Conference vicki::boats

If your alternator was big enough to support your current drains before,
it will do just fine with the new battery. 

    My question is why did a perfectly good 1 year old battery fail. Sure
    its being recharged? Low/no water? 
    
    Dont worry about the new battery. 12 volts for them all. Your new one
    just has more juice for the long run - so to speak.
    
    But find out whether your spending money on a new battery and have a
    charging problem from last year. Unless you absused the old one it
    should be solid this year. 
    
    Tell us more. Was the old one a marine deep cycle? How was it used?
    Like where?
    

    The battery was an Exide Nautilus Dual Purpose Marine Starting and Deep
    Cycle Battery.  Besides starting the motor, I use the battery to run my
    fish finder, two-way radio, radio and phone, sometimes all at the same
    time.  Because I run all this stuff I bought what I thought was more
    than I needed (the factory battery was smaller).  I did have one
    problem with it last year, after using the boat one weekend I went
    back about two weeks later and the battery was flat.  I got a jump and
    the battery ran good all day.  That was the last time I used it, it sat
    in the boat for the winter until last Saturday.
    
    Rick
         

    I forgot to add that the boat does have an charge gauge on the dash and
    this reads normal.
    
    Rick
    

Here's a wild shot.

The battery was not fully charged when the boat was layed up.

Winter finally tooks it toll.

JIm

    
    How about calling the manufacturer?
    
    
    

I'm a little suprised, Exide is a pretty good battery, second to Surrette

of course. Was there any visible signs of winter damage.

I dont know what calling the mfgr will do, but try it.

JIm

    I would bet there is somthing drawing it down. If it sat in the boat. 
    You may think about disconnecting the new one if your going to leave
    it in the boat for long periods. 
    
    And next year, charge the new one and bring it indoors.
    
    Jack

I just returned a Die Hard Gold that failed after one year. One cell was
dead. I'd say it's attributable to a manufacturing defect, and so did
Sears. They prorated it and for $15 I got a replacement. 

My charger is used for three boat batteries, a tractor battery, and two
motorcycle batteries, so there's nothing wrong with it.

Art

    All alternators charge at 13.4 or 13.8 volts.  How much current they
    put out is what makes them different.  The bigger the battery, the
    longer it takes to be recharged fully.  I have the largest Sears
    Diehard Marine made that is only used to start the engine and run the
    bilge pump. (Wooden boat, leaks alot)  I wouldn't trade the peace of
    mind this oversize battery gives me for anything.  I can leave the boat
    for weeks and not worry about it sinking or not starting.  The
    alternator (35 amps?) will then fully recharge the battery in a short
    period of time at cruising speed.
    Wayne
    

          <<< UNIFIX::DISK$AUX_SYSTEM:[NOTES$LIBRARY]SAILING.NOTE;1 >>>
                                  -< SAILING >-
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Note 1102.34                      Battery help                          34 of 60
UNIFIX::BERENS "Alan Berens"                         81 lines   1-MAR-1994 12:52
                             -< more on charging >-
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As should be amply clear, battery charging is not nearly as simple as 
one might think.

Assume your battery bank is nearly completely discharged and you want to 
fully recharge it as quickly as possible without damage to the 
batteries.

The first requirement is that the charging voltage be limited to some 
safe value, usually 14.4 volts for flooded-cell (conventional) batteries
and 14.1 volts for gel-cell batteries. This requirement is easily met by 
the usual alternator voltage regulator or shore power battery charger.

The next requirement is to get as much charging current into the battery 
as possible. At any state of (dis)charge, a battery will accept only so
much charging current for a fixed charging voltage. This so-called
acceptance current depends on the type of battery, its amp-hr capacity,
and its internal construction. Gel batteries typically have a higher
acceptance current than conventional batteries. 

When charging (at a fixed voltage) a deeply discharged battery first
begins, one of two things happen. If the charging source can supply
enough current, the charging current will equal the battery's acceptance
current (as high as 40 to 50 amps for a group 27 size gel battery and
well over 100 amps for a large gel battery bank). If the charging source
can only supply less than the acceptance current, then the charging
current will be whatever the charging source can supply. Shore power
battery chargers can rarely if ever provide a charging current equal to
the acceptance current. From this it should be evident that a critical
requirement for rapid recharging is a charging source capable of
supplying a very large charging current. Supplying anything less than
acceptance current lengthens the recharging time. For example, our Ample
Power alternator is capable of supplying a bit more than 100 amps at
14.1 volts. This is enough to supply acceptance current for two of our
three batteries if they are deeply discharged. Yes, the alternator gets
hot, but it is designed to. And a proper alternator regulator (eg, Ample 
Power) senses battery temperature and reduces the charging voltage (and
hence charging current) enough to prevent damage. 

As the battery recharges, the acceptance current (at a fixed charging 
voltage) decreases, falling to, say, 5 to 20 amps. This current is 
easily supplied by an OEM alternator or a shore power charger. It might 
take an hour or more of charging for the current to fall this far 
(depending on alternator output, battery bank capacity, and how 
discharged the batteries were). In this phase, there is no added value 
to having a high-output alternator. 

After some more time (as much as hours), the charging current will fall 
to a low value, say a couple of amps. Now the charging can be done by a 
wind generator or large solar panel. The acceptance current for a 
fully-charged group 27 Prevailer battery is about 0.3 amp or less at
13.8 volts. 

The total amp-hrs that must go into the battery somewhat exceeds the 
total used (inefficiency and all that). If you use, say, 100 amp-hrs per 
day, you'll have to put at least that much back into the batteries. This 
much from only solar panels or a wind generator is unlikely. A big solar 
panel might provide maybe 10 to 20 amp-hrs on a sunny day and it would
take an unusually windy day (in New England) to get 100 amp-hours from a
wind generator. 

Our liveaboard friends (who use ice for refrigeration) had both a large 
solar panel and a small wind generator. These weren't quite enough to 
supply all their electrical needs. And the wind generator was noisier
than a small gasoline generator in winds over 10 to 15 knots. Other 
brands of wind generators may be quieter, but I'd be surprised if 
they're not somewhat noisy.

There are a couple of interesting consequences of having a large battery
bank rather than a small one. First, for any given daily usage, the
percentage discharge of the batteries will be lower, which will increase
battery life. Second, the acceptance current will be higher, which will
decrease total recharging time (assuming a high-output alternator or
other charger). 

Finally, battery life is again increased by using two or more charging 
voltages. Our older design Ample Power regulator initially charges at a 
high voltage (variable, we use 14.1 volts) to maximize the acceptance
current. After a while, the charging voltage is reduces to a lower value
(variable, we use 13.8 volts) to fully charge the batteries without 
damaging them if the charging continues indefinitely. (In hotter climates 
than New England these voltages should be reduced.)

    Well, I put the new Delco battery in the boat last night and the engine
    started first try.  I think your right, it was just a bad battery. 
    It is possible that there is something draining the battery time will
    tell.
    
    Thanks
    Rick
      

If this was my boat, and I thought something was draining the battery,
I'd turn off all equipment, as if I was going to leave the boat. I'd
disconnect one battery cable, and put my VOM (on "current" setting)
between the end of the cable and the battery post. If there is a
measurable current flowing, and this can mean milliamps or more, it means
there is a current drain. Then, with the meter in the circuit, I'd start
pulling fuses (and breakers, if you got'em) until the reading went to
zero. That would narrow it down to that circuit.

In other words, I'd put on my Dick Tracy hat and detect (that's what
detectives do) the current drain. Could be a small light somewhere. Or,
it could be a conductive path across some built-up oxidation on some
terminals. 

  - Do you have a water thermometer on the boat that could be hotwired? 

  - Could the fuel gauge be ON all the time? 

  - Do any of your electronics use the 12V "line" to keep internal memory
    alive? My VHF FM radio draws current even when it's turned off, to
    keep the memory alive. It will flatten a DieHard deep cycle battery
    in about six weeks. This was my second reason for installing a Perko
    battery switch next to my batteries (paralleling for starting was the
    first reason). When that switch is off, *nothing* draws current.
    
...just some ideas.

Art

    I had a Delco go bad with just 1 season. The second season I put 2 deep
    cycle batteries in with a switch that included a built in voltmeter.
    All that season, it appeared that the batteries were gradually losing
    charge and that the alternator wasn't putting out the voltage it
    should. I suspected a bad alternator. When I was winterizing the
    engine and went to crank it, I got a flash and pop and, from that point
    on, it appeared as if I had a dead short. It wasn't until this Spring I
    found my problem....bad ground.
    
    In my case, there was a bolt thru a flange on the rear of the engine
    that, on 1 side, the battery ground wires attached. I had taken those
    wires off and cleaned them and things appeared ok. What I didn't notice
    at first was that the head side of the bolt going thru the flange had
    what I suppose is the ignition ground (~10 guage wire) attached. To get
    this off, I had to remove the nut holding the bolt in and take the bolt
    itself out. Where the bolt went thru the flange, there was a large
    build up of corrosion (looked almost like salt). Cleaned this up and
    put back together. Everything works fine now and even the voltmeter on
    my switch gives the correct charging voltage.

    I was curious if anyone uses one of those on-board battery chargers.
    I am thinking about spending the money for one of those units that
    charge up to three batteries from your engine alternator while your
    cruising and isolates the cranking battery while not in use. I use 
    three batteries on my boat, ie starting/gages, trolling motor, live-
    well/(backup starting). Do these devices work as advertised, are they
    worth the $200+ price tag???
    
    							TS
    

    I use an onboard charger for my two deep cycle trolling motor
    batteries, but it is the kind you plug in, doesn't work off the 
    alternator - more or less just permanetly installed, real nice
    convenience.
    
    -donmac

I need some clarification. There is a device that runs off the alternator

that charges batteries and will isolate them at the same time.

Doesn't really make a lot of sense $$$ wise. You can buy a 3 bank

isolator for a whole lot less.  Maybe $50.  There wont be any advantage

to this 12volt gadget unless it boosts the amp the alternator puts out.

For $200 this doesnt sound like a good deal to me.

Did i miss something?????????????//

JIm

I just bought a new boat 25' Bayliner Trophy

It has two outboards, each with their own starting battery.  The wiring diagram
shows that the various electric equipment is wired to one or the other of these
batteries.  Most of the electric stuff will only be run when the engines are
running, however, I do a lot of trolling and would like to alternate the
engine running to equal out the hours.  I also want to install a TV and Microwave

What I think I'm talking about is a battery isolator or marine USA battery
combiner, an inverter, and a deep cycle battery.  Is there any other way to
do this?  I would also like to wire the electronics to the deep cycle battery
instead of the starboard battery. 

Can I wire the inverter into two alternaters somehow, so that when either
engine is running it will charge the deep cycle (house) battery?
How would this work when both engines are running?

Does one have to used the inverters sold in the marine stores.  Can you buy then
cheaper somewhere else.  What about used ones?  RV stores.

I would also like to be able to use any of the batteries to start either engine
in case of an emergency.

I don't want to build a complicated setup of multiply battery switches that
you need an electrical engineering degree to figure out what each combination
does.

Thanks for the help

Gordon (rock'n 'n reel'n II)

    The devices are so called "on-board management systems". The two under
    consideration are the NAVIGATOR and the DUAL PHASE II. Per the
    advertisements, when the ignition is off the unit isolates the cranking
    battery from the others. When the ignition is on it allows up to three
    batteries to be charged from the engines altenator. I don't believe it
    increases the altenators current output. The units also make overnight
    charging less of a hassle "presumeably" by simply plugging the unit
    into a standard AC outlet. No fumbling around with batteries. I have a 
    small charger so when I do charge, it has to be one battery at a time.
    As well, I would like to have the ability of charging my trolling motor
    battery if it starts to drain during heavy use out on the water... 
    Will a three bank isolator aheive the same results????????  

OK, i got a handle on this one (i think)

First off, an isolator isolates the batteries on the 12v side of things.

Period. So that each battery does not know of the others existence, and

cannot drain the other down.

The 3 bank battery charger, has an isolaror built into it, and accomplishes

the same thing on the 110 volt side.  Since your batteries are connected to

one charger, you dont want them darin each other.

Bottom line, you talking about 2 different items.

Does this help?????


JIm

Gordon, to the best of my knowledge, an inverter cannot be wired to the

alternators, its gennerally wired to the battery(s). An inverter converts

12v to 110v to run various 110v appliances.  Before you buy one, you need

to understand what size you need.

As for starting, you need a battery switch to specify how you will start

either engine.

JIm

    According to the "West Advisor" (source of lots of technical info) in
    the West Marine Catalog, cheap inverters tend to go up in smoke.
    Apparently they had some difficulty finding a reliable one to 
    sell in their catalog.
    
    Bill
    

This is how I think it will look.  Is this ok? suggestions:


            stbd battery               port battery
                 |                          |
                 |                          |
                 +------isolator------------+
                           |
                           |
                   house battery
                           |
                           |
                     inverter

Gordon

Yup, looks OK.  Only one other item, is the connection of the charging system

to the isolator.

JIm

re .24:

There is a major problem with diode isolators -- the approximately 0.7
volt drop across the diodes. The output voltage of most alternators is
not adjustable, and the regulator senses the output voltage at the
alternator. Remote sensing regulators are usually only available as
add-ons. The output voltage of a normal regulator is a compromise
between fast recharging and not over-charging with the emphasis strongly
on not over-charging. Reducing the battery charging voltage by 0.7 volts
will do nothing except chronically and badly under-charge your
batteries, which will greatly shorten their life. If you use an
isolator, you must increase the alternator output voltage. Ample Power
(and others) make adjustable, remote sensing regulators (about $170 plus
the expense and hassle of installation). 

There are several notes (eg, 1845) in the SAILING notesconference that
discuss this. 

Alan

The Marine USA catalog has a good writeup on just that .-1.  They apparently
have done much research on the subject and recommend a battery combiner.
I'm not sure exactly how it works but I think it senses the battery charge and
when fully charged it opens the circuit.  If performs the same function as
an isolator without the drawbacks.  This is a relatively new concept (only a
couple or years old); does anyone have any experience with this unit.

Gordon

re .27:

The battery combiners look like they might be a good solution. They 
certainly avoid the diode voltage drop problem.

My guess is that they sense alternator output voltage. If the alternator
output voltage is higher than the battery voltage (ie, any time the
engine is running), then a relay closes to parallel the batteries. When
the engine is stopped, the relay opens to unparallel the batteries. My
further guess is that the relay, being electromechanical, is probably
somewhat less reliable than a diode isolator, especially since it
switches a (probably) large current when the batteries are combined. 
Given their small size, they likely aren't using a really rugged, heavy 
duty relay. 

Except for the relay, you could build one of these things for about $10 
in parts. 

Alan

    You could home brew a setup  using starter solenoids.  They do wear out
    if left in constant use, though.  There are solenoids made that are
    heavier duty for constant use, but I'm not sure who/what/where to get
    them.  
    
    Frankly, a good (simple) battery switching setup would be my
    preference.  
    
    Carl

I think that I understand how to set up a multiple battery system with
switches, isolators, battery combiners for a single engine (alternator) system.

However, what about two alternators?
Can both alternators charge the same batteries?
What would such a system look like?


         port engine                  stbd engine
              |                           |
              |                           |
          battery                     battery
              |                           |
                     battery switch
                          |
                          |
                     isolator/batt combiner
                          |
                          |
                     house battery
                          |
                      invertor

Thanks for the info

Gordon

    Since most systems come together at the the battery, there should not
    be anything mysterious with multiple engines. The switch is normally at
    the far end just befor the battery (meaning 2 alternators would be
    charinging a single battery or a bank of them).
    
    Just keep your grounds clean.

I'm no guru, but if 2 alternators are to cahrge one battery, or more than

one, i believe one of them will shut down, therefore leaving only one

to do the charging..

JIm

    
    Just a quick question...we've had our 87 Four Winns for a couple
    of months now. We've probably been out at least 10 times. 
    
    On a couple of occasions the engine has refused to crank upon 
    turning the key.....dead silence! Subsequent turns and it kicks 
    right over. My own guess is that I have a chip in the starter. 
    Any opinions? Should I wait to get it fixed?
    
    Thanks

    Had the same problem with an 88 Bayliner.  Turned out that the bolts that
    hold the starter motor together had shaken loose.  One had actually
    fallen out.I retreived it from the bildge, tightened it all up and no
    more problem.
    
    Hope your problem is that simple.
    
    Regards...Kevin

    Take all the battery cables off the battery, wire brush it, and put it
    back together. Next, disconnect completely both the battery ground wire
    to the engine (the thick cable) and the ignition ground (about 10 guage
    wire) and clean those connections. Only thing left then is the positive
    wire from battery to (via solenoid in some cases) starter. Disconnect
    that and clean it.
    
    I had an intermittent problem that turned out to be the solenoid. I had
    later problems that simply turned out to be a bad (ignition) ground
    connection.
    
    Of course, you should take a voltage reading on the battery before you
    do all this.

    I also had that problem, my solenoid was rusting.  It would work some
    times but not others.  I ended up just replacing solenoid every other 
    tear.