I've posted about this before in another unrelated thread outside of Reoville but here goes...
Silly as it may be, the mechanical nature of the REO makes me nervous. I've only used regulated devices so there's a lot less to worry about as far as safety goes. I do use an ohm meter when wrapping coils, make sure my batteries can handle the resistance of my coil (though I keep my coils between .5 and 1.2 ohm and still only use 20A rated batteries) and also check to ensure there isn't a short. Still... the lack of a safety net, so to speak, keeps me from pulling the trigger on a REO or any other mechanical device. I guess I'm concerned about not knowing when the battery voltage has dropped too low and could cause it to vent. Is it obvious when the battery needs to be pulled and replaced? Also, how messy (if at all) are the REOs? What accessories should be purchased? I'd imagine at least one extra spring and a few extra bottles if nothing else.
The start up cost is a bit high as well. Not the REO itself, really, but the fact that you need to grab a bottom fed atty right away as well. And that I know it'll just cause me to buy 50 more almost immediately. And probably a REO Mini to bring to work. Anyway, any comments or suggestions you folks might have would be appreciated.
Welcome to Reoville! I'm new here myself, but I love it already
I shorted a Samsung INR18650-25R the day I got my SRX clone (a couple months ago) since I didn't realize to screw the atty tight to the semi-hybrid connector before threading it to the tube (d'oh! noob not paying attention). Not much happened. Granted, I didn't hold the button 30 seconds or anything ridiculous. After realizing the coil wasn't firing, I took the topper off, checked the battery's voltage, and it was 1.-someodd volts. Retired the battery, realized my mistake, haven't shorted anything since. I really suspect most of the terrible short situations happen with batteries with high internal resistance. Eye-ball-o-metric'ing discharge curves and dead short topper to switch resistance, I probably threw 80-ish amps through that battery for all of a half-second. After that, there couldn't have been available energy in the battery to provide much more than 15 amps. Yes, I got lucky. The moral? Use high-drain IMR batteries, and be careful (no dead shorts/resistance below minimum safe) because it is still possible to put an IMR into thermal runaway. Thermal runaway does not mean explosion, but rather that the battery is experiencing a self-sustaining internal chemical reaction which produces lots of heat. Contain that heat (like in an unvented mod) and you have an explosion. AW 18650 IMR are fine, just avoid the 2000 if you're going below something like 0.6 ohms (Yes, I know the amp rating has a bit more room, but leave headroom). For cheaper, the Samsung 25Rs from illumation supply are great.
The Reo line-up is very carefully designed, and the mod itself has almost no way to short (read: you'd have to modify the switch or positive contact to run risk of mod short). Your atty, of course, can be shorted easily, by running wire straight from the positive to negative pole. If you do that, you'll be looking at neighborhood .03 ohms load, i.e. 140 amps from a freshly charged battery, except the spring will burn out hundredths of seconds before the battery catches full load. What if the spring doesn't burn out? Then the battery gets really hot and, within seconds vents, because the battery's resistance produces enough heat to burst its casing. Since there's a huge squonk/vent hole, the outgas will escape and my only suggestion is to leave the room (I hear lithium is bad for you) and thoroughly wash the mod and atty before using again. Since you used an IMR battery, the outgas wasn't flammable at the heats involved in venting. Since the outgas vented, it didn't "explode," sending a topper or whatnot flying. Of course, the battery, juice bottle and tube should be thrown out and replaced.
As far as over-discharge, you likely won't. Even at 0.3 ohms (the lowest I've run with Sony VTC4s), I find dissatisfaction occurs no lower than 3.3 volts. If your vape is not producing much vapor even though it should, isn't warm even though it was, or otherwise seems dissatisfactory, check battery voltage and charge it. If you somehow drop a battery below mfg. rated cutoff (usually 2.5-2.7 volts), consider it retired. Notably, you won't vent a battery by overdischarging it. You will, however, "cement" some of the electron exchange, which will increase the battery's internal resistance a bit. It's actually possible to do the math on what an overdischarged battery's new (lower) max amp rating likely is, but the safe bet is just retiring any battery which has been overdischarged.
Reos are only messy if you oversquonk and juice comes out of the atty's airholes, if there is a poor seal (highly unlikely if all your stuff comes from Rob - the quality and attention to detail are superb), when refilling the bottle (use a napkin under the tube to alleviate), or if, like me, your vapor is stupid dense and you get condensation.
I apologize for novelling you. The stuff I posted is the results of my research when I had very similar questions to yours. If anything I said was unclear, mention and I or someone with better expression skillzs will be happy to clarify.
And yes, I'm looking for RA (Reoholics Anonymous) now.. got my first Reo Saturday, two more and two more doors, two more atties coming this week. I know I've got a problem, and that problem is no Woodvil & Resin!
So far as spare parts, I got an extra spring for just-in-case, a delrin button cover (unnecesary, but I use it so unlocking is easier), and an extra spare bottle (not sure yet if tank crackers affect the bottle/tube).