Can anyone recommend a quality charger for 18650 liPo cells.
The Lowest Quality LION (LQL) charger I use with 4x18650 cells from an old notebook:
1. set the lab power supply at 16.75V (4x4.2V),
2. connect the 4x18650 pack via 4.7ohm/5Watt resistor to the power supply.
The resistor will limit the current to around 1A with discharged cells (4x3.5V), it will not create a constant current, however (the current will drop linearly to almost zero when charged). When "charged" the laboratory power source will maintain the "constant" voltage.
Use at your own risk, no warranties of any kind are provided
This is a fairly simple LiPo charger which works:
https://www.rcgroups.com/forums/showthr ... -Schematic
I added a 3A diode in the + rail:
For a different output voltage set R5/R4.
It charges with a constant current provided by LM317, and when charged to the required voltage the TL413 switches on and it pulls the LM317 down, thus it maintains a constant voltage.