Just buy a couple of these. They are DSTE made in China. Maybe not the very best , but then again not the elcheapo china crap either. Ive used this guy 4 times for 3 diffrent cameras...not a problem ever.....
2pcs DSTE D LI90 Rechargeable Battery for Pentax K 01 K 3 K 5 K 5 II K 7 | eBay
Thry run about $13 for two including shipping. And NO....hes not my brother , or friend....just got lucky and stumbled across him on Ebay....... USA located and ships fast and free !
And if you do get the Vertical/Battery grip.....Its got a couple features that I liked.
#1......a place for the Body contact cover to go in the grip so it isnt lost.
#2....a place in the grip for the rubber body plug so it doesnt get lost.
#3.....Comes with 2 inserts , one for battery , and one for AA (6 Batteries).
#4.....A spot to put a spare SD card just in case....nice !
I got mine from Tri-State1 on Ebay for $135 shipped....NIB.