More electrical musings...

[bridaus]

Not at the boat, so trying to debrief myself on what I discovered yesterday, undoing PO electrical wiring... and figure out what's going on. All opinions/thoughts welcome.

Background: Some battery somewhere is dragging down my house bank. I haven't ruled out one of the house batteries themselves. Found that even when I switched all battery switches off, still happened. Found that one of my house batteries consistently measured the same voltage as my bow thruster battery. Hmm. Then found a positive DC wire hooked to one of the two house batteries that when disconnected still had voltage. Hmm. Traced it back to one of two "posts" in the electrical cabinet in all KK42's. I can tell from the voltage that the bow thruster battery is supplying voltage to this post and therefore this line.

Questions

1. Is there any reason a bow thruster would be permanently wired to one of two house batteries? I say no, combiner only.
2. Does anyone with KK experience know what the INTENT of the two DC posts in the electrical closet mounted on the right wall towards the bottom are? Are they meant to be house, engine, bow thruster, or what? Or does no one else have them? In my opinion they should have house voltage only when house battery switch is on.
3. Bow thruster should only be hooked to a combiner and that's it in my opinion. Thoughts on that?

Extra credit: Any KK42 owners I would love if you could post pics of the inside of your electrical panel if easier than writing words to explain what you have... I would appreciate anything...

Just doing a lot of thinking while working on other things.... this will be a common theme with me, appreciate the read/help.

 

[Mikala]

Some battery somewhere is dragging down my house bank.

Are you sure it’s not a load, rather than a battery, dragging down your house bank?

 

[Molly]

The only way, I know of, to find a load dragging down the batteries is quite labor intensive. The thing you have to look for is amps, not volts. Therefore, you have to have a meter, set to amps, in series with the wire. I don't think it matters hot or ground. I started at the batteries. Take off the positive lead and place the meter in series. NOTE: I had it set at 10 amps, just in case. There should be very little load, maybe .1 or .3 amps. (assuming the battery switch is off)
I found 1 out of the 4 batteries on my boat had a load of a few amps. That's where the fun starts! You have to trace everything on that circuit. I lucked out, the first place I checked was it. The forward bilge pump was wired directly to the battery and showed a current. The pump was not running? So, I replaced the switch and BAM, problem solved. I also changed out the pump, just in case. Now my batteries can go 2 weeks, with the switch off, and still start the engines.
The biggest problem is that I actually go 2 weeks w/o using the boat!
That's another issue all together.

 

[bridaus]

Are you sure it’s not a load, rather than a battery, dragging down your house bank?

Gahhhh.... good point. I don't. More thinking and checking to do.

Still curious about bow thruster though.

 

[Larry M]

Our bow thruster is wired to our 1100 amp hour house bank as is our windlass.

Bow thrusters were not factory installed or an option offered by Krogen on the KK42, so who knows on the wiring.

Which electrical panel pictures are you looking for, we have 3? One panel is on the port side in the salon, one forward center in the engine room and one in the pilot house. I’ll be glad to send what you need.

Here are pictures of an electrical schematic for a KK42. If you print them out and tape them together the order is: 1 upper left, 2 upper right, 3 lower left and 4 lower right.

 

[bridaus]

Forward center in the engine room, thanks for the schematics!

 

[Larry M]

...

 

[bglad]

Answers

See below

Questions

1. Is there any reason a bow thruster would be permanently wired to one of two house batteries? I say no, combiner only. Yes. It expands the capacity of your house battery bank and unless you have a separate bow thruster charger is how that bank is charged. Why carry lead around that serves only to run the thruster unless it is causing a problem with the house system.

2. Does anyone with KK experience know what the INTENT of the two DC posts in the electrical closet mounted on the right wall towards the bottom are? Are they meant to be house, engine, bow thruster, or what? Or does no one else have them? In my opinion they should have house voltage only when house battery switch is on. No help here.

3. Bow thruster should only be hooked to a combiner and that's it in my opinion. Thoughts on that? I do not see a problem with it being connected directly as long as it has overcurrent protection both ends. Either way you go it should have overcurrent protection both ends.

Extra credit: Any KK42 owners I would love if you could post pics of the inside of your electrical panel if easier than writing words to explain what you have... I would appreciate anything...

Just doing a lot of thinking while working on other things.... this will be a common theme with me, appreciate the read/help.[/QUOTE]

 

[bridaus]

See below

Questions

1. Is there any reason a bow thruster would be permanently wired to one of two house batteries? I say no, combiner only. Yes. It expands the capacity of your house battery bank and unless you have a separate bow thruster charger is how that bank is charged. Why carry lead around that serves only to run the thruster unless it is causing a problem with the house system.

They are already connected via a battery combiner that uses intelligence to charge them. Connecting them permanently defeats that. Doesn't make sense to me.

Additionally, I think it's not good to connect batteries that are far away together permanently (these are approx 25ft apart), something about resistance on the long cables. I think they'd be constantly dragging the bank down whenever any charge went from one battery to the other. Kind of like a permanent heating coil... someone else with more knowledge may be able to explain better than I think I understand it.

 

[bridaus]

Larry, your gifts of pictures are more appreciated than you know. While they may not reflect my situation perfectly (they are so much better looking than mine), they give me an idea of what they could and should look like. The wrapped wires and terminal blocks in the middle are the same, but my PO's have scabbed on a hole bunch of creative additions... that I now get to untangle. I'll admit, I love this kind of detective work, even if I'm grumbling while I do it.

thank you again.

 

[bridaus]

Our bow thruster is wired to our 1100 amp hour house bank as is our windlass.

Permanently/directly, or through a combiner?

 

[bglad]

Peukert effect

Your logic would also apply to the combiner (25ft apart) permanently connected or not. Making house battery banks as large as possible should be a priority because of Peukert effect. Overruled of course if the thruster causes your house system grief.

Additionally, I think it's not good to connect batteries that are far away together permanently (these are approx 25ft apart), something about resistance on the long cables. I think they'd be constantly dragging the bank down whenever any charge went from one battery to the other. Kind of like a permanent heating coil... someone else with more knowledge may be able to explain better than I think I understand it.

 

[bridaus]

Your logic would also apply to the combiner (25ft apart) permanently connected or not. Making house battery banks as large as possible should be a priority because of Peukert effect. Overruled of course if the thruster causes your house system grief.

Sort of agree, BUT my combiner (Pathmaker) will disconnect when one side goes too low (which is what's happening).

But then because they are also direct wired, they all go low. It takes a few days. Nothing obvious running or drawing too much load, but I will have to trace it all.

For sure, I feel that either they should be on a combiner OR direct wired, but not both.

 

[bglad]

Maybe you have a bad battery. It will discharge the whole bank(s). If you find one warmer than the others test it. Test them all for that matter. That is an everyday on a boat kind of problem

Sort of agree, BUT my combiner (Pathmaker) will disconnect when one side goes too low (which is what's happening).

But then because they are also direct wired, they all go low. It takes a few days.

For sure, I feel that either they should be on a combiner OR direct wired, but not both.

 

[bridaus]

That was my first thought. Ordered a tester yesterday. Amazon guarantees it will be delivered today. That's crazy fast. We'll see.

 

[Larry M]

Our bow thruster is wired to our 1100 amp hour house bank as is our windlass. ...

Permanently/directly, or through a combiner?

No combiner. Thruster is wired directly to the house bank with over current protection and a disconnect switch.

Hobo is wired pretty simply. Two independent battery banks with two independent alternators, two voltage regulators and no interconnecting switches. In the first picture you can see the voltage regulators (blue) on the left and right side. One bank is for the engine and it’s gauges only. The other is for the house and everything else. In 12 plus years we’ve never been stuck or had to jumper one bank to the other. I do carry a spare alternator and voltage regulator that are interchangeable with either bank.

 

[JDCAVE]

...2. Does anyone with KK experience know what the INTENT of the two DC posts in the electrical closet mounted on the right wall towards the bottom are?

Can you elaborate, maybe with a photo?

Larry: I presume your bow thruster is 12 VDC?

I will follow up with photos of my “closets” in the ER, when I return home and am on WIFI.

Jim

 

[bridaus]

I'll get a pic this week. It's ugly. I feel that the wire going to the thruster is likely old and tired based on some of what I'm seeing. Lots of thoughts going through my head:

1. Get a dedicated charger for it.
2. Keep it permanent wired, increase the house bank (sounds magical), but then I should reconfigure the combiner to only combine "house" and "engine start" banks, not treating the thruster as it's own third.
3. New combiner, and rewire it all, removing the permanent link.

Will be at boat tomorrow to find the offending load or battery... hopefully I can find it.

PS: I did get my battery tester as Amazon promised, lightly tested the tester, nice.

 

[Larry M]

...Larry: I presume your bow thruster is 12 VDC...

Yes it is. By today’s standard it wouldn’t be sized for Hobo, too small but I’ve learned to live with it.

 

[diver dave]

3. Bow thruster should only be hooked to a combiner and that's it in my opinion. Thoughts on that?

.

Combiner, as in, a VSR (voltage sensitive relay)?
What would be the purpose? To prevent thruster action if engine is not charging? I guess I could see that as a safety feature, to protect swimmers/divers. Maybe that is great idea.

 

[bridaus]

Combiner, as in, a VSR (voltage sensitive relay)?
What would be the purpose? To prevent thruster action if engine is not charging? I guess I could see that as a safety feature, to protect swimmers/divers. Maybe that is great idea.

No, combiners/VSR's, in general, sense charging on one or two circuits, and connect batteries to allow the charging on one side to charge both sides in parallel.

So in effect, they are charging sharing solutions as I understand them.


I feel the problem with my wiring is that someone bypassed the combiner without realizing what it does...

BTW, it's not the end of the world they did this, it is just redundant, and could cause a safety issue under certain circumstances (thinking a circuit is disconnected when it isn't). But there are other problems, such as the one I'm chasing (batteries going flat too fast) and who knows, a fire if they did the hack job badly. I have to deduce it all, and come up with a plan, these discussions help with that a lot.

 

[JDCAVE]

Bridaus, I think I meant to quote Bglad, sorry for the confusion. He was the poster of the thread I quoted.

 

[bridaus]

A great article on ACR/Combiners/VSR's that helped me understand them: https://marinehowto.com/automatic-charging-relays/

My Pathmaker works similarly to the Blue Seas ACR's and others.

 

[JDCAVE]

Here are some photos of my electrical “closets”:

The “primarily” AC closet with separate Inverter and Shore/Genny neutral buss bars. To the left is the input from solar panels, MPPT controller and breaker. To the right is the Mastervolt battery mate which takes input from the alternator and distributes it to house, starter and Genny banks. Also there is a Prosport 6 as a dedicated starter bank charger:



The DC closet. The Blue Seas ACR is no longer used for combining the house and starter banks for charging. It is a back up and also to combine the two banks for emergency starting.





I have put Blue Seas breakers on the Webasto, fridge and freezer units. Formerly these were automotive breakers.

A future fall project is to go through all the terminal strips and buss bars and assign each number with a load. It will take some time.

 

[bridaus]

Pics of my sad closet. The original wiring is beautiful but since then...

 

[diver dave]

Pics of my sad closet. The original wiring is beautiful but since then...

Lacing is beautiful to my eye. [emoji106]

 

[Larry M]

I don’t think it’s that bad. It still has good bones. I’d get a friend with some electrical knowledge, he doesn’t need much and start tracing everything out. A lot of it is a two person job. It may take a few days but you’ll know what’s what when your done.

 

[dhays]

I feel the problem with my wiring is that someone bypassed the combiner without realizing what it does...

This was my first thought. It can be really easy for an owner to not fully understand their electrical system and then make mistakes.



Since you have that combiner, why not just disconnect the direct wiring and see what the effect is?

 

[bridaus]

This was my first thought. It can be really easy for an owner to not fully understand their electrical system and then make mistakes.

Since you have that combiner, why not just disconnect the direct wiring and see what the effect is?

I am the friend with electrical knowledge, and I have started tracing.

I did exactly what you mentioned, and some more... if anyone is interested:

1. Removed some wires that went to nowhere. There were a few.
2. Documented voltages on all batteries before and after charge.
3. Tested all battery switches.
4. Ordered some temporary bus bars and fuse panels to fix some obvious miswirings.
5. Independently charging each battery to and then testing each to see which ones come back to life, which ones need replacing. So far it isn't looking greatfor the house batts.... SOH ~ 50%
6. Continue to trace. I'd like some tricks for single person tracing, I think I have a tone device at home, and I'm going to make some long wires with alligator clips (or buy them) for this purpose.
7. Oh yeah, removed the one direct connect. It's original, so I need to figure out what it once did... thus the original reason for this post.


It's a long road I've started down.

Oh yeah, I also removed an extra battery tied to engine, unlikely needed. Will keep on boat in case.

I've started documenting loads in a spreadsheet...

I've documented what the Heart interface is measuring....


So much more... just need more time. Which is why you get my musings on the weekend.

 

[bridaus]

I don’t think it’s that bad. It still has good bones. I’d get a friend with some electrical knowledge, he doesn’t need much and start tracing everything out. A lot of it is a two person job. It may take a few days but you’ll know what’s what when your done.

Thank you. I have everything but someone who can go to the boat everyday, so I'll need to use some tricks.