Red Sanyo 18650 Cells Getting Hot While Charging

[1958 greyhound]

My whole pack is made from them, before i found this site.

They are not 4.2v cells they are 4 or 4.1

I charge to 4.0 and have had 0 problems.

 

[stefan1025]

My whole pack is made from them, before i found this site.

They are not 4.2v cells they are 4 or 4.1

I charge to 4.0 and have had 0 problems.

What is the source of this information? The datasheet claims 4.2V....

 

[DarkRaven]

I never had any cells that got warm, let alone hot, during charging, if charged at max 1A. That means no noticeable heat when touching and hardly any measurable temperature difference in relation to the environmental temperature.

Is this still true for you?

Not sure what the context was back then. I think this was about charging procedures under normal circumstances. I've had the usual suspects from Sanyo that got hot, like everyone else.

My whole pack is made from them, before i found this site.

They are not 4.2v cells they are 4 or 4.1

I charge to 4.0 and have had 0 problems.

They are 4.2V cells according to Sanyo and quite a few will still do 4.2V. New ones will also all do 4.2V. It's just the used ones developing problems over time. Maybe due to exposure to heat, long term storage and so on.

 

[stefan1025]

They are 4.2V cells according to Sanyo and quite a few will still do 4.2V. New ones will also all do 4.2V. It's just the used ones developing problems over time. Maybe due to exposure to heat, long term storage and so on.

If you operate the cells at 4.2V and 50C, they get damaged and exothermic in less than a year (see my first poste in this thread).
BTW, the extended temperature profile allows charging and discharging up to 60C with max. 4.15V (maximal cell voltage including all tolerances).

 

[Dietmar Rheeder-Kleist]

I'm currently working on about 1.2tons of laptop batteries. We So far we are seeing a majority of Red Sanyo's coming out of Lenovo/IBM 9 Cell packs. Although funny enough randomly the purplePanasonic 18650GR's come out of a slightly different model 9 cell but still Lenovo...

I'm using the LiitoKala Pro, I have 19 of them and 4 Opus chargers. After cracking packs, stripping electronics I then do a voltage test. I was previously accepting 1.5V or better to be put in line to be charged, but I was having like 50% heater/failure rate on the chargers. I'm also considering the wear and tear on the chargers, my fingers and most importantly time.

So I've adjusted my cut-off to 2.5V, which is giving much better results. I still have some heaters, but I went from like 40 odd per battery change ( 92 cells per change total) to today only 8 HH.


Basically your "normal batteries" should go through a LiitoKaala in about 6 hours depending on how charged it was before it started. The Liito seems to measure the mAh it takes to fully charge the battery(on quick test mode), not a discharge like the Opus does.
So the majority of my heaters are then "waitlisted"...
Next problem is I'm running out of storage. @ 1.2Tons of batteries, lets say about 3 packs per 1kg, Thats 3600 packs @ 6~9cells each:I have 20 000 ~28000 cells I need to test with only a 92 cell charging capacity which I can cycle maybe twice sometimes thrice per day.
Anyway so hence my sorting methodology.

Also once capacity tested and labeled, I then box up and let lie for 30 days. I then measure Voltage again and see who drops more than .2V. Anyone who does is waitlisted again.

 

[Cherry67]

I'm currently working on about 1.2tons of laptop batteries.

Oh, i can relieve you of some of this problem.
Just tell me where to find you.

(Uh Oh - found it. Just not my average travel route....)
Still, the IR issue could be of some interest for you, to save time on qualifying your cells....

 

[Dietmar Rheeder-Kleist]

I'm currently working on about 1.2tons of laptop batteries.

Oh, i can relieve you of some of this problem.
Just tell me where to find you.

(Uh Oh - found it. Just nor my average travel route....)
Still, the IR issue could be of some interest for you, to save time on qualifying your cells....

Surely the Internal Resistance require placing into a charger. I am trying to avoid this wear and tear.

So funny enough some of my recycling places actually told me they sometimes send drumloads to Germany for recycling. So I'm sure you can find them...

 

[Cherry67]

I'm currently working on about 1.2tons of laptop batteries.

Oh, i can relieve you of some of this problem.
Just tell me where to find you.

(Uh Oh - found it. Just nor my average travel route....)
Still, the IR issue could be of some interest for you, to save time on qualifying your cells....

Surely the Internal Resistance require placing into a charger. I am trying to avoid this wear and tear.

So funny enough some of my recycling places actually told me they sometimes send drumloads to Germany for recycling. So I'm sure you can find them...

Ah, i guess this are resellers which make a fortune out of them. Prices in Germany on ebay of 3 Euro/Laptop battery are not seldom, but average. even for qualified defects...

 

[DCkiwi]

#1 -- the initial voltage (alone) reveals NOTHING about its capacity. go ahead and [pre]charge them and test them.

#2 -- first [pre]charge should be SLOW. I recommend 20-50mA per cell. I also let them 'rest' a couple of times, say at 3.3V and 3.8V. I dont get any heaters (<0.5%) using this method. My thermal imager tells me so ...


Hope This Helps.

 

[BlueSwordM]

As always, let's pull out my way of recovering very low voltage cell.

I use 3 methods to treat cells using a CC/CV buck converter:

0-1.0V = 25mA charging over a period of 10 hours. I'm now being more careful than before since I'm now finding high capacity cells(high capacity power tool cells) that are discharged down to that level, and I want maximum recoverability for these cells.

1.0V-2.5V = 50mA charging to lessen chemical damage.

2.5V-3.0V = 250mA charging for it not to be too slow of course.

 

[DCkiwi]

[...]

I'm now being more careful than before since I'm now finding high capacity cells(high capacity power tool cells) that are discharged down to that level, and I want maximum recoverability for these cells.

ditto. totally worth it.

[...]

1.0V-2.5V = 50mA charging to lessen chemical damage.

2.5V-3.0V = 250mA charging for it not to be too slow of course.

WARNING: I do believe that that is out of spec for recovery charging, and may result in much higher 'heater' ratio.

Until a cell is over ... ~ 3.2V I go _super_ slow/gentle, and am reaping the rewards.

I think of this as 'slow cooking' a meal. I use 4s20p and 6s12p slotted rigs for this task. This keeps them all out of the way of regular processing.

Once cells have passed their first capacity test, and show stability at nominal voltage, then its back to 'regular' charge rates (which for me is <400mA, IE C/5 or less).

for me, 250mA is a pretty decent speed of charging, and I normally stick to this when in regular charging mode ... and all cells get up to 3.0V pretty darn quick. I find that the 'bulk charge' (sic) is more from 3.7-4.1V ... then is gets s l o w.

 

[winny]

Did read the entire thread, but perhaps I missed something. I too get alot of Sanyo heaters, but the ones which does not heat up, test good capacity, low internal resistance and low self-discharge, what about them? Does anyone have any data on if they are ticking time-bombs or was the production/life if these cells hit-or-miss in that they are either fine or not?

 

[DCkiwi]

Did read the entire thread, but perhaps I missed something. I too get alot of Sanyo heaters, but the ones which does not heat up, test good capacity, low internal resistance and low self-discharge, what about them? Does anyone have any data on if they are ticking time-bombs or was the production/life if these cells hit-or-miss in that they are either fine or not?

on review my previous post was a bit cryptic and did not come to the point.

------> cells that test good are good, and those that dont (maybe) arent.​

how they got to be failures or 'heaters' is quite a heated topic of discussion.

 

[Overmind]

Let me tell you my own observations:
Many times when trying to charge/revive recovered cells this problem can occur and it's not only for fakered Sanyos. Many others can experience the same (greenSonys are another often encountered example).

The cells are still recoverable and good to use even if this case.

Here's how I recover them:

- I charge them up to the point of overheating
- remove them, let them at cold storage a little and retry the recharge (and they will overheat again)
- at the 2nd overheat I stop charging them and let them be for about 3 days
- after 3 days, I continue to charge them; some will recover and fully charge and some will charge more but still not 100%
- I give the remaining ones 3 more days of rest and then I put them back to be charged - they will fully charge
- finally, I make the capacity measurement

I did this procedure on over 150 cells and all have been successfully recovered.

 

[Wolf]

Overmind,
So at no point in all this do you measure IR to determine the health of these cells?
Curious.
I find that IR is a measurement that will tell you the overall health of a cell.
Many spec sheets will show you the IR spec of the cell.





With that information you should be able to weed out bad ones really quick.
I certainly have found out high IR usually means bad.


Wolf

 

[winny]

cells that test good are good, and those that dont (maybe) arent. how they got to be failures or 'heaters' is quite a heated topic of discussion.

Please enlighten me.

 

[DCkiwi]

cells that test good are good, and those that dont (maybe) arent. how they got to be failures or 'heaters' is quite a heated topic of discussion.

Please enlighten me.

sorry, too cryptic (again), I guess. hope this helps:

In this case I was simply trying to say ... if your cells test good, then thats great, use them! some red's seem to be just fine ...

but the red sanyo's in particular (maybe also those sucky green Sonys too!) seem to have real problems with going low and/or being recovered from said out of spec state. as for why, and how to be get through this, and whether they stay good after recovery is ... under discussion here. frequently. my gut feeling still says it is to do with an old/defunct chemistry used in their electrolyte etc. but I cant recall where I read about that, so ... I dont have a reference, so I will leave it at that.

 

[Overmind]

@Wolf I did not had a reliable way to do that. I was thinking of building my own device for IR measures, but then I got some Opuses so I guess that's a good start.

 

[DCkiwi]

@Wolf I did not had a reliable way to do that. I was thinking of building my own device for IR measures, but then I got some Opuses so I guess that's a good start.

Nope, the Opus is not good for IR ---> only 'two wires'.

I say build your own ... better. Ignore those that say measure IR with a multimeter ... we all know thats a bum steer...

Me, I dont pay attention to IR for powerwall builds. For EV/micromobility applications I do try to ... use the best (low IR relevant) I got, but ... for me its about power over time, not power over time.

 

[Overmind]

@DCkiwi I think I could do it with 2 resistors, one in series with a cell, one in parallel with the cell+Rs .
For choosing them I should 1st consider some generally probable values just to make calculations easier.





Note: do excuse the paint job.