Overcharged battery

[Big Me]

I bought a new xtar VC4 charger this week and charged an unused Sony VTC4 battery which I bought it from a reputable vendor in February this year. (The battery was originally bought as a pair but as I only needed one it has been kept, untouched, in a plastic battery case since purchase.)

I waited until the light went green on the charger indicating that the battery was fully charged but when I tried to use it in either of my smok M65s it said "High Input" (which according to the manual means the battery is over 4.5v). I don't have a ddm currently so can't double check what the actual voltage is.

I didn't leave the charger unattended and I checked that neither the battery nor the charger was getting warm during the charge cycle.

My question is: is there a way to safely discharge this battery down to it's proper level or do I need to dispose of it?

 

[KenD]

If it's actually overcharged to 4.5v it's probably damaged and unsafe to use. However, xtar chargers have a really good reputation and it's unlikely that yours would've overcharged the battery. Perhaps the flaw is in your mod. Get a dmm or another way to test the actual voltage of your battery.

Sent from my C6903 using Tapatalk

 

[r77r7r]

You might want to check out this vid. It addresses the bad battery connections and might be your issue. I heard it's pretty easy to fix.

 

[Big Me]

You might want to check out this vid. It addresses the bad battery connections and might be your issue. I heard it's pretty easy to fix.

I've already done this to the two I have. Thanks for the suggestion, though.

 

[Ryedan]

I waited until the light went green on the charger indicating that the battery was fully charged but when I tried to use it in either of my Smok M65s it said "High Input" (which according to the manual means the battery is over 4.5v). I don't have a ddm currently so can't double check what the actual voltage is.

Either your charger is overcharging or the Smok M65s has a voltage meter that's out of spec. The only way you'll know which it is is to get a meter on the battery that you know is good. Pretty much any $15 DMM will help you out here. Until you are more certain what the battery voltage really is, there is no point in trying to answer your question. That depends on how high the battery voltage actually is right now.

 

[Train2]

I had one fluke battery - brand new LG HE from RTD Vapor - that went over 4.2 and kept charging, never finished.
I pulled it off as soon as it was clearly over spec, and contacted the vendor.
They said it was possible my Nitecore couldn't properly read the chemistry of that particular battery - or SOMETHING like that. I'd never before and never since had a problem with that charger (though I did just yesterday, get an Xtar). They were cool, and swapped me for another Samsung, to keep me happy.

Bottom line - I don't know if it's the charger or the battery or the compatibility between them - but I think this sometimes can "just happen". And so I never leave batt's charging overnight.

 

[Big Me]

Just ordered a DMM so I'll find out what's happened for sure when it arrives.

 

[yo han]

Bottom line - I don't know if it's the charger or the battery or the compatibility between them - but I think this sometimes can "just happen". And so I never leave batt's charging overnight.

Definitely the charger's fault. The battery is the passive component during the charge. The charger measures the voltage and needs to stop when it reaches 4.20V
The Nitecore recognizes different chemistries by the voltage of the inserted batteries but of all the different chemistries it supports, Li-Ion has the highest cutoff voltage. So even if it did recognize it as a different chemistry cell, it should never have been charging over 4.20V

 

[Big Me]

Finally got the DMM and the replacement leads (they were missing!) and the battery is reading 4.49v.

This battery needs to be disposed of, yes?

 

[Mooch]

Finally got the DMM and the replacement leads (they were missing!) and the battery is reading 4.49v.

This battery needs to be disposed of, yes?

In my opinion, yes. Especially since the battery has been in an overcharged state for days. It's just not worth the risk.

When a LiIon battery is overcharged it deposits metallic lithium metal. This metal can later form pointy little growths, called dendrites, that can pierce the insulator between the positive and negatives sides of the battery. This can lead to internal short circuits that result in severe heating and, eventually, thermal runaway. This is bad. It can result in bursting of the cell and flaming debris.

 

[r77r7r]

bursting of the cell and flaming debris.

That's your Avatar, right?

 

[Mooch]

That's your Avatar, right?

You're the first person who has got that.

 

[Big Me]

In my opinion, yes. Especially since the battery has been in an overcharged state for days. It's just not worth the risk.

When a LiIon battery is overcharged it deposits metallic lithium metal. This metal can later form pointy little growths, called dendrites, that can pierce the insulator between the positive and negatives sides of the battery. This can lead to internal short circuits that result in severe heating and, eventually, thermal runaway. This is bad. It can result in bursting of the cell and flaming debris.

Cheers for the confirmation.

For future reference, is it possible to discharge a battery like this safely and how would you do it?

If it's actually overcharged to 4.5v it's probably damaged and unsafe to use. However, xtar chargers have a really good reputation and it's unlikely that yours would've overcharged the battery. Perhaps the flaw is in your mod. Get a dmm or another way to test the actual voltage of your battery.

Sent from my C6903 using Tapatalk

Mine did!

 

[Mooch]

Cheers for the confirmation.

For future reference, is it possible to discharge a battery like this safely and how would you do it?

It can be done but unless you have a separate battery holder or mech mod around it probably can't be done very safely. You can use an automotive light bulb or 6V (or higher) flashlight bulb. But, that involves placing wires across the cell and if not done carefully it could short the cell very easily at the positive end.

Probably best to duct tape the cell up good and recycle/dispose of it as is.

 

[Big Me]

It can be done but unless you have a separate battery holder or mech mod around it probably can't be done very safely. You can use an automotive light bulb or 6V (or higher) flashlight bulb. But, that involves placing wires across the cell and if not done carefully it could short the cell very easily at the positive end.

Probably best to duct tape the cell up good and recycle/dispose of it as is.

Thanks again for the guidance. I had no intention of attempting it with this battery as you'd already advised I dispose of it.

 

[KenD]

Cheers for the confirmation.

For future reference, is it possible to discharge a battery like this safely and how would you do it?



Mine did! [emoji38]

Yeah, definitely seems like your xtar is faulty.

Sent from my C6903 using Tapatalk

 

[jwbnyc]

I bought a new Xtar VC4 charger this week and charged an unused Sony VTC4 battery which I bought it from a reputable vendor in February this year. (The battery was originally bought as a pair but as I only needed one it has been kept, untouched, in a plastic battery case since purchase.)

I waited until the light went green on the charger indicating that the battery was fully charged but when I tried to use it in either of my Smok M65s it said "High Input" (which according to the manual means the battery is over 4.5v). I don't have a ddm currently so can't double check what the actual voltage is.

I didn't leave the charger unattended and I checked that neither the battery nor the charger was getting warm during the charge cycle.

My question is: is there a way to safely discharge this battery down to it's proper level or do I need to dispose of it?

Bit late but thought I'd relate my experience with the eFest V4 charger.

In a word: Bad.

This charger routinely over-charged batteries, in the range of 4.24V, while I was using it.

Charger canned. Batteries canned.

Not a good charger imo.

 

[Haadkoe]

At the end of the day, how big of a deal is .04v?

Four hundredths of a volt doesn't seem like a catastrophe waiting to happen to me.

Thoughts @Mooch ?

 

[Mooch]

At the end of the day, how big of a deal is .04v?

Four hundredths of a volt doesn't seem like a catastrophe waiting to happen to me.

Thoughts @Mooch ?

Yea, seems pretty small, but...
While 4.2V is the voltage we all use to get the maximum capacity out of our batteries, it is high. Not high enough to age/damage the battery too much each time we charge it but it does reduce the life of the battery a lot versus charging to 4.1V.

Continuing to go another 0.04V higher sure doesn't seem like a lot but li-ion batteries at both ends of their voltage range act similarly...a tiny change can lead to huge differences. At the low voltage end, below 2.5V or so, even discharging a battery another 20mAh can plunge the voltage another volt. At the high voltage end, even charging consistently to just 4.24V can decrease the life expectancy of your batteries.

By how much? I don't have hard numbers in front of me but studies exist showing at least a 40% increase in the cycle life of a battery by charging at 4.1V instead of 4.2V. Going to 4.24V could mean losing a decent percentage of the cycle life you would have at 4.2V. I have multiple clients that spec a 4.0V or 4.1V charging voltage. The loss of capacity can be as high as 20% but the increase in cycle life allows them to build a product that doesn't require the battery to be replaced before the device otherwise fails in a few years. Most see 4-5 years before the battery starts losing significant capacity.

Another small concern is that as your normal charging voltage gets even a bit higher, you lose that much safety margin in case of charger component value drift or failure. At roughly 4.3V metallic lithium can plate onto the anode and excess gas is created by the cathode....not good. Charging to 4.24V is on the edge of that.

 

[r77r7r]

Great having you here, Mooch.