Just wanna share my little experience on the SDM focusing and K7 battery.
A bit of the background.....
Fully working DA* 16-50 + K7.
Then bought an original K7 grip + 2 after market lithium battery to go with it.
Then one day.....
My 16-50 feels a bit slow in focusing in door. It made a lot of "click" "click" sound, and feels like the sdm motor refuses to turn. Then I started to worry about the dead SDM issue.
Checked battery indicator, and its full... put on the Tamron 17-50, and K7 focused fast and good. So much be the DA* issue?
Since i know I've the original battery in the K7 body, and the after market in the grip, I'll just try another theory. I took the grip off, and put on the DA* again. My DA* spring back to LIFE! Put the grip on, test again.. and the SDM motor doesn't feel like moving again.
So I guess the moral of the story is.... SDM motor seems to be a bit more fussy about the battery we use. Even the K7 thinks the batt is full, I think the internal battery supply voltage might be different.
In the end......
I still use the after market batt in my grip, as I've two. One of them cause problem, and the other one is ok.
Anyone else got similar experience?