Owner`s manual

18
Reg Bus Wiring
The Reg Bus Interface:
The REG BUS communicates to the charger when any BMS regulators are regulating
and also if any regs are too hot. The charger uses this information to determine when to
turn down the charge current and when to turn off the charger.
The interface contains six wires connected with their respective pins as follows:
1. WHITE : Power supply (+5 volt DC)
2. BLACK : Reg over voltage condition (reg ON or reg hot) +5V will activate this line
and tell the charger to stop charging
3. RED : Under voltage condition – 0V on this line means under voltage active
4. GREEN : Power supply return (GND) – Refers to charger’s Batt Neg line
CAUTION: The GND return is NOT isolated!
5. YELLOW : Rudman bus negative
6. BLUE : Rudman bus positive
Note: The pin count reads from left to right when you are looking straight on into the RJ
receptacle. Or, when viewed from the bottom of the printed circuit board, pin #1 is the
square pin.
The optic components keep the local Batt POS and Batt NEG (battery or cell being
monitored) isolated from the charger’s Batt POS and Batt NEG. The +5 and GND are
powered from a 500 mA current limited power supply. All measurements are made
relative to the GND wire. It is important to verify all six of the wires are continuous
throughout the system.
NOTICE! On older models the GND on the reg bus is also battery negative on a
PFC charger!
The primary functions of the REG BUS are:
1. Supply power to the charger side of regs.
2. Support analog data exchange from regs to charger and analog control of charger
by the regulators (or other BMS).
3. Support digital data transfer and control of regs via the Rudman Bus (modified
EVILbus).
Optimally, the charger will run full current until the first regulator gets hot, then cut back
to save that regulator and then watch for the last one to come up to temperature to
indicate that all the batteries are fully charged. With new sets of batteries, it can take
several hours for the pack to go from the first one to top off until the last one tops off.
As the batteries age and become synchronized, the time is reduced to less than an
hour. At the end of pack life, the time gets longer if the batteries failure mode is self-
discharge.
How hot to run the regulators during the final absorption phase of charging is a function