NB-2L / NB-2LH "1200 mAh" batteries - any real ones?

Dear Experts,

The NB-2LH battery that came with my camera claims a capacity of 720 mAh.

On Ebay, and elsewhere, you can buy NB-2L and/or NB-2LH batteries that
claim much higher capacities, e.g. 1200 mAh. With some skepticisim I
bought one, and measured the capacity. You can see the results he

http://chezphil.org/lithium_battery_exageration/

It seems to me that the "1200 mAh" battery actually has about half that
capacity, and less than the original 720 mAh one.

Any comments? I would be very interested to know if anyone has a "1200
mAh" NB-2LH that does have this capacity; or are they all exagerated?
Do the vendors know what they are selling, or have they been misled by
their suppliers?

Looking forward to your comments.


Phil.

Phil Endecott wrote:

Dear Experts,

The NB-2LH battery that came with my camera claims a capacity of 720 mAh.

On Ebay, and elsewhere, you can buy NB-2L and/or NB-2LH batteries that
claim much higher capacities, e.g. 1200 mAh. With some skepticisim I
bought one, and measured the capacity. You can see the results he

http://chezphil.org/lithium_battery_exageration/

It seems to me that the "1200 mAh" battery actually has about half that
capacity, and less than the original 720 mAh one.

Any comments? I would be very interested to know if anyone has a "1200
mAh" NB-2LH that does have this capacity; or are they all exagerated? Do
the vendors know what they are selling, or have they been misled by
their suppliers?

Looking forward to your comments.


Phil.



It may be, as you suspected, incompetence coupled with a lack of
incentive for anything but. Your 2 x 600 mAh is a good theory
(probably the best one).
Another one might be the method of measuring capacity. You chose
a constant resistive load, rather than constant current or even
constant power load. Each will produce a different number.
(I assume you computed the integral of current over time for
the capacity?). Also, if you discharge a battery much more
slowly, you may measure a greater capacity. While your 7 volt
cutoff is reasonable, the chinese engineer may have chosen something
else.

On Mon, 02 Oct 2006 18:49:59 GMT, Phil Endecott wrote:

The NB-2LH battery that came with my camera claims a capacity of 720 mAh.

On Ebay, and elsewhere, you can buy NB-2L and/or NB-2LH batteries that
claim much higher capacities, e.g. 1200 mAh. With some skepticisim I
bought one, and measured the capacity. You can see the results he

http://chezphil.org/lithium_battery_exageration/

It seems to me that the "1200 mAh" battery actually has about half that
capacity, and less than the original 720 mAh one.

Any comments? I would be very interested to know if anyone has a "1200
mAh" NB-2LH that does have this capacity; or are they all exagerated?
Do the vendors know what they are selling, or have they been misled by
their suppliers?

The vendors probably know that they're paying much less for those
low grade batteries, and probably don't care what is inside them.
Several months ago I saved some older messages from the dpreview's
Olympus SLR Talk forum where someone (Jim Attfield, actually) did
some extensive testing of many Olympus PS-BLM1 battery "clones".
Sometimes you get what you pay for, as exemplified by the results of
this battery's test which unfortunately was not an atypical example:

[ http://forums.dpreview.com/forums/re...ssage=12850801 ]

Following on from my test of the PS-BLM1 clone (which you can find
in this thread
http://forums.dpreview.com/forums/re...ssage=12803121)
I have just completed testing the second clone which I refer to as the
'WT-BLM1', currently sold by SterlingTek.com (amongst others) on ebaY.

Disclaimer: findings for personal use only - if your E-1 blows up you'll have
to find someone else to blame :-)
Results of battery test on SterlingTek.com WT-BLM1 clone as follows:

Some comments:

The circuitry is not at the at battery ends, but is on a PCB sandwiched
between the cells and the bottom of the pack. This is a good location for
the temperature controlled charge gut-off. Compared to the PS-BLM-1
the circuit board is very flimsy, as is the whole case assembly. The cell
welds are fewer and poorer, the metal straps thinner and narrower.

There is no indication of the manufacturer of the actual cells however
they are recent and _clearly_ marked as 1300mAh, I am astonished
that this battery can be marked as a 1560mAh item, and to sell it as
a 1700mAh item is just laughable, not to mention deceitful.

The control board incorporates an SE666 battery voltage monitor IC
as in the PS-BLM1 which is supposed to cut the pack off completely
at about 5.6 volts thus protecting the cells from over-discharge - mine
didn't!

The voltage monitor controls what I believe to be a MOSFET power
switch to cut off the cells to prevent over-discharge. On this pack,
this _failed_ completely, the voltage oscillating between 5.4 and 4.8 volts
for a few seconds then continuing to discharge until manually cut off
by me at 3 volts.

There is no polyfuse, or any other type I can identify, therefore no
protection at all against short circuits and potential venting or explosion.
Charge control is via an ordinary 10K resistor rather than a proper thermistor.

The capacity test shows just over 1200mAh. I should point out that
I discharge at around 0.15C instead of 0.1C (i.e. 180mA or so rather
than 130mA) for an accelerated time curve. Manufacturers capacities
are usually stated at 0.1C discharge rate so I have no problem believing
this would achieve the cell's rated 1300mAh but to suggest that these
are 1700mAh (or even 1560mAh) is just a joke. The curve covers
around 405 minutes.

In summary, this is one to _avoid_ at all costs. Construction is poor,
charge control is poor, protection is non-existent and over-discharge
protection is questionable (failed on my sample). Get the PS-BLM1
instead, it lacks a few mAh capacity in comparison but more than
makes up for it in other areas.
Jim

In short, the batteries you've bought on eBay are may be of even
poorer quality and construction than the shoddy SterlingTek battery
tested here.

Note: This doesn't mean that all SterlingTek batteries are
comparable to the one tested. Some other models may be better, some
worse, and the same would be true for the same exact PS-BLM1 clones,
as unlike genuine Olympus batteries, the ones SterlingTek sells
probably vary from month to month, depending on who they choose for
their current suppliers and what they're willing to pay for them.

It seems to me that the "1200 mAh" battery actually has about half that
capacity, and less than the original 720 mAh one.

Interesting. Your test pretty much verified what I'd found myself just from
seat-of-the-pants testing (use in camera). It seemed that my 1200mah
SterlingTek was giving me about 75% of the battery life of the stock 720mah
Canon units.

The other issue with the SterlingTek battery is that it sometimes doesn't
want to charge. Don't know why, but sometimes I have to remove it from the
charger and reinstall it three times before it will actually charge.
Contacts are clean, and never an issue with my two Canon batteries.

The only reason we even consider falling for claims of 1200mah capacity is
probably because we've seen such dramatic improvements in NiMH AA batts over
the years (2700mah now being pretty common, vs 1600mah for a "premium"
battery not all that long ago).

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

"Phil Endecott" wrote in message
...
Dear Experts,

The NB-2LH battery that came with my camera claims a capacity of 720 mAh.

On Ebay, and elsewhere, you can buy NB-2L and/or NB-2LH batteries that
claim much higher capacities, e.g. 1200 mAh. With some skepticisim I
bought one, and measured the capacity. You can see the results he

http://chezphil.org/lithium_battery_exageration/

It seems to me that the "1200 mAh" battery actually has about half that
capacity, and less than the original 720 mAh one.

Any comments? I would be very interested to know if anyone has a "1200
mAh" NB-2LH that does have this capacity; or are they all exagerated? Do
the vendors know what they are selling, or have they been misled by their
suppliers?

Looking forward to your comments.


Phil.