D300 and MB-D10 battery order issue

[mark_beaumont]

<p>I've set my D300 so that it uses the batteries in the MB-D10 grip before it starts to use the camera battery. However it still seems to use some of the camera battery as well as using the grip battery. For instance both batteries were at 100% last week and now after some quantity of shots, the grip says 49% and the camera says 88%. Is this usual?</p>

[niccoury]

<p>That is usual. Why use both batteries? Either one will last you for days of shooting and cut down on weight.</p>

[Dieter Schaefer]

<p>I'd have to say yes, it is normal. The unused one in the camera will loose charge over time - 12% in a week is not unusual. The fact that the one in the grip is lower shows that it is the one being used - and that you likely shot quite a bit in the last week.</p>

[ShunCheung]

<p>Right, Lithium ion batteries will lose charge over time even sitting idle.</p>

[tobey_bilek]

<p>They loose charge sitting, but 12% in a week is excessive. I exchange monthy, recharge both, and the idle battery has lose 25%.</p>

<p>You results may vary if the battery does not register new as mine do.</p>

[fhmillard]

<p>I use the same configuration as mark; I have observed the same phenomenon; after charging, I "reorder" batteries -- grip battery is placed in mb-d10, etc.; I use my batteries until they are completely (or nearly) discharged, since Li "smart" batteries, as I recall from somewhere, need discharging as some kind of "calibration".<br>

I am interested in how the D300 mb-d10 combination uses batteries. The combo appears to use power from both batteries all the time, and not use one then the other</p>