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I use a U1 AGM as my starting battery on Gorbash.  It's located just under the small compartment cover in the aft cabin where I can reach it easily.  It has a high current in-line switch installed so I can connect it or disconnect it easily by feel.  It's been maybe a dozen years since I installed it so I'd have to take a look to remind myself of the details but basically it's wired to the starter with a short run of very heavy wire.  It's connected to my house bank of 4 golf cart batteries through an automatic combiner.

The boat is in western Washington so we never have to deal with extreme cold but I always use the small battery to start the engine and it has always started easily with the exception discussed below. 

The reason I used an AGM battery was so I could mount the U1 on it's side to fit comfortably below the wooden cover including being strapped down inside a standard plastic battery box.  This, of course presents the issue of what battery type settings to use on the TruPower charger and Balmer regulator for my mixed battery type situation.  I can't remember here sitting at home whether I chose AGM or flooded but I know it was whichever one was least likely to overcharge the AGM.  I think I remember that this left the house bank floating at a slightly lower voltage than ideal but it was by only a small amount. The current house bank batteries are about six years old and are due for a capacity check but last summer on a month long trip they seemed to take about the normal amount of time to get down to 50% - so it seems this slight undercharge is not hurting anything.

The problem that has occurred is that charging regime for the house bank appears to be unduly hard on the much smaller AGM even though all the stage voltages on the chargers are optimized for the AGM.  Early on I left the AGM connected to the combiner all the time and found that the first U1 AGM failed to hold a charge after three years.  Another died the same way about four years later.  The third AGM U1 is still going strong after another four or five years.  I now manually disconnect the U1 when we leave the boat for long periods or when the house bank is being recharged after a deep discharge.

I thought about replacing my four flooded house bank batteries with AGMs with all their associated advantages (and expense) but concluded that the source of the U1 failures was more likely from being charged in a mixed SIZE environment than from a mixed TYPE environment.  This conclusion came from watching my Link type battery monitor and noticing the large amount of time the U1 was facing unduly high voltages while the house bank was being charged from a deep discharge.  Of course this occurs at the end of the charging cycle for the house bank but still, the U1 is seeing 14 volts for what I think is way too long given that it is hardly used in starting the engine and so is almost fully charged during the entire house bank charging cycle.  Thus my habit of disconnecting the U1 except when needed.

This theory may in fact by haybag but the system works well enough that it hasn't been worth it to me to rework it.  I have fiddled with trying to get the smart combiner to use it's overvoltage protection circuit to cut off the "combine" when the voltage rises beyond 13.8 volts or so but that induced other problems.  As we're planning multiple month trips up the BC coast now, I will probably replace the house bank "just cause" and may consider AGMs for other reasons.  I would still be leery of the capacity mismatch and would probably still disconnect the U1 much of the time.

Your inputs are welcome!

Randy

Bob,

It does sound like you might have a bad battery cell or charger problem.  12.1V is too low.  I also have 4 T105s and after two full days at anchor and down 145AH they are at about 12.4V.

It's also true that your alternator will get very hot charging a depleted house bank.  I panicked a few months after installing my Ample alternator because it, too, would sizzle water.  Ample told to me to quite worrying - that the alternator was designed to run that hot.  THat was many years ago and all is still well.  Heat out door was not entirely a joke as per Stu.  I'd never advocate a dangerous practice like warming your hands in front of that open door but when you start out on a cold, wet morning down 225 AH, and can get the Admiral to steer, well, you know...sorry Stu couldn't resist.

Randy

We love all that heat!  Living in a cool and damp place, it's great to take a time out in the head with the access door open and hot air blowing out.  The heat is part of our leaving anchor process too.  The batteries are usually down 200 AH or so after a few days, so we wait 40 minutes for the water to heat up, take turns in the shower, and then count on the hot air from the alternator to dry out the lingering water in the head.  Perfect synergy!

It's not so great in the summer but we can stand it for a month or so....

Randy and Mary
Seattle

I'm in Anacortes.  We pull the boat every two years and put on two coats of Trinidad SR.  I have a diver change the zincs, give the bottom a quick brushing, and clean the prop every 9 months to a year.  The anti slime compound in this paint seems to work pretty well and there is never any hard growth on the hull.  We could problably do three years.

The only problem we run into is that there is usually barnacle growth on the prop. This spring, the yard coated it with one of the new paints designed for the job.  We'll see how it works.  It only takes one or two barnacles to kill the prop's performance, especially in reverse.

Randy

I'd recommend the walkthrough.  We have 1068, a Mark "1.5" and really appreciate the ease of using the walkthrough at anchor to get in and out of the dinghy.  We also use that approch at marinas to avoid splinters, rails, etc. 

It's not quite true that water "never" comes in through the transom!  It's happened twice to us over 9 years under very different conditions.  Once we had grabbed a park bouy as a power boat wake showed up.  It washed through the cockpit and spashed a bit of saltwater through the companionway.  The other time was two weeks ago in a nasty piece of water called Johnstone Strait.  35 knot winds against an opposite 2 knot current.  We were going downwind under partial jib and taking some water through the transom as the steep chop broke against the stern.  We put in the lower hatch board and didn't worry about it execpt for wet tennis shoes.

We've always had the M35A so we have no basis for comparison with the 25 but we have been slowed to 3 knots against a large chop and headwinds with the engine turning 2800 so there wasn't power to spare.

Randy

Monday and in Port McNeill to do laundry and restock.  Weather has been just plain cold - high 50s to low 60s max.  We're going to begin slowly moving south until it warms up.  Johnstone is fine most mornings about 4:30.  Delay and you're toast!

Randy

Guess we might as well continue this thread for trip reports!  Gorbash is in Greenway Sound on Broughton Island.  We're leaving in the morning for Tracy Harbour or Macenzie Inlet for a few days and then to Blunden Harbour for a few days.  We don't have to be back in Anacortes until July 30 but not sure when we'll start south.  It depends on the weather. If it stays cool and showery here, we may spend a week in Desolation to warm up before working our way home.

The marina operators say the activity here is down about 50% from last year.  The marinas are pretty open and most bays only have a boat or two.  The wildlife is here and have seen 3 bears and various other critters.

We've seen one other C34 in these waters and that was named Nemaste based in Vancouver.  We pulled in next to them in Echo Bay.  Nice folks.

How is (was) Princess Louisa?

Randy and Mary

Michael - let a day go buy and I'm out of sych with the thread!

You're on a good course to bag testing and buy a good charger.  The pain in your wallet will be short lived and your batteries will love you for it for years.

To tie up the thread on testing - Stu said it right.  What you're testing for is how the charger manages the batteries, not what they look like after the charge.  The test is to turn the charger on and see what voltage it settles on for final float (per the voltages given earlier).  If you can be at the boat, his idea of looking at the voltage during the bulk charge isn't a bad idea although any battery will be able to handle short term, high (up to 14.5v) voltages.  What cooks batteries is a high float that boils off water until the plates are uncovered or generates high levels of heat with overcharge.  BTW, the Fluke meter is a good choice!  I'm biased by working there for almost 30 years until 2001.

Also to complete a thought in the thread - putting the charger in with the batteries is how I "proved" it was the battery gasses.  Only takes a minute in the enclosed space to sound the alert.

Finally, I leave the charger on durinng the much of the year.  We have power on the boat all winter for heaters and dehumidifiers and in the summer to run the fridge.  Boats sink because of leaks too and I like to have long term power for the bilge pump.  I suspect this is a religious type discussion like anchors and anchoring which can be argued with merit on both sides.

Michael,

I agree with virtually all on the board that you would be much better off with a new charger.  I changed mine out less than a month after I bought Gorbash in '98.

That said, there is an easy measurement you can make that could buy you some time to make your charger decision.  If you let your charger take your batteries to full charge and then measure the float voltage with a digital multimeter, you can make an informed decision about how urgent your charger change needs to be.  Will assume temp in boat is 45 to 75 degrees or so.

Here's my opinion on voltages after full charge:

Above 14.1   Don't turn the charger on again.  It's cooking your batteries.

13.9 to 14.1  Will cook them over time, if for no other reason that they will use a lot of water and you or other owner will forget to check and top them off.  It only takes once.

13.8 to 13.9   Ok for well built batteries.  Watch water use at top of voltage range.  Depending on temperature, optimum float is 13.4 to 13.7, which is what chargers like the Tru-charge will hold them at.

Hope this helps. Any garden variety digital multimeter like those from Radio Shack will make an accurate enough measurement for this purpose.  Don't count on an analog meter, especially the panel type that comes with the boat.

Randy

That's quite an adventure and nice save!

Towing with the dinghy isn't all it's cracked up to be is it?  I read after towing through Nanaimo harbor that way that tying to the side, tug style, works much better.  Haven't tried it yet but plan to.

Randy

Craig,  I'm working on cables and interfacing so we should be able to try it out in the next week or so.

A few facts and opinions...

Facts (from Wikipedia):  Wet lead acid batteries start gassing at 14.1 to 14.4 volts.  The gasses generated are hydrogen and oxygen due to electrolysis.  The concentration of hydrogen required to support combustion is 4% to 75% ( http://hydrogen-fc.com/2007/01/06/flammability-range-on-hydrogen-and-other-fuel/ ).  Assuming I did my math correctly, 4% equals 40,000 ppm.  My CO detector, like the one mentioned in this thread, shows 40 to 200 ppm when in the boat or a small room with the batteries being charged from a fairly low state to full charge by a 3 stage regulator.  This means the hydrogen concentration in the boat is less than .5 percent of the concentration required to support combustion.

Observations and opinions:

All batteries give off hydrogen when charging and copious amounts when charging at higher rates.  I can hear every wet battery I own bubbling off oxygen and hydrogen when charging at even moderate rates.  Your batteries will vent hydrogen in the later bulk and float stages of charging.  It's normal and not something that needs to be "fixed."

Assuming that the current inexpensive CO detectors respond to virtually any hydrocarbon at roughly similar concentrations (a potentially dangerous assumption if they are less sensitive to hydrogen) than the false alarms we're getting are irritating but not dangerous.

Now, that said, here's what I do to keep my rear end safe from bad assumptions or erroneous calculations:  I make sure the boat is well vented with the dorades and solar powered vent.  We leave the hatch in the head open 2 inches with a screen in it.  Then I pull the batteries from the CO detector when we leave the boat so the marina manager doesn't call me in the middle of the night!

One concern I still have is with the hydrogen concentration in the battery box itself.  It's not vented and could build up a pretty high concentration of hydrogen and oxygen.  When I know the battery bank is down more than 50% (kids with video games), I lift the cushion and prop the cover up.  The solution is to put a simple vent in the compartment.  It's on the list.

A side comment:  For those of you still using ferro-resonant chargers, they hold voltage constant at 14 to 14.2 volts.  From the above gassing voltages, you can see why they kill batteries fast.  I suspect the reason some folks don't have problems is that their units are holding a voltage just under the gassing voltage.  The one I tossed over the side when we bought Gorbash was holding 14.2 and the PO complained of short battery life.








(Note, I can always hear slight bubbling from any battery I charge at high rate - this is oxygen and hydrogen boiling off)

On Gorbash, my CO detector goes off anytime the boat is closed up and the batteries are charging heavily.  The same detector trips at home when I leave in my office/ham shack closed up with the 4d I use for radio equipment charging heavily.  I've read that some CO detectors are sensitive to battery charging fumes.  This one certainly is.  I have another one to try out.

Ray, yes they are.  I've dropped ground wires over for my ham radio ground so I'm set up to do it.  I ran a wire from tthe block up through the right rear corner of the boat and dropped it over.  The only gotcha is to remember to pull it out before you start the engine and back out of the slip.  # 12 wire wrapped around your prop is even worse than a dinghy painter.

Craig,  saw your email about isolaters.  I've only been replacing about every 9 months so maybe I just need to do it more often.

Randy

Thanks Jon, I'll check it out.  The eye cups are gone and the plastic straps that attach the objective lens covers are broken.

Craig, perfect allignment is part of what you pay for in good binocs, and even then, there tends to be quite a bit of variation within the same model.  Astronomy buffs will try lots of pairs before they chose.  The practical difference is that well collimated binoculars are "easy" to see through with a crisp image that jumps out.  With poor collimation, you find yourself fiddling with focus to try to get a no eyestrain image but never quite achieve it.

Randy