[Richard Day]

I had purchased (2) Minolta NP-400 batteries (Li-Ion, 7.4V, 1500 mAh) as spares for my K10D and had no problem with them until I tried continuous shooting.
fn button/up arrow/continuous shooting/OK/OK
then select subject and go for continuous shoot by holding down the shutter release.
2-3 shots max then get 'battery depleted' on LCD. Top LCD show graphic of depleted battery.
Turn camera off and back on and the top LCD shows graphic of full battery.
Do continuous shoot again, same problem, same fix.
Same problem with both batteries and they are definitely fully charged.

Put in Pentax battery that came with the camera (Li-Ion, 7.4V, 1650 mAh) do the above and can shoot until the card is full.

The Minolta spares work fine for one shutter release/one shot.

Anyone else have similar experience?
Defective batteries or just not hot enough to do the work?

I have a "clone" NP-400 from a UK on-line store (7dayshop), which cost around $12, and it works exactly the same as the Pentax original.

I charge them both in the supplied charger with no problems. I also have another charger (again from 7dayshop) which I can use in the car and again, no problems.

I would suggest that you return the NP-400's back to the original supplier if they are within warranty as I suspect they are not even up to the NP-400 spec. Sorry I can't be of more help.

[Katsura]

Where was teh batteries purchased? There seem to be a lot of counterfeit battery/ memory cards being sold on eBay and other not so honest sources.

[clarenceclose]

Got them at Adorama from a post by Sailor regarding spare batteries for K10D
so I don't expect they are counterfeit.
ACD229 Adorama Replacement Rechargeable Lithium Ion Battery for Pentax DLI50 and Minolta NP-400 Digital Camera Battery, 7.4 Volts, 1500mAh.

Some others are available here with more mAh.
http://sterlingtek.stores.yahoo.net/cominpba.html
but I didn't get them.

The ones I got are called Power2000 professional digital camcorder batteries.
ACD-229 Minolta NP-400 7.4V 1500mAh Memory free, Dual safety fuse and the box says 2 year warrantee, for whatever that is worth. I only paid $14.95 each plus shipping. Vidpro corporation, PO Box 344, Jamacia, NY 11435, cells made in USA or Japan....www.vidprousa.com

[rprii]

In burst mode, you have your finger already holding down the shutter for 3 or 4 frames in a row (perhaps more), I would assume this would keep the SR activated between the frames, adding more electrical load. Even if it is what we, or Pentax, consider negligible, Clarence is using a non-Pentax battery and the added electrical load may have been enough to trigger the camera (or the battery) to cut the circuit.

Since I primarily shoot sporting events and try, sometimes not very successfully, to capture birds in flight, my K10D is almost always in continuous mode. I generally shoot between 3-20 consecutive shots and have never had an issue.
Glad to see other K10D owners offering their views. Obviously, as we all do, I visit several other Pentax forums and have seen very few problems reported with third party Li-ION batteries.