Connecting garmin fish finder direct to battery?

[chipd22]

I recently purchased the striker for garmin and I thought I could connect it directly to the jet ski battery but I'm finding very little instructions on this and I'm wondering if that's not wise to do.. If it is fine to do can someone point me to instructions for how to do this?
Also I was about to mount it on the transum but notice a lot of people recommending inside the hull for better performance is that true That this thing can work just as well using some duct puddy and sticking it on the bottom inside the hole?
I'm definitely not going to the "through the hull" installation bc I'm not cutting a hole in the bottom but if I could get away with sticking it on the inside of the hull that would be way easier
Thanks in advance

 

[Wildbill2873]

My xnsducer has a housing sealed to the inside hull. I use antifreeze for the liquid (it won’t work if it’s not in liquid).it snaps into the housing and seals with an o-ring. If you put it on the back the water disturbance from the jet will probably make it not work. It is similar with my boat xnsducer not working while moving. Hope this helps. Oh and the cup and xnsducer are stock for the fishpro.