Cell balancer wastage....a better design?

[Solarfun4jim]

It seems to my untrained thoughts, that passive cell balancers waste energy through bleeding energy off to resistors, active cell balancers have 20% losses sending charge between cells.....why not simply 'switch' the charge 'gate' on, for each cell according to the monitored voltage. ie the lowest first cell would start charging(solitary) until it reach the voltage of the next lowest. These two cells would then start charging till they reached the voltage of the third lowest cell and so on. No dissapating heat to burn off energy, no wasting energy transferred to another cell, only then to top up the cell that you took charge out of, to a higher level. Seems simple to me, but i guess there must be good reasons for BMS cell balancers appearing complex and wasteful. This would eventually ramp up to charging every cell to the max limit, but it could cut out a lot of heat build up in the early stages, thus prolonging battery life.
Still very much learning about this stuff....any thoughts why this would not be possible?

 

[SCClockDr]

The first issue to resolve in your proposal is the charger supplied voltage vs the individual cell voltage. The cell resistance of all the cells act as a voltage divider allocating the proper voltage for each cell.
An active balancer is sort of a trickle charger for individual cells. By keeping the amps low it can achieve precise balancing by not loading the donor cell. Especially at low SOC.
The usual charge setup of supplying system voltage to the battery/load junction allows for supplying current to the load while also replenishing the battery.

 

[Solarfun4jim]

If the charger supplied voltage is reduced to say 4.2v in the BMS or from charge controller, so that you are charging at an individual cell level, not at pack level, then as each 'gate' gets activated, the individual cell gets the 4.2v or whatever the parameter requires. It is all about opening individual gates as the cells equilise, to bring them online.
As i say, i'm no electronics geek, but that just seemed logical to me.

 

[SCClockDr]

@Solarfun4jim you may have the basis for an "All in one" system design advance.
Now to intrigue an electronics developer into designing, funding, & producing a competitive product. This is how Ford, Edison, & Jobs got started.

 

[Solarfun4jim]

@Solarfun4jim you may have the basis for an "All in one" system design advance.
Now to intrigue an electronics developer into designing, funding, & producing a competitive product. This is how Ford, Edison, & Jobs got started.

lol....if we suddenly see lots of them appearing from china now, we saw the idea here first