Charging 2S and 3S Lithium packs over USB-C with the LISC module
Charging multi-cell lithium packs often requires bulky chargers and power supplies. However, interesting modules have been released that can charge 2S and 3S packs with a simple USB-C charger.
These modules are labeled as “LISC” modules. Mine is labeled “LX-LISC-V2”. This article will introduce the LISC module and how to use it.
This module is a small PCB based on the IP2326 in a QFN24 package. The little board can charge both 2s and 3s packs. It has a built-in balancer for 2S. For 3S, an external balancer is required.
In theory, the charging current can be adjusted by swapping the onboard resistors. However, in practice, the SMD resistors are too small to be swapped easily. Just know that the maximum charging current is 1.5A, so the module might reach it, which is bad for cells with capacities below 1500mAh.
Here are the pins of the LISC module :
It is possible to setup the module in both 2S and 3S mode. If you are unsure what model to get, get the 2S version because it can be converted to 3S more easily if later needed.
To convert a 2S module into a 3S module, you need to bridge the 2S/3S pad with solder and remove the resistor next to it :
Here is a picture of two modules. On the left is a 2S module and on the right is a 3S module :
- The red led is always on when the module is powered.
- The blue led is the status LED :
- Blinking when an anomaly is detected, including when the battery is not connected.
- ON when the battery is charging - OFF after full charge
To charge a 2S pack :
- Make sure the module is in 2S mode (see 2S or 3S selection).
- Connect the battery to the module, including the balance wire.
- Connect a USB-C charger to the module.
To connect the battery to the module, I am using a 2S balance connector. Once cut in half, it can be soldered to the module’s pads and the other end can serve as a balance connector for the battery if it doesn’t have one.
To charge a 3S pack :
- Make sure the module is in 3S mode (see 2S or 3S selection).
- Connect an external balancer to the pack’s balance connector.
- Connect the main battery connector to the module.
- Connect a USB-C charger to the module.
LISC modules are excellent for charging packs on the go. They work with any USB-C charger, even those that can only output 5V. Charging speed will vary with the charger’s power, but it will work.
It is possible to build versatile charging adapters for use in car, on solar panels, etc. - Just add an appropriate connector and shrink-wrap the module.