Batteries and the fridge

[John Langford]

It would be interesting to know how many owners ever use their starting battery to start the engine. I always use my house batteries to start the engine and I can think of only one cold and snowy pacific northwest winter morning (Espar heater and frig going for many hours) in almost three decades when I felt the need to turn to "Both" to preheat and start the engine. Both the Perkins (in my previous 320) and the Universal engines start so easily after preheating that I think the house bank would have to be in pretty bad shape not to do the job.

All of this argues perhaps for adopting the Calder solution and foregoing a dedicated starting battery completely, especially if you have room in a storage locker for one of those compact emergency start packs.

[Craig Illman]

Ok - So what's the real difference between having a dedicated start battery and an "emergency starter pack". They're both batteries and have a finite life span. One is taking up space in a fixed location and one's portable. One could combine the design and stick the starting battery anywhere with a small charging circuit. As John suggests, use the house bank to start most of the time. Then, if ever needed, move the start battery close to the house bank and use a set of jumper cables to start your engine.

Craig

[Mike and Joanne Stimmler]

I am thinking of changing from my stock two 12 volt batteries to four 6 volt trojan golf cart batteries and I have read that they will fit into the same compartment under the dinette seat but can you use battery boxes and hold down straps or do you have to fasten and cover them some other way? What is the best location for the sepreate starting battery if I decide to go that way and can I still use the 1 2 b switch in the both possition since the're different battery types? How hard is the alternator upgrade?

Thanks,
Mike

[Stu Jackson]

Mike, peruse the Tech Notes, they have pictures, too.

[BillG]

Mike, I think you will be happy if you make the change to 4 six volt batteries and a separate starting battery.  I separated the 2 by using  the Balmar Duo Charger.  It doesn't make a difference if you use different types of batteries and I have a dedicated ON-OFF switch for the starting battery. My electrical upgrade was quite extensive and I can give you more details if you like.

[Craig Illman]

Mike - Check all the Projects on electrical upgrades as well. Peruse the C36 message board too. There is a great deal of information available to help you make the right choices to meet your needs. There's no single answer. It depends on how much money you want to spend. You might be able to get by with just a different regulator. The Jack Rabbit Marine site lists a new product from ProMariner that claims to "fool" a stock alternator into a better charging regimen. http://www.jackrabbitmarine.com/Detail.bok?no=2438

I have a Link20 shunt, a six position fuse block and a 150A breaker on the port side of my battery compartment. There wasn't room for normal battery boxes to secure the four T-105's. In the project pictures, you'll find various solutions to securing the batteries.

Craig

[Stu Jackson]

We use our start bank to start the engine some of the time when first leaving the dock or after being at anchor.  We also use the house bank to restart the engine after a daysail (simply because I'm sometimes lazy :) - but I will sometimes go below to change the 1-2-B switch over from house to start  (our alternator output goes directly to the house bank NOT through the switch, so we have no problems turning the switch with the engine running either).  That way we know every time we come on board that the start bank IS working.  

I have participated in the "start pack" discussions on this message board earlier and continue to believe that unless you have a great need for a start pack somewhere else in your life (i.e., second homes, RVs, etc.) it is preferable to have the built-in confidence in a properly wired and installed start bank, use it, and confirm its operation on a regular basis.

Edit: Jan. 2009 - I'm now in favor of calling the start bank the reserve or emergency bank.  The house bank is fine to start the engine.  The reserve bank should be just that: fully charged up, ready to go, but only need if the house bank dies.

Edit: Sept. 2009 - You should also remove the AO from the factory 1-2-B switch to the house bank and use another method to charge the reserve bank (switch, echo charger, combiner, etc.).

[jmnpe]

If you are going to have a dedicated starting battery, you should always at least start from it when leaving the dock. The best way to confirm that your starting battery is fully functional is to actually start your engine with it. Those who start with the battery switch in BOTH or from just the house bank will never know if that dedicated starting starting battery is ready to help them when they accidentally run everything else down or have a battery failure in their house bank.

My preferred  approach is to have a dedicated starting battery always connected to the engine starting circuit through a simple on/off ( normally ON ) battery switch, the alternator connected directly to the house bank, an electronic battery combiner/isolator AND mechanical on/off battery switch ( normally OFF ) connected between the house and start banks ( the electronic combiner takes care of starter bank charging when the engine is running ), and an on/off battery switch ( normally ON ) between the house bank and the house loads ( excluding the inverter if you have one ). This is a very "mindless" setup that requires no battery switch manipulations during all normal operations, but allows you to manually cross-connect the house and starting banks together if either bank should become unusable. This provides a simple, reliable configuration that many of my former cruising customers have put many sea miles on with no problems.

John

[Craig Illman]

I'm setup the same as John. After having it that way for almost two years now, there's nothing I'd change.

Craig

[David Sanner]

Here's another thread on battery location including a diagram of my setup.

http://c34.org/bbs/index.php?topic=3423.msg18905#msg18905

My setup keeps the starting battery separate from the house
with the alternator normally connected only to the starting battery.
(This works well for normal day sails as the house get shore charged)

It also allow me to join the banks or charge either independently.
To automate the setup I could add an echo charger but this setup
allows for a lot of control with minimal wiring changes.

I don't have my engine battery connected to my shore charger as
I didn't want it influenced by my fridge and house batteries circuit
with the constant cycling.  So in general the starting battery has absolutely
no load on it at the dock and gets topped off when I take the boat out.   
If I want to top it off all I have to do it put the battery selector on both.

I'm not sure if keeping the charger off the starting battery has any effect on
electrolysis  ... I believe one place where the engine (and shaft/prop) are
connected to the shore power ground is via the hot water heater.

-d

[Stu Jackson]

To continue and kinda "update" this thread, a search on "wiring diagram" will bring up some good followup reading on the subject.

[iwillmott]

When I use my ie2000 I hang it off a halyard ..takes all the vibration away and the boat doesn't turn inti a "drum"

[Ken Juul]

Neat idea. 

I bought one of those closed cell foam knee pads used for gardening to try and isolate the vibration.  Haven't tried it yet.

[C Martinson]

I'll put in my 2 cents.  I did some very rough calculations (using my high out put alternator) which showed I would need to run my engine TOO long for  my taste and wear and tear on the engine to keep my batteries charged to run the refrig and I couldn't comfortably use the microwave.  My current system has worked for the past few years- the fact that this has been WORKING is the real proof.....I use the Honda 2000 generator for hot water, my microwave and to recharge my batteries mostly for the refrig (Grunet electric refer).  This works great, I can keep the batteries charged to above 50% and monitor this with the link 10 system.  Also - I think very important....I installed the blue sea battery switch with the "isolator" which charges my starting battery and house bank of 2 batteries but also isolates them.  The isolatin without having to change the switch makes like less stressful for me.  It has off/on/combine so all I do is turn the switch to on and don't worry about it.....if I need to combine the house bank for starting I can switch it to combine.  No worries about running down my starting battery while sailing or at anchor.

I keep the generator in the cabin with an empty tank (be careful filling the generator tank -  it runs along time on a tank...I usually fill it 1/3 only so it runs dry before I put it away) and the gas cans in my dingy.  I need to turn off the eco switch for the microwave but otherwise it is very quiet!

One last thing - I also use a wireless thermometer (the "outside" sensor  in the refer) and the read out in the galley - this tells me things are working and helps guide me on non generator days or trips when to turn the refer on and off.

Chris

[waterdog]

This whole thread is highly outdated.   The real solution of course is to have 400W of solar panels on your bimini and 4 T105s!   I have this configuration with a dedicated start battery under the aft bunk, which I haven't wired yet, and a high output alternator with parallelling relay in the forward hanging locker uninstalled.   

I have the old AB refridgeration (not terribly efficient).   We run it cold enough so that the meat is always frozen and the ice cubes are always ready.   We run the microwave, flat screen TV, computers, cabin lights, shop vac, and anything else we care to all the time.   In two months, I've plugged in to shore power only twice and largely because we got tired of heating the kettle for dishes.   I haven't started the engine to charge the batteries. 

The biggest deficit I've seen is a 150 Ah on some high load / low output days.   

The only downside is a poor view of the sails standing at the wheel...