[inunneley]

Two weeks ago I went to my '89 Catalina 30 to take it out, and realized I forgot to plug in the shore power from the week before. Both house batteries were completely dead, but my designated starter batter started the engine fine. I motored for about 30 minutes before putting the sails up. Still not enough power from the house batteries to even run VHF or any electronics at all. After sailing I motored 30 more minutes back to the marina and still seemed not to have any charge in the house batteries. How much time should it take for the alternator to charge the house batteries to get electronics up and running? I plugged into shore power, went back this last week and all batteries were charged fine.

 

[Capt Len]

What does the ammeter read when running? How does the start battery get it's charge.?Sounds like at least one of your alternators (or regs) is not up to snuff. Or maybe the 1/2/0 switch was 0.

 

[jsaronson]

While the engine was running you should have been able to power everything off the alternator. If not, it is bad. What did you have running that both batteries were dead? A bilge pump should not drain 2 batteries in 2 weeks.

 

[eherlihy]

I agree with jsaronson, while the engine is running, there should be plenty of amps and volts to run most (if not all) of your electronics. 30 minutes is not enough to fully charge a battery, but it should be enough time to get some charge in the battery, and you should see >11.5V. With the engine is running you should see 14.4 volts on your volt meter.

If not, your charging system is not doing its job. Check the belt, look for loose or corroded connections, check the alternator field wire (not on all alternators), and also check the key switch (which sometimes provides voltage to the field wire).

 

[capta]

It sounds to me as if your alternator charges only your engine start battery. If this is not how it is supposed to be, then you have a problem in your charging system. If your battery switch separates the two banks, then this might be the problem, but if the house bank is dead it would not be good to switch to both as this will deplete your starting battery. Perhaps it is time to redesign your alternator charging system.

 

[MarkSF]

I'm also a bit suspicious about the state of your house batteries now. Yes they charged up, but will they hold the charge? Discharging them so deep usually doesn't do them any good, and the question is why they went so flat with just the bilge pump load.

I see new batteries in your future.....

 

[Don L]

How big are your house batteries and alternator? If a stock type 60 amp alternator that you ran 1 hour you may have gotten 50AH charge into the batteries if you ran the engine at a fairly high speed. So not much charge into a "dead" bank.

 

[Flint]

30 minutes x 2 would not be long enough to recharge your cells. As another member said, there may be another issue if your electronics did not power up while you were under engine power.

Two things to note though: A slow long charge will improve capacity. Depending on the age of your batteries, being run to complete discharge can cause damage and shorten the life of the battery.

regards
dg

 

[inunneley]

Thanks for all the replies. I was not able to run any electronics while the engine was running. I have only had the boat for a short amount of time, and have only day sailed, but I assumed the alternator would charge all the batteries. When I get down to the boat this weekend I'll have to take a closer look and figure out whats going on.

 

[MarkSF]

Question : does the boat have a switch marked "1-2-both-off" anywhere?

If so, are you familiar with its use? The traditional way of wiring it is that the alternator only charges the selected batteries. Eg 1 for start, 2 for house, both for everything. (or the reverse, depends on how it was wired). I marked mine S and H.

Its a good idea to avoid "both" as it links both banks together and you can discharge your good start battery into the dead house batteries.

 

[inunneley]

It has an switch that has the options "off" "DC" and "Both" on the electronics panel. I only use the DC selection. I assumed the Both selection draws power from the starting battery, and I don't want to do that.

 

[inunneley]

Question : does the boat have a switch marked "1-2-both-off" anywhere?

If so, are you familiar with its use? The traditional way of wiring it is that the alternator only charges the selected batteries. Eg 1 for start, 2 for house, both for everything. (or the reverse, depends on how it was wired). I marked mine S and H.

Its a good idea to avoid "both" as it links both banks together and you can discharge your good start battery into the dead house batteries.

So I can start the engine when "off" is selected on that switch. I've never used it while selecting "both".

 

[eherlihy]

Thanks for all the replies. I was not able to run any electronics while the engine was running. I have only had the boat for a short amount of time, and have only day sailed, but I assumed the alternator would charge all the batteries. When I get down to the boat this weekend I'll have to take a closer look and figure out whats going on.

Your assumption is probably incorrect. Most boat manufacturers install the OFF / 1 / 1+2 / 2 switch so that it simply selects the battery bank that will be used. If this is the case on your boat (and I'll bet it is) and you started the boat on bank 2, and ran the engine on bank 2, then ONLY bank 2 will be recharged. You would need to start the boat on bank 2, then switch to bank 1 WITHOUT SWITCHING TO OFF, in order to charge bank 1.

There are devices like an ACR or EchoCharge which will allow you to run on 1 bank, yet charge the other bank. Based on what you have written, I would be surprised if you have one.

No offense, but a pet peeve of mine has been with boat owners that do not have a basic understanding, AND a schematic of their primary electrical system. I have spent hours trying to figure out what all the switches and wires do, because the owner had no clue. Don't be that guy.

 

[inunneley]

Your assumption is probably incorrect. Most boat manufacturers install the OFF / 1 / 1+2 / 2 switch so that it simply selects the battery bank that will be used. If this is the case on your boat (and I'll bet it is) and you started the boat on bank 2, and ran the engine on bank 2, then ONLY bank 2 will be recharged. You would need to start the boat on bank 2, then switch to bank 1 WITHOUT SWITCHING TO OFF, in order to charge bank 1.

There are devices like an ACR or EchoCharge which will allow you to run on 1 bank, yet charge all banks, but based on what you have written, I would be surprised if you have one.

No offense, but a pet peeve of mine has been with boat owners that do not have either a basic understanding, AND a schematic of their primary electrical system. I have spent hours trying to figure out what all the switches and wires do, because the owner had no clue. Don't be that guy.

I definitely start the engine when the battery selector is on "OFF". I do that every time I sail. With that being said, what you're saying is with the selector on "off" no batteries are being charged, and if it's on "both", both batteries are being charged?

 

[eherlihy]

 

[inunneley]

Did you not understand my question? I thought it was clear. I'm trying to figure out how the switch works.

 

[MarkSF]

My explanation (and eherlihy's) is how a 1-2-both-off switch shoud work. You haven't got one, you have this off-DC-both switch. I have no idea what that is doing. You are best off asking someone with a Catalina 30 themselves. Find the Catalina forum on the web. It is very active.

Even if you find out how it should work, that is not a great guide to how it does work, given people's propensity to "improve" things.

 

[JimsCAL]

While I am not clear on how your OFF-DC-BOTH switch works, I would be concerned that since you have been running the engine with the switch in OFF, there's a chance you have fried the diodes in the alternator. The alternator must be always connected to a battery when running. That could explain why the nothing runs even after 30 minutes of engine operation. You need a voltmeter to check to see what the alternator is doing.

 

[GeorgeB]

Interesting questions. Sorry I didn’t see this thread a bit sooner. First a couple of background items. Unless your Catalina 30 has undergone a major electrical system upgrade, you most likely have the “factory” 40 Amp, internally regulated “Motorola” alternator. You may charge at close to 40 Amps initially, but then the alternator will quickly switch (through a series of diodes) down to a “float” level (somewhere around 5 Amps). You would need to run your engine all day to bring back a battery from the dead using this alternator. Second, electronics are pretty sensitive to volts and will begin to cut out when your battery drops below 10-11 volts (depending upon the instrument). Fortunately, motors aren’t very sensitive and you can crank a starting motor at a much lower voltage. (Trust me… personal experience. Buy me a beer and I’ll tell you a funny story.) Batteries don’t like to be discharged past 50%. The deeper the discharge, the less amps it will hold in the future and the faster the battery will discharge from its 100% state. If you have an “equalizing” function on your charger, I would use that function at your earliest convenience.

Now for the important stuff. You really need to spend a weekend and trace your wiring. What you have described is not a “stock” wiring configuration for your boat. If you can start your boat with the battery selector switch in the “off” position, then your charging circuit (and starting battery) are isolated from the house bank. There should be a battery combiner or echo charger relay connecting the two systems. Look for it and report back. (while you are at it, check for an “external regulator” too) Either one should be switching current to the house bank during the charge cycle. You might want to confirm this with your multi-meter to make sure this is working. A good idea for the future is to make a schematic (or wiring diagram) of you system’s “as is” state. This will help you in the future to trouble shoot problems and aid you if you decide to do future electrical upgrades.

 

[socal c25]

Well said GeorgeB, My Catalina 30 was wired correctly and I did the engine to panel upgrade too. The battery selector switch is usually a BIG red round switch that is marked "OFF" "1" "2" and "BOTH" you can switch between 1 and 2 and both BUT DO NOT GO TO OFF it will fry your alternator if it isn't already. My starting battery was 1 and house was 2 then I had another switch for a second and third house battery. Good Luck