Electrical Upgrades

[Van_Isle]

First off, for reference, there is another thread I started here: http://www.moyermarine.com//forums/s...9553#post89553 regarding relocating my heat exchanger in response, in part, to making room for an upgraded alternator.

Also for reference, the boat is a C&C 27 Mk III ('79 vintage).

Trying to make room for the heat exchanger relocate to the port side, I'm moving my batteries, and hope to add a dedicated cranking battery.

So There is no way that I can see to fit even one battery with proper cell orientation (port to starboard) next to the engine on the lower shelf of the factory original battery space. I might be able to shoehorn something in there .... but I'd do a lot of battery shuffling to do anything in the area of the carb. It is also, too close (by ABYC) to the carb / fuel lines / etc. I believe the spec is 2-foot minimum distance.... but even that doesn't apply as far as I see as it requires the fuel source to be open to the atmosphere.

Also as I mentioned in the other thread, my alternator has died and I realized the original 35 amp alternator just wasn't really proper for 220 amp-hr of house battery (2 x Group 27 flooded Costco deep cycles) and whatever I end up with for a start battery. I've gotten myself a Delco 75 amp alternator. So using the rule of thumb of 30% of battery capacity and assuming I end up with a cranking battery around 80 amp-hr that is (220 + 80)*30% = 90 amps. Not ideal, and I realize that I'm not going to get anywhere near 75 amps out of the RPM's generated by an A4, but certainly far better than the old one!

So some questions / notes for potential comment to start:

1) start battery .... anyone see anything wrong with a Group 24? I may not find a reasonable location for the battery though .... still thinking on that.
2) battery boxes .... anyone used these, or something similar? http://www.allbatterysalesandservice...cfm/4,248.html At least for the house batteries. I'm thinking of putting them under the aft seat of the dinette area (port side). I think these boxes would fit on a platform. Only the two house batteries would fit here. The location would increase cable distances significantly but the batteries move about 2-1/2 feet further forward. There's also a way to route cables forward to this area behind the cabinet holding the icebox on the port side.
3) the only, potentially slightly better location, for the start battery that I can fathom is behind the main bulkhead on the port side ... so a foot or so further aft than the location of the current batteries.
4) As far as I can see there are few sailboats out there that meet the ABYC requirements for separation between fuel and NON ignition protected electrical equipment. With the main bulkhead penetrated by the engine and the bilge open to this pass-through it seems to me that just about ALL the electrical equipment on-board must be ignition protected! Just think about the rear of the engine control panel in the same space as the fuel tank ... in an enclosure? Nope! I was thinking of putting new electrical panel in the area freed-up by moving the batteries, but it might be much better to centralize the electrical in the area of the dinette. Some of the electrical is flexible in location ... the battery switch, charger, galvanic isolator, automatic charge relay and I believe windlass components are all ignition protected. However AC switches and breakers, DC distribution panels, fuse panels, etc. are not (at least not all are).

Pictures to follow.

[joe_db]

I use a U1 size battery for my start battery. They are about half the size of a group 24. If you are using wet cell charging voltages, an AGM U1 will work and can be mounted sideways. They cannot leak acid, so no case required.

[edwardc]

I use a U1 size battery for my start battery. They are about half the size of a group 24. If you are using wet cell charging voltages, an AGM U1 will work and can be mounted sideways. They cannot leak acid, so no case required.

I use a U1 for a start battery too. My system is all Gel cells. The U1 is commonly used in Jet Skis. It's got plenty of oomph to turn over the A4, and is much easier to find a place to mount than a group 24.

[hanleyclifford]

Couple of things. Keeping battery cable runs short is top priority in design considerations. If you have any thoughts about long range cruising strive to have as much battery(s) on board as your boat configuration will permit. I don't waste space with small batteries, even a 24. Just start the engine with one of your 27, 29 or 31s which should be separately switched.

[Van_Isle]

I just picked up a barely used 20 amp Promariner AGM compatible charger to replace my 12 amp non-AGM compatible one. So perhaps I should bite the bullet and swap over to AGM's if it eliminates the need for boxes. Are the hold-down brackets and trays typically sold for marine use better / required over using straps?

[hanleyclifford]

I just picked up a barely used 20 amp Promariner AGM compatible charger to replace my 12 amp non-AGM compatible one. So perhaps I should bite the bullet and swap over to AGM's if it eliminates the need for boxes. Are the hold-down brackets and trays typically sold for marine use better / required over using straps?

Is this the one you bought? http://www.anchorexpress.com/ProMari...FdgDgQodmKoAdQ

[Van_Isle]

Same except the "non Pro" version which is a 2 bank vs. 3 bank model. A mute point I think if a ACR or Echo Charger is used since the charger would have both sets of bank wires connected to the house bank and the ACR/Echo would handle the start battery .... regardless if charging source is the charger, alternator or solar. That's my understanding at least.

[Van_Isle]

I think after doing some reading I'll stick with the flooded deep cycles. The last ones did ok for about 6 years and these ones are less than a year old.

Regarding the charger ... doing a bit more research and I figure the best setup is to connect the charger to both the house and start batteries. Then a Blue Seas ACR or a Yandina battery combiner. Both can be set up with either a manual switch or a relay triggered on presence of AC power to disable the combining functions. So that way the Prosport can vary charging output to each bank depending on sensed state of charge without charge being redirected by the combiner (e.g. the Prosport is not a fixed 10 /10 amp charger ... it can vary output, as in: 20 amps to bank 1 & 0 amps to bank 2;18 & 2; 10 & 10, etc.). Charging with the alternator would of course be handled by the combiner.

The Yandina 100 seems to be a good deal ... I like the unlimited warranty! Shipping to Canada is ugly ... pushes it up to about the same price as the Blue Seas.

By the way, a thumbs-up to Promariner, who are sending me free a couple of the caps used to change charging profiles. They answered my request within hours of me sending it. Same for Yandina, who's technical support got back to me in less than an hour to answer some questions about their 'disable' feature.

[sastanley]

V_I..I've been perfectly content with flooded batteries. Unless you have the space for 6v golf cart batteries to wire in series I still think flooded is the the best amp hour bang for the buck.

I seem to recall at least once at anchor where I had to rip apart my 1977 battery compartment to lug my GR24 flooded start battery to my buddy's 2004-ish Beneslow with high-dollar AGMs and jump start him...maybe twice.

[BunnyPlanet169]

Unless you have the space for 6v golf cart batteries to wire in series

which are flooded wet cells....

I still think flooded is the the best amp hour bang for the buck.

Every so often, one of the trade magazines does a piece on battery technology and charging, often written by Calder. The engineering trade-offs are interesting, but in the end, flooded lead acid is exactly as Shawn suggests - always the least expensive way to power DC loads given the typical usage and charging profiles.

The trade-off for lowest cost, however, does have impact on our generally smaller boats.... Batteries are heavy and take up space, and this is generally considered a 'freebie' on a displacement, non-racing sailboat. 6V golf cart batteries are really durable, but you need two and they're big and heavy. 12V AGMs are (nearly?) maintenance free, and don't need water or off-gas hydrogen, but cost ~30% more than conventional 12V lead acid for the same AH. This may be a good trade-off on a small boat.

Comparisons:

http://catalogs.westmarine.com/app.php?RelId=6.4.7.5