Two flat batteries

[sonicbomb]

I put two one year old married Samsung 30Qs both on the the charger at 3.6 volts. Came back an hour later to find neither of them charging or registering any data on the screen of my Nitecore D2. I checked them both with a digital multimeter and they are both dead flat at zero volts.

I have had the D2 for about three years of trouble free use, and it appears to be working fine since the incident. Both the batteries were performing well and holding a good charge. Neither were ever used over the CDR or charged with more than 500 mA

I can imagine that possibly an 18650 could develop an internal fault and zero out. But for two to do so simultaneously seems highly unlikely. It seems more likely to me that the charger has developed a fault, or can at least be considered untrustworthy. I have a new Nitecore D4 on order in any case.

I'm not looking for any advice but I would be interested in peoples opinions on what might have happened.

 

[r77r7r]

Weird that it totally discharged them.

 

[Topwater Elvis]

An old Pila and an xtar did something similar, put 2 cells in at 3.4v two hours later it seemed as if they hadn't charged at all, removed cells checked with multimeter both had gone lower.

I would do as you are, suspect the charger & replace it.

 

[Mr. Relentless]

1 to 4.5% discharge per month for stored batteries. So if stored at 50% they could be dead in a year, depending on room temp.

 

[untar]

1 to 4.5% discharge per month for stored batteries. So if stored at 50% they could be dead in a year, depending on room temp

Yep.
How to store 18650 batteries safely

 

[SissySpike]

DC vampires suck them dry when your sleeping

 

[Rossum]

1 to 4.5% discharge per month for stored batteries. So if stored at 50% they could be dead in a year, depending on room temp.

I've never seen cells self-discharge that fast. I have a pair of HG2s here that I got in the spring of 2016. They have zero cycles on them, but I've kept track of them in storage.

• Unfortunately, I did not record their voltage "as received", but I took them to 3.70V on 2016-06-16.
• I checked them on 2017 02-12, so about 8 months later. They were down to 3.67V and I took them back up to 3.71V.
• I checked them again on 2018-02-09, so about 12 months. One was down to 3.68V and the other at 3.69V. I took them both back to 3.70V.

I have other spare cells in other locations and the data is quite similar; it's well under 1% a month.

 

[untar]

1% is in "1 to 4.5%" range

We also don't know if those were completely unused cells or if they saw use and then had a long pause. Since they're 30Q I don't know how to check manufacture date (which can also contribute if it lies far in the past at the date of purchase) but for most other batteries I check here
18650 Date Code Lookup Tool
to see if I get fresh produce straight from the battery trees.

 

[Rossum]

1% is in "1 to 4.5%" range

Since you didn't quote anyone for context, I'm going to assume this was in reply to my post directly above yours. I said my experience is that it's "well under 1% a month.

We also don't know if those were completely unused cells or if they saw use and then had a long pause.

Yeah, it will be interesting to see whether well-used cells behave differently. I just took a pair of HG2s out of service after two full years. They were rotated once a day through my "ADV" mod, so the each have ~365 cycles on them. Now these were not "full" cycles; basically never below 3.7V. Still, the wear on them clearly detectable using an AC resistance meter; they show ~22 mΩ vs ~15 mΩ for some of the same age that have no cycles. I'm going to keep them around for at least year to see what happens in terms of self-discharge and AC resistance.

Since they're 30Q I don't know how to check manufacture date (which can also contribute if it lies far in the past at the date of purchase) but for most other batteries I check here
18650 Date Code Lookup Tool
to see if I get fresh produce straight from the battery trees.

Yeah, I noticed that too, and it makes me a bit reluctant to buy more 30Qs. But that's OK, I really don't need anymore cells right now anyway.

 

[untar]

To get higher degradation you need to store them at a hotter place like on a radiator or maybe a fireplace.
Presumably being in Florida isn't enough

 

[Rossum]

To get higher degradation you need to store them at a hotter place like on a radiator or maybe a fireplace.
Presumably being in Florida isn't enough

A radiator? What's that? We only have air conditioning!

Seriously: Yes, my results are for cells that have been kept in comfortably controlled climates (well, except for the total of about 16-18 days when the power was out after hurricanes Matthew and Irma), but neither of those periods was really all that hot.

I would also speculate that the rate of self-discharge will be higher at a higher state-of-charge; in other words one would see a faster drop from 4.2V than from 3.7V on the same cell.

And of course none of this directly addresses the question originally posted by @sonicbomb. If I were a betting man, my money would be on a fault in the charger being responsible for the flat batteries.

 

[Mr. Relentless]

OP said one year old batteries. Didn't say stored for a year. I didn't catch that until now. So probably the charger.

 

[Imfallen_Angel]

you put them in upside down?

 

[Imfallen_Angel]

But on a serious note...

How much wear on these batteries?

Did you check what the readings are on the charger to see what it was doing?

Did you put them back in and check if the charger was analyzing them?

Have you tried another battery, even a cheap AA or AAA? just to see what the charger does for the first few minutes?

 

[ScottP]

Sounds like the cells collapsed internally. I have had it happen to one 18650 and two car batteries. They work fine one minute and completely dead the next.

 

[Ionori]

Sounds like something @Mooch would be interested in.

 

[Mooch]

An internal protection device, perhaps a CID if there is one in those cells, might have been tripped. This would disconnect the cell internally and give you a zero volt reading.

Even if you discharged those cells to zero volts they would bounce back a bit in voltage after the discharge stopped. I’m not sure they were discharged to zero by the charger.

But I can’t explain what would trip the internal protection other than a short circuit.

(Edit) or perhaps a drop.

 

[classwife]

Moved to Batteries and Chargers from General Vaping Discussion

 

[mimöschen]

(Edit) or perhaps a drop.

Ah. Now I get it. Must be the mysterious "voltage drop".

 

[sonicbomb]

Thanks for the replies guys