I have the charging dock from DJI where I can put all 3 batteries on the charger at the same time.  I read in the instructions that I can update the dock.  Is this something that is still possible?  And how do I do this?  Is there any advantages to updating this dock?

There have never been any updates for the charging dock.

Hi, Shawgod. Thanks for reaching out. Yes, the charging hub has a firmware upgrade port, but currently, the charging hub of Phantom has no new firmware to upgrade, so there is no need to upgrade. The new firmware will be released if an update is needed. For your reference, please check this link (page 5) to see how to update the firmware if necessary. Firmware updates are normally released to improve the products' performance. We hope this helps. Thank you, and have a nice day.

DJI Tony Posted at 3-24 20:26
Hi, Shawgod. Thanks for reaching out. Yes, the charging hub has a firmware upgrade port, but currently, the charging hub of Phantom has no new firmware to upgrade, so there is no need to upgrade. The new firmware will be released if an update is needed. For your reference, please check this link (page 5) to see how to update the firmware if necessary. Firmware updates are normally released to improve the products' performance. We hope this helps. Thank you, and have a nice day.

How do I know if there is a update for this and when to update?

Shawgod Posted at 3-25 05:22
How do I know if there is a update for this and when to update?

So far, there has no updates. But if there is one, it will be published on the DJI website for user's reference.