So I've finally acquired and tested enough 18650 cells to build something, and I have a sudden need to do so (The UPS powering a large portion of my electronics died a couple days ago). But I'm finding a gap in my knowledge.
Everyone talks about the battery and BMS portion of building a pack. Occasionally people talk about the inverter, but rarely does anyone talk about how they get the AC from their wall into the pack. So the question is relatively straight forward:
120v 60hz AC outlet here ------ magic here ------ balancing BMS connected to 18650 cells here (still deciding, but let's say 7s for now)
What replaces the magic? I believe that connecting DC power straight in to the BMS is usually possible, but I've also been told that constantly powering lithium ion batteries is bad and that you should have some form of "charge controller" I'm just not sure what that looks like exactly.
So if I want to build a basic UPS from a bunch of 18650s, what exactly do I need to make this work? (ignore the output side for now, both because it's already been discussed, but also because in the end, I don't really need it as every item plugged into that UPS just converted the AC output right back to DC12v anyway, so I'll probably just use a DC-DC converter instead of an inverter powering a dozen wall-warts for this build)
Everyone talks about the battery and BMS portion of building a pack. Occasionally people talk about the inverter, but rarely does anyone talk about how they get the AC from their wall into the pack. So the question is relatively straight forward:
120v 60hz AC outlet here ------ magic here ------ balancing BMS connected to 18650 cells here (still deciding, but let's say 7s for now)
What replaces the magic? I believe that connecting DC power straight in to the BMS is usually possible, but I've also been told that constantly powering lithium ion batteries is bad and that you should have some form of "charge controller" I'm just not sure what that looks like exactly.
So if I want to build a basic UPS from a bunch of 18650s, what exactly do I need to make this work? (ignore the output side for now, both because it's already been discussed, but also because in the end, I don't really need it as every item plugged into that UPS just converted the AC output right back to DC12v anyway, so I'll probably just use a DC-DC converter instead of an inverter powering a dozen wall-warts for this build)