This weekend the batteries died while on the mooring. I had it switched to #2 house leaving #1 starter unused. There was not enough juice in any or all of the batteries to spin the engine with the compression levers released. This is the first time it has happened. I thought the number 1 was separate but apparently not. How are the connections to the 3 way selector switch supposed to be connected?
3 way battery switch
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My guess is that unless you have a battery isolator, combiner, or similar device wired into your system, that one battery drew down the other as it discharged.
See the following for how to use and wire an isolator:
http://www.thejump.net/fishingarticles/Ship-Shape.htm
See the following for how to use and wire an isolator:
http://www.thejump.net/fishingarticles/Ship-Shape.htm
Why do you leave any battery turned on while not on board ?
If you do that for your Bilge pump you should have that wired through a 3 way switch directly to a battery... On/Off/Auto, leave it in auto when you leave the boat.
Must be a Draw some where.
Bee
If you do that for your Bilge pump you should have that wired through a 3 way switch directly to a battery... On/Off/Auto, leave it in auto when you leave the boat.
Must be a Draw some where.
Bee
Moorings are hard on boat batteries mainly because they are not recharged fully before storing the boat. A partially charged battery, left over time, will sulfate and loose its ability to hold charge. Most people know that to charge both batteries from the alternator the switch has to be positioned to "Both" but a lot of them forget to turn the switch. The normal method of wiring the switch is to take the positive battery leads coming from each battery and connect one to the Batt 1 post and the other to the Batt 2 post. No other wires should go to these switch posts. In a properly operating switch the combining of the battery (a) and (b) positive terminals should only be possible if the switch is manually placed in "Both"
Now you have exceptions of items that may be hard wired by-passing the switch. The most usual are a) a bilge pump and b) an inboard battery charger. A bilge pump can be hard wired just to one battery bank or it may be hard wired to both. In such a configuration a stuck float switch on a bilge pump can wear down both batteries irrespective of the position of the switch.
I would worry about the condition of the batteries first and their ability to hold charge and then concentrate on the cause for the discharge.
Now you have exceptions of items that may be hard wired by-passing the switch. The most usual are a) a bilge pump and b) an inboard battery charger. A bilge pump can be hard wired just to one battery bank or it may be hard wired to both. In such a configuration a stuck float switch on a bilge pump can wear down both batteries irrespective of the position of the switch.
I would worry about the condition of the batteries first and their ability to hold charge and then concentrate on the cause for the discharge.
KISS
Start here: http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101
You can also do a search right here on this Message Board using this exact phrase on "It All Depends on How it's Wired" which may find some more links for you to read and consider.
Start here: http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101
You can also do a search right here on this Message Board using this exact phrase on "It All Depends on How it's Wired" which may find some more links for you to read and consider.
I'm not judging you on how you left your boat. If it was "quite a while", Benny might be right and the starting battery simply went dead, but that might take months (think about how long you'd have to leave you car before the battery goes dead - yes, it will take less time if the battery is not fully charged, but not THAT much less)
But I'd guess either the switch is broken, or was not wired correctly in the first place. I found the switch in Coatue drew from Batt #1 no matter what position it was in, and it was wired correctly. Replaced the switch, all was well.
druid
But I'd guess either the switch is broken, or was not wired correctly in the first place. I found the switch in Coatue drew from Batt #1 no matter what position it was in, and it was wired correctly. Replaced the switch, all was well.
druid
There really isn't enough information here to say one way or another. If you have any equipment, like a bilge pump, wired directly to a battery, that could be a cause of the problem. Also, self-discharge is another possible cause of the issue.
What kind of batteries do you have?
How are they charged?
What is wired to them?
Do you have a combiner, echo charger, isolator or anything else connecting the #1 and #2 battery banks??
What kind of batteries do you have?
How are they charged?
What is wired to them?
Do you have a combiner, echo charger, isolator or anything else connecting the #1 and #2 battery banks??
to clarify the situation, we had motor sailed for about four hours. The batteries were fine. We were on a guest mooring for two nights. Refrigeration was running, some lights at night, nothing else. On the morning we wanted to leave the batteries were too low to crank the engine and we needed a jump start. The question was why did the battery switch draw off both batteries and not just the house battery as that was the position on the selector switch.
Most boats
Orion,
Most production boats come wired from the factory with a 1/2/ALL/OFF switch. The alternator is fed directly to the common post of the battery switch. When set up this way you need to select ALL when the motor is running in order to charge ALL banks. If you leave it on bank 1 bank 2 gets no charge. When you shut the engine off you then need to switch to the #1 bank or house bank so as not to discharge the start/emergency or #2 battery.
The better way to wire this is to have the alternator feed directly to the house bank and then use either a ACR (automatic charging relay) or an Echo Charge to feed the start bank. There is a lot of info on this subject on these forums.
My guess is that you never fully charged the start battery then killed the house bank to boot by running the refrigeration..
Orion,
Most production boats come wired from the factory with a 1/2/ALL/OFF switch. The alternator is fed directly to the common post of the battery switch. When set up this way you need to select ALL when the motor is running in order to charge ALL banks. If you leave it on bank 1 bank 2 gets no charge. When you shut the engine off you then need to switch to the #1 bank or house bank so as not to discharge the start/emergency or #2 battery.
The better way to wire this is to have the alternator feed directly to the house bank and then use either a ACR (automatic charging relay) or an Echo Charge to feed the start bank. There is a lot of info on this subject on these forums.
My guess is that you never fully charged the start battery then killed the house bank to boot by running the refrigeration..
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