Batteries: there's good, bad & ugly?

[Traveller]

Hi2all,

I've come across two cases now of batteries acting "strangely"... :wtf:

Now there are batteries that charge in a timely manner, hold their charge for a reasonable time when idle, power our lazors adaquately and have a reasonable shelf life of 1~2yrs. Then there's the bad apple that doesn't quite charge to norm levels (i.e., 3.7V batt. -> 4.2V @full charge), heats up like crazy during charging, maybe holds it's charge only a short time, etc. The above cases I understand. What I can't figure out are batteries that do everything a good, normal battery will do, except power a lazor "cleanly". Unfortunately I have no electronics background so I can't describe it on an engineering level, I can only give examples of what I mean...


CASE STUDY 1
Battery: Ultrafire 10440 3.6V 500mAh (unprotected)
Setup: LOC 660nm & Flexdrive 4

Out of 7 10440s, only TWO can "properly" power this setup to it's 300mW op (sorry, I don't know what the driver is set to...). As for the other five, the setup outputs 300mW for about 10s and then is drops constantly (linearly) down to like 50mW...


CASE STUDY II
Battery: Ultrafire 15266 (CR2) 3.6V 600mAh (unprotected)
Setup: "standard" CN 532nm module & linear driver set to output "<120mW"

Batt. 1 produces a stable 60mW output (), for the entire duration of the tests (45s each). Batt. 2 produces around 80mW for the first ~20s and then it increases at a linear rate to over 130mW... and maintains this output for the remainder of the test...


So like... what the deal-eee-oh?

I don't understand why these batteries act the way they do... . I'd love a way to prove that the battery is the reason behind the odd behavior but as I stated above, I'm, no engineer and all I have is a simple DMM... :thinking: Is it commonplace to find batteries that behave "oddly" (odd not meaning dead or completly defective)...?

 

[Traveller]

ah...

:bumpit:

 

[billg519]

I have had a few oddball batteries too. I had two 14500's that went bad and leaked from the positive end. All the other 14500's purchased at the same time are still good.
A couple of my other batteries appear to be weaker and shorter lived than the rest. Well, batteries from DX and similar places are cheap, not necessarily high end or of consistant quality. You probably got a couple of bad batteries. I have an 18650 that runs a flashlight only half as long any normal 18650 of the same mAh rating. There are testers for checking capacity and discharge rates of batteries.

 

[Traveller]

...appear to be weaker and shorter lived than the rest ... There are testers for checking capacity and discharge rates of batteries.

Thanks for the feedback

Well in my case, "weaker" may be accurate. I wouldn't mind such a tester, assuming there are simpler, affordable versions... could you possible provide me with an example (link or simply brand name will do) thanks!

 

[Benm]

It seems there are some bad batteries out there. I've never had them as bad as described here, but many of them are very far from the rated capacity. Don't be too surprised to get a CR123 rated for 800 mAh that will poop out in less than half that under normal loads (1C or less).

 

[LarryDFW]

I'm, no engineer and all I have is a simple DMM... :thinking: Is it commonplace to find batteries that behave "oddly" (odd not meaning dead or completly defective)...?

Traveller;

The cheaply-made Ultrafire batteries are very inconsistent.

I have tried them in some UV lights I made with very poor results.

Look for "name-brand" lithium ion batteries.

I try only to use #18650 batteries, since quality brands are more readily available in that size.

I like Panasonic, Sanyo, Samsung, and LG brands, since they are U.L. rated.

LarryDFW

 

[jayrob]

I read somewhere that there was a batch of bad 10440's...

For RCR123's and other Li-Ion, if you want protected batteries. AW is the best brand. (IMO) Most of the time you can get AW brand at lighthound.com...

And they ship lightning fast!

For non-protected 18650's, I have tried Larry's batteries, and found them to be excellent...

 

[Tech_Junkie]

Another thing to consider is age. You might just have some batteries close to the end of their shelf life.

 

[Traveller]

The cheaply-made Ultrafire batteries are very inconsistent ... Panasonic, Sanyo, Samsung, and LG brands ...

I read somewhere that there was a batch of bad 10440's ... AW is the best brand (IMO)...

Thanks for the feedback, Gents! Jay, I'm the one that wrote about that "bad batch" of 10440's... However, I bought a bunch of Ultrafire 3.6V CR2s recently for my Mini Jay Green and some of them also drop my laser's output by like 100% after 15sec of use... :-/

I'd just like a way to tell if a battery is "bad" using my DMM (plus maybe some simple loading device) so that I don't get a heart attack everytime my new Lazor drops it's power 100%...

 

[Tech_Junkie]

You answered your own question. Use one of those dummy loads that they use to set diode currents.

Test Load KIT (AKA Dummy load, unassembled) - $5.75 : rkcstr.com, Micro-Drive and laser diode electronics

 

[Traveller]

Use one of those dummy loads that they use to set diode currents.

Thx for the "confirmation" and link :beer:

However, it's beyond my level of know-how... :-/

"You MUST have the tools and skills necessary to assemble surface mount components!"

 

[Tech_Junkie]

I'm sure someone could sell you a complete one. PM Ryan (Rkcstr) I'm sure he'll hook you up.