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[N4SRN]

I read the fine articles by K0BG in May2015 QST, but find my 2015 Subaru Forester battery a bit more puzzling than expected.

The negative chassis ground site seems clear, but there's a lot going on at the positive battery terminal. What might be the correct Positive power cable attachment site?

Bret/N4SRN

[KT4NR]

Might look in a service manual or ask your mechanic where accessories would attach. Stereo guys would also know. Hard to see what's going on with the doohicky to the top of the picture from this angle.

[N4SRN]

I did find http://forums.qrz.com/index.php?attachments/img_0948-jpg.280526/ with a similar Positive battery terminal connection.

[W8JX]

I do not know why many still insist that a direct battery connection is needed. I have NEVER used one in over 40 years of mobile hamming and never had a problem. Modern cars typically have unused aux power connections on main fuse panel that you can use.   

[KD5BVX]

I did find http://forums.qrz.com/index.php?attachments/img_0948-jpg.280526/ with a similar Positive battery terminal connection.

Yes, looks like that should work.  Props to you for wanting to wire direct - it will eliminate the chance for problems down the road.  Other "easy way" methods may work (and some try to suggest them as the same or better for some reason), but wiring direct is the best choice if you can do it to basically eliminate the chances of issues later on.  Why not just do it right the first time and be done with it is what I always ask. 

Keep us posted as the progress of your install - many here enjoy photos of installs. It may even help someone down the road or give ideas that someone hasn't thought about. 

[W8JX]

Props to you for wanting to wire direct - it will eliminate the chance for problems down the road. 

What problems down the road???  40 years ago a car had a small alternator and a small internal bus but today cars have 100 amp plus main buses to run cars and accessories and ham radio gear is a very small load on that buss yet many seem convinced that direct wiring is a must have even today. Bizarre.

[KD5BVX]

Believe I said "best choice if you can do it" and not "must do" or "must have".  If you want to wire your installs that way, go for it and I respect your choice.  If someone wants to do it the direct method, to eliminate the chance for interference and other issues that "tapping in" might introduce, run direct to the battery. 

It's each person's choice.  Hams are to use best practices and to suggest something that will probably work but could also cause or result in issues goes against that.  The suggestion to run direct, or affirmation toward someone that it is a good choice, is not bad advice for them. 

[W8JX]

If someone wants to do it the direct method, to eliminate the chance for interference and other issues that "tapping in" might introduce, run direct to the battery. 

The direct method can induce its own problems. The long sloppy power leads can act as a antenna to pickup interference from car. I have always used a in line filter choke on power feed to rig(s) as this keeps noise from car out and prevents RF for rig back feeding into car on power feed. Simple and effective. Maybe in 1975 when cars had limited busses and power capacity a direct battery feed was needed to co stable voltage but today's cars have 120 to 150 amp and more alternators and have aux 20 or 30 amp feeds on main fuse block too. It is better to use the power distribution system in a new car than to try to use 70's technology and thought process on how to power a rig in a modern car.

[K5LXP]

Even in the olden days when I worked in the 2 way business, we never connected directly to the battery.  It was just an invitation to connection problems not the least of which was a ground fault, caused by acid wicking up the strands of wire and corroding the connection.

The direct to the battery practice is propagated primarily by the auto manufacturers.  For the few mobile installation guidelines that exist, they often specify a direct connection to the battery. 

From the Ford manual:

"Power connections should be made directly to the battery and fused as close to the battery as possible. "

Chrysler leaves it up to the discretion of the installer:

"For higher power transmitters, including amplifiers, connect the power (battery +) lead at the battery or at the power distribution center or at the positive jump-start post, if the vehicle  has  one.  "

Looks like GM got it right:

"Connect the positive lead to the auxiliary power terminal and connect the negative lead to the battery-body connection point "

Anymore, with computers monitoring every parameter of every system in the vehicle, a direct connection to the battery can result in a check engine light coming on because it senses current going somewhere it can't account for.  Compared to messing around with clamps or side post adapters, and the latent corrosion problems, connecting to the positive distribution point and a chassis ground point is way easier and more reliable anyway.   No reason not to do it.

Mark K5LXP
Albuquerque, NM

[N4SRN]

I am connected direct as shown in the QRZ images posted above, up and running, and will report back any issues. My prior 2009 Subaru Forester install was more straightforward as the electronics were simpler on the positive battery post, so we shall see. I do place multiple Mix31 ferrite beads on all wires/cables with 2+ winds through each core, depending on diameters, to help reduce common mode currents.

At present, my greatest sin is using a temporary mag-mount antenna with coax through door gasket. My 2015 Forester has more air bags than ever and a sun roof, so I'll be looking for a professional 2-way radio installer to put a NMO hole and Larsen 2/70 antenna in and route wiring. Presently SWR 144-148 is 2.0:1 down to 1.6:1 so I know I have suboptimal antenna conditions - no ground plane to speak of at all.

I am hitting my local repeaters, so am at least functional.

[W8JX]

Anymore, with computers monitoring every parameter of every system in the vehicle, a direct connection to the battery can result in a check engine light coming on because it senses current going somewhere it can't account for.  Compared to messing around with clamps or side post adapters, and the latent corrosion problems, connecting to the positive distribution point and a chassis ground point is way easier and more reliable anyway.   No reason not to do it.

Mark, we do not agree on much but do here. Today's "smart cars" that can even report a burned out light bulb require a different mind set for powering add on accessories than from the distant past when a direct battery connection was the path. You need to feed your rig from main fuse panel and not battery and anyone that suggests that a direct battery connection is better has no real understanding how modern cars work. Kinda like the IT guys that always recommended nuking and re-installing windows as SOP to fix a problem because they were pretty clueless too on how and why it works and how to fix it proper.     

[KC1ACL]

stick a marine battery and a small solar panel in back and solve your issue easily.then the engine compartment will not be a issue. just my 2 cents

[N4SRN]

Mark, we do not agree on much but do here. Today's "smart cars" that can even report a burned out light bulb require a different mind set for powering add on accessories than from the distant past when a direct battery connection was the path. You need to feed your rig from main fuse panel and not battery and anyone that suggests that a direct battery connection is better has no real understanding how modern cars work. Kinda like the IT guys that always recommended nuking and re-installing windows as SOP to fix a problem because they were pretty clueless too on how and why it works and how to fix it proper.     

So how does one connect through the fuse box? Is there a fuse with a power connection that I can just plug in?

[W8JX]

Mark, we do not agree on much but do here. Today's "smart cars" that can even report a burned out light bulb require a different mind set for powering add on accessories than from the distant past when a direct battery connection was the path. You need to feed your rig from main fuse panel and not battery and anyone that suggests that a direct battery connection is better has no real understanding how modern cars work. Kinda like the IT guys that always recommended nuking and re-installing windows as SOP to fix a problem because they were pretty clueless too on how and why it works and how to fix it proper.     

So how does one connect through the fuse box? Is there a fuse with a power connection that I can just plug in?

Typicality a car/SUV will have a few fuse panels. A main one usually under the hood and at least one or more in car somewhere. Locations vary with car/SUV.  Main panel, usually under hood, you will find at least one unused aux feed with no fuse in it and a stud to bolt feed too. (it is that way on GM trucks/SUV's and main panel is protected with a fusible link from main battery) On sub panels in cars they is usually empty sockets as well that have spade connectors on them. Also remember that fuses in sub panels are all fed from same buss or buses meaning that they are all capable of same current potential within limitation of main buss fuse under hood.

[KD5BVX]

Mark, we do not agree on much but do here. Today's "smart cars" that can even report a burned out light bulb require a different mind set for powering add on accessories than from the distant past when a direct battery connection was the path. You need to feed your rig from main fuse panel and not battery and anyone that suggests that a direct battery connection is better has no real understanding how modern cars work. Kinda like the IT guys that always recommended nuking and re-installing windows as SOP to fix a problem because they were pretty clueless too on how and why it works and how to fix it proper.     

So how does one connect through the fuse box? Is there a fuse with a power connection that I can just plug in?

Typicality a car/SUV will have a few fuse panels. A main one usually under the hood and at least one or more in car somewhere. Locations vary with car/SUV.  Main panel, usually under hood, you will find at least one unused aux feed with no fuse in it and a stud to bolt feed too. (it is that way on GM trucks/SUV's and main panel is protected with a fusible link from main battery) On sub panels in cars they is usually empty sockets as well that have spade connectors on them. Also remember that fuses in sub panels are all fed from same buss or buses meaning that they are all capable of same current potential within limitation of main buss fuse under hood.

I think he meant what does he use to actually make the connection.