Amp Hour reading in the mornings....

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jefndeb

Guru
Joined
Jun 11, 2018
Messages
621
Location
US
Vessel Name
Indigo Star
Vessel Make
2006 Mainship 400
Hello,

We headed north one month ago in our 2006 Mainship 40 (Savannah to Chesapeake Virginia so far) and we have anchored out as many times as was possible. Looking at our electrical budget and our 440AH AGM House battery bank, and although this will be different for each boat, I was just wondering if an overnight AH reading of from 75 to 100Ah, as shown on the Victron web portal, is what to expect with the fridge/freezer on, anchor Light, maybe a small .5 amp DC fan going and that's about it...

This is a historical record of about 30 days, some at anchor some not....but its easy to see the ones at anchor....:thumb:

Jeff
M/V Indigo Star
 

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That seems about right from what you have operating. I generally do around 140-150 overnight but I am running a refrigerator and separate freezer, chart plotter, NMEA 2000 network, VHF radio, Sirius Radio, and anchor light. When both the refrigerator and freezer are off, I draw about 6 amps.

Tom
 
Hello,



We headed north one month ago in our 2006 Mainship 40 (Savannah to Chesapeake Virginia so far) and we have anchored out as many times as was possible. Looking at our electrical budget and our 440AH AGM House battery bank, and although this will be different for each boat, I was just wondering if an overnight AH reading of from 75 to 100Ah, as shown on the Victron web portal, is what to expect with the fridge/freezer on, anchor Light, maybe a small .5 amp DC fan going and that's about it...



This is a historical record of about 30 days, some at anchor some not....but its easy to see the ones at anchor....:thumb:



Jeff

M/V Indigo Star



Your fridge/freezer will be the biggest user of Ah. Consumption will depend on the on/off cycle which will largely be driven by the ambient temperature.
Your consumption is similar to my experience - about 40Ah over night at 24v. 80Ah equivalent at 12v.
 
Anchor light probably second highest user, if you have not swtched it to LED (after which it's insignificant).

Sent from my SAMSUNG-SM-G891A using Trawler Forum mobile app
 
Looks about right to me as well. I have a smaller fridge, no fan and led anchor light so I use as little as 50 Ahrs overnight.

David
 
That’s right in line with what we use. Fridge o-night, a few lights here and there, some music, and running the inverter / electric coffee pot in the am we have used 75 to 100 amp hours when I start the generator after 9 am. We have 4 Trojan T 105’s. In theory 450 amp hours with 200 usable. All lights are LED.
 
That seems about right from what you have operating. I generally do around 140-150 overnight but I am running a refrigerator and separate freezer, chart plotter, NMEA 2000 network, VHF radio, Sirius Radio, and anchor light. When both the refrigerator and freezer are off, I draw about 6 amps.

Tom

Why do you leave the chart plotter, NMEA 2000 network, VHF radio and Sirius Radio on while asleep?
 
We use about 50 to 80 amp hours overnight at anchor.

One DC frig and one AC freezer are the only things running regularly amounting to about 50 amps. The electric blanket, if used, uses around 20 to 30 amp hours per night.

We have never had the anchor light on since we anchor in designated anchoring areas or in remote anchorages away from any traffic. We avoid contributing to the light pollution at anchorages.
 
syjos, is your electric blanket ac running off of the inverter or dc? Thanks
 
syjos, is your electric blanket ac running off of the inverter or dc? Thanks


It's a standard 120 VAC home electric blanket running off the Victron Multiplus true sine wave inverter/charger.

We've learned over the years that digitally controlled electric blankets will only work with pure sine.

I am a Victron dealer.
 
Syjos

My wife listens to trucker radio for Coast to Coast through ear buds, the VHF for emergencies like a tsunami warning last year, and chart plotter in case we have to move in a hurry due an anchor dragging in the wind that wasn’t forecast. The chart plotter has a “sleep mode” that turns the screen off. The power draw on all three is about 4 amps.

Tom
 
Why do you leave the chart plotter, NMEA 2000 network, VHF radio and Sirius Radio on while asleep?


This is an interesting question and I see Tom has replied to it for you.

I was also trained to have a vessel in ready mode at anchor by a captain with 35 years of experience operating large vessels for private companies around the globe.
He had a very disciplined routine before turning in that he passed on to us. The predeparture engine room checks were done in the evening, the rudder was centered, the windlass and all nav and com equipment were left on in ready mode. This left the vessel in a position to respond quickly to an emergency during the night with a turn of the key on the mains.

I can see both sides. Saving power and preserving the bank make sense. But, where power supply is adequate, I like the security of being instantly ready without booting up in the case of an emergency should one arise and one can imagine a few potential emergencies when anchored in a range of ports around the world. It seems like reasonable discipline for a professional captain and good enough for me.
 
This is an interesting question and I see Tom has replied to it for you.



I was also trained to have a vessel in ready mode at anchor by a captain with 35 years of experience operating large vessels for private companies around the globe.

He had a very disciplined routine before turning in that he passed on to us. The predeparture engine room checks were done in the evening, the rudder was centered, the windlass and all nav and com equipment were left on in ready mode. This left the vessel in a position to respond quickly to an emergency during the night with a turn of the key on the mains.



I can see both sides. Saving power and preserving the bank make sense. But, where power supply is adequate, I like the security of being instantly ready without booting up in the case of an emergency should one arise and one can imagine a few potential emergencies when anchored in a range of ports around the world. It seems like reasonable discipline for a professional captain and good enough for me.



Does sound reasonable, but unless the plotter has been adjusted for night viewing, turning it on can cause instant night blindness.

I know someone who had a collision in a crowded anchorage when a wind change had everyone moving to another bay. He blamed night blindness due to the plotter.

I have a neutral density filter to throw over the screen before boot up. I’ve used it twice in 18 years!
 
Does sound reasonable, but unless the plotter has been adjusted for night viewing, turning it on can cause instant night blindness.

I know someone who had a collision in a crowded anchorage when a wind change had everyone moving to another bay. He blamed night blindness due to the plotter.

I have a neutral density filter to throw over the screen before boot up. I’ve used it twice in 18 years!

Yes, MFD screens are left on and in night mode.
But, even where you are unable to see outside, whether from darkness/night blindness or fog, hopefully we are capable of piloting the vessel in non VFR mode with the equipment we have......radar, chart. AIS, etc.
 
Yes, MFD screens are left on and in night mode.

But, even where you are unable to see outside, whether from darkness/night blindness or fog, hopefully we are capable of piloting the vessel in non VFR mode with the equipment we have......radar, chart. AIS, etc.



In a tight spot it’s hard to beat the Mk 1 eyeball.
 
I also leave the plotter on in standby overnight at anchor (cuts power consumption significantly compared to full on, but it wakes up quickly). VHFs get turned off when we go to bed in most situations.
 
In the 40+ years cruising the PNW and inside passage, we have not experienced emergencies in the middle of the night requiring instantaneous turn on of electronics.

Sure, we've had to pull anchor because of another boat dragging towards us, wind shifts or uncomfortable swells caused from strong tidal current. But, the depthsounder and plotter turns on fairly quickly and the radar is warmed up and ready to transmit in the time it takes to retrieve the anchor.

We do plot the next days route, conduct engine checks, stow all loose items and be ready to leave in the morning since we always "get up and go" early and have coffee and breakfast underway.

We use enough electricity during the day while anchored that we try to leave unnecessary equipment off while asleep to reduce generator run time.

Commercial vessels run their generators at night so they can leave electronics on without consequences. And leave someone on watch.
 
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It just dawned on me that 40 years ago, the only affordable electronics on small pleasure vessels under 35 to 40 feet were a VHF and depth sounder. Pleasure boaters with money and larger boats had maybe a radar and Loran C but that was not common. And until the mid 80's, depth sounders were flashers, not digital. I remember buying my first affordable digital depthsounder made by Hummingbird. I thought it was a miracle to be able to see a digital representation of the bottom contour and depth in actual numbers instead of interpreting the flasher! And being able to see fish on the screen!

Our first radar and Loran came on a 34' Mainship that we purchased in the mid 80's.

First plotter and GPS was running Nobeltec VNS on a laprop in the 90's when SA was turned off.

I talk to guys older than me describe pleasure boating in the 60's and 70's when they cruised up to Desolation Sound, Broughtons and further north with only a compass and chart, maybe a CB and depth flasher. And in 16' to 20' outboard runabout. With their children.

Innovation has improved pleasure boating in many ways and we are safer with electronics and has made it less difficult for new boaters to get started.

But, have we become dependent? And is that good or bad?
 
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It's a standard 120 VAC home electric blanket running off the Victron Multiplus true sine wave inverter/charger.

We've learned over the years that digitally controlled electric blankets will only work with pure sine.

I am a Victron dealer.

Thank you.
 
I leave my NEMA 2000 network on which also powers the AIS and the 4" displays. The AIS is important as it's collision avoidance just as the anchor light (never know when someone is coming into the anchorage late at night or leaving before dawn). The 4" display in my stateroom draws next to no power, has the anchor drag alarm, and displays wind, depth, heading, time and speed.

Ted
 
In the 40+ years cruising the PNW and inside passage, we have not experienced emergencies in the middle of the night requiring instantaneous turn on of electronics.

Sure, we've had to pull anchor because of another boat dragging towards us, wind shifts or uncomfortable swells caused from strong tidal current. But, the depthsounder and plotter turns on fairly quickly and the radar is warmed up and ready to transmit in the time it takes to retrieve the anchor.

We do plot the next days route, conduct engine checks, stow all loose items and be ready to leave in the morning since we always "get up and go" early and have coffee and breakfast underway.

We use enough electricity during the day while anchored that we try to leave unnecessary equipment off while asleep to reduce generator run time.

Commercial vessels run their generators at night so they can leave electronics on without consequences. And leave someone on watch.


I've yet to ever have one of those moments either. But the plotter in standby draws about 0.5 amps, so especially since we added solar, it's not a significant draw. I tend to leave it on all day at anchor (and often with the VHFs on during the day too). The power draw from all of that is still no more than the savings from switching the anchor light to LED.

At a dock with no shore power, I do shut all of that stuff off.
 
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