Jeremy Harris wrote: I've been charging high capacity packs with three different DC-DC converter chargers for well over a year now, with excellent results, Doctorbass has done the same long before I did it.
Doctorbass wrote:I just bought the celllog breakout module from Robin of RWaudio. they fit 4 celllog connected for up to 32s and are isolated with very small relay.
I know Jeremy & Doctorbass are experts at using the small DC DC converters to do tricks with charging high voltage bulk charging (Doctorbass) & also using for cell level charging too (Jeremy & Doc). You guys are great for that.
Why isn't there an easy way to charge at the cell level using a single, yes, just one, DC DC single cell isolated output converter at high amps (maybe 3.6v @ 50+A or 100A for A123) & have it "shared" on an Opto-Isolated Relay to send the charge in sequence through the opto-isolated relay to one cell at a time while also connected in series in an isolated switching mode sequence for x-string of cells in series using heavier balance tap wires to carry the higher amps??? The wires may not have to be too heavy, since the charge is switching between the cells one at a time in series with the opto-isolated relay.
I know this idea has been thought of, but why hasn't it been done already?
(Btw, I'm not at all knowledgeable in understanding the electronics design of charging, so I'm probably missing the obvious not knowing what is "obvious". )
This was pointed out to me by PM:
problem is that the relay failure is important risk and you also need a delay between each relay to avoid the condition where two or more relay are ON state at the same time due to magnetic hysterisis of their coil.