Vehicle is a 2019 XC90 Momentum. I want to install power pole pigtails, in the passenger compartment to feed my amateur radio VHF/UHF mobile radio. I like to come directly off the battery with fused cables. I note there are three possibilities for the positive cable. Two red cables, one larger than the other under a cover on the top of the battery as well as a third connection under a cover to the front of the battery, forward of the two on top. The two on top look like they have fusible links installed. I cannot tell if the forward most connection has a fusible link. My connection would be a lug piggy backed on to the current lug connector bolt. There are sufficient exposed threads for my purposes that I can make the hook up without disturbing the current connections. Is one of the three connections better suited and recommended for my purposes or can any one of the three be used without harm to either the vehicle or radio? Or, is there a better place within the passenger compartment that I should utilize. thanks for your time and interest. Happy Motoring.

I'm sorry I don't have any direct experience with the XC90 models, but I would suggest that you take a close look at the fuseboxes in the passenger compartment. Check for an unused circuit, perhaps one for the optional high-rent stereo system or heated windshield. These new cars have a lot of (relatively) high-powered electrical devices so are more likely than older cars to have easily accessible places to draw significant power.
When I installed an aftermarket trailer lighting system in our previous XC60, I was able to draw power quick and easy from an unused circuit on the fusebox in the cargo area. Not much power required there, but you get the idea.

73!

-Will
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XC60 / Odyssey

I have used the cigar lighter socket (25A fuse) for 40 watt VHF for years,
and maybe its OK for your 100 watt HF rig too?
14 volts X 25 amps = 350 watts

73 N1BB