Charter Co says run engine 4 hrs daily (!) to charge batteries

[denverd0n]

Originally Posted by Snore

Charter companies charter to credit card skippers. So, they issue directives to cover their butts and make their lives easier.

Exactly. Their instructions are meant to account for the least common denominator. That is, the most inattentive charterers they are likely to get.

[Moontide]

Charging hours is related to electric usage and alternator size, not the size of the bank. With smaller battery bank will need to charge more often, but total hours will be almost the same. With lead acid you are not going to get the batteries to 100% unless running for a long time due to the absorption charge pattern.



Also, can turn off a refrig when going down at night. Main problem if you do is remembering to turn it back on in the morning. (Note: not necessarily true for freezers though).

[Dogscout]

Don't forget that the AP uses alot if energy. You are gonna need to run the engine or a gnny at some point. Your chartering and it may be unsatisfying to have to run the engine. But live aboards do it al the time. There seems to be a never ending balance between power consumption and use. I know people with 4k watts of solar that one have enough. It's like water, it funds level on its own. If you have it you will use it. All electric boat, induction cooking, dishwasher, clothes waaasher, cloudy days never ending ****

[winschwab]

Chartered a cat from Dream Yacht Charter in USVI last January. Boat was Euro electrics with 240 volt system and no generator, no battery charger. On arrival batteries were way low, and the only solution was run the engine. Told to do that morning and evening: most annoying. Maybe that's common, but it would have been nice to be forewarned.

[Pcpete]

We chartered a 48’ powerboat there a bunch of years ago. The generator was well insulated and the exhaust was a whisper, the loudest part was the tiny bit of water splashing. The boat had cold plate freezers plus the refrigerator and three air conditioners. The only times we turned off the generator was. When we plugged in at Virgin Gordy and Bitter End.

[nmccubbin]

The problem is not inadequate batteries, but lousy fridges
Perhaps also wimpy alternators. The standard alternator on standard engines is too small for cruising
Our 20 year old engine driven fridge and freezer need about 1/2 hour per day in the Caribbean
6” insulation and top loading. Less convenient than the drawers common in stock boats but more efficient
We are about to convert to electric and expect to run on solar only. Many cruising boats do

[kavw]

Originally Posted by rslifkin

Honestly, the fact that something like that is in a boating course is shocking to me. Battery systems, charging needs, etc. are so boat specific that it's pretty much impossible to make a generalization like that. Depending on systems design you may need multiple hours a day of generator or engine runtime when away from shore power while another boat could go a week without burning any fuel.

It’s an ASA boating course, so doesn’t surprise me.

[seandepagnier]

if you are running the engine at anchor, upwind of me, I will come knocking on your boat. Most people move when I ask, but one guy didnt. I moved and anchored upwind of him and smoked him out with a wood fire He was complaining from his dingy but didn't even have courtesy to use the oars : instead he used a 25hp outboard! I was laughing because I won. Humans are at least somewhat evolved for wood smoke unlike engine fumes.

I woke up too many times with diesel headaches. It is about 1% efficient at generating electricity. You might as well start cutting fruit trees down to get the fruit if you seriously consider charging batteries this way.

I have too much solar power as it is, and keep half my panels below most of the time (solar panels last longer if they arent in the sun)

[kavw]

Because charge rate tapers off, yes it is better to charge twice a day, and at high RPM, not idle.
I’d tell people 2000, I’d you have an amp gauge, you lower the rpm Until the amps drop, the increase a touch.
Try to time your charging with moving the.l boat upwind from breakfast to snorkelling spot, or afternoon spot to where you anchor. And then sail what’s sailable. Not much point sailing 4 hours from west end to Norman island when you can motor upwind for an hour and half then have good sail for hour and half and get there earlier. Obviously weather and itinerary will dictate.

[argonauta1]

Well yes, battery capacity is minimal. Maybe a couple of 180 Amp hour gels but without upsizing the charging capacity about 360 Amp hours for house batteries is all that can be handled. Otherwise it will be necessary to run the engine with its probable 120 amp hour alternator, about 8 hours/day! Our upgraded system had 800 amp hour house bank and one 120 amp hour alternator, the original plus a 300 amp hour additional alternator driven off the diesel flywheel. Also had a wind gen and two solar panels.

[Bmorgan562]

Originally Posted by frolson71

Getting ready for a charter in the BVI in 2 weeks. The charter Co is telling me that I have to run the engine at 1500 RPM 4 hrs a day, 2 hrs in am and 2 hrs in pm! Does that sound remotely right? Hat will seriously dampen our enjoyment. Oceanis 35 if it matters. TIA

sounds like they know it has electrical issues(charging issues to begin with. ). it does not sound remotely right.

[PaulvR]

Sounds about right,
I have 2 X 100A alternators and a serious compressor for 2 huge fridge/freezers all off the engine with a cruising scale battery bank,
So I need 45 mins twice a day partying in the islands, or 45min once a day when 'remote'.
I guess they figure the additional engine hours are worth not having to run out the chase boat and crew :-)

[Lake-Effect]

Originally Posted by Bmorgan562

sounds like they know it has electrical issues(charging issues to begin with. ). it does not sound remotely right.

No, the charter company advice matches our charter experience in 2019 with a fairly new 41' Sun Odyssey. The boat had no generator, no solar, and you're not likely to be on a slip with shorepower for the next 7+ days. So motor is the only charging. We managed with approx 2 hours engine running a day (hopefully en route), and shutting off the fridge if/when the low-battery alarm went off in the wee hours (eg 4 AM), cos we didn't have anything that needed to stay frozen.

[mcon12000]

Originally Posted by frolson71

My ASA 104 course materials say "expect to need at least two hours of engine time every day to keep the batteries properly charged....an hour of charging to the morning run and another hour later in the day...should suffice."

Having to run the engine for twice that, or a full 25% of my waking hours each day on my trip, seemed excessive and at variance with what I was taught. Hence my question.

Hello,

I’m a cruiser with a large house bank who is also has an ABYC certification in marine electrics. It doesn’t matter what the ASA course states and what they do teach is generalized or based on the typical 30’ production boat. It’s not surprising at all that you’ll need to run the engine four hours a day with a LA bank. Being a charter boat with a small alternator and no solar getting the bank to a full charge is going to take time. I doubt you’ll get the bank to a 100% state of charge in four hours twice a day but I don’t have the details to confirm I’m correct. As an example it takes a half a day of motoring to hit float on a 400ah LA bank that was depleted to 50% SOC and that’s with a large externally regulated alternator. I’m not going to bore you with the details here other than to say LA batteries are really inefficient from the absorption portion on using the engine. This is why you see so much solar on actual cruisers boats it the most efficient way to charge LA to 100%.

[lestersails]

In my more than dozen Caribbean bareboat charters the most common problems were the electrical system. Tired, small battery banks I think were at the root of most of the problems. My assumption is (as suggested above) that previous charterers are careless and abuse the batteries. I am really careful about juice use - the folks I sometimes charter with just don't get it that you cannot leave the cabin fans and lights on in the head all day. I ask them to consolidate trips to the refrigerator, and I don't tend to use the autopilot a lot. I am confident many of my brethren are not so concerned.
On the last charter, the battery mgmnt system was was constantly alarming for low charge. Had the chase boat come out to tell us "sorry, not a problem at all, your batteries are fully charged, but the BMS is shot" I'll bet that will be a problem for the next ten people that charter that boat.
Since I am careful with consumption, I generally found that two hours a day was plenty. But as they say "Your experience may vary."
The final comment would be to pile on re the charter company's perspective. Since the charterer pays for the fuel, the owner pays for the engine service and repair, and the charter company staff don't have to listen to the engine droning for hours in that idyllic bay, but the charter management company has to support the calls from boats with dead batteries, they are fully incentivized to shift the costs to someone else (the name of the game in many businesses). Voila! Four hours a day it is.