Battery / switch system upgrade log

thataway · Posted: Sat Feb 25, 2012 3:45 pm Post subject:

This breaker is to protect the alternator output circuit.

"ignition protected is to the ABYC standard:
E11.4.15 Ignition protection - the design and construction of a device such that under design operating conditions:

a. it will not ignite a flammable hydrocarbon mixture surrounding the device when an ignition source causes an internal explosion, or

b. it is incapable of relasing sufficient electrical or thermal energy to ignite a hydrocarbon mixture, or

c. the source of ignition is hermetically sealed.

This is different than a circuitry such that if the breaker blows, that the alternator diodes will not fail. For example the make before break battery switch protects alternator diodes, The alternator field disconnect, and as does the "Zap Stop" which protects alternators from an open circuit. I am not aware of any similar circuit on outboards--but some may exist on the newer motors.

ferret30 · Posted: Sun Feb 26, 2012 2:26 am Post subject:

I worked on the boat all day and well after dark. I got the new switch in, new batteries installed, and everything wired back up again. One thing I noticed was that the 50A thermal ignition breaker is actually installed between the switch output and the house panel, not between the motor and the switch as I had thought. But I'm really thinking it would be hard to accidentally turn off the switch while the motor's running.

I had purchased two battery boxes to install the group 24s into, but after giving it a shot in the port lazarette (the less cluttered one), I realized it wasn't going to work. It was impossible to get the lid on the box in the compartment, and this was in the mostly open one and without a battery. I considered taking the hatch off as was mentioned before, but I'd be exposing core and don't want to attack the re-sealing of a hatch right now. Also, I'd have to remove the hatches any time I wanted to inspect water levels, poke around, etc.

So I'm going to stick with the batteries in trays with rubber terminal covers. A lot easier to work with and boxes seem like overkill (now) in the lazarettes.

Tomorrow I'm going to install the ACR box. I ran out of daylight and it started snowing so that wasn't going to happen today. I ended up using 12AWG wire and 30A max waterproof fuse holders since that was the largest I could find at WestMarine. If the fuses burn out I will go online and find larger waterproof fuse holders.

Space is really tight in the starboard compartment! I'm trying to figure out where to put the ACR. It would be nice to go on a side wall of the compartment, but I don't want to accidentally drill through into the motor well or out the side of the boat!

Other things I did today:

* Removed the pivoting kicker bracket from the port side to make way for the swim step. I will probably fill the holes I can't reuse with thickened epoxy (3/8" holes). For now I installed stainless nuts/bolts/fender washers with plenty of butyl tape to keep the water out. I've been reading several articles that say gelcoat over epoxy is fine under certain conditions. Since these holes are relatively small, I'm planning on filling them up with epoxy, then eventually grinding them down 1/32" or so below the surface, sanding and covering them with gelcoat. If it fails I can always take it back to Tern Boat Salvage for more work!

* Installed the iPad RAM mount under the overhead shelf.

* Replaced berth lights with 9 LED units from marinebeam.com.

* Mounted the fire extinguisher on the aft dinette seat box right next to the door. It's actually pretty out of the way there and easy to access from inside or outside. It wouldn't fit between the door and the window on either side, and I didn't want to put it behind the stove.

* Tossed the ol' bulky crusty life ring and put in a floating cushion.

* Put the ACR ditch bag on board (water, condensed food, solar blankets, duct tape, strobes, whistles, flares, flashlight, knife, water purification pills, mirror, first aid kit, waterproof matches, floating VHF, compass, Nalgene bottle, orange distress flag, etc.)

I probably left something out but nobody's going to get this far anyway,,,

CAVU · Posted: Sun Feb 26, 2012 12:05 pm Post subject:

ferret30,
When I was installing a battery switch in the lazarette I glued a small piece of 1/2 in plywood to the side of the compartment with 5200. This gave me a solid surface on which to mount the switch. Since I knew the thickness of the plywood it made drilling holes and selecting screw length easy. It is still solid after 9 years.

ferret30 · Posted: Mon Feb 27, 2012 12:58 pm Post subject:

I received an interesting and useful response from Blue Sea when I asked them why there isn't a stand-alone AFD (alternator field disconnect) device. I send a question last night at 10pm or so and got a response this morning before 8:30 am:

Sea Wolf · Posted: Mon Feb 27, 2012 1:29 pm Post subject:

thataway · Posted: Mon Feb 27, 2012 3:53 pm Post subject:

It would be interesting to know why Blue Seas feels that there is no longer a danger of diode destruction due to unregulated output?

Blue Seas sells at least two manual switches with AFD, and many of the other large battery switches have make before break switching of the major terminals, avoiding the necessity of an AFD.

However, with the VSR, the engine output is directly sent to a battery (maybe thru a switch) and the relay does not close, to charge the second battery until voltage indicates that the first--usually starting battery--is well into being charged (voltage of 13,8). It does not open the second battery switch, until the battery voltage drops to 12.7--and there is no charging.

The 1/2/all/off type os switch is for manual control, and total disconnect when you leave the boat (except for the auto bilge pump). When running with this type of switch, you will normally run on "1", which is the starting battery, and use the VSR to charge the house battery.

ferret30 · Posted: Mon Feb 27, 2012 4:47 pm Post subject:

Here's a drawing of the wiring scheme I'm planning:

Adding all these breakers drives the cost up quite a bit!

ferret30 · Posted: Mon Feb 27, 2012 4:52 pm Post subject:

ferret30 · Posted: Mon Feb 27, 2012 6:14 pm Post subject:

Here's an alternate schematic. Since I'm using breakers at the batteries, I think I can just piggyback the AFD on the switch terminals and use the breakers in lieu of fuses:

ferret30 · Posted: Mon Mar 05, 2012 4:27 pm Post subject:

Here's how I ended up wiring things together. I spoke to an engineer at Blue Sea (located in Bellingham) and he, as well as a guy at Fisheries Supply (awesome store) recommended not using extra breakers, especially when they would/could carry starting current.

I installed the breakers (Blue Sea 7720) adjacent to each battery, and connecting them to the ACR, using 6AWG.

Jazzmanic · Posted: Mon Mar 05, 2012 7:22 pm Post subject:

Nice graphic Ferret. Yes, your project looks very similar to what I ended up with. Since I had already purchased 4 AWG cable for the ACR to battery terminals, the Blue Seas rep suggested I use 80A fuses. He also suggested I use terminal fuses, which fit in perfectly with my project goal since one of my goals was to clean up the terminals. Those are pretty cool gizmos, they attach to the battery post with it's own separate fuse block so that it keeps the terminals clean and tidy.

My install went well after thoroughly researching and thanks to the advice you, Dr. Bob and others shared.

Peter aka Jazzmanic
C-Dancer - 2005 22' Cruiser

ferret30 · Posted: Mon Mar 05, 2012 7:59 pm Post subject:

Interesting. I didn't even notice the terminal fuses, but they definitely would have saved me some space in the compartments. Do you have any sort of fuse somewhere between the batteries and the motor? Or are you just protecting the ACR bridge?

How do you cover your battery terminals with those installed? Boots? Battery box? Could you snap a picture of your install if you get a chance?

Jazzmanic · Posted: Tue Mar 06, 2012 3:12 pm Post subject:

f30,

Yes, the fuse block and terminal fuse protected the circuit from the ACR for both positive leads to each battery. They also come with their neat little cable cap as well.

Here's a pic:

As for the battery terminals, I bought single Blue Seas cable caps but think I may need to exchange those for the dual-entry caps since all of the terminals have at least two cables connected to each.

I have these:

Thinking of changing to these:

If I get back to the boat this weekend, I'l take some pics. I'm thinking of going to the Fisherman's Terminal gathering and there, we can compare notes.

Peter

ferret30 · Posted: Tue Mar 06, 2012 6:57 pm Post subject:

I have the same ones you do. The problem with the second ones you posted (I think) will be that they will only cover the threaded post. The larger clamp on posts will be exposed (assuming your batteries have marine and automotive posts like mine).

Robert H. Wilkinson · Posted: Tue Mar 06, 2012 9:40 pm Post subject: battery switch system

Not to rain on your parade but to caution others- from what I've read and from what marine mechanics have told me, the so called dual purpose batteries are not what they're cracked up to be. Much like so called "all season tires" - they do not do both jobs as well as their dedicated, single purpose counterpart. A marine starting battery should be designed and used for that purpose only. Disconncting it should be the first thing you do after anchoring and reconnecting it should be the last thing you do before restarting. The service life of a true deep cycle battery is calculated based on the # of cycles it can withstand, taking into account the % of discharge and the charger ( its quality, capacity and whether it can be programed to match the bank). If a deep cycle battery is used for starting purposes it can damage your starter and if a starting battery is cycled too often or too deeply you will be the proud owner of a group 27 box anchor!! Also, any wiring done on a boat must conform to abyc code or it can void your insurance policy. Good luck with your project. Regards Rob