Or does it depend on the charger?
If safe, will it affect the battery in the long run?
Depends on the charger.
If its a real cc/cv charger with real termination (zero trickle charge after full) then its perfectly fine and safe. No harm to the battery.
With a junk charger, your battery could explode if left on the charger. Fire plus hydrofluoric acid for your lungs.
It will either be a Nitecore i4 Intellicharger or OPUS BT-C3400.
I’ve left a lot of batteries charging overnight with my Opus BT-C3400 charger.
That is prob the one I will end up buying.
Thanks mate.
My pic is real, I have the video to back it up.
So it’s not this Great White?
No but I like the song.
So, assuming you’re talking about li-ion
— do you have good ones, not risky ones?
— has someone confirmed that either of those chargers does have zero trickle charge?
Having some trickle charge does not mean — 100 percent of the time — that you’d have a problem, or notice it.
But it does mean that you eventually may have a problem.
Given that a problem is either non-noticeable or very serious — don’t rely on anecdotes.
Look up the review and test on the actual product you decide on.
And remember — fireproof surface, ventilation, and not left overnight in a building containing anything, or anyone, you care about.
Sometimes the best chargers can miss a termination. ie: they dont switch off when charged at which point they are little different to cheap chargers.
So provided it all works as it should, its all good to sleep while it charges, some have enough safety built in you could probably let your half wit cousin/neighbour/whatever use them. But then again, it might not be…
Personally, I wouldnt leave the best charger, charging the best batteries, while I slept, or while Im not home. But if youre more of a risk taker, at least make sure its in the garage or undercover on a large patio type thing.
/0.02
A LiIon charger will NEVER miss termination (It is not possible with the charge algorithm), it is something NiCd and NiMH chargers does.
With LiIon chargers the problem is trickle charge, you do not want extra charger pumped into a LiIon battery. Most charger do terminated fairly well and a day extra on the charger is not a problem.
Generally it is not recommended to leave electric equipment plugged in, some spike on the mains voltage can damage it and anything can happen. This risk is very very low in most residential areas and a bit greater in industrial areas.
I leave mine plugged in overnight all the time. I use xtar and opus chargers though.
OP doesnt specify what batteries he is using. But thanks for the clarification, I was not aware li ion chargers did not suffer from missed terminations. Is it true for every li ion charger, even cheap nasty ones you review as bad chargers? Do they all use an algorithm that ends in a low trickle charge?
You can have LiIon chargers that is lacking the termination circuit or they can charger to too high voltage.
The termination for LiIon is a steady state condition, i.e. you can always measure it. For NiMH/NiCd it is a state change, you can measure exactly the same values before and after termination and will never know it has terminated if you miss the state change (This is a bit simplified, a good charger may have a temperature sensor as backup).
Very few chargers turns the current 100% off, there will usual be a small charge or discharge current after termination. Often it is low enough to not have any practical implications for normal usage.
Yes, spent a bit of time making sure they are legit.
No but the OPUS is highly recommended.
Good points, thanks.
Opus charger and eneloop batteries.
And some imedions also.
I left an Eneloop in a Nitecore i4 almost every night for some months now, as a couple gets cycled in a single AA flashlight used as constantly on night light, I haven’t had problems so far but I don’t know if it trickle charges the cell and by which amount, nor if will affect the lifespan of cells doing so.
I melted a little bit of the case of a Maha charger just last month.
Found it that way in the morning after I’d left it overnight charging eight D size Tenergy NiMHs.
One of the eight cells, or one of the slots, overheated enough to wrinkle the case plastic.
All the cells still test good after charging, so it wasn’t a dead-shorted cell, it was just “that happens” and hey, the plastic is fireproof.
But ya know, it’s not something that I think is really a good idea to risk repeating.
Under 3 years, so warrantied, and they replaced it after taking a look at it.
I’ll never leave even high end cells on a good charger overnight again.
I’d never leave a li-ion cell unwatched in a charger.
Overheating is one thing, worth worrying about.
Venting hydrofluoric acid and flame is — a good chance of losing everything, not worth any risk.
I’ve only had two li-ion cells vent in the time I’ve been using them — both found that way, inside the metal box, weeks or months after I’d put them away, with the chemical stain around the positive end showing they’d lost their contents. Both of them were rechargeable RCR123 cells made by SomethingFireSomething — among the first li-ions I ever bought.
Do ya feel lucky? Well, do ya?
Perhaps relevant to the safety concern: don’t EVER leave a li-ion charging unwatched.