Handlobraesing
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-dV and dT/dt termination are about the same until about 300 cycles. After 600 cycles, batteries used with dT/dt is almost as good as new, -dV charged batteries are ready for recycling.
Does -dV termination reduce battery life? Yes!
- Thread starter Handlobraesing
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abvidledUK
Flashlight Enthusiast
4 years ago maybe, perhaps less so today.
300 cycles plus, that's probably a long time for most people.
-∆V, ∆T∆t, don't some chargers monitor both.
I wonder which happens first, -∆V or ∆T∆t
( ∆ is alt J on my imac )
Found this, of interest:
http://www.powerstream.com/NiMH.htm
300 cycles plus, that's probably a long time for most people.
-∆V, ∆T∆t, don't some chargers monitor both.
I wonder which happens first, -∆V or ∆T∆t
( ∆ is alt J on my imac )
Found this, of interest:
http://www.powerstream.com/NiMH.htm
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SilverFox
Flashaholic
Hello Handlobraesing,
If you are using a charger that terminates with 10-15 mV per cell - delta V, you are using old technology. The current chargers are using 3-5 mV per cell.
Another thing to keep in mind is that our newest high capacity batteries only have a life expectancy of 300-500 cycles.
Tom
If you are using a charger that terminates with 10-15 mV per cell - delta V, you are using old technology. The current chargers are using 3-5 mV per cell.
Another thing to keep in mind is that our newest high capacity batteries only have a life expectancy of 300-500 cycles.
Tom
Handlobraesing
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SilverFox said:
The life is based on what termination method?
SilverFox
Flashaholic
Hello Handlobraesing,
I believe the cycle life is based on an IEC standard that involves 0.1C charging for 16 hours and 0.2C discharging.
Tom
I believe the cycle life is based on an IEC standard that involves 0.1C charging for 16 hours and 0.2C discharging.
Tom
He did quote a 4 year old book....which was likely written on information a year older than the publish date. A lot has changed since 2001 when the information was likely gathered for the 2002 publishing date.
wptski
Flashlight Enthusiast
I don't want to see anymore quotes from the Battery Universiity because that data is dated too!
Whoever asked above, Dt/dt occurs first. Using -DeltaV does overcharge a bit, that's where the voltage drop comes in.
Whoever asked above, Dt/dt occurs first. Using -DeltaV does overcharge a bit, that's where the voltage drop comes in.
koala
Flashlight Enthusiast
So who would take up the challenge to replicate the test condition on today's cells? :naughty: 
wptski
Flashlight Enthusiast
I can't view the pic or whatever it is in the #1 post from my wireless connection.koala said:So who would take up the challenge to replicate the test condition on today's cells? :naughty:
What charger "only" uses Dt/dt for termination? User's here are quoting from Battery University about today's chargers a combination of all termination methods plus temperature and time backup. Where are these superduper chargers at??
Since what I've read and can remember, Dt/dt termination method occurs at higher charging rates. NegDeltaV occurs just several minutes after Dt/dt. Doesn't seem like much of a lifesaver.
Oh yeah, I think that person that started the post should do the testing too.
SilverFox
Flashaholic
Hello Erasmus,
:devil: Are you a power user, or a casual user... :devil:
Tom
:devil: Are you a power user, or a casual user... :devil:
Tom
eluminator
Flashlight Enthusiast
I don't think there is one "best" solution. My charger uses a combination of things including dV²/dt² and -dV. It also reduces the current near the end of the fast charge. It does not use temperature however.
Temperature would probably be a good method if the temperature could be sensed reliably. I don't know if that's the case.
Like others have said, 100 charge cycles is a lifetime for some applications. I charge the cell in my Arc AAA light about every two months. 100 charges would be 16 years. Already the cell I use is outdated, not to mention the flashlight.
Of course if I could get 1000 charges out of the cell that would mean I would live for over 160 years. I'll have to work on that.
Temperature would probably be a good method if the temperature could be sensed reliably. I don't know if that's the case.
Like others have said, 100 charge cycles is a lifetime for some applications. I charge the cell in my Arc AAA light about every two months. 100 charges would be 16 years. Already the cell I use is outdated, not to mention the flashlight.
Of course if I could get 1000 charges out of the cell that would mean I would live for over 160 years. I'll have to work on that.
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wptski
Flashlight Enthusiast
HeHe, finally a much needed a real observation!eluminator said:
I was keeping an eye on a charge cycle for another thread and decided to scope voltage on another charger that does two cells at a time, something I guess I've never done! I watched it slowly climb and then level off. I thought, is this ZeroDeltaV? It then slowly dropped and bingo, the green finish LED came on! I always thought that -DeltaV was a very sharp drop, it isn't at all.
If anyone wouold like to see it, let me know and I'll post it. Hmmm, I could also use a temperature transducer, plot the temperature for the Dt/dt point and mark the point too!
HarryN
Flashlight Enthusiast
Bill - I would enjoy seeing the plots if it is not too much trouble. I am slowly gathering enough info to buy my first "real" R cells and charger, and any info posted is great.
Handlobraesing
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wptski said:
It's better to go by the data provided by credible publishers who gathers data from various first hand sources. You gotta realize corporations like Duracell have a fully stocked lab with calibrated customized instruments that are capable of conducting the experiment with consistency. Reputable companies typically rate their products using the industry standard method too rather than using some peculiar methods that is meant to make their products have good number under their optimized test.
abvidledUK
Flashlight Enthusiast
Erasmus said:
Put them in the correct way round !!!
wptski
Flashlight Enthusiast
Have you forgotten the Quest Battery link? They suggested against using the most widely used form of termination, -DeltaV! So are they correct?Handlobraesing said:
Another point. Have you noticed that the new batch of fast chargers designed for the new high capacity cells are single cell chargers? I wonder why?
Brighteyez
Flashlight Enthusiast
If your insinuation is that the content on batteryuniversity.com is of some fly-by-night origin, you may want to look a little further into the resources behind that site. If you'll take a look at http://www.cadex.com/, (the corporate site behind batteryuniversity.com) you'll probably find that Isidor Buchman might just know a little bit about battery charging and conditioning. Probably a bit more than the folks at Gillette who aren't really in the business of making rechargeable batteries or chargers. I'd be more inclined to think that chargers and batteries under the Duracell branding are sourced solely from OEM/ODM vendors rather than being developed by either Duracell or Gillette.
Handlobraesing said:
wptski
Flashlight Enthusiast
I question the Battery University suggestion that "today's" chargers use a combination of -DeltaV, 0DeltaV, Dt/dt, temperature sensing(whatever that is?, maybe they mean temperature cutoff?) and timed cutoff! What chargers do all that?Brighteyez said:
