House Batt?

[Welti]

I went out on my Cal-25-2 yesterday and though the engine (outboard) started up fine, no power to anything else on the boat. No radio and no autopilot. The boat was not used for around 6 or 7 weeks but I did check and it was plugged in to shore power. I have AGM batts that at least are not ancient. Not sure exactly how old they are, but never had any issues before. Where should I check first? I do have and know how to use a voltmeter etc. How to proceed?

[danstanford]

Happened to me and it was that the breaker on the dock pylon had tripped. Everything else was proper but no juice flowing.

[Tin Tin]

Plug in to shore power, put your voltmeter on the battery terminals and see what you get. Your batteries may be so undercharged that an automatic battery charger will not revive them - then that is another exercise.

[Kettlewell]

Most batteries in decent shape should last 6-7 weeks without any charging, but you may have something drawing power on the boat. One time a bilge pump float switch did in my batteries over the winter. The switch stuck in the on position and flattened the batteries. I would first check the voltage at your battery posts to see where you are. If the voltage is under 12 you probably need to replace them. If the voltage at the batteries is OK I would suspect corrosion and/or loose connections somewhere between the battery, battery switch, breakers, and loads.

[TrentePieds]

And if you have to change them, get proper "flooded" batteries rather than AGMs. If ever you heel enuff to spill electrolyte from flooded L/A batteries, you'll have bigger problems than just electrical ones :-)

With flooded batts you can "dip" them with a hydrometer and get a REAL indication of their State of Charge and of their general health.

All circuits but the bilge pump should be off when you leave the boat for any length of time. If the BP comes on often enuff to drain your batts, you'd better find out where the water is coming from :-)

And to repeat what others have said or implied: Check your "umbilical" twixt the power outlet on the dock and the 120V connection for it on your boat. Then check the circuits twixt the 120V inlet and your battery charger.

TrentePieds

[S/V Illusion]

Originally Posted by Welti

I do have and know how to use a voltmeter etc. How to proceed?

Given your first question, my advice is find someone who knows how.

[Pete7]

Originally Posted by S/V Illusion

Given your first question, my advice is find someone who knows how.

Close, find someone who knows to show you how. We all started somewhere and being able to use a multimeter pretty essential on a yacht. Otherwise just read the instructions carefully and go for it.

Take the voltage of the battery terminals first before turning anything else on or charging anything. That reading will be quite telling as to the state of the batteries and their charge level. Post it on here and we will give you the verdict good or bad.

Pete

[Welti]

Good advice. There WAS a small heater that I normally leave on, prolly only 100 watss or something. I'm not sure if it was running when I got to the boat this time, could be that the shore power was off for a long time. I wonder why the house batt was affected but the outboard motor batt was fine. Hard to say I guess, depends on how it was wired. Fortunately the guy who did it has his boat a couple slips down from mine, so I guess I should just ask him, next time I see him.

[Be Free]

Originally Posted by Welti

I went out on my Cal-25-2 yesterday and though the engine (outboard) started up fine, no power to anything else on the boat. No radio and no autopilot. The boat was not used for around 6 or 7 weeks but I did check and it was plugged in to shore power. I have AGM batts that at least are not ancient. Not sure exactly how old they are, but never had any issues before. Where should I check first? I do have and know how to use a voltmeter etc. How to proceed?

As I understand it, you have at least two batteries, your outboard started fine, but nothing else had power. That tells me that either your house battery is dead or the house battery is not connected to the house circuit.



The first step should be to identify your house battery and how it is connected to the house bank. For the most part you can ignore your start battery since we know it was charged and working.



Once you have identified your house battery, verify that it is charged. If it is not charged then you have found the cause of your problem and identified a new one (house battery is not charging).

If the house battery is charged then you are looking for something that would affect everything on the house circuit. Prime suspects are cabling between the house battery and the bus/fuse/breaker panel.



Remember that cabling problems can be on the positive, negative, or both. Look for loose or corroded connections.



Don't assume that switches are on, fuses are not blown, or breakers are not tripped until you have verified that they are working.

[Welti]

Originally Posted by TrentePieds

And if you have to change them, get proper

All circuits but the bilge pump should be off when you leave the boat for any length of time. If the BP comes on often enuff to drain your batts, you'd better find out where the water is coming from :-)

TrentePieds

I DO have one of those small heaters, designed to prevent condensation. it is maybe 100 watts. i normally leave it on in the "winter" (I live in Socal so "winter"!).

[Welti]

I will check that. i don't think it is the connection from house batt to the rest of the boat. I mean, I have not changed anything in the wiring or done anything out of the ordinary and it has been working fine for a year and a half. My best bet it shor power was off. I wonder if maybe my slip-neighbor maybe tripped a common main breaker at some point and interupted my power for a significant time.

Originally Posted by Be Free

As I understand it, you have at least two batteries, your outboard started fine, but nothing else had power. That tells me that either your house battery is dead or the house battery is not connected to the house circuit.



The first step should be to identify your house battery and how it is connected to the house bank. For the most part you can ignore your start battery since we know it was charged and working.



Once you have identified your house battery, verify that it is charged. If it is not charged then you have found the cause of your problem and identified a new one (house battery is not charging).

If the house battery is charged then you are looking for something that would affect everything on the house circuit. Prime suspects are cabling between the house battery and the bus/fuse/breaker panel.



Remember that cabling problems can be on the positive, negative, or both. Look for loose or corroded connections.



Don't assume that switches are on, fuses are not blown, or breakers are not tripped until you have verified that they are working.

[GordMay]

Originally Posted by Kettlewell

Most batteries in decent shape should last 6-7 weeks without any charging, but you may have something drawing power on the boat...

Self-discharge rates can vary considerably for different battery chemistries.
➥ https://www.batterypowertips.com/why...-in-batteries/

[Welti]

I found the issue. A GFI had tripped for some reason. There is one between the shorre connection and the battery manager. I just had to squeeze In there to get access to it.