Who Leaves Their Batteries Unattended to Charge?

I have several Li-ion chargers all of which claim to stop charging once the led indicator changes color. (I also mainly use the premium unprotected sony, sanyo, LG etc cells) However I still never leave them charging overnight or when I am out of the house for even an errand. Am I being too paranoid? What do you guys do?

I usually check in on mine every once in a while. if I'm gone I'll ask someone else to check on them.

I might be paranoid too... i put the whole thing in an aluminum box just in case something goes wrong.. I'd rather have the box ruined than my house burned down

I did a measurement on my charger. When it's green, there really is no current coming out. So yes, I leave my batteries unattended when charging (if I have to - usually, when I am charging my batteries, I am working with lasers, so I am usually sitting right there).

The issue is NOT nessicarily the Charger. Batteries with moderate damage can 'spontaneously combust' (go Boom and flash). Best thing I know of is to put them in a fireproof container when charging. If you've ever seen a cell go up, you already know that you don't want to wait around until after the shock wears off to do something about the fire... Go to a hardware store and but an empty one gallon paint can (not the best protection, but better than none), put the charger and the cell(s) in the can while charging.

If your house never burns down then you aren't paranoid, you are smart !
Whatever you feel is "safe" will be. It's kind of a thing where you are the one who defines the term for yourself.
I have various chargers (home made and purchased) that I trust to function normally BUT that doesn't mean that I plug them in and forget about them. (Which is getting much harder lately...)
It's just one of those things that has ingrained into me over the years, like respecting electricity. Don't stand in a puddle when working with AC wiring. Likewise don't leave a heavy-duty battery charging on a counter in a small room with a door closed overnight. (Can you say >BOOM< !)
Adequate ventilation - for fumes or cooling,
proper surfaces - non-reactive or fireproof,
reliable equipment - non-damaged, good condition, functioning within ALL parametres,
all are considerations when charging.
And I do it all so automatically and instinctively that it was hard to break it down for writing it here. Usually it takes only a couple of seconds to assess it all under the circumstances and just do it the right way.

So do what you think is right.
As you become more familiar with your equipment and how it responds to the cycles the better you will be able to know what to do and when to do it.
Are you paying attention to what is happening when you "check" it now ? Are the batteries cool, warm, or getting almost hot ? Is the charger making more noise at some times versus the others ? Is your safety enclosure working as a heat sink or is it a potential trap for explosive fumes ? Are there even any fumes to worry about ?
If you can answer all questions easily (even ones not asked here) then you have everything under control.
If you don't understand what the questions pertain to then you might want to look into the actual processes involved and find out what should be happening and what could happen. (in a worse case scenario for example.)
Different battery types made from differing materials will require different processes to be recharged. What works fine for one may cause complete breakdown for another.
As always, it comes down to knowing what you are doing. How you get to know is up to you.

Sorry for the bog block answer. Kind of slow here at work at the moment.

Now I am scared!

My chargers' green light goes off when my batteries (all of which are unprotected) reach 4.18V, but I leave it in for an extra hour and it still charges to 4.2V. I always check on it periodically taking the voltage and feeling it if it's warm or not because I'm a bit paranoid lol.

It's also a good thing to measure the internal resistance of the cells just to make sure. I think drlava posted a thread on how to do that. Basically damaged or older cells will have a higher internal resistance which leads to lost capacity and higher temps during charging/use that can lead to explosion or fire.

I regularly check the temps and they have always been fine. I am familiar with my equipment and my cells. I am not new to this stuff. I use only high quality and I never abuse them. None are old. I believe I take the right steps I only asked because I want to go biking for a few hours and I usually would unplug them but I wanted to see what others think.

I never leave cells to charge unattended. I know that my charger works properly, but even so... I'm a little paranoid.

Typically I just check on the batteries every 5-10 minutes, feel the temp...

No container... I should really get one. They are in a kind of spot where I don't expect anything would ignite though, but would probably do quite a bit of cosmetic damage:undecided:

IIRC there are special bags sold that would work well.

I can't really say I leave mine unattended but at the same time I kind of trust my charger since if the voltage exceeds or drops, the timer limit is hit, or some spiffy charging function say its done, then it stops charging, it has an optional thermal monitor but never got it.

Kmor2004 said:

I can't really say I leave mine unattended but at the same time I kind of trust my charger since if the voltage exceeds or drops, the timer limit is hit, or some spiffy charging function say its done, then it stops charging, it has an optional thermal monitor but never got it.

Click to expand...

I'm curious what charger are you using?

My thermal monitor consists of my pointer and middle finger

Although my charger has specific programs for different types of battery, temperature sensor and other security systems,
the truth is that I of as almost all of you, I'm never far away when I recharge my batteries.

Paranoid? Do not think, only precaution, in case something goes wrong

I put my charger in a ammo box from the military, yes i may be slightly paranoid, but you can never trust something from another country with a reputation of its own. I also check it every hour to feel it its getting to hot.

Alright well I will keep up my paranoia then. Thanks all.

Normally I keep an eye on my batteries. I usually know how long it takes them to charge and sometimes I leave them unattended but for the most part I am usually nearby. I don't so much worry about them but you know... the fear of an exploding battery lingers.

I would not say I am paranoid. I would say charging Lion batteries is like watching your kids. Just keep an eye out

I never charge those lithium cells when i'm not in the house and awake. The chance of something going wrong may not be that big, but it would be nasty if it somehow set off a house fire talking the whole appartment with it.

If batteries are dodgy i put the charger in a metal cooking pot, just so i can slam the lid on in case the things catch fire.

Its not the battery explosion that i'm worried about, but just the remote change of one venting some gas, shooting off onto a flamable piece of furniture (or wooden floor?) and then catching fire. Taking some precautions probably isnt all that paranoid since batteries have burst into flame in real life situations.