Just to clarify in the case of of the Pentax battery I am fairly certain terminal "T" is a thermistor temperature feedback terminal.
Regards David

quote:3496ace15f="ChrisA"]Now there's a thought. Haven't thought about that one since I returned the original K-5, which did have a different charger.
[/quote]I've found several, but they seem to have just two contacts, not three.
Is that relevant? What's the third contact with the D-Li90 for anyway?

Hi Chris
For my test I will be using the OE Pentax charger, I believe it has more control over charging current and the final result. The reason I think is the "T" terminal is used to feed the charger with an accurate battery terminal voltage and or voltage via a thermistor to give an indiction of internal battery temerature, this gives safer more accurate charging.
If the charger has only two terminals the voltage it uses to monitor charging can be affected by circuit volt drop in the chargers circuit. A battery may for instance be up to 8v but because of volt drop the charger may only see 7.5v. This could cause over charge of the battery. Many 3rd party chargers have a built in temp sensor and or stop charging for a second or two while it monitors battery terminal voltage, this reduces the chance of battery over charge or damage. In addition I believe some non OE chargers may slightly under charge to reduce the chance of battery damage.
See http://www.electronics-lab.com/articles/Li_Ion_reconstruct/ for a typical Li-Ion battery circuit.
I use a Hahnel Unipal charger but only whilst away from home, the batteries seem well charged and so far have never heated up during charging. I have checked terminal voltage after charging and its similar to the Pentax charger result.
MY RESULTS TODAY
I took the Hahnel battery off charge this morning (OE Pentax Charger) and the terminal voltage is 7.85v as is the voltage between + & T.
The voltage after 20 shots with the Bigma set to AF and Stabiliser in No1 was 7.82v across the same terminal positions. If you wait several minutes this voltage may creep back up slightly if the battery is healthy.
Ensure you dont short out the battery and use an accurate Digital meter for the test. Hope this is of help.
Kind regards David

Quote from Chris
I'd be much obliged if you would, thank you.

Hi Chris
I put an Hahnel on charge tonight if you havent got a Hahnel I can put my OE Pentax on in the morning.
Regards David

I doubt its the Bigma, I was expecting it to use lots of power but I have the Bigma fitted 90% of the time and the battery still seems to last for several days shooting 200 plus photos a day.
Also I dont think the Bigma uses any power with the camera in auto off or manualy shut down, I have forgotten to switch the camera/lens off many times and it hasnt made any noticable difference to battery life.
Have you tried another charger, it wouldnt be impossible that its not fully charging the battery?
If you like I could check the terminal voltage of one of my batteries after a recharge and after say 20 photos to take off the battery surface charge and you could compare yours. PS my camera is a K7.
Regards David
David

What lenses are you using could it be the Lens antishake system or constant auto focus using the power? Clearly something is wrong.
Regards David

Ummm yes, now I understand, this is what you get with a combination of excellent technical skills and some lovely gear.
Regards David

What a brilliant set of photos, pleased I hit the link. Now how the heck do you get such sharp images.
Regards david

I have a K7 and dont use Liveview much, I do however frequently review photos on screen and am amazed how long the battery lasts. I have never counted the shots but it must be many hundreds, the spare Hahnel battery which has slightly lower AH also lasts ages.
You can tell the energy requirements of Liveview is high by the heat generated in the camera. I'm not surprised Liveview flattens the batteries quickly. It's a viscious circle as a hot battery performs worse and may appear flat when its just too hot to perform properly.
Regards David

Best of luck, I hope its not faulty but if it is lets hope SRS are sympathetic and exchange it ASAP.
Regards David

Sorry if I seem to be dismissing your problem, I am certainly not and was only relaying my personal experience. From what you say this lens/camera combination dont seem to be performing correctly. If you have only just got the lens you should be able to exchange it, avoid repairs as Sigma seem to have a very long turn around time.
It sounds to me that it has a problem, has someone got the same lens for you to try nearby, Lincolnshire is probably too far, but you could try mine if your passing by.
Finaly £600 is certainly not cheap if it doesnt do what it should do so best of luck and hope you get it sorted soon.
Best regards David