2 Year "AW123" Test

[jayflash]

I've got some MP brand unprotected RCR123 and protected 123 cells from AW that are two years old. They've all been cycled at least 25 times and the MP cells were only used in an HDS 60 because the light, supposedly, will protect the cells. The protection circuits in the other cells rarely functioned because I'd catch the cells before they were that depleted.

The MP cells held up well, still providing ~20 minutes of run time in the HDS on high, before reducing to a lower level.

The six protected cells provided from only 90 seconds to 25 minutes of high level in the HDS. These same cells lasted from 10 - 25 minutes in an E1L which draws ~700 mA.

Four, new UltraFire protected 123 cells all provided about 30 minutes of light in the E1L.

The greater deterioration of some cells appeared to be random, but may have suffered damage I was unaware of. I'm guessing normal manufacturing variation could just as well be the reason for the differences of run time.

Any thoughts?

 

[kitelights]

My first question is what charger did you use and how much overcharging were the cells subjected to?

I just bought a Pila IBC because it appears to be the only charger (non-hobbyist type) that doesn't overcharge.

Silverfox did an intricate breakdown on how overcharging in .5v increments drastically affects the life of cells.

It appears that the most popular (inexpensive) chargers being used, almost all overcharge at least .5v and some up to 1.5v.

Since you haven't mentioned which charger, I'm just speculating. If I were a betting man, my money is on the charger as the culprit.

 

[VidPro]

. If I were a betting man, my money is on the charger as the culprit.

Twas once said on this forum, "A great charger will even charge cruddy batteries" , and something like, " The charger can make all the difference in the world".
it doesnt have to be expencive, but if it follows some logical specifications for how a battery likes to be dealt with , its worth its weight/cost in batteries.

pila is specncive, but they sure did things correctally for most of thier products.

 

[shadowjk]

I was under the impression that the batteries' protection circuit were more of a last-resort thing, and if you repeatedly used your battery in a way which triggered the protection circuit, you'd significantly reduce its lifespand?

 

[SilverFox]

Hello Jayflash,

Although it is possible to run R-CR123 cells at higher loads, it seems to drastically cut into cycle life. It looks like it is time to replace your cells.

Tom

 

[linterno]

I learned from Tom (Silverfox) that protection PCB is something we should not base our charging control on. But, having a protection circuit that doesn't work all the time is like having an air bag in our cars that only works some times when we crash. From my point of view the protection circuit should work all the time. If the charger wasn't the best and tried to over charge the batteries, then the protection circuit should stop at the safety voltage all the time.

Why having protections circuits if they are not safe because they don't work?

 

[shadowjk]

I thought protection circuits specifically had thresholds for overcharge higher than the point at which battery starts taking damage, but lower than the point where it starts venting with flame... Same for overdischarge protection...

In other words, the protection circuits keep your batteries safe but not necessarily healthy?

Correct me if I'm wrong...

 

[jayflash]

Tom is most likely right because all the cells were heavily loaded. I used the Nano and DSD chargers but always checked the voltage when the charge cycle ended and unless I'd let the cells in the Nano for a longer time, they stayed well below 4.20 volts. Usually I'd stop the charge at ~4.10 volts. Several times I cooked a cell overnight in the Nano and got to about 4.23 volts. The DSD would not charge to above 4.05 volts.

Some cells were somewhat abused and all heavily used.

 

[VidPro]

Tom is most likely right because all the cells were heavily loaded. I used the Nano and DSD chargers but always checked the voltage when the charge cycle ended and unless I'd let the cells in the Nano for a longer time, they stayed well below 4.20 volts. Usually I'd stop the charge at ~4.10 volts. Several times I cooked a cell overnight in the Nano and got to about 4.23 volts. The DSD would not charge to above 4.05 volts.

Some cells were somewhat abused and all heavily used.

with them tiny batteries its a lot harder to keep at 1-2C discharge rates.
from what you said your maxes are 3C discharge rates?

would you say the ones that were used with high discharge rates ARE the same ones that are having trouble now?

myself i dont like to discharge battery to fast, just under the principal that a light that works for less than 1/2 an hour, doesnt Last enough Time to be usefull. thanks to LEVELS we can now have our cake and discharge to fast too

they have li-poly batts that have 10C discharge rates, and i usually dont need them , but i got some because they "FIT" a project, and at the capacity. it is amasing to me how Different acting they are than the 1-2C rate li-polys i was using , and was used to.
they are very "connected" umm, seems like very low resistance, seems like more metal plates , very different.
mabey a battery that was fully speced for the discharge rate your using, As Opposed to some advertisment CLAIM of its ability, would handle the rate much better and still live for a long time.

at any rate your observations are interesting, i always wondered about such things, While Cramming in as much capacity (TIME) into a light that will fit in it.

 

[wasBlinded]

Testing ten recently purchased AW R123 cells, I found a wide variation in their ability to maintain a 1 ampere draw. Amp-hour capacities varied from 288 mAh (way too low) to 515 mAh, the latter being reasonable for that rate of draw.

 

[jayflash]

How many times have the cells been cycled? I forgot whether LiIons need a few cycles to provide maximum discharge performance. Mine all provided good performance at an ~1 amp discharge rate although some have lost capacity after two years.

 

[wasBlinded]

Li-ion cells don't seem to gain from cycling. I tested each of my AW R123 cells 3 times, and they did not improve over those cycles and usually got a little bit worse.

 

[jayflash]

Perhaps the highly reactive lithium requires very tight quality control to insure even and close capacity between cells?