Why does this PILA question have everyone stumped?

[brightnorm]

All my PILAs which were 4.14v and higher when received never recharged to that level again. The PILA charger would register green but the cells never got above 3.85-3.95v. Evidently the PILA charger is dumb and the cells contain over and under charge protection. The puzzle is that the built in charge protection allowed them to be initially charged to a normal level, but not ever afterward. In a few instances the voltage of some cells mysteriously increased after being off the charger for a while.

To date no one has been able to answer this question or offer a solution. As a non-electronic type I appreciate the PILA's protection circuit and their good reputation; I wouldn't feel comfortable going to more esoteric/unprotected cells.

Any insight into this problem will be much appreciated.

Brightnorm

 

[Topper]

Beat the tar out of me. I like them just fine like they are.
Very good question though. At a glance I thought they use a big multie charger at the factory not a little 2 cell charger like we get. Perhaps while in the process of making they get zapped then protective ends installed then wrapped
just a guess /ubbthreads/images/graemlins/thinking.gif
Topper /ubbthreads/images/graemlins/smile.gif

 

[Doug Owen]

My guess is the component cells never were charged with the included circuit, but were installed charged (with the higher voltage).

It would be a PITA to charge each completed cell after the fact.

Doug Owen

 

[Topper]

I thought that was what I said /ubbthreads/images/graemlins/thinking.gif
Topper /ubbthreads/images/graemlins/smile.gif

 

[Doug S]

[ QUOTE ]
Topper said:
I thought that was what I said /ubbthreads/images/graemlins/thinking.gif
Topper /ubbthreads/images/graemlins/smile.gif

[/ QUOTE ]
You did. Doug O is simply agreeing with you. If it makes you feel better, I think what you are saying makes good sense too. /ubbthreads/images/graemlins/grin.gif

 

[Topper]

Good to know Dougs stick together and thet agree with me, at least this time /ubbthreads/images/graemlins/crackup.gif /ubbthreads/images/graemlins/crackup.gif
Topper /ubbthreads/images/graemlins/smile.gif

 

[Klaus]

In addition to the already expressed expert opinions it might also be that the charger is at fault and is only charging to that <4V level due to whatever reason - we saw the R123 chargers being set randomly, Cris (CM) reported his PILA charger to charge upto 4.7V so probably this unit is just set too low ?

Either try to measure the chargers voltage without cells attached or even better try to have your cells loaded with i.e. a MAHA or whichever other LiIon capable charger you can lay your hands on to see how they behave then - if you are seeing this with multiple PILA I would personally **guestimate** the charger to be the bad boy here - unless you have a lots of cycles on all your cells already - I did saw aged LiIons recently which also didn´t properly charge to the fully 4.2V anymore.

Klaus

 

[andrewwynn]

my two cents:

I 'spanked' one of my LiON AAAs with a direct short lasting about 3/4 second (wow did it get hot).. after this accident, that cell would no longer charge to a value over 4V.. that is.. until i updated my charger to be more 'universal' and I could charge at a much slower rate.. I was able to charge it up to about 4.17 no-load off the charger after that... so.. maybe the charge rate is just too high, or you 'spanked' the cells with some serious discharge rate at some point affecting their charge performance afterwards.

I don't know what can be done to change the charge rate other than putting another pack in parallel (make sure they have equal charge first!).. but that's initially what i did with my AAA that got it to working well.. a C/3 charge did wonders to get a much fuller charge on my AAAs... i can't see any reason why that wouldn't work with any LiON battery.

-awr

 

[brightnorm]

I don't have the electronic smarts to experiment but another strange thing is that I have three Pila chargers and they all produce the same result.

The final part of this is that several PILA cells charged to 3.87v-3.92v but after sitting a while (about a half hour) they were up to slightly over 4v!

Probably I should just accept the less than ideal charging and stop driving myself to distraction over this. (Easier said than done. /ubbthreads/images/graemlins/frown.gif)

Brightnorm

 

[wptski]

[ QUOTE ]
brightnorm said:
I don't have the electronic smarts to experiment but another strange thing is that I have three Pila chargers and they all produce the same result.

The final part of this is that several PILA cells charged to 3.87v-3.92v but after sitting a while (about a half hour) they were up to slightly over 4v!

Probably I should just accept the less than ideal charging and stop driving myself to distraction over this. (Easier said than done. /ubbthreads/images/graemlins/frown.gif)

Brightnorm

[/ QUOTE ]
I use a Triton not a Pila charger on my ten 168S. All come out at 4.15V but drop to around 4.1V after sitting a bit. One of the last new batch checked 4.05V(new) and this one turned out to be a bad cell!

I also think that you have a bad charger but how could you have three bad ones? Got a friend that uses Pila's that could try your cells?

I've read so much about Pila cells being smart, chargers dumb or the other way, I emailed Pila about this. Come to think about it, the Pila person was out of town that week but I should have recived a answer last week!

 

[Doug S]

[ QUOTE ]
brightnorm said:
I don't have the electronic smarts to experiment but another strange thing is that I have three Pila chargers and they all produce the same result.

The final part of this is that several PILA cells charged to 3.87v-3.92v but after sitting a while (about a half hour) they were up to slightly over 4v!

Probably I should just accept the less than ideal charging and stop driving myself to distraction over this. (Easier said than done. /ubbthreads/images/graemlins/frown.gif)

Brightnorm

[/ QUOTE ]
Norm, here is an alternate theory that would be easy to test. I haven't seen anyone post the exact details/schematic of the Pila protection scheme so we can only guess about it. Your cells may be fully charged but the protection scheme is preventing you from measuring the full cell voltage. Suppose that when the cell protection triggers the charging termination it leaves only a very high impedence path from the actual internal cell to the terminals. It waits for application of a load to turn on the low impedence path. Here is a way to check for this. While monitoring the terminal voltage of the charged cell, apply a small load, say 10 ohms, 100 ohms or about anything else you might have on hand. See if the cell voltage *increases* in response to the load application.

 

[wptski]

[ QUOTE ]
Doug S said:
Norm, here is an alternate theory that would be easy to test. I haven't seen anyone post the exact details/schematic of the Pila protection scheme so we can only guess about it. Your cells may be fully charged but the protection scheme is preventing you from measuring the full cell voltage. Suppose that when the cell protection triggers the charging termination it leaves only a very high impedence path from the actual internal cell to the terminals. It waits for application of a load to turn on the low impedence path. Here is a way to check for this. While monitoring the terminal voltage of the charged cell, apply a small load, say 10 ohms, 100 ohms or about anything else you might have on hand. See if the cell voltage *increases* in response to the load application.

[/ QUOTE ]
DougS:
Why would Norm be the only Pila user that has a problem measuring the voltage of his cells? /ubbthreads/images/graemlins/thinking.gif

 

[brightnorm]

Doug,

I don't have any resistors to try that with.


Bill,

Jon of JSBuRLYs told me that others have mentioned this also but I don't recall seeing posts about it.

I appreciate all the feedback.

Brightnorm

 

[wptski]

[ QUOTE ]
brightnorm said:
Doug,

I don't have any resistors to try that with.


Bill,

Jon of JSBuRLYs told me that others have mentioned this also but I don't recall seeing posts about it.

I appreciate all the feedback.

Brightnorm

[/ QUOTE ]
Norm:

Me either! Your just a technoid mutant and want a answer. /ubbthreads/images/graemlins/grin.gif

 

[Doug S]

[ QUOTE ]
brightnorm said:
Doug,

I don't have any resistors to try that with.

Brightnorm

[/ QUOTE ]
OK, Norm, alternate test: put cell in light and run for a couple of seconds. Remove and remeasure.

 

[brightnorm]

I actually tried that with my L4. Before test PILA was 3.87v, after about 5 seconds was 3.85v. D@mn

BN

 

[brightnorm]

[ QUOTE ]
wptski said:
Your just a technoid mutant and want a answer. /ubbthreads/images/graemlins/grin.gif

[/ QUOTE ]

I resemble that remark. I don't mind "mutant", some of my best friends are mutants, but "technoid"? That sounds suspiciously like "techNERD".

BN

 

[Topper]

Hi BN, if the volt fits wear it if not shake it off. /ubbthreads/images/graemlins/grin.gif
Topper /ubbthreads/images/graemlins/smile.gif

 

[Doug S]

[ QUOTE ]
brightnorm said:
I actually tried that with my L4. Before test PILA was 3.87v, after about 5 seconds was 3.85v. D@mn

BN

[/ QUOTE ]
Well barring the unlikely scenario that you have three defective chargers, it sounds like the cells are defective. There is one observation that you have reported that I cannot make any sense out of. This is:

"The final part of this is that several PILA cells charged to 3.87v-3.92v but after sitting a while (about a half hour) they were up to slightly over 4v!"

 

[wptski]

[ QUOTE ]
brightnorm said:
[ QUOTE ]
wptski said:
Your just a technoid mutant and want a answer. /ubbthreads/images/graemlins/grin.gif

[/ QUOTE ]

I resemble that remark. I don't mind "mutant", some of my best friends are mutants, but "technoid"? That sounds suspiciously like "techNERD".

BN

[/ QUOTE ]
Norm:

/ubbthreads/images/graemlins/yellowlaugh.gif

This may a dumb question but have you tried another meter? That might sound funny but I had somebody build a electronic unit for me that had a setting which they used a DMM to adjust. Come to find out that their DMM was .5V low!

That doesn't explain the voltage increase on your cells after setting a bit though!