Question about connection of 2 way batt switch

[Timmay]

Hi everyone,
I went to install a new fuse panel today and was going to turn off the power via the 2 way batt switch but it did not turn off the power to the stock fuse panel. It seems the only thing it is connected to is the OB. With the switch off, the outboard would not trim. I also switched it to batt 1 and batt 2 but the lights in the cabin stayed on.
Is this the correct way a 2 way switch should be connected or should it kill all the power on the boat when switched to "off"? Thanks in advance. Timmay!!!

[Duane Dunn, Allegro]

Sounds like the dealer or owner who installed the switch really didn't know what they were doing. A Off|1|2|Both switch is not something the factory installs.

There are a number of ways to install batteries and switches, the big red multi position switch is the old school way of setting things up.

With one, battery 1 positive goes to input terminal 1 on the switch, battery 2 positive goes to input terminal 2 on the switch, and all load positives (or switch panel positive inputs) go to the common positive output on the switch. The negative grounds from both batteries, then motor, and all loads goes to a single common point.

Use is as described in the link below:

Most single engine boats built in the last 40 years are equipped with two nearly identical (and undersized) marine batteries, used interchangeably for starting or house loads. Prior to starting the engine, the operator would turn the OFF–1–2–BOTH battery switch to the BOTH position to have both batteries’ full cranking power. With the engine now running, the switch would stay in the BOTH setting, and both batteries would be charged while powering to the day’s destination.

Once the engine was turned off (while anchored or under sail) the operator would (in theory) return the switch to the 1 or 2 position, and reserve a battery for starting. When it was time to crank the engine again, the battery switch would be turned to BOTH, or possibly to the reserve battery, and the engine would be started.

While it works, it is subject to user error that can result in both batteries going dead if you forget and leave it on both, as well as can result in blown alternator diodes if you switch it at the wrong time while the engine is running.

The much better way is shown here using a series of single switches (or the new all in one multi switches that combine the 3 switches shown below into a simple single switch) along with a combiner.



Read the details here
http://www.westmarine.com/webapp/wcs/st ... Relays.htm

This kit gives you the main parts required in the new single switch form.

http://www.westmarine.com/webapp/wcs/st ... sNum=12106

[Timmay]

Thanks Duane, it looks like the person who installed it just connected it to the motor and left the factory switch panel connected to the battery. It's not problem, I will fix it while I am doing the wiring for the new devices. Happy sailing! Timmay!!!

[Kelly Hanson East]

As an aside, the concept of starting and house batteries should not be followed on a Mac, as a rule. If you want two batteries make them identical and of the deep cycle variety (choose the technology to suit your pocketbook)

This has been discussed in several threads on this board.

[The Mutt]

You will need to look at charging your batteries as well, we have a VSR ( Voltage Sensitive Relay) in circuit, the outboard positive and negative connect directly to the start battery, no lights, etc are connect to our start battery, positive and negative leads connect to the VSR, the positive and negative of the additional battery connects to the VSR, when the start battery reaches 13.2 volts of charge the VSR allows the additional battery to charge, when the charging ceases the VSR swithes off disconnecting the link between the batteries. Charging from solar panels, Shore power etc are easily added by connecting directly to the start battery circuit, the VSR automatically includes the additional battery when required, I have the same setup in our Range Rover, works like a charm, the start battery is alway ready to turn over the outboard, the additional batteries (2 X 6V deep cycle batteries 225 Amp/hr) keep the engel fridge freeze cold, the lights bright and music playing.

Glenn

[The Mutt]

I forgot to mention, the big red battey switches are great until you forget to switch them over and both batteries drain, I keep a single lead handy to connect the batteries positives together if I ever get a flat start battery.

Glenn

[rockman]

I think the need for two batteries to start the engine is "old school diesel". The modern batteries that all the current 2 and 4 stroke engines that are fitted to the average mac, should only need one charged battery to get them started.

With modern technology, you can setup a system that does all the switching and charging work for you. Its better to design a system that does not rely on a user switching things over. There is less chance of stuffing things up by forgetting to switch over the battery if its all done automatically.
If you search these forums you will find some great examples of this type of technology.

[Duane Dunn, Allegro]

No searching necessary, just get the kit I referenced above and here, it reduces what used to be three single switches in the "Alternative to the big red switch" method to one switch that you just turn on and leave on. It includes the combiner that joins the two batteries together when the voltage is high enough to indicate a charging source is present. The charging source can be your motor, a shore power charger, or any other source such as a solar panel, wind generator, etc. It eliminates any chance for operator error and let's you enjoy boating.

It's also very simple to wire. While the switch in the picture below is red,
it is not the old school "Off|1|Both|2" big red switch.
It is the latest single switch and combiner approach.


In the "Off" position all loads are disconnected from the batteries. Moving the switch to the "On" position does two things. It joins the house loads to the house battery (lower left), and it joins the engine to the starting battery (lower right). This is the normal operating mode, both banks are separate. When a charging source on either side of these two separate systems raises the voltage the combiner (bottom center) joins the two battery banks so they both can charge at the same time. As soon as the voltage drops indicating the absence of a charge source, the combiner separates the battery banks again so you cannot drain the starting side with excessive use on the house side. The switch also has a third position "Combine" for use if the batteries on the starting side go flat. When you switch to the "Combine" position the motor can now draw power from the house side as well to hopefully get the motor started.

I used to be a proponent of the single bank approach for our small and simple boats. For years I had my two batteries connected in parallel as single large bank with a efficient e-meter to monitor use and a portable backup jumper battery as a backup. This worked great and I never had a problem. I felt the then three switch method shown in the diagram I posted was overly complex for our small boats.

When I added my larger motor I installed a dedicated starting battery at the recommendation of BWY as they have found that the large bank of 6v golf cart batteries I installed to a few years back wasn't that good for starting. Personally I don't see the logic to back this up, but I went ahead anyway. Even the largest motors we install on our boats can be started by almost anything in my opinion. At the time I put in the starting battery I also went to the single new generation "Three in one" switch and a ACR combiner as shown above. This is such a simple fool proof system it's hard to argue with it.

[The Mutt]

Duane, What you call an automatic charging relay (ACR) we call a Voltage Sensitive Relay (VSR), Must be an American/Australian thing, I've set up the same system as you twice, once in the and again in the Range Rover, the only thing I left out is the combining switch, I've found before, if there's a switch someone will play with it, I had that situation recently when a diesel mechanic fiddled with all the switches he didn't know about on the dash, he disabled the engine, switched on an emergency air pump, switched on some high power work lights (don't know how they didn't see them on) and flattened the starter battery, I was told it was flat when I drove the vehicle to them, when I arrived they had the battery on charge wondering why I was still flat, power draw was almost twice what the charger was putting out.

Before someone askes the question ... all switches are clearly marked, all the added wiring on the vehicle and on the are clearly marked with tags and covered with clear heat shrink.

Glenn

[Kelly Hanson East]

Ill argue to keep it simple.

You spend a lot of coin (500 USD??) to get a setup that is immune to forgetting to move the switch, but you add a lot of complexity and heavy gauge wire.

Given that with anything less than a 60 HP motor, the pain of flat batteries is a 5 minute pull start, this does seem to me a case of Better being the enemy of good enough.

...the alternate view...

[Duane Dunn, Allegro]

The kit is only $157 plus a few cables. It can be installed for under $200. The wiring with the single multifunction switch is simpler than the previous 3 switch installation. I always felt the key to my single bank "Simple" system was the amp hour meter which cost just over $200 as well. (Note: a cheaper voltmeter is of no use for measuring the power left in your batteries when you are actively using the boat. It is only accurate after the batteries have sat un-used for 24 hours.) My approach was that with the meter you were able to head off a problem before you would get to a dead battery situation.

Now I actually have both, a fool proof switching system and the amp hour meter so I can re-assure myself that I don;t have the problem the switch and combiner is protecting me from. I even still have the portable jump starter on board for backup to the emergency that should never happen.

Mutt,

I'm sure they are the same thing, this is mine

[Timmay]

Thanks for all the great info. I definately have a fear of running out of battery on the water. I have a Yami 50 and there is no pull start, and I hear they are hard as heck to push start.
I definately like the "non manual switching" idea. How reliable are they? How long do they normally last?
Timmay!!!

[Kelly Hanson East]

Are you sure the yammy doest pull start? My Merc has a pull start under the engine cover

[The Mutt]

Our Force 40 has a pull start on the top pully under the cover, same as the old lawn mowers.

Glenn

[Russ]

I definately like the "non manual switching" idea. How reliable are they? How long do they normally last?
Timmay!!!

I have the same one as Duane (pic below). It's very simple, solid state and I expect it to last as long as the boat.


RE: Pull starts. Our Suzi 70 has an emergency pull start under the hood. It came with a rope in the parts box. I've never tried it and probably should just to see if it's doable. I wouldn't expect it to be easy.


--Russ