Batteries for the H37C

[Ed Schenck]

Well, as usual, Maine Sail is right. AGM batteries require too much careful charging to be in a boat like mine. Since coming back to Ohio the boat has been on the cradle. Sometimes it is plugged in and sometimes I go to find it unplugged. I think they are shot after five years although I still have lights from the start battery.

The pictures don't really tell the story. You can barely see the start battery in the first picture. The red top under the icebox down and to the left. Then the first house battery, also on the hull under the icebox. Now imagine if that start battery required checking for water level! The second picture are house AGMs 2 and 3. There was a 4th in the bilge.

So you H37C owners, where do you put flooded batteries? Since my cruising is going to be very limited I am thinking a start battery and then two house batteries to total about 200aH.

 

[Benny17441]

Yes, just size the battery banks to fulfill your current needs, no need to pay to lug around extra ballast. Even in our hot weather down here never checked the water on the batteries more than twice a year. Usually get 4 years use out of wet cells so no need to worry about maintenance schedule. Nothing wrong with having a small battery bank which meets your needs for short trips. If you decide taking a longer trip the rather than expanding the bank use the Honda generator to recharge underway or as needed.

 

[Jim Legere]

Ed, I am a proponent of having the batteries under the cabin sole. I have 3 group 24 batteries down there, sitting on plywood shelves right under the removable floorboards. I just cut the shelves to shape and then glassed a small wood stringer on each side to support them - more from coming "up" than "down" as the shape of the keel wedges them in. I suspect that the same could be done on a shoal draft boat like yours. It makes them easier to check than the stbd. cockpit locker. Mine are standard wet cell lead-acid marine deep discharge. I check them about twice a year and they have lasted 5 years to date. BTW, I left one group 27 battery in the stbd locker as the 'starter' battery, but in actual fact I usually start the thengine on the house bank; the starter battery is for emergency backup.

 

[Bill1565]

Ed we have 4 T-105 Golf cart batteries in our keel sump. Starting batt is in engine room, forward of engine. I'm going to a city council meeting which will kill the AM, but I can send you pictures later today if you want. BTW I like 6 v golf cart batts, a pair if those will get you 200+ ah and last forever.

I am adding 2 more golf cart batts in the v bert to drive an electric windlass and to expand my house bank.

 

[Ed Schenck]

I like the batteries in the bilge(keel sump). But I think T-105s are too tall for a shoal draft boat. I don't know if we can tell how much clearance but here is a picture of my Grp 31 AGM in the bilge. I also don't have much bilge space because of A/C pump in aft section and a secondary bilge pump in forward section(where the current battery is).

I assume you put wet cells in a box. Nice thing about AGMs, just strap them down. I too start my engine on the house. But Jim, is your start battery in the starboard locker way down on the hull(original place) or did you move it up? Is it wet and in a box?

 

[Blaise]

Midnight Sun has four t-105's under the V berth on a shelf. I also have the starting battery in the original location next to the engine. It sounds like a lot of weight forward, but it is offset by crew weight in the cockpit. The battery cables run forward in the bilge to the battery switch in the galley. They are 0-2 I believe. As big around as my thumb. I suffer no voltage loss from the run. I replace them every two years, which is probably overkill for Trojan batteries, but I abuse them racing orrshore.

 

[Bill1565]

Ed 3 pix of T-105's in the sump of a S/D 37c. set on 1/2" pieces of starboard om the sump. Moved bilge pump. Sorry I didn't measure the clearance but I'd guess 2".

 

[Ed Schenck]

Thanks Bill. So you too have the shallow bilge. And the T-105s are not too high. Your wiring looks kind of light, maybe #2? No problem unless you have some high amp requirements. My Ham radio draws pretty good to transmit. So I can get 230 amp-hours with two of the Sam's DuraCell EGC2 batteries(http://forums.hunter.sailboatowners.com/showthread.php?t=132350 ). I'll have to move that little backup bilge pump. Then if I ever want two more I'll have to clear the section aft of that one where the main bilge pump lives. I think I will just move the starter battery to the shelf behind the icebox and put it in a battery box. I like having clear access to everything in the engine room.

P.S. forgot to ask. Why the starboard, why not right on the bottom?

 

[Bill1565]

P.S. forgot to ask. Why the starboard, why not right on the bottom?

Keel bolts have fender washers and smaller washers and maybe lock washers on sump floor. By lifting batteries I got more horizontal clearance between keel bolt nuts. As you can see, height was not an issue.

I used to have group 31's in parallel. Took out half the wiring to the bus bar, now have pairs of T-105's wired to bus bar on the theory that I won't be drawing or replacing more than 100 amps from each pair. Wiring frtom bus bar to panel/chargers etc is 2/0 .

No SSB or Ham Rig no plans to add. That is last century stuff.

 

[Ed Schenck]

Ouch, that last statement hurts. But where is this bus bar that you write of?

 

[Mathurin]

(4) T105's and a group 31 for the engine in a compartment behind the chart table. The location is ideal for maintenance and to keep wires short (close to the engine and electrical pane). Weight wise it's not ideal as it's on the same side then the fuel thank and larger water tank...

 

[Ed Schenck]

I remember that picture. Wouldn't work for me though. My A/C is behind those cabinet doors that you are blocking. I'll do two in the bilge if they will fit. I will know next week after I finish painting the mast.

 

[Bill1565]

Ouch, that last statement hurts. But where is this bus bar that you write of?

Engine room .

Had an SSB/Ham rig with antenna tuner/ insulated backstay when we lived aboard in the '90's. Didn't get much value out of it. E-mail was painfully slow, Ham restrictions greatly reduced what yoiu could talk about, family ashore d/n have ssb capabilities. Sorry if I hurt you.

 

[Ed Schenck]

Well it looks like the DuraCells will fit in the bilge, just barely. They are 7" wide and there is eight inches between the aft set of keel bolts. Height is definitely an issue however. The top of the post is 11 1/4" while the bottom of the sole hatch is 13". But there are those two reinforcement stringers. They will have to be cut down to clear the tops I think. I'll replace the #4 wire with #2 to a new bus bar.

I spent part of yesterday in the starboard locker removing the last two batteries. That Optima starter battery still reads 12.78 volts. And it was attached to the combiner. Not sure how it stayed charged. And I finished the mast painting ! ! That took eight different trips to the lake to sand, prime, and paint.

 

[Jim Legere]

Hi Ed,

You have been busy while I have been goofing off - sailing. My floorboards don't have those stringers on the underside. Maybe they are not necessary? Easy enough to unscrew them and then test for flexing...

 

[Ed Schenck]

Probably right Jim. But I'll make exact models and maybe the posts don't align with those stringers. If they do I'll just notch the stringers. Those two batteries are too heavy to be using them to test any theories. I wonder if I should worry about the battery cases resting on those keel bolt washers? Maybe some rubber washers are in order.

 

[sandpiper10471]

I removed the stringers when I put the batteries into the sump. No flex or squeeking. The stringers were totally unnecessary.

 

[Ed Schenck]

Maybe you don't weigh enough Bill. I'll remove them and give it the 200 pound jump test. Thanks for the info.

 

[rblevens]

Might as well jump in here... I want to see what electrical works and what doesn't in a controlled manner.
The pic is under the starboard cockpit seat. The shore power socket is right there. Can someone make heads or tails out of this mess?
I feel I should be able to hook up shore power and use cabin lights. Then one by one check 12v systems.

 

[Ed Schenck]

That plywood top is over the ice box. Originally that was a white top with a door so that you could get to your beer without going below. Many of us have insulated that door and then covered it over. 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