At the moment functions of the BMS are:
* LVC (2V)
* HVC (3,65V)
* early balancing (1A bleeder), starts at ~50% SOC (state of charge) - this is the main advantage if compared to almost any other BMS
* unlimited power.
* gradual power decade on near-to LVC condition - it won't cut off you unexpectedly in middle of traffic, will give some time to stop safely.
You may ask why and how power is unlimited. Thing is, all decent motor controllers do have current limiting and additional limiting is not needed. My BMS does not have power switches on battery line, + and - of the battery pack connects directly to motor controller's "power" input. All you need is a standard fuse between battery pack and controller to prevent fire if wires or controller goes down. This allows to make the BMS very compact and save some energy that could be wasted on power switches.
You may also ask how LVC works if there are no power switches. Most decent motor controllers (all ebike controllers I know) have two red (BAT+) wires: thick and thin one. Thick one connects only to power mosfets inside the controller and thin one connects to internal voltage regulator to supply the logic. Thing is, if supply is removed on thin supply wire, the controller switches off and consumes absolutely no power, zero amperes. That means thick red supply wire (black as well) can be always connected to battery pack and draw no current, while thin red supply wire goes thru BMS - it is connected to BAT+ when: ignition is on, no LVC condition detected and charger is not connected. BMS switches power to thin red wire off when ignition is off, LVC condition detected or charger is connected. Thin red wire requires very low current and thus a small mosfet inside the BMS. I have tested this on many controllers, including GoldenMotor, Crystalyte, Infineon (Lyen).
HVC and charger control is done in similar way. Decent chargers do have "AC sense" output and "power" input.
AC sense is needed for BMS to know when charger is connected either to AC line (if onboard charger is used) or to battery pack (if portable charger is used). AC sense signal can be taken from charger (if it has this function) or simply as a switch on charger's connector, to know when cable is connected to vehicle. Actually AC sense signal can be not used at all, BMS can function without it. But it's recommended.
Charger's on/off is controlled via charger's control input, if it has this function. If not, additional module can be added to BMS to switch AC line or DC line (between charger and battery).
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