New HVC-Limited Charge Controller - v4.0.8.
The charge control logic works in conjunction with the HVC opto signal from the LVC/HVC/Parallel Adapter boards, to ensure that no cell is allowed to go over the HVC set point (4.16V for LiPo; 3.62V for LiFePO4). There is also an adjustable low current auto-shutoff feature that uses a trim pot to set low current trip point. The Charge Controller uses the opto-driven HVC signal to modify the duty cycle of a pulse width modulation (PWM) circuit that "throttles" the current in order to keep any cell from exceeding the HVC set point. In effect, separate CV modes for each channel.
The Charge Controller is simply inserted between the supply and the pack to be charged and the HVC opto signal is connected. There is a "Start" button and a single LED on one end of the unit. Once the "Start" button is pressed, the LED will be red, to indicate the CC mode is active. Once the 1st cells hit the HVC point, and the throttling begins, the LED will be orangish in color, but will transition to green, once the cells start getting full, and the current drops (CV mode). Once the current drops to about 180-200mA, the cells are about as full as they will get and the LED will be fully green. Once the current drops below the value set with the trim pot, an auto-shutoff circuit will cut the charge current and shut off the Charge Controller. The set point is adjustable from 0 to about 2.5A. As an added safety feature, this circuit will also shutoff the Charge Controller should the supply current be cutoff prematurely, for some reason. This will prevent the Charge Controller logic from draining the pack.
There are several configuration choices, a "barebones" PCB-only option, that includes detailed assembly/test instructions; a partial kit of the PCB + all non-Mouser items; and a complete kit. Included with all options are the custom end plates for the Hammond extruded aluminum case. The links below are for a Bill of Materials (BOM) Word file that has links to all the parts; and a link to the assembly/test instructions:
Charge Controller BOMCharge Controller Assembly & Test Instructions
Both kit options include the pushbutton switch, with a length of two-conducter hookup wire; a set of 14-gauge input and output wires; and a set of JST/BEC pigtails for the HVC opto signal.
