Different battery charger location. Thoughts?

[Loren Beach]

After finally refinishing the aft cabin bulkhead(s), around the hanging locker, I was propping up the new charger and about to drill four holes to attach it, and a couple more larger ones for leading the AC cable and the three DC wires. And... the new temp sensor wire. Lots of hard-to-ignore holes.

Before unlimbering the drill, today we got to pondering whether it might be best to (figuratively) step back a ways and be sure that we still have the best compromise for a charger location. Kind of like refocusing on the forest, rather than seeing just one or two trees, as it were.

Background: the EY factory location for a charger on our O-34, was to attach it to the backside of the port side aft hanging locker, accessible , very awkwardly, from under the cockpit seat. After taking delivery, I had to replace the ancient OEM ferroresonant charger that had ruined the original batteries.

This was after buying the boat in 1994. After removing the old charger, I then found a different location for the new Xantrex solid state charger, on the rear side of the bulkhead that is beside the gallery range. i.e. just inside the aft cabin. inconspicuous and yet easy to get at when needed. That charger had to replaced back in 2010, and the ProMariner replacement had been working fine until a couple months ago.

The new one, a new-generation Promariner 20 amp charger, has a different size and wider footprint and would have to mount on the adjacent face of the aft cabin hanging locker. This is visually sorta-kinda OK with us, but before drilling any new holes in the teak today, I got to scoping out the path for rerouting the cabling, and that lead to wondering if it might be prudent to reconsider the whole location. Perhaps.

It would be easier to run shorter cables (both AC and DC) if this new one could live on the port side of the cabin, under the aft overhang of the chart table top. I recall seeing pix on this site of 80's Ericson's with a new charger in the "knee well area" on their model and recall comments that it was not too intrusive on Viking knees when seated at the Nav Desk.

Such a location would guarantee the vital air flow the charger requires, as well.

If you have experiences and wisdom to share, please do so!
I will try to add some photos tomorrow or so - of the area(s) in question.

Thanks Much!

 

[peaman]

My 20A charger is in the knee space as you describe (sixth image) and it's a good solution for me.

 

[Dave G.]

I think, since you asked, that shorter cables, better airflow, and better aesthetics(?) =knee well area. Photos ? We don't need no stinkin photos !

 

[Loren Beach]

We tried some tentative charger placement ideas today. A move to the "knee well" under the nav table is do-able, but barely. Major wiring changes required, also. Maybe...

So, we are again looking at the first idea, mounting the new charger to the front of the hanging locker in the aft cabin. It will not be very visible from the main cabin, and the work to bring wires in from under the FRP shelf will be minimal. (Well, as minimal as work like this ever is on a boat!)
We do feel better for having taken some time to really consider an alternative, and not be left later wondering about the "road not taken" , as it were. Here are some photos of both possibilities. I have not drilled new holes yet, but at least can now make some sawdust without wondering about alternatives.
As usual, the actual install work will be a fraction of the total time consumed by the whole project.
Note the now-updated varnish on the locker front and adjacent teak surfaces. IMHO, it passes the 4 foot test, although not too much
closer.
A huge thanks to the EY viking ranks for thoughts to ponder!
Loren and Kathy

 

[peaman]

Too bad that charger isn't available with an optional faux wood grain enclosure to help it blend in! But I agree that the hanging locker mount is the better choice.

 

[toddster]

What about the inside of the hanging locker? Should be hidden.
As you probably know, when in doubt, longer AC (high voltage) wires and shorter DC (low voltage) wires is better.

 

[Loren Beach]

"Hidden" is not a good idea for a device that relies on convection first and a fan second for cooling. The previous charger was more compact, but it had external cooling fins down each side plus a noisy internal fan when it was working hard. I am inclined to follow the guidance of the install instructions and give it lots of air above. Also, that hanging locker is normally full of clothing and foulies - as well as some engine maintenance & heavier spares down in the bottom part.
(I suppose the solution to all these concerns might seem to be a bigger boat... but if I had a bigger boat it would just fill up with even more "stuff"! )

 

[Kenneth K]

How about under the nav table but against the hull.

 

[Loren Beach]

How about under the nav table but against the hull.
View attachment 54927 View attachment 54929

Certainly possible, but we worry about retaining "enough" knee room--- still considering this strongly however. Thanks for the suggestion.

 

[toddster]

"Hidden" is not a good idea for a device that relies on convection first and a fan second for cooling. The previous charger was more compact, but it had external cooling fins down each side plus a noisy internal fan when it was working hard. I am inclined to follow the guidance of the install instructions and give it lots of air above. Also, that hanging locker is normally full of clothing and foulies - as well as some engine and rigging heavier spares down in the bottom part.
(I suppose the solution to all these concerns might seem to be a bigger boat... but if I had a bigger boat it would just fill up with even more "stuff"! )

I have a hanging locker similar to that (it's only 12 inches wide) that has been given over completely to Big Blue Victron Boxes*. It remains to be seen whether this was really a good idea. At least the charging systems are operating more efficiently than before, which was the impetus behind the project. I rarely need to run the generator any more. It does get a little warm in there, but the open front seems to provide adequate ventilation. So far... There is a door to the aft cabin, normally latched open that conceals the front of it.

But that used to be where the extra life jackets and harnesses lived. Still haven't found a good home for them. And of course, if any guests ever stay in the aft cabin, they are SOL on locker space. But at 12 inches wide, and already containing the backs of the AC panels, mine wasn't very good locker space to begin with.

*Multiplus charger/inverter, Isolation transformer, two solar charge controllers, wind generator controller, Auxiliary battery charger. Oh, and the fourth house battery at the bottom. Lynx busbar on the bulkhead just outside the locker.

 

[Kenneth K]

Certainly possible, but we feel that we need the "knee room" the way this part of our interior is built out. Thanks for the suggestion, however.

Well, that is some beautiful cabinetry and trim work in your Olson!

 

[Loren Beach]

How about under the nav table but against the hull.
View attachment 54927 View attachment 54929

I see that you installed the extra side-of-case DC ground wire. Since this goes to the same 'ship's ground' that the main DC wire goes to, I am wondering why this is simply not wired to the other ground internally? Our prior charger had such a terminal post and I recall that the marine electronics shop that sold it told me that it should not normally be needed, so I never added that wire. I have to wonder why this illogical-seeming terminal post exists. (?)
For extra points, does your charger ever get warm to the touch and is the fan noise very noticeable?

 

[Kenneth K]

Not sure I understand it completely, I just followed the manufacturer's instructions:

In an AC circuit you have three wires--the hot and the neutral carry the current, and the ground is just there in case of malfunctions. I think the chassis ground is the same idea. When the charger is in use there will be current going through the internal DC wire. But there would only be current going through the chassis ground if something malfunctions. In this case, the chassis ground prevents your body from becoming the ground.

Others will have better info about the charger getting warm. I rarely use mine because I have solar. The fan is variable speed. It usually comes on at high when the charger first fires up. On high it's pretty noticeable. But during most of the charging it operates at a low speed so it's pretty quiet. Cooling air enters at the bottom of the case and exits from the slot you see at the top of the charger's face.

 

[Kenneth K]

About the chassis ground, I had another thought as I was folding laundry: Running the chassis ground back to the the boat's ground bus bar just protects you from getting shocked (ie, becoming the ground) if a component or wire shorts itself against the charger chassis. That short could come from either an AC or a DC component.

If one chooses instead, to run the chassis ground back to an internal ground connection, why would one chose the DC ground and not the AC ground. Protecting yourself from an AC short seems more important. And sure, all the grounds wind up in the same place, but most of us wouldn't have the "guts" to shortcut the chassis ground to BOTH the internal AC and DC grounds. Running a separate chassis ground wire to the boat's common ground seems to solve all those delimmas.

 

[Loren Beach]

Sometimes it's possible to get a bit lost in terminology, and this might be my problem. The charger wiring install instructions, intended for a world-wide audience of RV, marine, and off grid users may take some interpreting. i.e. some of it may not apply to our boats.

The 'bonding' reference might be a case in point, as it has become rare for modern boats to have a hard-wired bonding circuit. I note that by the 80's, EY was installing all-composite thru hulls and leaving the owners to choose (or not) to attach anodes to their prop/shaft/strut as needed for their home waters.
(Not sure, but I recall that bonding (with a wire) all the metal thru hulls together was important in the long era of wooden hulls, where 'stray currents' could actually attack the wood around a metal thru hull. )

The relationship, if you allow it, between a boat's AC and DC ground is another point of possible puzzlement. I find that some advice calls for these two ground circuits to be combined and other advice is to have them be separate. They are separate on our boat, from the factory, So, I have always left them alone. This alone might be grist for another discussion, IMHO.

On the whole, what I believe is most important is the sharing of real-world experience & knowledge here and the oft-noted result that not all solutions are perfect.
And, thanks again for attempting to educate me, and I guess I will have to continue to compartmentalize some of the not-quite-fitting-together facts, pending more education.

Returning to the opening question, sort of, I may just run a short piece of wire from the side "ground stud" to the main DC ground terminal on the bottom of the charger. Perhaps.
After all, these DC grounds all travel about 6 or 8 feet to a large bus bar in our engine compartment, and I doubt that an extra few feet of wire will have any effect on the speed the potential movement of the electrons... (?)

 

[Kenneth K]

In thinking it over some more, I really don't think it matters what you do with that external bonding stud.

If there is an AC fault inside the charger unit, the AC ground (on the 3-wire power supply cord) that you connect to the charger will pick up the fault and cause the appropriate circuit to trip on your AC electrical panel. The charger will then shut down and have no AC input or DC output.

If there is a DC fault inside the charger unit, no externally installed fuse can add protection. An installer would typically add fuse protection somewhere between the charger's DC output post and the battery that is being charged. This provides overload/short protection in the charger's DC output wiring, but provides no protection against an (upstream) short inside the charger, regardless of whether or not a DC grounding wire is attached to the external bonding stud.

So, yeah, I suspect the bonding stud has more to do with installations with a dedicated "bonding" system.

Perhaps, just verify with an ohmmeter that there is no electrical connection between the external bonding stud and the AC ground connection post on the charger. If there were such a connection, and you ground the bonding post to DC, you've just created the AC-to-DC ground connection you said your boat does not have.