# Charging power scratch pad

From OrbSWARM

Feel free to skip to the end to see how many kilowatts of power we need... it's more than 3. Lead-acid batteries can be charged at a maximum of 0.3C. Assuming (assuming!) we go with our 7 amp/hr 12v volt batteries, this is what things look like... We are using 5 batteries per orb * 6 orbs = 30 batteries We also have an unnamed battery system in the mothership, but we'll talk about that later. 0.3 * 7 = 2.1 amps 2.1 amps * 12 volts = 25 watts 25 watts draw per battery for 5 hours. (you'll note that we put more electricity into the battery than we get out... that's correct. It's actually about 1.2:1) 25 watts * 30 batteries = 750 watts 750 watts * 3 sets of batteries for swapping = 2,250 watts The orbs need 2,250 watts for 5 hours to charge 3 sets of 7amp/hr batteries for a full day of performances. It is possible that we might need to switch to batteries with more capacity. If we switch to 10amp/hr batteries, we'll need 3,200 watts for 5 hours. In actuality, our power requirement will probably drop a bit over the course of the 5 hours. But the peak power requirement -------------------------------------------------- Now to talk about the batteries for the Mothership..... This is an Illumination question but I'll try to tackle it.... Lighting.... 50 watts (night time only) Laptop Computer ... 100 watts (during performance only) second laptop computer???... 100 watts (??? during performance only) radio gear... 10 watts (during performance only) GPS beacon... 10 watts (most of the time) Sound... 50 watts (most of the time) Drive motor ... 400 watts (during travel only) (if we go with electric power) Let's take a wild stab at it... lighting 50 watts * 8 hrs laptop 100 watts * 8 hrs 2nd laptop 100 watts * 4 hrs radio 10 watts * 4 hrs GPS 10 watts * 20 hrs Sound 50 watts * 8 hrs = 2,200 watt/hrs charging will take 660 watts for 5 hrs drive 400 watts * 3 hrs = 1200 watt/hrs charging will take 360 watts for 5 hrs -------------------------------------------------- -------------------------------------------------- So, to sum it up: (these numbers are probably inflated but not too much... actual peak draw is reasonably correct. Average draw might be *0.7) And PLEASE someone check my numbers for inadvertant bullshit! between 2,250 and 3,200 watts for 5 hours for the orbs 660 watts for 5 hrs for mothership 360 watts for 5 hrs for mothership electric drive system 4.2 kilowatts for 5 hours to charge the sucker up. (Oh, and I still have to find the actual equipment that can charge all this stuff up...That is a LOT of charging to be done! I'm looking at forklift battery chargers...)