I believe we have come to the stage where our
BMS's should be capable with current limitting sofftware.
I look at a lot of
BMS's and they only have shunts for current limitation. Yet they have fets to shut down for LVC.
Using PWM to limit the current flow through these LVC FETS before the shunt or with more parallel higher resistance fets, IMO would make for better efficiency than to just be using shunts alone. Lose the need for HCC, if the
BMS even has this or its fast enough to shut down before failure,.. One could short a battery out and not blow the LVC output fets of the
BMS and use a simple fuse for battery over current discharge protection.
A person with a 48v system can use a brushed controller and some average filter caps on the output and use the throttle of this brushed controller to controll the current, this idea can be installed into a
BMS and regulated by the manufacturer or user to achieve better compatability to varying systems and add a better over current protection regime for the cells.
Manufactures could use this to limit their packs current abilitiues to spec, Not unlike the Cycle analiyst can in some controllers. Batteries are too expensive to play around with.
Absolute max current needs to be controlled and set solid at the output stage of the pack IMO, and not essentially be a part of an inclusive series resistance of the
BMS shunts and controller shunts added together.
The more protection pack manufacturers have against overloading cells, the more protection they have from unwanted returns.. Users will enjoy the added protection as it wont interfere with their modification tinkering of the controllers.
Yeah take it to the limits is one thing. but who really wants to over draw current over their cells capablilty and specs?
