Spare battery

one of my 2 k5 batteries died.

I wonder if the Hahnel HL-PL90 (D-Li90) Lithium Ion Rechargeable Battery can be considered a good alternative http://www.bristolcameras.co.uk/shopping_cart.php or I must pay all the money needed for the original one :/

there are some tests here: http://www.dpreview.com/forums/thread/2924664

As you can see from those figures, the Pentax battery is the only one that's up to spec, the others are a long way adrift.

I would only ever buy original Pentax batteries.

Also bear in mind that leaking from other batteries might well invalidate your warranty.

I've used Hahnel batteries for several makes of camera, including 2 Pentax dslr's, over the last 15 years or so and have never had a problem or noticed any difference in performance over the branded ones. I'm not sure that lab based tests are always a good indicator. Others might have different experiences, but I would have no hesitation in recommending them.

Quite pleased with my third party battery. I bought two, which combined with the Pentax original, i find that plenty of juice for a whole day out and about shooting.

Ideal world i would have original batteries but they are so costly. And Chris says, in real world use i cannot see any huge difference between the two.

well Hahnel delivers what promises according those tests, that's why it looked for me the best among the 3rd parties.