Do batteries go weaker if not used ?

What is on the bomboneri? Its unlikly for a battery to go so flat even after
10 years.

It has a little light, and it operates from 3 AAA batteries.

ALL batteries will self discharge while sitting unused on the shelf.
Depending upon the type of battery the rate of self discharge rate can
be infinitesimally small, as in the case of silver oxide or
camera/watch type batteries and Li-Ion for example, or quite high in
the case of carbon-zinc (obsolescent), or the Ni-Cd and Ni-MH types in
the rechargeables.

When it comes to the AA, AAA etc, (non-rechargeable) types then you
should only buy alkaline cells of reputable brand name since these
have a shelf life of at least three years from date of manufacture,
and then only if they are of Japanese manufacture. Chinese made
batteries (even with a well known Japanese brand name) are not as good
as those made elsewhere. Their shelf life is quite poor in my
experience.

Before buying bulk batteries which you intend to use next year you
should make sure they are current technology alkaline and that they
have a storage life date of 2009 or later. Good batteries don't
usually come cheap and if the price appears to be too good to be true,
then it probably is...

On Thu, 23 Nov 2006 09:18:02 GMT, Ross Herbert


Chinese made

    Make sure they're not "Buzz" brand. I bought some cheap 9V alkaline
ones from Vorlac a long time ago. Every one of them leaked badly and
caused significant damage to the gear they were installed in.

    If you're going to store batteries for a long time, put them in a
sealed container or bag in the fridge (not the freezer). I kept a Tandy
D cell in the fridge for about 9 years then used it and it still had
plenty of capacity.

Hmmmm... one wonders whether keeping it in the fridge for 9 years has
actually saved you money. ;)

    Sure! Tandy gave it to me for free back in 1993 when they were
running the Free Battery Club. :-)
    I never had a use for a single D cell, so it stayed in the fridge
for all that time. I finally connected it to an LM3909 LED flasher,
which it powered for a couple of years.

Hands up those who had more than one card? ;-)

Dave :)

you mean all those cards I have in my wallet are now no good?

BTW  Do batteries go weaker if they are used?
You just can't win!

d:)

    I can tell you for sure that Energizer 2.5AH AA NiMH cells rapidly
go weaker even if you don't use them. Their rate of self discharge is
amazingly high compared to others I've used, especially in this warmer
weather.

Bob

Good, it's nice to know I'm not going crazy. I use those for my camera
flash unit, and if I charge them fully then leave them for a week they
are virtually useless...

    Exactly the same with me. Last week I fully charged a set of them &
put them into my digital camera. When I went to take some photos 6 days
later, the low battery warning immediately came on.
    I've got some old PowerBase 2AH cells which still have plenty of
charge in the same camera even after a few weeks, so it's not the camera
pulling a lot of current when turned off.

Rate of self-discharge of NIMH is quite fast but nothing like what you
describe.

Your charger is probably overcharging the NiMHs.  When this happens the
cells vent gas and go dry internally.  Then they hold even less charge.

    I'm using a Lightning Pack 4000N charger which is well known for its
multiple methods of preventing overcharge. That's why I bought it.
    It's only the Energizer 2.5Ah cells which are doing this. Duracell
2.65AH cells, Sony 2.1AH cells and PowerBase 2AH cells charged in it
don't have this problem.

Everything else Eveready make is crap, so it's not that surprising their
NiMH are no exception.

MrT.

I bought some NiMH batteries from the camera shop, 2500mAh powerbase
AA's from my speedlite (flash) and they have been going strong for
over a year now. These cells get abused too.

    I bought my PowerBase 2AH cells in mid 2003 & they're still going
great. Sanyo 2.1AH and Jaycar PowerTech(?) 2.3AH ones have come and gone
while they've just kept going.
    As for the Energizers, I've got a few sets of them & it looks like
it's only the 'oldest' (14 months) ones which have developed a very high
self discharge rate.

    We aren't alone in having Energizer 2.5AH NiMH cells (supposedly
made by Sanyo) self discharging at an absurd rate. Check out a
discussion on the subject at:
 
http://www.stevesforums.com/forums/view_topic.php?id92%856&forum_id51%&page=2

    Quote from preceding: "Conclusion: Self discharge of these
Energizers is in the order of 25% per day...totally useless. Could be a
bad batch, but once bitten twice shy.".

    I entirely agree.


Bob

http://www.stevesforums.com/forums/view_topic.php?id92%856&forum_id51%&page=2


I've been using 2 sets of them in a large Metz flash unit and they seem to
have plenty of charge, even after sitting around for a month, but it's hard
to judge it gets used at widely different power settings.

If I get a chance I'll do a discharge cycle and see how much power they
deliver.