Shore power quandary

[wully1]

My boat is in the marina for the winter, hooked up to shore power.

There is a 'Cold Watcher' heater plugged in. It is set to keep the temperature above freezing and hardly ever kicks in when I'm aboard. I've had it for years and store it in the garage once the boat is back on the mooring.

The Sterling battery charger is also connected to keep my two 110 ah batteries topped up. I occasionally use some tools on board - soldering iron, hot glue gun and a fluorescent inspection lamp.

Everything else is switched off.

Currently my boat is consuming more power per month than my house! I hooked up an in line electric meter and the marina and my meter are in agreement.

Where is the power going? Anyone have a clue?

 

[sailorman]

My boat is in the marina for the winter, hooked up to shore power.

There is a 'Cold Watcher' heater plugged in. It is set to keep the temperature above freezing and hardly ever kicks in when I'm aboard. I've had it for years and store it in the garage once the boat is back on the mooring.

The Sterling battery charger is also connected to keep my two 110 ah batteries topped up. I occasionally use some tools on board - soldering iron, hot glue gun and a fluorescent inspection lamp.

Everything else is switched off.

Currently my boat is consuming more power per month than my house! I hooked up an in line electric meter and the marina and my meter are in agreement.

Where is the power going? Anyone have a clue?

why have the batteries on charge, mine are only charged when i am o/b
i use a 13amp plug in thermostat ( set @ 5 deg C ) controlling an oil filled rad, i use very little power

 

[TonyBuckley]

More than your house? That's insane. My house runs at 200w (obviously at 230v) when quiet. Heating is oil and log burner.

How are you judging this - Kwh?

I guess your marina supply is limited to 16 amp?

Power generates heat - it must be going somewhere. My marina charges nothing for power so I don't watch closely.

How is the marina supply connected; I just take direct via a cable and block.

Love to know the answer.

 

[VicS]

My boat is in the marina for the winter, hooked up to shore power.

There is a 'Cold Watcher' heater plugged in. It is set to keep the temperature above freezing and hardly ever kicks in when I'm aboard. I've had it for years and store it in the garage once the boat is back on the mooring.

The Sterling battery charger is also connected to keep my two 110 ah batteries topped up. I occasionally use some tools on board - soldering iron, hot glue gun and a fluorescent inspection lamp.

Everything else is switched off.

Currently my boat is consuming more power per month than my house! I hooked up an in line electric meter and the marina and my meter are in agreement.

Where is the power going? Anyone have a clue?

We dont know how much electricity your house uses but just how much is the boat apparently using. How many of kilowatt hours per day, week or month ??

 

[wully1]

More than your house? That's insane. My house runs at 200w (obviously at 230v) when quiet. Heating is oil and log burner.

How are you judging this - Kwh?

I guess your marina supply is limited to 16 amp?

Power generates heat - it must be going somewhere. My marina charges nothing for power so I don't watch closely.

How is the marina supply connected; I just take direct via a cable and block.

Love to know the answer.

I too would like to know. It makes no sense.

All our lighting in the house is LED or energy saving lamps. We run an oil fired underfloor heating system, kettle, toaster, bread maker, 2 computers, router and oven. Cooking by gas.

I'm currently only running the small heater and checking the meter reading, I'll repeat with only the charger to see what's going on.
Nothing is running hot ( apart from the heater...) my battery bank isn't boiled dry.... I'm stumped.

 

[longjohnsilver]

Immersion heater? Must be something pretty beefy.

 

[[2574]]

Are you quite sure that nobody is "borrowing" your shore power connection each and every day in your absence?

 

[wully1]

Immersion heater? Must be something pretty beefy.

Isolated. Never really used it and the water out the tap is definitely cold.

The boat sat on the hard all last winter and didn't use much power at all. I thought it must be the shore power meter but my in line one more or less agrees.

 

[VicMallows]

Along the same lines as Robih, is your own in-line meter securely locked away (inside the boat perhaps) ??

 

[wully1]

Along the same lines as Robih, is your own in-line meter securely locked away (inside the boat perhaps) ??

Not much chance of that. It's a quiet place, no one around this time of year and I'm down at random times almost every day.

 

[spannerman]

The boat sat on the hard all last winter and didn't use much power at all. I thought it must be the shore power meter but my in line one more or less agrees.

The fact you boat used less when on land would worry me, are you sure that you don't have a problem with the shorepower thats dumping current into the water, which could make you extremely unpopular with neighbouring boats.
I say this as yesterday we took up a boat for a service and found that the sterndrive ,steering cylinders, trim cylinders and transom shield are SEVERELY corroded due to a shore power problem and we need to replace the lot which will be about £16,000 in total.
We still have to identify the source of the problem so it doesn't happen again, we also had a Princess V45 with damage to both drives and it was traced to the next boat which had a bad shorepower installation.

 

[John 32i]

Something not right.....I have a small bar heater on a thermostat and intermittently charge my batteries - last bill for three months 60 units @ 0.1150 = £6.90

 

[Gordonmc]

I'll repeat with only the charger to see what's going on.
Nothing is running hot ( apart from the heater...) my battery bank isn't boiled dry.... I'm stumped.

I suggest you might want to turn off and disconnect everything including the charger. That will show up a current leak to earth of your meter still shows draw. If there is none, then progressively turn on your items of kit, starting with the charger.

 

[TonyBuckley]

I suggest you might want to turn off and disconnect everything including the charger. That will show up a current leak to earth of your meter still shows draw. If there is none, then progressively turn on your items of kit, starting with the charger.

+1

 

[wully1]

+1

Good plan

 

[superheat6k]

Good plan

Maplins offer a decent clamp on current meter (also with other functions) for around £15. Place this over the live lead only somewhere along the shorepower line and see what current is being drawn as you switch on and off various services.

Most houses will have a typical amp draw of say 5 - 30 amps when the household are up. Your domestic fridge which is on / off all the time pulls about 0.25 amps when on. 1 kWH (1 unit) per hour will draw just over 4 amps. So if you are using more than your house you should easily be able to measure this.

Even a large battery charger around 30amp output (at 14vdc) will not exceed 500 w at full tilt, which would be about 2 amps on the supply. At trickle charge expect just a small current draw way below 1 amp. Most chargers are fairly efficient so the loss would only be around 10% of the specific load.

Finally if you do have a substantial leakage into the water then please be very very careful, and if you are not comfortable working around electrical system please get someone in who is, and ideally someone with marine experience. Remember electricity is quite safe until you forget it is dangerous.

 

[AntarcticPilot]

Your "Cold Watcher" heater shouldn't be using much at all while the boat is afloat, if the thermostat is set simply to keep the boat above freezing. The water the boat is floating in is going to be above freezing point - it would be ice if it wasn't! A boat that is ashore will get colder than one that is afloat for this reason.

 

[oldvarnish]

A boat that is ashore will get colder than one that is afloat for this reason.

I once left a boat in Nova Scotia for the winter and was strongly advised to keep her in the water, even though it iced over. They swore it was warmer that way.

 

[aluijten]

I've had a similar experience with a Victron battery charger that had quite a substantial idle load on the mains. So it kept the batteries happy but wasted a lot of energy in the process. This was noticeable because the housing of the charger was quite warm 24/7 even with the batteries in float-state. As far as I could determine there was nothing malfunctioning on the charger so it seemed a result of poor design.
It has now been replaced with different brand charger.

 

[Spirit of Glenans]

I've had a similar experience with a Victron battery charger that had quite a substantial idle load on the mains. So it kept the batteries happy but wasted a lot of energy in the process. This was noticeable because the housing of the charger was quite warm 24/7 even with the batteries in float-state. As far as I could determine there was nothing malfunctioning on the charger so it seemed a result of poor design.
It has now been replaced with different brand charger.

The upside to that scenario is that the surplus heat from the charger was keeping your boat frost-free.