Power what while at anchor?

I have a new to me boat that is having power issues. We have gone out cruising for an afternoon and dropped anchor for a few (4-5) hours. I left all navigation systems on, not thinking, and then my engine wouldn't start without a jump...
My generator batter is separate (isolated?) so I could use that as a jump battery. I just replaced the generator battery on Saturday. Today I load tested the other 5 house bank batteries and all were good (I had the old generator battery tested too- I was told it was time to replace) I have an alternator and separate battery charger, so I wouldn't think a few hours at anchor would drain 5 batteries? What am I missing? I want to be able to spend several days at anchor (with occasional running of engine/ generator)
So what do you all leave on while at anchor? Nothing except what is being used? Only the refrigerator and radio? Do you constantly turn breakers on and off?

What do I leave on,

Fridge
Freezer
Wine cooler
Sat dome
Tv/stereo
Two computers
Various lights

But I have plenty of battery power to support my bad habits.

STD advice, get a copy of Nigel Calders, boat owners mechanical and electrical version 3.

Then, you need to do an inventory of your electrical loads and their associated amp and hourly amp hour demands. You really need to do this for your boat and your loads against your battery capacity. That will get you a start on the basic math. An anmeter that registers you boats loads as you turn them on/off is a huge help, but even without it one can generally do some inventory and math and come relatively close enough for planning purposes.

Immediately, you have a constraint to consider. Your house loads are not isolated from your start batteries. My design philosophy is that I am untrustworthy when relaxed and the system needs to be designed by me to protect mine own self from stupid moves or forgetfulness. I have a responsibility to those on board and not being able to start my engine at will constitutes an unacceptable danger. There is room for other philosophies, but this is mine.

You note you had the batteries load tested. I extrapolated this to mean that you took them to some kind of auto testing lace and they put a starting load on the battery and checked whether they could accept a charge. Such tests are better than nothing, but don’t really tell you the capacity of the battery from a deep cycle perspective. Especially for batteries that have been run flat, which is very hard on those batteries.

Personally, I have a 1200ah house bank which many people consider to be sizeable, also fully isolated from my starting batts. My best biggest loads are my fridge and freezer, with the fridge consuming 90ah/day when the weather is hot and it is opened frequently. On the same day I might use another 40ah for the freezer. With small loads here and there I would easily hit 200ah/day minimum. If I’m only out for a night, I’m pretty relaxed. If I’m going to be out for more than two nights, I hawkishly turn everything off that is not being used. Use whatever you need. Waste nothing.

Anyway, figure out the amp hour capacity of your batteries when new, take a sizable amount away from that number. Figure our your biggest loads and start doing the math. Only plan to use about 40% max of your calculated capacity. Personally I would not count your starting batts and find a way to isolate those critical batteries from the recreational house loads.

Apart from the dedicated genset start battery, are the other 5 all interconnected and serving as house and start? In other words, is there no dedicated start battery?
If that is affirmative,you still should not end up with insufficient in 5 batts to start the engine.
What size are the 5 batteries?
Are you sure they were all charged before you anchored?
My boat, like most IGs, lacks dedicated start batts,odd, but the system seems to work, for us and other owners.
Our backup is starting the genset and using the charger. I had to do it just once,right after we got the boat, soon realizing the batts needed attention. Using the genset should work to get you started.
Look at how much battery you have, and how much battery you are using. Add up your loads. If your batts can`t sustain 4-5 hours,accepting they are in good condition, and were actually charged,your demands on them are too great. You need less demand, or more battery,or both.
And look at your charging system(s),the adequacy/output of the alternator,and/or the dock charger, to ensure when you go out, you start with full batts.
Many boats have at least some solar power onboard,it`s a great asset.

You currently have the system I preferred for 20 years. A house bank for both starting and house use and a single isolated battery. In your case the isolated battery starts the generator.

Have to ask the question of how did five batteries (your house bank) go flat in five hours. When you speak of navigation systems did that include radar?

Suggestion, get a Kill-A-Watt meter and find out how much power your refrigeration is drawing. Even an inefficient domestic refrigeration system (110v big box refrigerator) should not draw more than 17-18 amps per hour. That should not flatten fully charged batteries in so short of time.

When anchoring almost EVERYTHING should be shut off with the exception of the bilge pump & alarm, the reefer , cabin lights at night , cooling fan in a cabin and FW pump.


Its the reefer that will probably kill the batts , so think upgrade when replacing it.

With five house batteries if you anchor out for five hours and you can't start your engine, something is wrong: the batteries are bad, your start battery is isolated and it is bad or ????


Either study your boat's electrical system and figure out what is wrong with the help of Calder's book or get a marine electrician to help you with it.


David

One question though, you have 5 batteries, but what type of batteries?

L

Crawdaddy said:

So what do you all leave on while at anchor? Nothing except what is being used? Only the refrigerator and radio? Do you constantly turn breakers on and off?

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We turn off most of our nav electronics... although I might use one or the other again overnight for anchor (location) and/or depth alarms.

But generally everything else -- plus the anchor light -- is on (2 fridges), or can be on when necessary (microwave, coffee maker) or when/if we choose (TV, stereo, interior lighting, etc.). Then we run the genset (to cook) at least twice/day (assuming we aren't running the ACs) and charge batteries and make hot water then.

For best insight, confirm some other info:
- the 5 "house" batteries are also your start batteries?
- those 5 batteries are all in one bank?
- how many engines?
- what brand, type, size batteries?
- how old?
- what's your battery charger?
- were your batteries actually charged when you set anchor?
- and so forth.

In the meantime, an easy tip: convert all your interior lighting and your anchor light to LED... if you haven't already... and that'll probably cut your power requirements for lighting by about 95%.

-Chris

Something is wrong.
Nav systems? Does this mean chart plotter, radar, depth sounder, VHF radios, laptop, etc? Even if the load was 10 amps DC, then the drain was 50 amp-hours.
Refrigeration? A single frig draws about 5 amps, so that is about 25 amp-hours. Add a separate freezer is another 25 amp-hours.
Misc cell phone chargers and cabin lights with filament bulbs? Add another 25 amp-hours.
So the total for 5 hours is 125 amp-hours. That is about the 50% SOC for a single 8D battery or a pair of 6V golf cart batteries.
You should have had no problem starting your engines from that point.

So my guess is that your batteries are a long way from "good" or you have mixed battery types in your bank leading to circulating currents within the bank and going dead prematurely. Or there is a bad connection issue in one or more cable connections.

PS Welcome aboard!!!

All good advice here. Just as a point of reference when we're at anchor with the refer, lights, radios, etc. on we draw about 9-10A during the day. At night with everything except the refer and anchor light off we draw an average of about 3-4A.


Ken

I agree, something is wrong. How do you know that the batts were fully charged? How old are they? Most load testers aren't worth much. If they are wet cells measure the specific gravity.
Many boats have battery chargers attached to the genny and shore power so charging dead start batteries can be easily done. A set of jumper cables are nice to have.

I shut down everything except the refrgerator. The cabin lights breaker is on so we can use cabin lights as needed. All my cabin lights are LED so they draw very little. We only turn the pressure water pump on when we need it. We let it pressurize the system then turn it off. All nav equipment and VHF radios go off as soon as the engine is shut down. I have two battery banks (a start battery and four house batteries) that are connected by an automatic charging relay (ACR), so once the engine is off and the sun goes down the two battery banks are isolated. When the sun is out my solar charges both banks via the ACR.

Alot of great advice and how old are the batteries is probably the best one.

One thing we do to conserve power is we freeze gallon milk jugs and place them in the fridge, we leave off the frig overnight with no issues and over time we use the jug of water for cooking or the dogs.

Every new to you boat requires a little time to sort out everything, what you are going through is normal, enjoy!

Welcome Crawdaddy.

Great advice so far. One thing that caught my eye was the idea that you could anchor out for several days and only run the genset “occasionally”.

I have a decent sized battery bank of new batteries. I still run the genset for a couple hours in the morning and then again at night to keep the batteries charged.

Are wind turbines not something trawler owners use? I've never had one on any of my sailboats (the only kind of boat I've ever owned), but they're common on cruising sailboats in conjunction with solar, especially since they can take advantage of wind at night and during periods of overcast skies. Storms, even.



Just wondering is all.

A lot of good ideas here. For me the biggest improvement was getting a handle on my power usage. It turned out that some additions I had made over the winter was consuming about a 1/3 of my usable capacity. I had added some USB outlets to the boat to power my toys. This caused my inverter to stay on 24 hours a day drawing around 3 amps out of the battery bank (72 amp-hours). I never considered the effect of drawing 0.3 amps from the 120VAC system would have on the bank. Now when we are at anchor I keep the inverter off unless we need it.

Why do you need your inverter to power a USB outlet?

L

Lou_tribal said:

Why do you need your inverter to power a USB outlet?

L

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What I installed was 120VAC to USB adapters. No wiring required. At the time it just seemed so easy to plug the adapters into existing outlets.

TomandJeri said:

Are wind turbines not something trawler owners use? I've never had one on any of my sailboats (the only kind of boat I've ever owned), but they're common on cruising sailboats in conjunction with solar, especially since they can take advantage of wind at night and during periods of overcast skies. Storms, even.

Just wondering is all.

Click to expand...

For fair weather cruising I don’t think they make too much sense, because underway the alternator is doing the work and we anchor as protected from the wind as possible.

In winter the winds around here would probably be strong enough, even in anchorages, for it to “sometimes” help with charging.

TomandJeri said:

Are wind turbines not something trawler owners use? I've never had one on any of my sailboats (the only kind of boat I've ever owned), but they're common on cruising sailboats in conjunction with solar, especially since they can take advantage of wind at night and during periods of overcast skies. Storms, even.



Just wondering is all.

Click to expand...

Wind turbines can be great when you are in an area that has consistent wind. I've never boated in such an area. Few powerboats use a turbine though even in those areas. I think it would make sense if you have a good place where it could be mounted and you were in an area that had consistent favorable breezes at night.

FF said:

When anchoring almost EVERYTHING should be shut off with the exception of the bilge pump & alarm, the reefer , cabin lights at night , cooling fan in a cabin and FW pump.


Its the reefer that will probably kill the batts , so think upgrade when replacing it.

Click to expand...

Only if your system isn't up to the job.

The only thing we ever shut off is the 240v domestic hot water system
Everything else stays on 24/7

NWSeadog said:

What I installed was 120VAC to USB adapters. No wiring required. At the time it just seemed so easy to plug the adapters into existing outlets.

Click to expand...

I was bamboozled by the drawdown of my house batteries thinking I had only the fridge on. I discovered that the 2800 w inverter was powered up and inverting because I had one usb charger plugged into a cell phone. The “idle” current draw of the inverter is very low, but at low power output the efficiency is very low, and hence 12 volt draw a lot higher than you expect. Use 12 v USB adapters, and turn the inverter off to conserve battery.

Island Cessna said:

I was bamboozled by the drawdown of my house batteries thinking I had only the fridge on. I discovered that the 2800 w inverter was powered up and inverting because I had one usb charger plugged into a cell phone. The “idle” current draw of the inverter is very low, but at low power output the efficiency is very low, and hence 12 volt draw a lot higher than you expect. Use 12 v USB adapters, and turn the inverter off to conserve battery.

Click to expand...

Very true. I’ve started to turn off the inverter when I don’t need it. If I don’t, there are always ways that folks on the boat will find to have a constant drain on the battery. Unfortunately, I need the inverter at night to run my wife’s CPAP. Someday I’ll see about a 12v option for that.

TomandJeri said:

Are wind turbines not something trawler owners use? I've never had one on any of my sailboats (the only kind of boat I've ever owned), but they're common on cruising sailboats in conjunction with solar, especially since they can take advantage of wind at night and during periods of overcast skies. Storms, even.



Just wondering is all.

Click to expand...

This is why.....

Thanks for the replies; I obviously need to learn the systems and getting the manual that a few people have suggested will be a start. As well as figuring out what is drawing and how much. I attached pics of the current set up, including the charger and alternator. If anyone wants to see the actual set up. The house /starting battery is a Deka DP31DT Battery 31 875ca 205m@23a 100ah... the batteries were replaced in 2014. The batteries must not have been charged, and now I have to figure out why. We are on shore power, so as you can see the charger is on and it reads 'charged'. We are plugged in all the time currently except when out for 8-9 hours of which is only 4-5 hours anchored. I did remove all terminal fittings, checked them and reattached yesterday. I also found out the refrigerator terminals to the condenser were loose, so it wasn't working at all. And the list keeps going... thanks again for the replies.
Jason

Oh yeah- someone asked what was on:
Depth x2, radiox2, radar x2, chart plotter x2, autopilot and refrigerator (not sure it was actually on as loose terminals and was intermittent), anchor windlass.
I had the electronics on on both upper and lower helms. I do turn off hot water, freezer, fresh water pump at breaker, but do leave all other breakers on, but no need for lights in day. Does that still draw if wall switch is off?

I will risk my 2 cents, even if it has nothing to see with your issue.
I would advise you to check all of your battery/alternator crimped connectors, clean them if needed (I can see that some look like a bit corroded on batteries), and protect the crimp using liquid tape and / or heat shrink and / or electric tape.
I can see that used cables are not tinned copper so I would even more recommend you to protect the crimp so cable itself will not start to corrode especially if you are in salt water.

L

My starting batteries are for starting only. There is a 12v house bank for nav lights and electronics that is kept separate. My inverter banks are 48V. There is an emergency battery for radios and other electronics that is separate from the 12v house bank. You need at least one battery that will always be separate and fully charged for starting. I was a commercial fisherman, and when fishing tuna, shut down and drifted at night. There was no one to call if I couldn't start. Now I usually anchor in remote places. I'd hate to pay the bill of a tow service if I couldn't start.

As the boat is "new to you" you can`t know how the batts were treated, so a good check of condition is indicated. They are all connected so one bad one affects all. Wonder if the fridge with its loose connections was constantly making start up power demands for 5 hours, that would draw.
Charger says "full" but that might be for those batts in their condition,whatever that may be. Can you get any more info out of the charger readouts? Battery voltage?
The charger may not working well either,I`ve read some very negative comments on TF about Xantrex,it could be worth checking output.

You had things on I would not while anchored for lunch in a (presumably) quiet secure location. I don`t think leaving the breaker on for equipment not in use would make demands.

You say you had the hot water off, if it is fed via an inverter, wonder if it was powering something else. Usually hot water is heated by a loop from the engine,or by mains type electricity.
It might be worth getting an electrician onboard to take a look.