Eneloop related, help please

[SilverFox]

Hello Handlobraesing,

If all my cells were 2500 mAh capacity, I would be happy with a 250 mA cheap charger. Since they are not, I am not.

The BC-900 offers some range in charge rates, and as long as it does not malfunction it may be a good compromise for cells 2000 mAh and higher.

Tom

Tom

 

[wptski]

Hello Dan,

I use my Schulze isl 6-330d.

Tom

Tom:

I'm away from my manual, going from my memory of it! At 100ma, it's no time limit, no termination, no capacity, etc. but is it like 250ma does have some limit(s). I don't remember what/which. It doesn't have multiple capacity ranges like the Pro Former I mentioned above.

 

[Bullseye00]

re: I heard that these Eneloop cells only retain their charges under certain temperatures. From what I've read about NiMH batteries, 90 degrees Fahrenheit seems to be the threshold where self-discharge starts to get markedly worse. This may be what you heard?
I can say this for certain, I've used them right out of the package and gotten a decent amount of use out of batteries made 6 months ago. You can't really do that with regular NiMH batteries.
Also, I've run some very basic, crude tests. At 4 weeks, my control group of Eneloop batteries reads a higher voltage than a set of Energizer 1850's and a generic set of 2000's charged at the same time. And that's the ones left at "room temperature" in my apartment which probably hasn't been below 80 degrees since the test began. The "room temperature" that Sanyo used for Eneloop testing was 68 degrees Fahrenheit, I believe. The test group that I've refrigerated(high 30's to low 40's) is doing even better, both the regular NiMH and the Eneloop. I kinda messed the test up because I lost the readings that I made shortly after I took the batteries off the charger. Considering that and the fact that I'm only taking voltage measurements(no load) with a meter, I really don't think it's worth giving any actual numbers, but I think it's safe to say there are definite trends that indicate both Eneloop and refrigeration are effective, especially if combined.

 

[SilverFox]

Hello Bill,

At the 250 mA rate, it will terminate the charge on - delta V, but there is no time limit. I believe the capacity limit is still in effect at this rate.

Tom

 

[Al]

Whenever I want to charge my NimH's and have the time ... CCRANE

 

[SilverFox]

Hello Al,

The Ccrane is a good charger, but I don't believe it will do a forming charge. I believe it charges at around 1.0 amps with 2 cells and at around 0.5 amps with 4 cells. It also terminates the charge at the end.

The forming charge uses a 0.1C charge rate and runs for up to 16 hours. If we use a 2500 mAh cell, we need a 0.25 mA charge rate that continues for 16 hours.

The Ccrane charger can not do that.

Once the cells are formed and in use, the Ccrane charger seems to do a good job. The forming charge is only critical if you want to get the absolute best performance from your cells. Most people ignore it and just go to normal charging.

Tom

 

[Al]

Hello Al,

The Ccrane is a good charger, but I don't believe it will do a forming charge. I believe it charges at around 1.0 amps with 2 cells and at around 0.5 amps with 4 cells. It also terminates the charge at the end.

Tom

True enough although I'm pretty sure the CCRANE goes into trickle mode and stays there indefinitely.

 

[Canuke]

Dan:

This charger Pro Former will do that but it's really meant for the first forming charge on a pack or cells plus you need a power supply for it. Your cells or pack must be completely discharged too!

Given that the Eneloops come charged, is this still necessary? Or would they qualify as "pre-formed"?

 

[Al]

Were the various "shootout" tests reported on CPF done on cells that were subjected to a "forming" charge before the tests were run or were they just "conditioned"

Quote from one of these sites:

http://www.imaging-resource.com/ACCS/BATTS/BATTS.HTM

"I found out right away that it was easy for results to vary as much as 50% between runs, depending on the charger used, the charge time, and probably the phase of the moon. I settled on a protocol that involved charging the batteries for a minimum of 5 hours in the Maha C204 chargers (which brings them pretty nearly to full capacity), and then popping them in very low-rate trickle chargers for at least 10 hours more. (To be sure the batteries are fully "topped off," I now always let them sit in the trickle charger overnight or longer.)"

Possibly either method yields similar results?

 

[SilverFox]

Hello Canuke,

Interesting question...

I tend to do a forming charge on all of my cells, including the Eneloop cells. There have been some reports of "unbalanced" Eneloop cells, so it could be that they are just charged up.

Forming takes a long time. I don't believe any of the battery manufactures do it. Most of the battery usage is at rates low enough that the forming charge may not have a noticeable benefit. However, when we get to 1C or higher currents, it seems to improve the cells performance.

Tom

 

[SilverFox]

Hello Al,

Cells for testing are both formed and conditioned.

Tom

 

[1idjack]

x2x3x2: 8 for $18 is great. Where did you see that price?

 

[x2x3x2]

from a local "Challenger" store here in singapore

 

[Siliconbug]

Secondly, is $18 for an 8-pack of AA Eneloop cells cheap or is there somewhere i can get them cheaper?

So far I know, Fry's sold 4AA for $7.99 about 2 weeks ago.
Hopefully Fry's will do it again.