1987 MK 1 Electrical System Upgrade - Feedback Requested

[Jon W]

Don't let the spots of fresh white bilgekote fool you. I did that a few months ago. No factory boats this vintage came this way? Great news for me if that's the case.  Jon W.

[KWKloeber]

Don't let the spots of fresh white bilgekote fool you. I did that a few months ago. No factory boats this vintage came this way? Great news for me if that's the case.  Jon W.

Just from comparing photos it sure looks like it 'belongs there' -- not an add on.  No evidence of it being tabbed on or scabbed on.  More like someone fell asleep and forgot to make a few cuts. :-)

k

[Noah]

Looks a bit similar to my 1990. I would post some pics but I am having some issues with uploading photos from my Mac after the new Forum software upgrade (some confusion over .jpeg vs .jpg formats as well as sizing. I had a formula that worked before but no more.. so I will try and post some pics this weekend after I figure out a workaround. Meanwhile, Jon maybe swing by my boat this weekend to see. I have some cleaning up to do after the boatyard, so I'll be there.

[KWKloeber]

Looks a bit similar to my 1990. I would post some pics but I am having some issues with uploading photos from my Mac after the new Forum software upgrade (some confusion over .jpeg vs .jpg formats as well as sizing. I had a formula that worked before but no more.. so I will try and post some pics this weekend after I figure out a workaround. Meanwhile, Jon maybe swing by my boat this weekend to see. I have some cleaning up to do after the boatyard, so I'll be there.

before you upload, change your jpeg files to jpg extension.  I had the same problem because some of my photo editing software saves as jpeg, and the upload doesn't recognize that file extension.

k

[Noah]

Thx Ken. Need to go to my desktop machine for that. I am spoiled by my IPhone and iPad UNTIL I run into snags like this one.

[Stu Jackson]

Don't let the spots of fresh white bilgekote fool you. I did that a few months ago. No factory boats this vintage came this way? Great news for me if that's the case.  Jon W.

The bumps at the bottom and sides seemed to "imply" it was added on. 

Yup, the paint fooled me! 

I can't speak for other boats, 'cuz I never had the nerve to ask another owner to let me go back in his aft cabin and look!   

All I can show you is what I have.   

Anyways, it's a cosmetic piece that you should be able to drill without any issues.  ITWMB, that's what I'd do.

[Jon W]

Thought I'd post the current thinking of the charging system upgrade project. Was having trouble visualizing what was crossing where, so drew boundaries around each section. Keep in mind this is still a work in progress, nothing is firmed up yet, and I'm on a steep learning curve.

Biggest changes are moving the 1-2-B switch from the nav station distribution panel to the battery box area (with shorter wires may use 1/0 instead of 2/0) and creating a spot under the sette near the stbd water tank to put most of what would have been in the battery box. Current goal is to see if I can empty the box of everything needing service/access except the batteries. In the schematic it shows the 1-2-B switch as connected to the box, I may look to an area near but not in the battery box to keep it away from the fumes.

As always feedback/ideas are welcome.   Jon W.

[patrice]

Hi Jon,

Ok, looking at your picture, you don't have the space I have on this side.
my Aqualift is more to starboard, so I have space between engine compartment and the aqualift.

[Stu Jackson]

Jon,

1.   It appears to be your choice to move the 1-2-B switch from the electrical panel.  If your reason for doing so is ONLY wire sizing, then I continue to offer the approach that 2/0 and 1/0 wire is dreadful overkill.  I understand I differ with Maine Sail about this, see my links on page one in Reply #6.  Even #2 (NOT 2/0) would be a vast improvement over the #4 OEM.  Of course, this is your boat and your choice.  My #4 OEM wiring has been working just fine for the 17 years we've had the boat, but I recognize it could be considered too small.  The starter load is high, but essentially instantaneous.  If I was rewiring my boat, I'd use #2, not #4 and not 1/0 or 2/0 unless you have a honkin' big inverter.  Only YOU can make that choice for you.

2.   There is an inconsistency in the wire sizing as drawn.  You show 2/0 from the house bank to the PDP and then 1/0 from the PDP to the #1 post on the switch.  Same on the negatives.

3.   Solar is shown going to the C post of the switch without a controller.  As drawn, you would need to leave the switch in the on position for any battery bank to be charged to have the solar work, and a controller is necessary (see the Electrical Systems 101 topic for Maine Sail's excellent explanation).  You should run the solar output to the house bank PDP with a controller.

4.   Alternator output (AO) is shown as #1.  You will have difficulty connecting this heavy wire to the back of the alternator without strain relief.   Maine Sail shows how to on his website.  I maintain that for the distance and the amperage, #2 wire is sufficient for this service with a 100A alternator. 

5.   The alternator negative is shown going to a Power Post and then to a bus bar and then to "Ships' Ground."  That is simply the engine.  The negative wiring as shown doesn't make sense.

6.   Are you using the internal regulator or are you moving to an external regulator?

7.   The wiring shown in the blue box "Underneath settee by fwd water tank" is unclear.

8.   If you are using the Smart Gauge (SG), what purpose is served by the shunt on the house bank negative? 

 

[KWKloeber]

6.   Are you using the internal regulator or are you moving to an external regulator?

Jon,

I'd suggest it's better to put $$ into an external multi-stage regulator (NOT just for voltage loss) than putting $$ into heavy copper that's a bear to manage.  The rest of the post makes more sense if you go with an ExR. 
A start battery near the engine alleviates the need for huge oversized size cables to it (voltage loss when cranking.)

1.   ...............  My #4 OEM wiring has been working just fine for the 17 years we've had the boat, but I recognize it could be considered too small.  The starter load is high, but essentially instantaneous.  If I was rewiring my boat, I'd use #2, not #4 and not 1/0 or 2/0 unless you have a honkin' big inverter.  Only YOU can make that choice for you.

I must echhooooo Stu about the cable size.  00 is a BEAR! I did complete new 00 wiring for a C30 and the owner was so sorry he ever did it.  Plus he didn't measure well and has like 6 feet extra that's he had to bury somehow along the way.   It's so heavy and unmanageable that you need to be very careful setting the lugs on short jumpers (his battery box).  You can't twist the cable to align the lugs if one is off 90-degrees.

4.   Alternator output (AO) is shown as #1.  You will have difficulty connecting this heavy wire to the back of the alternator without strain relief.   Maine Sail shows how to on his website.  I maintain that for the distance and the amperage, #2 wire is sufficient for this service with a 100A alternator. 

There's not an issue using lighter pos/neg cables at the Alt - sized for the load and with short jumps to the power posts -- voltage loss becomes moot because (1) the external regulator compensates and (2) it's such short runs.  Your current 4 awg that we did is a-ok.

I suggest on your schematic, adding the voltages at leu points for (1) high-rate charging, starting, and typical house use.  Might be very enlightening.

5.   The alternator negative is shown going to a Power Post and then to a bus bar and then to "Ships' Ground."  That is simply the engine.  The negative wiring as shown doesn't make sense.

Harness negative conductor should also be shown running to the neg busbar (Mates, don't rely on the engine block.)
I'd show your jumper from the neg power post to a starter bolt (Mates - don't rely on the engine block or bell housing for the high-load negative - cable it direct to the starter.)

[KWKloeber]

You will have difficulty connecting this heavy wire to the back of the alternator without strain relief.   Maine Sail shows how to on his website. 

Stu,

Ok as self-sufficient as I've tried to be, I need help -- I've used up what little brainpower I had tonight trying to find the web content with the strain relief on the alternator.    Was it on pbase or SBO website?

HELP!  A link, s'il vous plait

Thanks,
Ken

[Jon W]

Stu,
Nothing is firm for the 1-2-B switch location. For example I just redrew another version with the switch back in the nav station distribution panel replacing all 1/0 with 1 AWG. ABYC chart shows 1 AWG good for up to a 20ft pos/neg run to carry 120A to meet 3% voltage drop.

The wire gauge is evolving, I'm in the concept phase, not detail design phase. I've found lots of variation the more I read. Examples -  Jim Moe used 4 AWG on the house batteries and 2 AWG on the starting battery with 150 A fuses, Mark Elkin used 1 AWG and a combination of 100A and 150A, you suggest 2 AWG, Mainesail says 1/0 or 2/0 and 250A minimum on the battery bank.

Solar, windlass, auto pilot (currently missing) are only shown to have room to connect in the future. That is why neither a controller nor the solar panels are shown at this time.

"Negative wiring doesn't make sense" - On the boat today the negative from the alternator is 4 AWG going to the newly added power post (part of harness upgrade). The busbar (also newly added with the harness upgrade) has 8-10 small gauge negatives and a single jumper from the busbar to the power post. The power post is connected to the engine with 4 AWG. I'm calling that "ships ground" in the schematic. What doesn't make sense?

Currently using the existing internal regulator installed. I read Mainesail conversation that there is value to external regulation, but it is minimal with flooded batteries. AGM and other more exotic batteries is a different story. With external regulator I would also need to add temp sensing of the batteries and alternator to avoid over driving and burning up the alternator.

The wiring under the sette near the stbd water tank is concept only while trying to minimize what is in the battery box and prepare for future additions.

The battery monitor is shown as a SmartGauge, and per their wiring diagram does not need a shunt. However I may be using a LinkPro which identifies a shunt in their diagram. The reason - I currently have an old Link 10 installed. Was thinking to get a new LinkPro connect it to the house, and the old to the reserve. That way I get more info than just voltage on the reserve.

Ken,

I didn't show the harness neg because I need to stop somewhere. Otherwise I'd be showing the fuel pump, level gauge, blower motor etc. negatives. Not sure that is needed in light of what I'm attempting to do.

Jon W.

[KWKloeber]

there is value to external regulation, but it is minimal with flooded batteries. AGM and other more exotic batteries is a different story. With external regulator I would also need to add temp sensing of the batteries and alternator to avoid over driving and burning up the alternator.

Ken,

I didn't show the harness neg because I need to stop somewhere. Otherwise I'd be showing the fuel pump, level gauge, blower motor etc. negatives. Not sure that is needed in light of what I'm attempting to do.

As long as you have enough drive in the alt V adjustment -- I guess that's second best (to overcome V loss in favor of lighter cables.)

I was thinking showing the harness neg ("now that you mention it" actually one line listing them all) was for the next guy in line  --

kk

[Jon W]

Now that you mention it that is a good idea. Maybe even make subset diagrams of the engine compartment house battery bank, etc..    Jon W

[mainesail]

I read Mainesail conversation that there is value to external regulation, but it is minimal with flooded batteries. AGM and other more exotic batteries is a different story. With external regulator I would also need to add temp sensing of the batteries and alternator to avoid over driving and burning up the alternator.


Jon W.

The main point of that article is really your USE and battery choices determining the choices you make. You have chosen quality 6V deep cycle batteries not cheap auto batteries with a deep cycle sticker slapped on.

If your use is essentially weekends and are then then connected back to the dock with a shore charger then the IR set to a high enough point can suffice and work fine so long as we are not seeing much if any voltage drop between alt and batteries.  Every battery being charged on a boat will benefit from battery temp compensation but you don't have to add it...... If you choose to pay for AGM or GEL batteries then you really should be upgrading the charging system or the money will really be wasted..

If you bought an inexpensive bank it becomes "disposable" compared to more expensive batteries and the hit in life won't be a big deal compared to the expense of upgrading the charging system..