Charge tech has been in place for quite some time it's the bms and type of cells used that limit the charge rate. If your bms allows 40a input and the cells have say 3-5c charge rate then a 2600 mah cell can take almost 7a charge rate instead of maybe 2-2.5a from a standerd cell,this means almost 3x faster charge time.But ofcourse the better cells cost more as does a charger.I've been using a Hyperion eos 0610i/duo 2 for 6 years now and it's able to charge LiPo,LiFe,NiCh,NiMh,LiOn,Pb with built in balancing and monitering (I do a bunch of r/c stuff) and can charge at 10a output properly fully charging 5000mah packs in less than 20 min,and when setup in parallel 20ah in around an hour.Biggest problem in this quest for fast rates is the expense that charger is listed at $300 and high rate cells are like 11-15 bucks each as apossed to 2-3 for regular rate cells and this added expense unfortunatly makes a big difference to those just looking for cheap transportation.