best 3500mAh cells, or the max capacity is just over 12,000 mAh.
When using powerbank you can use 2 USB slots so you can charge 2 devices at once, USB has a protection circuit against overload. On the LCD, you can see the voltage current supplied by powerbank.
Test in my” home lab”
Other good review is on: http://lygte-info.dk/review/Review%20USB%20battery%20box%20Tomo%20M4%20UK.html
Tested the USB voltage depending on the 18650 battery voltage (Or by accident the voltage on the USB powerbank output is not the same as on the batteries) next tested reverse protection, over and under voltage protection.
It would not be good if the battery voltage was the same as the USB output
Typical voltage 3.6V-3.7V 18650 cells is 4.2V at full charge but at load it drops rapidly to 3.8V and below.
If the USB voltage = 18650 voltage, the power bank would have a small capacity and was practically unhelpful
Powerbank/Charger TOMO M4 has inside a USB circuit that keeps the 5V voltage constant..that’s good
Overvoltage and discharge protection: If the battery reaches a voltage of 4.2V, the charger stops charging this is OK but .
TOMO manufacturer at M4 charger did not specify protection against excessive discharge, I tested that if the battery is discharged to the 3.2V battery charger will shut down .. (I tested it 6x)This protection is very useful to protect the 18650 li-ion battery from destruction.
The voltage on the PC USB was only 4.4V so it will not be a charger, but the manufacturer could pack or give the option to plug in a powerful adapter just like it has a Soshine charger.
I was very pleased that the charger is charging excellent industrial 18650 cells that do not have a button top.
2in1 Powerbank charger 4 × 18650 batteries technical parameters:
- LCD Display: Yes
- Protection: Against reversing, battery recharging
- Separate charging circuit especially for every 18650 battery
- Support of older 18,650 li-ion batteries: yes
- Battery saving: The display turns off after 20 seconds
- Input: 5V / 1.2A
- Output: 5V / 1A, 2A
- Battery: 4 x 18650 li-ion battery (not included)
- Dimensions (length x width x thickness): 13.00 x 8.40 x 2.60 cm
- Package includes: 2in1 PowerBank Intensive Charger and 1 x USB Charging Cable