I've done projects with a single 18650 cell (charging IC, battery protection IC, and boost converted ot 5V), but now I want to power much more LEDs. Specifically, I'm planning to use WS2812B-ECO LEDs from BTF-Lighting. From their claim it's 0.3W per LED, and I'll have 300 of them so that would be 0.3W * 300 = 90W total, to be driven at 5V.
# How many batteries?
So one question is how many batteries do I need? I'll likely run these at half brightness so 45W, but let's go ahead and plan on the 90W and let's say we power them for 1 hour, so that would be 90Wh needed (right?). So I need roughly 18Ah of power from these batteries. What I'm struggling to think correctly about is that these batteries actually put out 3.7V (before boost conversion to 5V) so if one battery is 3.7V and 2.6Ah, then if I have a 1S7P battery that would be 3.7V and 18.2 Ah, but that isn't really enough because wattage-wise that's actually 67.34W.
Is the correct way to think about this in terms of watts then? So to get 90W from a 3.7V source that would be 24.32Ah and with 1 battery providing 2.6Ah that would be 9.35batteries or rounding up to 10 batteries, so a 1S10P 18650 battery pack. Is that right?
# And how to boost it?
In my 1 battery designs I use a boost converted to scale up the 3.7V to 5V, but the issue I see coming is that these boost converters can handle say 2-4A max. In this case at 5V I would need 18A. How does one boost a 1S10P battery pack outputting 3.7V to 5V to provide 18A worth of power at 5V? Any ideas?
Any advice here would be helpful. Thanks!
# How many batteries?
So one question is how many batteries do I need? I'll likely run these at half brightness so 45W, but let's go ahead and plan on the 90W and let's say we power them for 1 hour, so that would be 90Wh needed (right?). So I need roughly 18Ah of power from these batteries. What I'm struggling to think correctly about is that these batteries actually put out 3.7V (before boost conversion to 5V) so if one battery is 3.7V and 2.6Ah, then if I have a 1S7P battery that would be 3.7V and 18.2 Ah, but that isn't really enough because wattage-wise that's actually 67.34W.
Is the correct way to think about this in terms of watts then? So to get 90W from a 3.7V source that would be 24.32Ah and with 1 battery providing 2.6Ah that would be 9.35batteries or rounding up to 10 batteries, so a 1S10P 18650 battery pack. Is that right?
# And how to boost it?
In my 1 battery designs I use a boost converted to scale up the 3.7V to 5V, but the issue I see coming is that these boost converters can handle say 2-4A max. In this case at 5V I would need 18A. How does one boost a 1S10P battery pack outputting 3.7V to 5V to provide 18A worth of power at 5V? Any ideas?
Any advice here would be helpful. Thanks!