Batteries for the H37C

[rblevens]

My boat does not have that AC outlet nor that switch box seen in that first photo.

Those two batteries in the second photo are in the original location. The farthest in is likely the start battery. Mine is wired to the red battery switch as position #1. The second battery is probably the house battery and goes to pos. #2. An owner has added the tiedown for a second house battery. If you have followed this thread then you know I had two batteries on that shelf. And the two down below.

You need to do some wire tracing and report back. Starting at the alternator there should be a red wire to the starter. Then a red #4 across the engine to the battery switch. On that same starter post a wire going to port through the bulkhead and across the fuel tank, the 12 volts to the panel. You will need the plywood top removed in the q-berth to best understand the wiring AND the plumbing. Back in the engine room a black #4 bolted to the rear of the Yanmar and going to the batteries. This should get you started with more questions.

These two links will help. I can provide large copies if you need them.

http://hunter.sailboatowners.com/in...&cat_id=38&aid=6732&page=article&mn=37-cutter .

http://hunter.sailboatowners.com/in...&cat_id=38&aid=6546&page=article&mn=37-cutter

OK- started on the wire tracing last night- more today.
(still need to look at your wiring links)

Old batteries:
I started by getting all the crummy batteries out- one battery was labeled as a 6v- isn't this a 12 volt system? I really can't get down there (under the fridge) very easy- do they have to go down there- is it the best spot? I want them in battery boxes and strapped down- I think everything on this boat should be able to withstand a rollover... open for debate. ( I do have a tendency to over engineer things. I have read through the posts- I will start w/o using extra house batteries for now- heck maybe just a starter battery (won't that supply juice to the house as well or are the isolated from each other?)

Alternator red wire:
The alternator red wires goes over the 2xbattery switch.
there are 2 different 2xbattery switches next to each other.
I can't see the back of the (main) battery switch- I guess I can figure a way to get a mirror!? Maybe I can unscrew it from inside the boat and pull it into the boat revealing the wires on back.

Shore power:
I traced the shore power connection- it does look like it makes it over to the power panel. Can I get an adapter to hook it into a normal 110 source (or is it 220v) just for testing lights and such?
This leads me to the inverter- I assume an inverter in there somewhere?
So with 110 hooked into the shore power connection- I should be able to supply power to the DC side and test all that?

Let's see where this takes us...

Thanks for your help!

 

[rblevens]

Another quick thing- the 110v outlet above the fridge (under the starboard seat in last nights pic) apparently goes over to a compressor for the fridge- which may have been added in- looks newer. I assume this boat was tied up 99.9% of the time to shore power.
Was the original fridge a DC current?
The other dodad with the switch looks like a 12v DC (or 6V see othe post) supply thing...
I want to strip some of the crap outta there and start fresh

comments...

 

[Ed Schenck]

Rick, when I send the wire I will include some electrical diagrams. There was no refrigeration on the boat unless it was an option that I don't know about. If your alternator goes directly to the battery switch that is a change and a correct one. A second battery switch is a not uncommon upgrade. I would have to see it to know how it is wired. You are correct in 1) the batteries should go someplace else and 2) that you should pull the switch into the cabin to better examine and understand it.

As for 110AC you will see in the original wiring diagram that it simply runs from the shorepower connector to the AC breaker on the panel. From the panel there are two AC breakers, one for starboard side outlets including the one in the picture and one for the port side outlets. There was no inverter, might have been a charger under the nav table. The AC going to the fridge would be a previous owner thing. Some guys gutted those little dorm fridges and stuck the parts in the icebox. I added normal DC refrigeration to the icebox. The installation is in the "Owners Mods".

I plan to keep my start battery down next to the icebox but out where I can get at it. My two new batteries are going in the bilge. I like the idea of the weight being centered. In what I am sending you will see that I originally had the start battery and two house batteries right where yours are(were). They were gels so no boxes were necessary so long as the posts were insulated.

 

[sandpiper10471]

I managed to get four Trojan 105's into the sump below the cabin table and a group 27 start battery just forward of the grate at the bottom of the steps. (deep draft model) They are hooked up with a automatic combining relay which should take most of the user incompetence error out of the system.
Coming from your AC load centre, you should have a wire going to a battery charger. I believe this would have been an owner add-on. Mine, a Truecharge 40(amp), is wired in to the starboard outlets circuit. Probably should have its own breaker. Also on the panel I have a breaker for the hot water heater.
Ed S - For short trips like you are planning, I think a good 12 V start battery and two 6V golfcart batteries would suffice. The house bank would support your autopilot and fridge for at least a day of sailing.
Currently there is a discussion going on (see ACRs under recent posts) regarding proper hook-up of the alternator. Recommendation is directly from alternator to house bank. Something worth considering.

 

[Ed Schenck]

My current sketch goes like this. Add bus bars near the shunt(picture) and move the combiner or new ACR to the same bulkhead. Doing this because the inverter/charger is right there on the back of the icebox. Keep the start battery right under the shunt.

The two new 6 volts(230ah) go in the bilge with #2 cable to the bus. Wire the alternator to the bus bar for the house. I can still get in the locker by putting my legs through that hatch and over the engine. Getting the batteries off that ledge gives me more storage.

 

[Ed Schenck]

You were right Bill. There has to be a platform under the batteries in that bilge compartment. The template fits between the bolts but not between the nuts. Can't have that battery sitting on those sharp corners. The forward most keel bolts are fine, just the next set aft are a little too close together.

 

[SailH37]

Here's what I did since I wanted to keep all 4 batteries, but wanted them to survive the inverted test too. I fiberglassed down a base to get that slightly larger platform needed, then screwed down 4 battery tie down bases with screws long enough to penetrate old figerglass shelf underneath. Then built sides and a top with hinges and 1/4 twist latch lever. Now they won't go any where and they won't get clobbered by foreign objects. I used regular large car batteries so that when I'm down in the islands later, I can find one versus having to order a 6 volt coffin. In the process of doing the batteries, it was a good time to move the refrigerator compressor. I temporarily stuck it where it was living when I installed the unit several years earlier, and it was time to move it to a more secure location so things weren't so fragile in the locker. To backtrack, I installed a Wacco (Adler Barbour) unit that had everything all put together. Albeit small, all I had to do was remove the old ice box, fiberglass a shelf in to hold it, then slide it in. I didn't remove any cabinetry inside and was able to use the existing hole inside.
s/v Renasci

 

[Ed Schenck]

There must be a story associated with your long abscence. At any rate, "Welcome Back".

 

[redhead78]

Hey all, reading your thread about batteries gets me thinking. Now I have 2- 12 volts batts. They are almost at the end of the road, would I be better with 4 6v batts and a starter batt? Would it be advised to keep my 2 yr old blue seas switch. Would it be same as now, starter as #1,then, 4 -6vs as #2, and both= together? Red

 

[Stu Jackson]

Hey all, reading your thread about batteries gets me thinking. Now I have 2- 12 volts batts. They are almost at the end of the road, would I be better with 4 6v batts and a starter batt? Would it be advised to keep my 2 yr old blue seas switch. Would it be same as now, starter as #1,then, 4 -6vs as #2, and both= together? Red

With a boat as large as yours, 2 12V batteries ain't gonna do much, 'specially if you have a fridge and want to stay a night on the hook.

Your ideas are good ones. Either 3 or 4 12V batteries for the house bank and a separate reserve bank, or use 4 6V for over 400 ah.

You may be interested in this Electrical 101 topic: http://c34.org/bbs/index.php/topic,5977.0.html

Make your house bank #1, easier to remember. Least for me.

 

[Benny17441]

In order to properly size a battery bank you need to conduct a power survey. Calculate your usage in amps for a time period that you regularly stay away from a recharging source. To small or to large a bank have their drawbacks. There is not a to small battery bank if you carry a genset with you.

 

[Ed Schenck]

This thread started when I decided to remove four 12 volt AGM house batteries and replace with two 6 volt wet cells. So I am replacing 380 amp-hours costing $900. with 235 amp-hours for $180. The reduction in amp-hours won't hurt me now that I am no longer cruising. The 235 will be more than adequate for the occasional overnight or two in Lake Erie. So far my 900CCA AGM 12 volt start battery is hanging in there.

 

[Bill Roosa]

To ease the pain of calculating your power usage you can set up a simple excel spreadsheet to do the math. I used the following columns:
Electrical item, current draw, total AH, and then a single column each for the hours of the day. The total AH column is just the sum of the hours row times the current draw. The rows are just the individual electrical loads and a bottom row that sums each column's AH used. Then all you have to do is put the fraction of an hour each device is on in the appropriate time column.
Is it 100% accurate, probably not but it will certainly give the 95% solution for sizing the components.

 

[Ed Schenck]

Here is a spreadsheet that one of our members posted some years ago. You can modify it as necessary. For example maybe you don't have any LED lights. Lot of work for daysailing or weekend cruising. But maybe you have bigger ideas.

Whoops, doesn't like my ".xls" file. Will take me a minute to load.
OK, uploaded as a PDF. E-mail me if you want the spreadsheet.

 

[Stu Jackson]

The link I provided earlier also has what is called an "energy budget."

 

[Bill Roosa]

There is one on the resources-downloads-general page also

 

[redhead78]

Can I mix, say 4- 6volts #1 house, then a 12 volt on #2 as a start batt. Red

 

[Ed Schenck]

Absolutely. Doing it myself. If you have studied this thread you can see that all my charging goes to the house bank. The start battery is totally isolated EXCEPT when a charger(alternator, solar, shorepower) is working. Then a combiner opens a relay and ALL batteries are charged. The start battery is strictly backup. I switch to the house bank, start the engine, and never touch the start battery. Well except to check the volt meter(Link 2000) once in awhile.