Go Back   Steve's Digicams Forums > Digicam Help > Batteries or Power Packs

Reply
 
Thread Tools Search this Thread
Old Dec 12, 2002, 12:27 PM   #1
Junior Member
 
Join Date: Dec 2002
Posts: 7
Default Refrigerating NiMH batteries

I recall having read something about refrigeration preventing or slowing self-discharge of NiMH batteries. Is there any truth to this or info in this?
pilot is offline   Reply With Quote
Sponsored Links
Old Dec 12, 2002, 1:04 PM   #2
Junior Member
 
Join Date: Nov 2002
Posts: 28
Default

That's the case with batteries in general, but I have no idea whether NiMHs are an exception to or a great example of the rule.
Doug39 is offline   Reply With Quote
Old Dec 12, 2002, 2:17 PM   #3
Senior Member
 
Join Date: Sep 2002
Posts: 3,585
Default

NiMh batteries should be stored at room temperature. Storing them in a refrigarator will not improve their storage life. Room temperature has been defined at 72 degrees. One site stated that the life would be less if the temps reach greater than 86 degrees. I hope this helps.
gibsonpd3620 is offline   Reply With Quote
Old Dec 12, 2002, 4:23 PM   #4
NHL
Senior Member
 
NHL's Avatar
 
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,544
Default

The answer to the NiMh self-discharge is to top them off the night before or during breakfast with a superfast charger like the Rayovac. It only takes a couple of minutes and surely they wouldn't discharge fast enough for the (next) day use!

Put them in a refrigerator, only leads to losing or forgetting about them. Most NiMh can be bought with a free trickle charger which can be used to prevent the self-discharge, and also a fast charger becomes a trickle charger when the charging cycle is finished and you can leave the battery in it forever (some folks are skeptical of doing this).
http://www.stevesforums.com/phpBB2/viewtopic.php?t=4249
NHL is offline   Reply With Quote
Old Dec 13, 2002, 11:07 PM   #5
Administrator
 
steve's Avatar
 
Join Date: Jun 2002
Posts: 2,535
Default

Nothing takes the zap out of a rechargeable battery faster than cold temperatures. Just ask anyone who lives up north and uses their camera outdoors. Refrigerating NiMH would not be productive.

-Steve
steve is offline   Reply With Quote
Old Dec 31, 2002, 10:22 PM   #6
Senior Member
 
Join Date: Jun 2002
Posts: 668
Default

Yes the freezeing of batteries was a 50's thing. Battery power lose can occur by dropping on sidewalk, always store spare batteries in holders like Thomas Dist supplies.
Gary
Gary Senkus is offline   Reply With Quote
Old Jan 7, 2003, 7:18 AM   #7
Junior Member
 
Join Date: Jan 2003
Posts: 2
Default

I think we need to distinguish between storage and use. Storage in the freezer will give you great shelf life according to the charts I've seen from the battery makers.

For example, according to page 6 of this reference you would still have nearly 95% after 90 days!

http://www.gpbatteries.com.hk/catalo..._technical.pdf

Just allow them to warm to room temperature before using.
Chuck S is offline   Reply With Quote
Old Jan 7, 2003, 8:27 AM   #8
Senior Member
 
Join Date: Sep 2002
Posts: 3,585
Default

Chuck

If you store NiMh batteries in a freezer, they will discharge fast. One of the weakness of these batteries is they do not last in cold weather. Ask our friends from the northern US and Canda.
gibsonpd3620 is offline   Reply With Quote
Old Jan 7, 2003, 8:48 AM   #9
Junior Member
 
Join Date: Jan 2003
Posts: 2
Default

Are you sure they aren't talking about how fast they discharge during use in colder weather? All the engineering data I've seen shows greatly reduced self-discharging during storage (not use) at temps around 0C.

This is reasonable since the chemical reactions that result in the discharge slow at colder temps. Just don't ask them to deliver under those conditions!

Still, I may be missing something and I'll always rely on real-world experience. Thanks.
Chuck S is offline   Reply With Quote
Old Jan 10, 2003, 7:32 AM   #10
Senior Member
 
BillDrew's Avatar
 
Join Date: Jun 2002
Location: Hay River Township, WI
Posts: 2,512
Default

I don't know about self discharge in the cold, but usefull capacity does drop for my camera (Casio 3000) in the cold. How serious an issue cold is will depend on the specific camera's cut-off voltage so YMMV.

Since I am frequently away from an electrical source and in the cold for long week-ends or longer, I simply don't use NiMH at all any more. After a couple of days of self-discharging, then using them in the cold, I get less than 15 shots out NiMHs. Disposable Lithium AAs last about 500 shots, cost about $11/set of four, and don't seem to be effected much by the cold. Disposable Li batteries do not seem to have the advertised 10 year shelf life, at least not when stored at outdoor temperatures (-40 to 100F/-40 to +40C) for a couple of years, but are much better than the self discharge of NiMH.
__________
In Minnesota - where everyone can walk on water several months of the year.
BillDrew is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 3:24 AM.