I've mentioned this befo you should simply parallel the bank and
install a small starting battery. If you want it to be high quality
and "idiot proof" and a battery combiner (the smaller ones are cheap.
Why invest in an "emergency" starter when the same money give you a
proper solution?

BTW, the small Yanmar will *usually* starts with under 5 seconds of
cranking, but it isn't self bleeding, so it can get balky if the line
gets dirty or airbound. I just started my two engines after winter
layup - one fired quickly, but the other took about 30 seconds of
cranking. My point is that in real life problems always come in
groups - the morning your battery dies could also be the morning the
fuel filter clogs. Why rely on a pack of D cells that cost the same
as a proper battery?


Roger Long wrote:
It's amazing how complicated simple things are when you start thinking
about them.

A little research in Calder's book shows that he, at least, considers
bilge pumps on the battery side common.

But..

I've already decided to run both my batteries as close to parallel as
possible to minimize the depth of the discharge cycles and get maximum
life out of the expensive AGM cells. This goes against the
conventional wisdom of always maintaining a dedicated starting
battery. I'm going against the grain because:

a.. This is a sailboat and I will not be helpless if the engine
doesn't start. I've cruised in boats with no engine at all.
b.. The engine can be hand started, at least in warm weather.
c.. I'm going to be mostly daysailing and short cruising this year.
d.. I have very minimal ship's service loads so it is unlikely that
I'll run the batteries flat.
e.. I can start this little engine with a portable emergency
battery. It's even been done with a handful of flashlight batteries.
So, if I want a dead ship except for the bilge pump, I have to decide
which battery to use. That means that a long run of pumping with the
charger off, as could happen with the boat unattended in a storm,
would drain one battery down. I also would only have half the battery
capacity for bilge pumping under the same circumstances. That is not
ideal. Worse, if one battery did die, I would have to get into the
panel and switch the bilge pump. That's not good.

I guess that, for now at least, I'll just leave things as they are
with the bilge pump wired into the bus. That means leaving the switch
on "Both" when putting the boat away and being sure to turn everything
except the bilge pump off.

A good solution for my situation would be two bilge pumps, one on each
battery. That would provide redundancy. It should be simple to run a
second line and another through hull in this boat. I'll just wire them
into the same float switch. I'm going to take a look tomorrow. We're
doing a lot of through hull work anyway and we'll have the equipment
right there to punch one in above the waterline.

The ramifications just go on. I just realized that the bilge
discharge fitting is 3/4 and the pump hose is 1 /18. That means there
is a reducer somewhere. That's a kludge I'd better track down. That
would be another reason to go to two pumps of the same total capacity.

I actually agree with all your points and it's probably the advice I'd
give someone else. However, I'm opting for simplicity and economy
over the certainty of being able to start the engine in all
circumstances. I'm not even going to invest in the emergency battery.
The proper place for that, as you say, is in a box hooked up with the
combiner, etc.

My emergency propulsion for this year at least, will be good ground
tackle and the willingness to wait for a wind. I'm going to try hand
starting. If it does prove impossible I'll invest in a more
sophisticated system. This is also a boat with no major electrical
loads. I'll also be upgrading a lot of stuff before starting long
cruises. This will be a duff around close to home and get to know the
boat summer. I'll probably be spending a lot more time working on the
systems than sailing. Aside from saving money, I'll have a much
better idea at the end of the summer exactly what the boat needs and
how I want to set up a more complex system.

Even on a cruise Downeast, sailing in to anchor and rowing ashore to
pick up a $40 car battery for a jump start wouldn't be a major
emergency in this part of the world. Another two or three hundred
dollars could be spent on much more critical things at this point than
avoiding the slight possibility of that exercise.

--

Roger Long



"Jeff" wrote in message
...
I've mentioned this befo you should simply parallel the bank and
install a small starting battery. If you want it to be high quality
and "idiot proof" and a battery combiner (the smaller ones are
cheap. Why invest in an "emergency" starter when the same money give
you a proper solution?

BTW, the small Yanmar will *usually* starts with under 5 seconds of
cranking, but it isn't self bleeding, so it can get balky if the
line gets dirty or airbound. I just started my two engines after
winter layup - one fired quickly, but the other took about 30
seconds of cranking. My point is that in real life problems always
come in groups - the morning your battery dies could also be the
morning the fuel filter clogs. Why rely on a pack of D cells that
cost the same as a proper battery?

Roger, I like your parallel bilge pump idea, but I'm not sure how you can
run this through one float switch as I've never heard of a DPST bilge
switch. Is there such an animal available? Without it you will have
difficulty isolating one battery bank from the other.

I'm quite new to the sailing game and can't address many of your points, but
I've risked my life and family in many other kinds of self-reliant endeavors
and I've found that it is most important to rely on YOUR style of operation,
not just "general practices". The row-in-for-a-quick-battery approach had
me in stitches; not because I was laughing at you, but because it resembled
my own unconventional, but practical, style of risk assessment: If you're
not vulnerable, why be defensive!
Padeen

"Roger Long" wrote in message
...
I actually agree with all your points and it's probably the advice I'd
give someone else. However, I'm opting for simplicity and economy
over the certainty of being able to start the engine in all
circumstances. I'm not even going to invest in the emergency battery.
The proper place for that, as you say, is in a box hooked up with the
combiner, etc.

My emergency propulsion for this year at least, will be good ground
tackle and the willingness to wait for a wind. I'm going to try hand
starting. If it does prove impossible I'll invest in a more
sophisticated system. This is also a boat with no major electrical
loads. I'll also be upgrading a lot of stuff before starting long
cruises. This will be a duff around close to home and get to know the
boat summer. I'll probably be spending a lot more time working on the
systems than sailing. Aside from saving money, I'll have a much
better idea at the end of the summer exactly what the boat needs and
how I want to set up a more complex system.

Even on a cruise Downeast, sailing in to anchor and rowing ashore to
pick up a $40 car battery for a jump start wouldn't be a major
emergency in this part of the world. Another two or three hundred
dollars could be spent on much more critical things at this point than
avoiding the slight possibility of that exercise.

--

Roger Long



"Jeff" wrote in message
...
I've mentioned this befo you should simply parallel the bank and
install a small starting battery. If you want it to be high quality
and "idiot proof" and a battery combiner (the smaller ones are
cheap. Why invest in an "emergency" starter when the same money give
you a proper solution?

BTW, the small Yanmar will *usually* starts with under 5 seconds of
cranking, but it isn't self bleeding, so it can get balky if the
line gets dirty or airbound. I just started my two engines after
winter layup - one fired quickly, but the other took about 30
seconds of cranking. My point is that in real life problems always
come in groups - the morning your battery dies could also be the
morning the fuel filter clogs. Why rely on a pack of D cells that
cost the same as a proper battery?

"padeen" wrote in message
...
Roger, I like your parallel bilge pump idea, but I'm not sure how
you can
run this through one float switch as I've never heard of a DPST
bilge

Yup, I just realized that with a groan. There is no substitute for
sitting down and sketching out a schematic. Otherwise you end up
focusing on only part of the picture as you stand in the marine supply
store freaking out over how much it's going to cost you when the wife
sees the credit card statement.

If I weren't trying to keep battery drain parallel, I could just bring
the wires of the two pumps together at the switch which has enough
capacity for the amps. I'm using Rule's which (at least claim) to be
very tolerant of running dry. The pumps are only a foot apart anyway.

However, doing this with a pump on each battery would create a tie
between the systems which would become the main battery lead if I
turned the selector switch from both. FLASH BOOM!

So, I'll be calling the store first thing this morning and telling
them to send me another of those $40.00 switches. It's a good thing
our marina lets you stay aboard because that's where I'll probably be
sleeping this summer

--

Roger Long