Charging At Anchor

[Tom.B]

Ok... When I wake up after a night at anchor, I like to top off the batteries a little bit before I get underway (auto pilot pump is a power hog and will shut off if voltage drops below 12.0V... yes... I plan on increasing the wire gauge to the pump soon... that's not the point). Is it better to fire up the genset to run the A/C battery charger or run the main engine and use the alternator?

Standard old Motorola 70A alternator that never puts out more than 50-ish amps anyway, versus new Iota 55A charger.

What say ye'?

 

[Russell Clifton]

Tom, Alternators are not battery chargers. They are made to maintain the batteries charge. Use your generators battery charger.

 

[DavidM]

Russell is correct.

I assume that your IOTA charger has its IQ4 Smart Charge option. In that case it will charge at a high bulk rate of about 50 amps initially. Your simple float voltage internally regulated alternator will not charge that fast with a mostly charged battery.

But I am surprised that your hydraulic autopilot pump draws so much current. I think mine draws maybe 5 amps and only when the autopilot commands a turn adjustment.

David

 

[Tom.B]

The run from the tie-in point is kinda long, and during the install, I didn't upgrade the wire from the breaker to the tie-in. Just the tie-in to the pump. It's kind of hard to describe without knowing the odd way our electrical system is, but let's just say that I know why, I just haven't fixed THAT part yet. (Si-Tex AP's go off the moment voltage drops below 12.0 and with the pump running on smaller than optimal wire gauge, the voltage drops teeter at 12 volts. Thus, one or two good tugs by the pump can cause it to shut off. No big deal. Just an annoyance)

 

[Brooksie]

If you are firing up to get underway, during which time you will be charging, why would you want to run your engine w/o load or your generator for that matter. Your autopilot problem is a different issue (wiring issue) because once you are underway & charging you have 13-15 volts available and the AP should work fine. The best thing you can do for your engine/s is to move off slowly after you start them & weigh anchor.

 

[Bay Pelican]

Tom

Use your generator before you start out. You have answered the question yourself when you acknowledge that if you don't charge the batteries before leaving the autopilot cuts out for low voltage.

On Bay Pelican we frequently charge immediately before leaving anchor in the morning. The overnight discharge, raising the anchor and the combination of autopilot, radar and perhaps navigation lights leaves the batteries fairly low if I don't charge them up before raising anchor. I also have a 70 amp alternator. It takes hours to make up for the overnight discharge.

Marty

 

[Tom.B]

If you are firing up to get underway, during which time you will be charging, why would you want to run your engine w/o load or your generator for that matter. Your autopilot problem is a different issue (wiring issue) because once you are underway & charging you have 13-15 volts available and the AP should work fine. The best thing you can do for your engine/s is to move off slowly after you start them & weigh anchor.

I wouldn't consider the genset to have no load on it while pumping a 50A charger into service

And while I may have 13-15 volts at the battery with the main running, that's not what I have after a 25' run of #12 wire for the first ten feet and then #10 for the next 15' driving a high-torque hydraulic pump yammering on and off many times per minute. That is, of course, the problem that still needs fixing.

 

[psneeld]

like most electrical questions..."it depends".....

if your batts are way down...sure a "quick charge" from a big charger/genset would be appropriate.

if your house batts are only down 50 to 100 amp hours and you are going to run all day....I think it will not hurt your alternator and most likely have your batts topped off by happy hour.

A 50 amp 110 charger is hardly tasking anything but a 1000watt genset. If you have a 5kw diesel set...it's barely asking 1kw and that's only if it's a really inefficient older charger.

I think your "boating style" may be a better answer.

I wake up first, have the coffee pot ready to go, so I'll fire up my little 1000 watt Honda to run the coffee pot and start a charge back to the batts. Only if I was going to make a big, hot breakfast (electric galley now has a propane range top so even I may change my routine) would I fire up the 8kw genset. By the time I have my coffee and do morning chores (about an hour) it's time to shut down and get going. The alternator finishes what the batt charger/genset started.

 

[BigJim]

Rather than make a new post I have a question relating to power use at anchor.

What loads do you leave on when you lay down for the night and what current do they draw?

I am asking specifically about DC loads, pure or off the inverter with no generator running.
VHF
Cabin night lights
Heater/blower/fan/pump
Anchor lights
GPS alarm
Radar
Refrigerator/freezer
??
I am trying to understand why these large battery banks are deep discharged in 8 hours or so.

 

[MikeD]

Rather than make a new post I have a question relating to power use at anchor.

What loads do you leave on when you lay down for the night and what current do they draw?

I am asking specifically about DC loads, pure or off the inverter with no generator running.
VHF
Cabin night lights
Heater/blower/fan/pump
Anchor lights
GPS alarm
Radar
Refrigerator/freezer
??
I am trying to understand why these large battery banks are deep discharged in 8 hours or so.

A simple solution is too install a battery monitor (I have litterally just done this last weekend on Siesta). You then individually measure each load and work out where your problem is.

In my case the only loads that are left on overnight are:

- anchor light
- VHF
- water pumps
- bilge pumps
- stereo/Tv when in use
- lighting (now all LED) when in use
- diesel heater fan (when in use)

Last weekend we used all of the above and found that we only consumed 20AH in one evening at anchor.

Our fridge/freezer are run from a compressor that is driven by the engine. We find that it holds temperature well overnight.

Mike

 

[Codger2]

A simple solution is too install a battery monitor (I have litterally just done this last weekend on Siesta). You then individually measure each load and work out where your problem is.

Do I ever agree! FF has been preaching SOC meters for years and Flywright finally shamed me into doing it. (With a lot of help from Scott, my rag boat neighbor.) The SOC meter sure answers a lot of questions and changes your "at anchor systems set up."

1) House
2)Start batt
3) Time to go
4) House SOC

These are but a few screens you get. There are many more. Too many to talk about here.

 

[DavidM]

BigJim:

Refrigeration will be your biggest draw- between 50 and 100 amphours in a 24 hour period. Next will be your anchor light- about 2 amps all night so 20 amphours. Interior lighting until you go to bed, maybe another 10 amphours, less with LEDs.

A GPS anchor alarm will be nil for most systems. You aren't going to run your radar at night asleep are you?

A Espar type forced air diesel heater can draw about 5 amps for its blower and diesel pump. Depends on the temps as to how many hours it runs at night.

So in a 10 hour overnight period, you might use 50 amphours without diesel heat and double with diesel heat running all night..

David

 

[BigJim]

A simple solution is too install a battery monitor (I have litterally just done this last weekend on Siesta). You then individually measure each load and work out where your problem is.

In my case the only loads that are left on overnight are:

- anchor light
- VHF
- water pumps
- bilge pumps
- stereo/Tv when in use
- lighting (now all LED) when in use
- diesel heater fan (when in use)

Last weekend we used all of the above and found that we only consumed 20AH in one evening at anchor.

Our fridge/freezer are run from a compressor that is driven by the engine. We find that it holds temperature well overnight.

Mike

I agree I have a SOC meter in my garage. I have four freezers that I cannot allow to go without power for very long. So along with my 2 generators I felt the need for some quiet power as well. If the power is off at night I can run the entire garage off the 2 large wet cell batteries I have. I also can charge them off Photovoltaic if need be.

Back to my question then. Why are folks with 6 or 8 8D batteries reporting they are at or near 50% SOC?

I can run my toaster OR my microwave off my inverter and not go below 50% SOC after running the garage all night.

I have this all quantified on a spreadsheet using my SOC meter and my "Kill a Watt" meter. (The PC died and is being recovered,,, I hope)

 

[fryedaze]

Do I ever agree! FF has been preaching SOC meters for years and Flywright finally shamed me into doing it. (With a lot of help from Scott, my rag boat neighbor.) The SOC meter sure answers a lot of questions and changes your "at anchor systems set up."

1) House
2)Start batt
3) Time to go
4) House SOC

These are but a few screens you get. There are many more. Too many to talk about here.

I am a new believer in the battery monitor. Gotta have one.

 

[fryedaze]

Tom, Alternators are not battery chargers. They are made to maintain the batteries charge. Use your generators battery charger.

BUT..... they can be if they are set up with smart multi-stage regulators, IMHO. If I was in Toms shoes I would put a 100 - 150 amp alternator on with a smart multi-stage regulator.
I will be adding multi-stage regulators to my boat this winter. I havent decieded on what ones yet.

 

[MikeD]

BUT..... they can be if they are set up with smart multi-stage regulators, IMHO. If I was in Toms shoes I would put a 100 - 150 amp alternator on with a smart multi-stage regulator.
I will be adding multi-stage regulators to my boat this winter. I havent decieded on what ones yet.

I agree, we have a multi stage regulator and the alternator does a great job in recharging the batteries each day (when the engine is running).

Mike

 

[Tom.B]

Scott... 3.5KW Genset... Not sure if that makes any difference, but I suppose I could use it for morning coffee too. ;-)

I have plans for a new alternator, but because of the engine and genset placement, I think 100A would be the MAX alternator I could put on because I don't have to room to add a wide belt. It's going to have to stay with a single v-belt alternator. So my options are limited. Still, it is in the plan for next year. I don't trust my Motorola to last much longer. Keep wanting to pull it out and take it in for a rebuild. Just ain't gotten to it yet. ;-)

Big believer in Victron Battery monitor too... I keep it on "I" (amp draw) and watch it every 5 minutes because I have no life :-D

 

[MikeD]

Big believer in Victron Battery monitor too... I keep it on "I" (amp draw) and watch it every 5 minutes because I have no life :-D

Me too and I think that means I have no life as well :lol:

 

[ddfishon]

Do I ever agree! FF has been preaching SOC meters for years and Flywright finally shamed me into doing it. (With a lot of help from Scott, my rag boat neighbor.) The SOC meter sure answers a lot of questions and changes your "at anchor systems set up." 1) House 2)Start batt 3) Time to go 4) House SOC These are but a few screens you get. There are many more. Too many to talk about here.

I work in the land of acronyms but don't get this one -- SOC?

 

[Alaskan Sea-Duction]

Walt, where did you get your system?

 

[DavidM]

BigJim:

Several reasons why people run out of battery capacity:

1. Those big, heavy 8D batteries are not really deep cycle batteries and using them as such has cut their capacity to half or less. This is the #1 reason.

2. Boaters use more amphours than they think. Until you have an E Meter, you can't know for sure. I have heard numbers reported from 50 to 200 amphours a day.

3. Boaters stay at anchorages for multiple days and run their batteries down. If they don't have an isolated starting battery, then their engine won't start.

David

 

[BigJim]

I work in the land of acronyms but don't get this one -- SOC?

State of Charge. Like how happy your batteries are.

 

[BigJim]

BigJim:

Several reasons why people run out of battery capacity:

1. Those big, heavy 8D batteries are not really deep cycle batteries and using them as such has cut their capacity to half or less. This is the #1 reason.

2. Boaters use more amphours than they think. Until you have an E Meter, you can't know for sure. I have heard numbers reported from 50 to 200 amphours a day.

3. Boaters stay at anchorages for multiple days and run their batteries down. If they don't have an isolated starting battery, then their engine won't start.

David

So would my fellow PNW boaters be offended if I put my Burgey wind generator up at an anchorage? I think my net electric use could be a push with a wind generator and I could anchor for days without sparking the air polluter/morning wrecker.

 

[BruceK]

I work in the land of acronyms but don't get this one -- SOC?

State of Charge.
Are SOC meters good or a WOFTAM? Good I think, though I don`t have one.

 

[BigJim]

State of Charge.
Are SOC meters good or a WOFTAM? Good I think, though I don`t have one.

They allow you to display how many Amps or Watts you have consumed from your batteries as well as how many you have put back into them, hence their "state of charge."

An old fashion Hydrometer and an accurate Volt meter is a very useful tool as well.

 

[C lectric]

SOC means State Of Charge

Keeps track of amp hours in and out so you know the state of charge of the batteries.
It gives other info also but the main purpose is to track amphours.

 

[Codger2]

Big believer in Victron Battery monitor too... I keep it on "I" (amp draw) and watch it every 5 minutes because I have no life :-D

Very funny! I do the same damn thing!

 

[Bay Pelican]

Tom

Don't know how often you anchor out, but if you do so on a regular basis you may want to consider getting a second charger. Gensets are more efficient when loaded. One 55 amp charger lightly loads even a small genset. You could cut your run time in half if you use two chargers. Since a 55amp Iota costs approximately $250 you would save money by reducing diesel usage by 60 gallons (assume $4 per gallon) over the life of the charger. In addition your genset would be more properly loaded.

Marty

 

[hollywood8118]

Ok... When I wake up after a night at anchor, I like to top off the batteries a little bit before I get underway (auto pilot pump is a power hog and will shut off if voltage drops below 12.0V... yes... I plan on increasing the wire gauge to the pump soon... that's not the point). Is it better to fire up the genset to run the A/C battery charger or run the main engine and use the alternator?

Standard old Motorola 70A alternator that never puts out more than 50-ish amps anyway, versus new Iota 55A charger.

What say ye'?

First get a SOC meter to see what you are actually using, second pitch that inadequate alternator and get a bigger one with a smart reg.. I run a 125A twin belt alternator and get over 100a @ 1600rpm cruise. Most boats never use all available main engine power at cruise so why run the genset if you don't need to.
I know many here like the gas Honda inverter generators but personally I wouldn't ever consider one unless I didn't have a diesel generator and the place to install one.. I guess if the boat is too small it makes sense but there are a lot if issues to deal with having the thing on deck

Regarding the wind generator, rarely do they make enough power at anchor to justify the cost, annoyance due to sound, vibration that can transmit through the hull.... we had one on our cruise across the pacific and it never did much except at sea.
HOLLYWOOD

 

[Tom.B]

First get a SOC meter to see what you are actually using, second pitch that inadequate alternator and get a bigger one with a smart reg.. I run a 125A twin belt alternator and get over 100a @ 1600rpm cruise.

Not sure if you read my other posts. I have a meter and can't run twin belts, but plan on upgrading alternators soon.