Whats going on with my 25R 18650s?

[The60WattGUY]

Hey guys,

Im experiencing something odd i got these 2 cells 25r samsungs they are married always used them together but they are acting weird now..
For example if i put them in vape mods (multiple mods) it wont fire over 20watts anymore super strange, i use to use them at 100w in a dual box mod just fine since its 20/25amp but now it wont fire anymore in all my mods, so i thought ok maybe its dead but they show a full charge on my charger and 4.2v super odd..
I put in complete different batteries in those mods and it works just fine its clearly the batteries...

The batteries are not even a year old tho id say about 8 months did i really use it up already?
Whats going on here?

Also i rotate batteries so theres no way i used the entire 300 cycles already so yea.. Im confused guess ill toss them out.. bummer

 

[Rossum]

they show a full charge on my charger and 4.2v

That doesn't tell us much. What you really need to know is what happens to their voltage under load, but that isn't easy to determine without some means of being able to put a load on them while also being able to measure their voltage.

 

[the wind]

mod will work with other batteries but not those(solved) are the contacted points dented?also it might be one of the two thats defective.

 

[GeorgeS]

Simple.

Ether by charging or discharging to fast they can no longer hold a load.

These are 'spent' and need to be replaced.

Remember that LION batteries can only be cycled a handful 100 times. Overheating by charging/discharging to fast will cut the number of cycles dramatically.


g.

 

[UncLeJunkLe]

Do you have any mods that show battery sag when you hit the fire button? My guess is one or both of them are sagging a good bit under load and the battery charge level indicator would show sagging well below half under load at full charge. Why? Probably because the internal resistance has increased a good deal, enough to seriously hinder performance under heavy load. One or both of this married pair has reached the end of their service life. FWIW, for me, Samsung 25Rs have always had the worse longevity compare to other brands, even Efest (which is pretty embarrassing), so I stopped using them. I'm a 1-battery, low wattage vaper (7W-25W).

TBH, unless it happens frequently and shortly after the batteries are new, and to pretty much every battery you buy, the "why" doesn't really matter. You got 8 months of service and you already diagnosed all you need to know: both or one of the batts is tired and ready for recycling. You can't fix old & tired (in fact, you can't fix most battery problems unless it's merely dirty contacts). Batteries are relatively cheap when bought from reputable battery retailers like 18650BatteryStore, IMRBatteries, LiionWholesale, etc. Vape retailers are usually high priced for batteries and you could be buying clones, rejects, etc.

 

[The60WattGUY]

mod will work with other batteries but not those(solved) are the contacted points dented?also it might be one of the two thats defective.

Sorry late respond you mean my batteries dented no they are not neither are my mods also its the battery cause the battery acts the same in multiple mods, but the battery it self looks brand new on the outside anyway

 

[The60WattGUY]

Do you have any mods that show battery sag when you hit the fire button? My guess is one or both of them are sagging a good bit under load and the battery charge level indicator would show sagging well below half under load at full charge. Why? Probably because the internal resistance has increased a good deal, enough to seriously hinder performance under heavy load. One or both of this married pair has reached the end of their service life. FWIW, for me, Samsung 25Rs have always had the worse longevity compare to other brands, even Efest (which is pretty embarrassing), so I stopped using them. I'm a 1-battery, low wattage vaper (7W-25W).

TBH, unless it happens frequently and shortly after the batteries are new, and to pretty much every battery you buy, the "why" doesn't really matter. You got 8 months of service and you already diagnosed all you need to know: both or one of the batts is tired and ready for recycling. You can't fix old & tired (in fact, you can't fix most battery problems unless it's merely dirty contacts). Batteries are relatively cheap when bought from reputable battery retailers like 18650BatteryStore, IMRBatteries, LiionWholesale, etc. Vape retailers are usually high priced for batteries and you could be buying clones, rejects, etc.

Thanks bud, make sense

 

[tj99959]

Simple overlooked fact about batteries:
Over time (usage) the mAh of the battery degrades, and they just don't last as long. We all know that part. But, what we don't think about is that as the mAh degrades so does the CDR, and that 20 amp battery becomes a 10 amp battery. (or even less)

And, asking that degraded battery to do the work of a fresh battery AINT GONNA HAPPEN

 

[Rossum]

But, what we don't think about is that as the mAh degrades so does the CDR, and that 20 amp battery becomes a 10 amp battery. (or even less)

I doubt it, at least not to that extent. @Mooch has done some pretty abusive cycle testing in the past, which has certainly degraded the capacity of the cells, but IIRC, the temperatures they reached during discharge didn't rise very much...?

 

[Fidola13]

What does a “dented” battery contact (I have a few in the pos end) mean?

 

[Mooch]

What does a “dented” battery contact (I have a few in the pos end) mean?

Too much pressure on the positive end from the mod’s battery contact. Eventually the battery can lose good contact and/or the dented contact can interfere with proper operation of the venting disk below the top contact. This can cause an explosion instead of a controlled venting of the battery in case it is abused (short-circuited, crushed, etc.).

 

[Mooch]

I doubt it, at least not to that extent. @Mooch has done some pretty abusive cycle testing in the past, which has certainly degraded the capacity of the cells, but IIRC, the temperatures they reached during discharge didn't rise very much...?

A few degrees-C at the most, usually less. The DC internal resistance of a cell at the end of its life just doesn’t rise too much in my experience. You don’t need to adjust the CDR much in most circumstances.

The capacity drop however, as you noted, can be very large.

 

[Fidola13]

Too much pressure on the positive end from the mod’s battery contact. Eventually the battery can lose good contact and/or the dented contact can interfere with proper operation of the venting disk below the top contact. This can cause an explosion instead of a controlled venting of the battery in case it is abused (short-circuited, crushed, etc.).

Thanks Mooch.

 

[the wind]

What does a “dented” battery contact (I have a few in the pos end) mean?

have a mod that dents the negiative end,we must be polar opposites.

 

[UncLeJunkLe]

I usually get dents in the positive plate of batts when I drop a mod hard. The impact forces the battery into the pos contact in the mod and dents the battery pos plate. Since the positive contact in most mods are considerably narrower than the positive plate on the batt, it's not uncommon for that to happen after a hard drop. I always check that when I drop a mod now, no matter ho whard the drop is. The dent is rarely more than about 1-2mm but it's a dent nonetheless.