----- Original Message -----
Sent: Tuesday, April 22, 2008 4:08
PM
Subject: Re: You may quote me - Battery
life
On a more serious note are
there batteries out there that are better at holding a charge than
others?
I use my cameras intermittently so do not have a need to charge my
batteries everyday as part of a normal routine. Having had a
digital camera with a voracious appetite for batteries I decided to buy
a dozen batteries, planning on keeping two recharged sets in the camera
bag as spares.
Alas all too often I found that not only the batteries in the camera but
also the spares were unserviceable when I wanted to use them. Now I include a
set of disposable batteries in my bag as back-up .
Michael
PS my woes having been eased by a later camera which uses two AA
batteries instead of four and which last longer when in use but the basic
problem remains.
yes..
JUNE 2005 Pc user magazine (australian, so details are useful only for
international brands) - AA batteries tested
One of the squids at PC
User computer rag tested AA batteries to see which
ones offered the most
bang for the bucks - here's the reslts.
Nickel Metal Hydride NiMH) is
the most popular type of rechargeable AA,
having much greater capacity than
the older Nickel Cadmium (NiCad) type,
with the added advantage of being
more forgiving of poor charging regimes.
NiMH cells have their most
appropriate application in high- drain or
high-use devices, such as digital
cameras, handheld computers and cordless
phones. Not only are they touch
less expensive than disposable
batteries (after even just a few charge
cycles, you will often have earned
your money back), hut they are capable
of delivering more current. This is
especially important in applications
such as electronic flashguns, where
the flash can recycle much more
rapidly. But how long do NiMH batteries
really last? Which are the
best brands? And are higher-capacity cells worth
the extra money? We tested
16 NiMH AA batteries to answer these questions.
. How much
capacity?
Bbatteries are rated by their ability to deliver current over a
period, in
milliamp -hours (miAh). A 2,000inAh battery should be able to
deliver
2000mA for an hour, or 20mA for 100 hours. In practice, there are
limits to
the maximum current the battery can deliver, otherwise you would
be able to
start your car with just 10 of them. The capacity of the battery
is also
affected by a number of parameters, such as temperature, time and
even
differences between each individual battery of the sante
type.
. What we found
The only real duds in terms of capacity
were a couple of lesser-known
brands, Vapextech and Powerbase, which
reached only 44% and 52% of their
rated milliamp-hours, respectively. Other
lesser-known brands, Titanium and
Jackson, were failures for another
reason. We had extreme difficulty in
getting two cells from each of
these
There was also a lot of variability in the performance of
the
higher-capacity (2,200/ 2,300/2,500mAh) cells, leading us to the
conclusion
that you maybe better off buying 2,000mAh batteries from a
trusted brand
than high- capacity cells from a no-name.
So the
results are below (the test technique was explained but I've not
included
it because it'll just bore most folk- on the left is the battery
brand then
the price per 4, next is the current rating (what charge the
batteries
claim to have) then next was the charge measured by the bloke
testing the
things. The final value is the % of rated values.. ie, the
higher the
better
:-)
DoCo
$18 2,500
1,900 76%
DSE (Dick Smith)
$20 2,000
2,300 115%
***
Duracell
$20 2,050
1,800
88%
Energizer
$25 2,500
2,150 86%
Great Power
$12 2,100
1,550
74%
Jackson
$14
2,000 1,450
73%
Powerbase
$30 2,500
1,100
44%
Powerizer
$12
2,250 1,600
71%
Powertech
$21
2,000 1,550
78%
Powertech
$22
2,300 1,500
65%
Sanyo
$25 2,500
1,800
72%
Sony
$25 2,300
2,100
91%
Titanium
$18 2,400
2,000
83%
Vapextech
$14
2,500 1,300
52%
Varta
$20 2,000
2,000 100%
***
VVPOW
$10 2,300
2,000 87%
(RTY - see below) $8
2,500 2,800 112%
(see below)
SHOPPING FOR BATTERIES: WHERE TO GET
THEM
Electronics stores :Dick Smith, Jaycar, Altronics Drawbacks:
None.
Benefits: Lower prices, consistent quality, *bulk discounts often
apply*
Chain stores:Kmart, Woolworths, Drawbacks: none.
Benefits: Lower prices,
consistent quality. Suggestions: buy up on
the "15% off' days.
Discount stores Drawbacks: Unknown brands, Can be
rubbish Benefits, may be
inexpensive
eBay, eBay Australia
Drawbacks: Unknown brands Can be very inexpensive but
don't forget
postage - comments: Look for reputable sellers and
known
brands
So which were the best performers? Energiser and Sony
performed well
reaching over 85% of their rated power, Sony's 2300mAh were
outstanding
reaching over 90%, But the big surprise was Dick Smith
Electronics' house
brand 2,000mAh cells, which overdelivered on their
promise, reaching
2,300rnAh. DSE is possibly being exceptionally generous,
or DSEs
manufacturer could only supply 2,500mAh cells, or they put on a
wrong
label. Whatever the reason, were not complaining. In fact, even if
these
were 2,500mAh cells, they would still have reached over 90% of the
rated
capacity
Big European battery maker Varta may have benefited from
the same
phenomenon, or else it makes extremely efficient batteries,
because it
reached 100% of its batteries' 2,000mAh rating.
also read this about batteries:
then this on LiIons
btw, I bought a bunch of cheapo Chinese rechargeables and found on
testing them, superior to anything I've ever bought - RTY NiMH from
Ebay. these are the ones at the bottom of the list - $8 for 4 (I now
have tested over 50 of them, had them variously from 6 months to
a year with no duds! :)
karl
