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Kouri

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    Corey

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  1. Ah, I spend most of my time with the lightsaber groups where the electronic knowledge is more commonplace. The short version is, as nifty as this setup is, the way the battery pack is disassembled and rewired makes it a fire hazard at the base of the wearer's skull. The board in this photo is likely the battery pack's protection that prevents the cells from pushing too much electricity, and shuts them off if they get too hot or the voltage drops too low. With the board separate, this setup has three big unprotected lithium batteries stuffed inside the helmet. Something simple like letting the charge drop too low can damage the cells to the point they won't hold a charge anymore. Or something more serious like a short from a loose wire or some other bridge might cause the cells to start pumping electricity and heating up until they damage whatever happens to be inside the bucket at that time. I'm not trying to be overly critical of Skippy's work. This really is a very nice setup, and I'm sure he's taken great care of it so it hasn't cause any problems. I'm just suggesting tweaking the power supply to make it safer.
  2. I'm fairly certain your pack's a mis-named 11.1v nominal pack using three 3.7v nominal 18650 batteries (full charge is about 12-12.6v, but batteries aren't supposed to be rated at their topped-up voltage). That probably explains why the second indicator is off by about 15% - you'd probably have better accuracy with an 11.1v lithium-ion or lithium-polymer voltage checker. Something like this perhaps: https://smile.amazon.com/dp/B06Y1HVR53/ As far as I can tell, the battery pack's protection circuit was left inside the pack's old case to use as a charging adapter. That should help balance things during charging (since the voltages are probably a bit uneven splitting off the two cells for 7-8v to the 5v regulator), but that still leaves you with three unprotected lithium-ion cells inside your helmet, which is a safety concern. If you want to keep the batteries in the helmet, I'd suggest permanently wiring the protection circuit back to the cells and only using them with the full 11-12v line. Your 5v regulator looks to have a 25v max, so you're fine feeding it more voltage, though it might give off more heat. Alternatively, if you can find some way to insulate these from moisture, a 3x18650 holder (like this: https://smile.amazon.com/dp/B071ZQ2X2T/ ) and three *protected* 18650 cells would give you the same amount of power in the same amount of space while also giving you the option to swap batteries if you happen to run down mid-troop. If you want to cut down on space/weight, you could also use a 3xAA battery holder with three protected 14500 cells.
  3. Just going to add a bit on battery info. 3.6 and 3.7 are just nominal voltages - the voltage of any lithium-ion varies with the charge level. A properly protected lithium-ion will be at 4.0-4.2v fresh off the charger, spend most of it's run time at ~3.63.7v, then shut itself off to prevent damage when it drops to ~2.5v. Recharge and repeat. It's very important to get a protected cell - aside from the fire hazard (a shorted cell won't necessarily go *boom*, but it can heat up to the point of damaging equipment and even starting a fire that water won't put out), an unprotected cell might charge over the typical 4.2v limit and damage the iComm circuitry. The size lithium-ion to use in a AA holder is perhaps more commonly referred to as a 14500 (name identifies the size - 14mm diameter, 50mm long). In the US, Trustfire is a decent budget brand. I've used XTAR that work well. Genuine Ultrafires are fine. Try to avoid something-fire brands from chinese sellers - they might very well be knock-off cells of dubious quality. Especially avoid any 14500 rated at anything much higher than 900mAh - it's almost guaranteed to be a chinese cell with a fake rating. Most 14500s will be rated at 800-900mAh.
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