Mercury battery charging module

[lurking_out_loud]

Has anyone installed the battery charging module on their 9.9 4 stroke? I am planning on adding a TR-1 to my boat later this month. It looks like I need to add a second battery to keep up with the draw of this unit. How has it worked? Did you install it or have a dealer do the work? This looks like it should be your basic plug and play gizmo, but you never know.... Any comments or suggestions would be greatly appreciated.

[Streetwalker]

You will need the second battery. I installed the charging harness for the same reason. It was easy to install, just a few wires & under heavy tr-1 use ( ocean) I have yet to see any noticable battery drain at the end of the day. I would wire it direct to the battery that the tr-1 is hooked up to. You also will need to make sure your merc is equipped w/ alternator, you should be able to get that by referencing the serial #