1987 MK 1 Electrical System Upgrade - Feedback Requested

[Jon W]

The 20A was moved to be next to the reserve battery per JSail's feedback. Just haven't posted the new diagram yet. There is a 250A MRBF at the reserve battery and also at the house battery bank.

The cut off wires are 2 from the AC charger to the reserve battery, one from the SmartGauge to the reserve battery (3A fuse), and one (going to the left side of the diagram) goes to the future fluxgate compass. Anything related to the solar system and autopilot are only for me to remember to consider something will be required. Types and brands have not been investigated.

The 150 A fuse on the alternator output wire was moved from the engine compartment to the house bank battery box per the feedback from yourself, Mainesail and JSail. I asked whether a 150A MRBF would be applicable for this purpose and the feedback was that it is. Several photos were posted in support of this idea. I chose the MRBF terminal type fuse instead of ANL or MIDI to reduce connection points and wire inside the battery box.

The windlass has a breaker based on feedback from this message board. The purpose as I understand it is if you want to turn the power off to the windlass you can.

As evidenced by 5 (now 6) pages of conversation to this post, I'm not an expert in any of this. The 20A fuse on each end of the Echo charger is per its' online wiring diagram.

Both banks are flooded type which should be acceptable to use with the Echo charger. The difference between the house and reserve bank is the reserve is a maintenance free/sealed battery. I was asking for suggestions for CCA size and brand for this type battery since US Battery does not seem to carry a maintenance free flooded type. I plan to use US Battery brand for the 4x 6V GC batteries.

Jon W.

[KWKloeber]

The 20A was moved to be next to the reserve battery per JSail's feedback. Just haven't posted the new diagram yet. There is a 250A MRBF at the reserve battery and also at the house battery bank.

Ahhhh OK, I hadn't checked that post yet.

The 150 A fuse on the alternator output wire was moved from the engine compartment to the house bank battery box per the feedback from yourself, Mainesail and JSail. I asked whether a 150A MRBF would be applicable for this purpose and the feedback was that it is. Several photos were posted in support of this idea. I chose the MRBF terminal type fuse instead of ANL or MIDI to reduce connection points and wire inside the battery box.

Yep, I hadn't thought about the entire positive bus already being protected by the MRBF, and of course the alt cable size is sufficient for the fuse.  I suppose it's just redundant so not an issue, simply that it seems unnecessary unless I'm missing something (does happen   , so many eyes does help catch things.)

The windlass has a breaker based on feedback from this message board. The purpose as I understand it is if you want to turn the power off to the windlass you can.

I hadn't thought about a shut off -- good idea!  :-)  

As evidenced by 5 (now 6) pages of conversation to this post, I'm not an expert in any of this. The 20A fuse on each end of the Echo charger is per its' online wiring diagram.

Yeah, I'm no Echo user, but maybe Maine Sail can chime -- possibly the schematic is generic in the event that a source isn't already protected?   

Both banks are flooded type which should be acceptable to use with the Echo charger. The difference between the house and reserve bank is the reserve is a maintenance free/sealed battery. I was asking for suggestions for CCA size and brand for this type battery since US Battery does not seem to carry a maintenance free flooded type. I plan to use US Battery brand for the 4x 6V GC batteries.

USB has a "low maintenance" one.  I'd think a Penn/Deka 27 (or 29) starting battery would provide enough MCAs - or an aftermarket Penn (WallyWorld, sears, etc) would be fine since you don't need a true deep cycle 


Jon W.

[KWKloeber]

The 150 A fuse on the alternator output wire was moved from the engine compartment to the house bank battery box per the feedback from yourself, Mainesail and JSail. I asked whether a 150A MRBF would be applicable for this purpose and the feedback was that it is. Several photos were posted in support of this idea. I chose the MRBF terminal type fuse instead of ANL or MIDI to reduce connection points and wire inside the battery box.

OK, I see where that may have grown legs.  Noah's schematic has that cable as a #4, and the battery cables are 2/0.  So a smaller fuse was needed on the alt cable, than is on the battery cables.   Some things just keep on giving, even after other items get changed (as did your battery cable sizes.)

Ken

[J_Sail]

Yes, Ken nailed it. It's true that Jon can eliminate the 150A alternator fuse since the wire is already protected by the 250A battery fuse. And, the battery fuse can indeed be 250A so long as entire path from the battery is always at least #1 wire rated at 90C or higher. (#1AWG @ 90C has an ampacity of 170A if passing thru engine spaces and using the 150% rule gets you just barely to 250A). Using wire with insulation rated at 105C would improve the safety margin and would be a good idea. I probably inadvertently contributed to Jon putting that fuse in, because at one point I told him that if he used an external regulator he could get by with less than #1 AWG to the alternator so long as it was appropriately fused at the battery end. That's what I did when designing my brother Noah's layout. Then when a fuse appeared at the alternator end in Jon's diagram I told him to move it back towards the battery, without noticing that it was unneeded due to the heavier wire used.

The Echo Charger indeed comes with a fuse at the end of each positive lead and that's sufficient if they are long enough. If you lengthen them you need to move the fuse to what becomes the new end of the wire, which is what Jon is now effectively doing.

As Jon noted, a "maintenance-free" sealed battery is typically still a flooded design, not AGM and probably has similar enough charging characteristics to work fine on the Echo Charger (and besides, the reserve battery rarely sees any use). Ken is right that a starting battery is a better choice for the reserve than a deep cycle and is also cheaper.  The expert on battery characteristics, though, is MaineSail and I defer totally to him.

Wire Ampacity table below:

[J_Sail]

Regarding your preference to avoid putting the battery switch at the battery compartment:

The benefits of the 1-2-B at the house battery box make sense, but there is also a convenience to having it centrally located at the navigation station. It may be a sealed switch, but the back of the switch being exposed to fumes inside of battery box is a concern to me. I looked at nearby locations, but not happy with them. This is one of the reasons I spent time moving as many fuses out of the box as I could. Nothing is final yet.

I checked with BlueSea and they said it's fine so long as you avoid putting the switch directly over the batteries without any ventilation (note, their switches are well sealed, some lesser competing products may not be). Also, the ABYC standards call for the battery switch to be as close as possible to the batteries. I have communicated separately with MaineSail and suggested he weigh in for the benefit of the larger C34 community.

So long as there is decent access to see/replace them, I would probably keep the fuses in the battery compartment as well and use some protectant on the exposed surfaces. Moving them out is fine, too, but not at the expense of longer cable runs to them or reduced access.

[mainesail]

The ABYC standards actually prefer the switch to be located with the shortest wire runs possible and also to have easy access. Catalina has rarely met the ABYC standard for "as close as practicable"... One could easily argue they have grossly ignored the ABYC standards with regards to battery switch location and they should instead be using remote battery switches if they continue to insist on placing battery switces in the AC/DC panel.

As an example our 2005 C-310 had battery cables that went from port settee, through the bilge, over to starboard then up to the switch panel (near the toe rail). Of course another 2/0 cable then ran all the way back to center-line and onto to the engine starter. Meanwhile the batteries were less than 3' from the engine and a switch could have easily been mounted flush in the settee bulkhead...... Pretty absurd and a huge & needless waste of 2/0 wire....

11.6.1.2.2 A battery switch shall be mounted in a readily accessible location as close as practicable to the battery.

Blue Sea switches all meet ABYC, CE & UL1500 and SAE J1171 Marine Supplement for ignition protection. They are also IP66 rated for water resistance. Take one apart and you'll find o-rings keeping them sealed.... The also use tin plated copper for the terminals not bare brass like cheaper switches.. Provided the battery compartment is ventilated, to ABYC standards, and you use a good terminal grease, there really should be no corrosion.

Ignition protection is really only required for devices inside an LPG locker or on a gasoline powered boat. IP is not technically required for battery compartments though it is never a bad idea to use IP components in a battery space, which the Blue Sea battery switches are..

[Jon W]

For what its worth -

The comment about ABYC approved ventilation caught my attention. I found a definition in an old thread on the Cruisers Forum. Paraphrased it said -

"ABYC E-10.7.10 states:
A vent system, or other means, shall be provided to permit the discharge from the boat of hydrogen gas released by the battery. The CONSERVATIVELY required number of air changes per hour (A) during bulk charge conditions is given by the following formula:

A = (0.045 x N x I) / V

Where:
N = Number of cells in the battery
V = Volume of compartment in cubic metres
I = Charge rate in Amperes"

With a rough calculation I got ~ 140 air changes per hour required for 12 cells. If it must be discharged overboard, maybe AGM batteries are a better choice?

Have been trading E-mails with ProMariner Tech reps to understand why a ProSport 20A 2-bank charger will not last with the new much larger house bank. The answer was it is undersized for the duty, will work too hard and overheat. Typical sizing for a charger is 10% of the bank AH's. They recommended a ProNautic 1250 (12V 50A) or 1260 (12V 60A). Seems like a 1240 (12V 40A) would be close enough and less money.

Have also been trading E-mails with Balmar Tech reps about the Balmar MC-614 external regulator with battery and alternator temp sensing. I asked if the harness(s) could be extended beyond 54" long? Their response – the 20 foot battery temp sense harness is the same as the 54" alternator temp sense harness except for length. The regulator harness can be longer than 54" with no impact to performance. When I suggested 15 feet, they responded that might be the limit, but no reason why. Still waiting for a response to whether the "special Balmar connectors" are available if I make my own harness. Now I know the regulator can safely be moved up to 15 feet from the alternator giving more options on where to put it.

Jon W.

[KWKloeber]

The ProSport manual says it all.....

If your application is for 4D or 8D large capacity batteries, please refer to ProMariner's website
www.promariner.com and view our ProNauticP Hardwired Charger Assortment for a model that is
correct for this group size of batteries.


Consider also your starting battery, which may also need charging while your house bank is charging.  The 50 amp would also provide better longevity (working less hard) than the 40.  I know it's a tough bullet to bite for a larger charger, but probably worth the additional capacity.

k

[KWKloeber]

Seems like a 1240 (12V 40A) would be close enough and less money.\
Jon W.

What's the cost on both -- percent increase?

k

[Noah]

Jon— I think you are overworking the air exchange/venting issue.  Not sure how your boat ventilates, but as you have seen on my boat, I have a large grill vent in the battery box into the salon, two Dorades in the salon, a solar vent in the aft cabin, that are all constantly moving air—that's even if I keep all my ports and hatches closed—which is rare.  Lots of folks have used the same setup as me; four 6v flooded batteries in main salon battery box and one maintenance-free 12v starter/emergency battery under the aft bunk, or in the engine compartment, and haven't had any problems with venting. I wouldn't sweat it if I were you.

[mainesail]

For what its worth -

The comment about ABYC approved ventilation caught my attention. I found a definition in an old thread on the Cruisers Forum. Paraphrased it said -

"ABYC E-10.7.10 states:
A vent system, or other means, shall be provided to permit the discharge from the boat of hydrogen gas released by the battery. The CONSERVATIVELY required number of air changes per hour (A) during bulk charge conditions is given by the following formula:

A = (0.045 x N x I) / V

Where:
N = Number of cells in the battery
V = Volume of compartment in cubic metres
I = Charge rate in Amperes"

With a rough calculation I got ~ 140 air changes per hour required for 12 cells. If it must be discharged overboard, maybe AGM batteries are a better choice?

Have been trading E-mails with ProMariner Tech reps to understand why a ProSport 20A 2-bank charger will not last with the new much larger house bank. The answer was it is undersized for the duty, will work too hard and overheat. Typical sizing for a charger is 10% of the bank AH's. They recommended a ProNautic 1250 (12V 50A) or 1260 (12V 60A). Seems like a 1240 (12V 40A) would be close enough and less money.

Have also been trading E-mails with Balmar Tech reps about the Balmar MC-614 external regulator with battery and alternator temp sensing. I asked if the harness(s) could be extended beyond 54" long? Their response – the 20 foot battery temp sense harness is the same as the 54" alternator temp sense harness except for length. The regulator harness can be longer than 54" with no impact to performance. When I suggested 15 feet, they responded that might be the limit, but no reason why. Still waiting for a response to whether the "special Balmar connectors" are available if I make my own harness. Now I know the regulator can safely be moved up to 15 feet from the alternator giving more options on where to put it.

Jon W.

This is the problem with the net.... ABYC E-10 does not include what you posted above for air turn-over and there is no requirement for air turn over. ABYC E-10 has been around since 1968 and I suspect we've learned a bit since then. The poster was likely posting an antiquated version of the standard which no longer applies.

This is the current standard as it applies to battery venting:

ABYC E-10 July 2011 (Current Standard)
"10.7.9
A vent system or other means shall be provided to permit the discharge from the boat of hydrogen gas released by the battery.

10.7.10
Battery boxes, whose cover forms a pocket over the battery, shall be vented at the uppermost portion of the cover.

NOTE to 10.7.9 and 10.7.10: These requirements also apply to installations of all batteries whether they employ removable vent caps, non-removable caps, are "sealed" or "maintenance free" batteries, or have pressure regulated valve vent systems with immobilized electrolyte (gel and AGM batteries)."

[Jon W]

I have two dorades in the salon area which are always open, and added vents in the battery box to the wiring diagram last week. I'm going to look into Ron's idea of teak vents. I may be over thinking, but it seems to be driving good conversation and answers to my rookie questions.

Glad I posted the formula and info from the Cruisers Forum. Debunking information and keeping folks on the right path is one of the great things about this site and its' participants.

Jon W.

[Stu Jackson]

I may be over thinking, but it seems to be driving good conversation and answers to my rookie questions.

Jon,

Not at all.  This is the perfect place for it, and a wonderful example for others.  Keep up the good work.   

Many times, on this and other boating forums, folks come in only AFTER having major issues because they didn't ask first.     Go figger...

[Jon W]

Thanks Stu. Lots of views on the topic, hopefully others are benefiting as much as me.

Hi Ken,
   Depending on where you price the two chargers, the difference seems to be $40 to $120.

Jon W.

[J_Sail]

If the various amperage capacity models within the ProNautic line are properly/conservatively designed with temperature-controlled fans and thermal limiting, then picking a size should only impact how rapidly they can charge a large battery bank, not how many years the charger will last before failure (other than perhaps a slight difference in fan life if a smaller unit runs its fan for more hours). I realize those assumptions for proper design are all "IFs'", but I would not automatically assume that a more expensive 60a unit will last any longer than the 40a unit. Perhaps one could put that direct question to ProMariner support (though they may not actually know without asking their design team).