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

[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

[Cheechako]

Depends on your fridge use. But it could be so. Engine drive fridge or electric?
I got by with 1.5 hours or less twice a day with either system. But the fridge could be marginally cold at times, not freezing.
-One thing is if you are moving every couple of days and motoring a lot (as is often the case) you get a good hard freeze when doing that.
-With the engine drive fridge, you can often just run 1/2 hour or so and freeze the plates. Do that 3 x a day instead of two long runs.
-If ice is available, load in a couple of big blocks before you leave to help out.

[Tetepare]

28 hours/week and 14 starts just to charge. I’m surprised any of the boats coming out of charter still run.

[Lake-Effect]

We chartered a Jeanneau 41 in the BVIs in 2019 and it was just a fabulous time. If there was any single thing that approached being annoying, it was that the battery bank was undersized. The biggest uncontrollable draw was the fridge. The low voltage alarm would go off most mornings at 4 or 5 AM. I would just silence it, turn off the fridge (it didn't warm up appreciably in 3 hours) and we'd do some motoring in the AM to bring the charge back up. And there were a couple passages that were mostly motoring.

I hated running the motor, period. Especially when we were sailing or moored/anchored. I recall we could mostly get away with roughly 2 hours of motor running per day.

So, yeah, expect that some motor running will be unavoidable.

[rslifkin]

Many of those boats have nowhere near enough battery capacity. And the instructions have to cater to people that won't pay any attention to battery charge levels, etc.

[frolson71]

Originally Posted by Cheechako

Depends on your fridge use. But it could be so. Engine drive fridge or electric?
I got by with 1.5 hours or less twice a day with either system. But the fridge could be marginally cold at times, not freezing.
-One thing is if you are moving every couple of days and motoring a lot (as is often the case) you get a good hard freeze when doing that.
-With the engine drive fridge, you can often just run 1/2 hour or so and freeze the plates. Do that 3 x a day instead of two long runs.
-If ice is available, load in a couple of big blocks before you leave to help out.

Fridge is electric, but shuts off on its own when battery goes below 12.0v. Definitely we plan on getting ice. Wish our boat had a solar array to help with this. Thx!

[Shrew]

I run my generator for at least 2 hrs every morning and 2 hrs at night. We time it while we're prepping, cooking and eating either meal. During that time, we heat the water tank, charge our phones, tablets, laptops, and hotspots, and watch the news on TV.

How long do you think it should take to recharge the batteries??

[flee27]

And here is the big variable with charters. Not being negative about chartering just realistic.

You have no real idea without being at the boat and looking how many AHs you have in the bank. Once you know this you have no way of knowing what the condition of the bank, and the charging abilities. With these variables it is really hard to do much planning.

Your one guaranteed plan is to expect some issues. Roll with them if the are only inconvenient and have fun on your adventure. Some charters are more adventurous than others. Many have chartered much more that I have but I have done enough to feel I have a good sampling, and to know to expect problems.

Hope you have a great time.

Foster

[Cheechako]

Let's face it, too big a bank takes a very long time to re-charge. So yes, having at least an adequate bank size is nice, but having a huge bank would not solve the problem either.

[frolson71]

Originally Posted by Shrew

I run my generator for at least 2 hrs every morning and 2 hrs at night. We time it while we're prepping, cooking and eating either meal. During that time, we heat the water tank, charge our phones, tablets, laptops, and hotspots, and watch the news on TV.

How long do you think it should take to recharge the batteries??

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.

[JC Reefer]

Originally Posted by Cheechako

Let's face it, too big a bank takes a very long time to re-charge. So yes, having at least an adequate bank size is nice, but having a huge bank would not solve the problem either.

Good point.

[rslifkin]

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.

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.

[Wolfe10]

The answer is IT DEPENDS.


It depends on what battery bank is in there-- both its amp-hr capacity and its condition (new vs about to be replaced).


It depends on what alternator is in the boat-- basically, its amp rating at the engine RPM you will be running it.


It depends on what battery isolator is in the boat-- the diode-based ones lower charge voltage by about .7 VDC unless the boat is fit with a smart regulator with sense wire on the battery side of the isolator. That materially lengthens charge time.



It depends on how often the refrigerator is opened, how many 6 packs of warm beer are put in, etc.


If there is a battery monitoring system (showing amp) the answer is run it until charge rate drops off. Most efficient use of the engine/alternator is discharge to 50% SOC, recharge to 85% SOC, repeat. Yes, for long battery life, batteries should be brought up to 100% once a week. But, as they say, not your problem.

[Lake-Effect]

Originally Posted by Cheechako

Let's face it, too big a bank takes a very long time to re-charge. So yes, having at least an adequate bank size is nice, but having a huge bank would not solve the problem either.

The Goldilocks problem. "Just Right" in a charter boat would be a battery bank capable of running most things and needing only the charging from typical charter motoring.

4 hours a day of engine running... doesn't seem like the sweet spot.

[JPA Cate]

Originally Posted by Tetepare

28 hours/week and 14 starts just to charge. I’m surprised any of the boats coming out of charter still run.

What Tetepare wrote made me ask myself the question, "During Covid restrictions, charter companies were hemorrhaging money; I wonder how many fridge systems got topped up with cooling gas?"

I would make the assumption that the company wants the OP to have cold maintained in the fridge for both their satisfaction, and since it is their boat, and their requirement, the OP should do as they told him. Not doing it could make the fridge have to work harder than it should, and the company wants to eke out a long service life. I can't blame them. It's gotta be a hard thing, for them, too.

Ann