liveforphysics wrote: For smallish sized packs, backpack makes a lot of sense. Backpack with a compact, quiet, high current opertunity charger and a few Nano-tech packs able to be charged in 6mins makes boatloads of sense. Even if you only have a couple hundred watt-hours, you can really leverage them well with a setup like that.
Quick "opportunity charge" sounds like a good idea. Problem is, where to find a powerful (around a kW) yet compact and quiet charger. The Meanwells many of us use are 350W/kg. The Flatpack2 I just bought is 800W/kg. However this is nothing compared to the power density of some of the DC-DC converters that are around 2000W/kg. Problem is the DC-DC are typically max 70V in (48V nominal). They are small beacuse Switching frequency is in the 100kHz to MHz range. (Most 110V mains PSUs seem to be 10's to 100kHz range)
So is there some source of compact 110V to 48V PSU/chargers I've not found?