SD14 Battery Life

[sattvakarma]

I've read that best would be Pentax D-LI50 orignal battery, it has usually even bigger capacity than Sigma one (otherwise they are identical). And find some better charger

Thanks for this info.

I was not aware of this...and only knew that Minolta NP-400 was parts compatible with the Sigma BP-21 Li-ion battery.

Have you tried it in real? The above mentioned Pentax battery as a replacement for the Sigma BP-21??

 

[sattvakarma]

I have used three different battery chargers - two Sigma units and one other brand.

The problem occurs with two different SD14 bodies used in similar conditions.

The batteries are rated at 7.4v. I used a multimeter to measure the voltage on a freshly charged battery, and it read 7.7v. I also measured a battery after the cameras battery indicator began to flash, and it read 7.4v. Is it possible that the camera's circuitry is somehow misreading the voltage and giving me false low battery indications?

I am inclined to suggest that your batteries are probably the culprit. Try a new unit.
(If you have friends with Sigma gear...borrow a battery to test and be doubly sure before a purchase!)

And with Li-ion chemistry batteries...always buy the freshest stock of batteries. The battery life countdown starts from manufacture date...irrespective of use ...and best way to keep them going for long is maintaining them at about 50% charge when not in use.


Additional notes with reference to this conversation:

When it comes to batteries...the open circuit voltage is BUT one of the variables involved in ascertaining the charge capacity of a battery.

It CANNOT be relied upon exclusively to predict charge capacity.

Most accurate way to test battery charge capacity is under load...or discharge state. Most battery power sources for professional/industrial use will specify this testing parameter...to judge/decide end of life for the battery unit.

Unfortunately, for small disposable batteries (portable applications)...it is difficult to do such a test as parameters are not mentioned...and they are cheap to be simply disposed off and new units purchased ...from the manufacturer's perspective that is!

If one is really inclined...the test parameters can be calculated from the battery chemistry reference documents and the specifications of the battery under test. You can then perform the test to see how good the battery charge capacity is...

 

[Arvo]

Thanks for this info.

I was not aware of this...and only knew that Minolta NP-400 was parts compatible with the Sigma BP-21 Li-ion battery.

Have you tried it in real? The above mentioned Pentax battery as a replacement for the Sigma BP-21??

No, I've not used D-LI50 personally. Like I said, I have read that on some forums

 

[Arvo]

Is it possible that the camera's circuitry is somehow misreading the voltage and giving me false low battery indications?

Of course - but quite unlikely for two different cameras.
(Same for chargers - one could be faulty, but two?)
It was known story for SD10, where weaker capacity battery set with higher output voltage (different technology) lasted much more - but I've not heard similar things about SD14, esp considering that many SD14s allow take much more pictures than yours.

Sure you can clean you batteries and cameras battery contacts (pencil eraser comes handy), it is possible that some buildup there lowers voltage.

Otherwise your shooting conditions and camera settings are quite similar to mine, thereby I would bet on batteries being faulty.

One more thing - do you use multiple lenses? It could be that (somewhat faulty) lens is drawing abnormal current from battery too.

 

[ambaker]

I purchased a couple of cheap batteries from China on €Bay. They had a higher storage rating than the original battery, and last measurably longer. I've had them for about a year, and so far so good.

 

[sattvakarma]

Hello,

Just wanted to add some information to this thread which ought to be useful to members...

Arvo, what you read on some forums about the Pentax D-LI 50 battery as a suitable replacement for the Sigma BP-21 is CORRECT

Just wanted to experiment for myself and in the process got some batteries from Japan as a friend was traveling and willing to do the shopping for me ...and i really needed some new batteries for my SD14!

The Pentax D-LI 50 battery works with my SD14 flawlessly!

In all respects visually and mechanically, it is identical to the Sigma BP-21...and even fits seamlessly in the SD14 battery compartment. (The much cheaper (ridiculously cheap!) clones that i also have, fit a little snugly...and need some persuasion when it comes to taking them out!)

The Pentax battery capacity though is rated higher than the Sigma BP-21...it is 1620 mAh@7.4v compared to the 1500 mAh@7.4v for the Sigma.
Can't really say how much of a difference that will amount to in real life use...at the moment that is.

Additional Info:

I have purchased an original Pentax accessory...comes in a little white box with an instruction manual. And the description on the battery and the printed manual say its Pentax Ricoh Imaging Co....so i presume its one of the latest batches in production...as currently that is how the Pentax entity is known after changing ownership...more than once in the recent past that is...the previous owner being Hoya Corp.

I have also purchased the Sigma BP-21 battery. Which also comes in a little box and instruction manual...the box following the same branding scheme as the SD14 packaging.

Prices paid:

Pentax D-LI 50 @ 6280 Japanese Yen.
Sigma BP-21 @ 6550 Japanese Yen.

For those interested in making purchases...the same are available much cheaper in the US online camera stores...

Hope this helps!
Cheers,
Sattva

 

[Arvo]

I purchased Pentax D-LI 50 some months ago either and it's working very well for me too. I can't directly compare its performance to Sigma one - my short shooting sessions are usually not exhausting either battery power, but both last more than some cheap noname 3rd party batteries.