This is important and applicable to stocking up and maintaining your stash.
TL;DR: Tank your batteries out of your mods if you are not going to use the mod for a while.
I want to stress the importance of never leaving a battery in a mod long term. The most common reason is "quiescent drain". Quiescent drain is the voltage your mod "robs" from your battery when it's "off'. A mod is not really "off" (unless it has a kill switch), it's just in standby waiting, listening for that signal to turn on and get to work. That takes a certain amount of current to run in standby mode, some mods will have more quiescent drain than others. Some Yihi chips are really bad about this and Yihi has refused to fix the issue. I actually vented a battery 2 times leaving it in a mod.
But the real reason is why I'm posting this - corrosion...
I had to go out of town about 4 months ago and took a bunch of gear with me. One mod, my oldest Pico 75W, I left in my backpack this whole time with a battery in it. I thought I took the battery out, but apparently I was wrong. When I went to go get it tonight, the battery cap wouldn't budge so I had to get pliers to screw it off. The battery was OK, it still had charge of above 4.0 but not quite 4.2. I used that mod when I was out of town that day so I would say it lost extremely little charge. So that's good in terms of quiescent drain on the Pico 75W.
But the reason the cap wouldn't come off is because there was this white corrosion all over the battery cap threads and the threads on the body. This definitely wasn't there before. It's a really hard, white, kind of powdery-looking stuff. And it doesn't come off with 91% rubbing alcohol. The mods works despite the corrosion.
This was obviously due to the battery being in there for too long. I can't think of what else would cause that. But I don't know what this white stuff is, either. It's not on the battery contacts at all. The battery is fine and it's clean. Samsung 25R Green.
This is the same corrosion I saw someone else post a pic of on their Pico battery about here a year or 2 ago. I believe it was
@englishmick. His was was really bad and it was the whole way down the battery tube IIRC. Mine isn't nearly that bad at all. Maybe he he can post that pic here if he still has it (if in fact is was him). It was originally posted in a different thread, I think.
Tomorrow I'm going to try soaking the cap in vinegar and I'm reasonably confident that will take care of it because I've used a vinegar soak to remove rust a few times. The threads on the mod will be a bit tough since I can't soak that in vinegar without completely disassembling the mod, which I have done before a few times. The screw heads are a little stripped and I had to rig the button a bit as it lost it's soft clicky feel that Picos have. So I'd prefer to leave it alone in that regard as the button works like new now. Without being able to soak it, it'll never get those threads 100 % cleaned.
Maybe tomorrow, if I'm not feeling lazy, I'll snap a couple pics before I try to clean it.
Not a big deal as I have other mods to replace it. The reason it bothers me is mostly because I want to see how much longer this mod will last without me doing stupid crap like this. It's about 5-6 years old and was used heavily for at least 4 of those years. Other then the now-fixed fire button, it has a dimmer screen than it did when it was brand new.
I hope you stockers will learn something from my carelessness (you're welcome
).
