Do I need a generator?

[MCNav]

I'm looking at a 34' sports cruiser that will be moored in the Med (South France). I will use it 90% for day trips (nav gear, stereo, water heater, fridges, cruising, lights on in the evening, some cooking etc..) and 10% for overnight stays and longer dashes (Italy, Corsica, Sardinia maybe Spain).

There is no AC, nor a generator. It has a shorepower socket. My question is if the onboard battery would have enough juice to support the above activities or if I should look into a generator or would a backup battery be enough? Do boats have equivalents of car alternators that charge up the battery while engines are on?

 

[MCNav]

Yes, battery charger for shorepower is standard. I'm more concerned if I got like 48 hours without plugging it in. Are generators normally needed when there's no shorepower at all for extended periods of in-operation of engines? Or if something needs more juice than the battery provides (ie AC)?

 

[blueglass]

For the kind of use you suggest I reckon you can manage fine without a genny. Yes your engines will have alternators which charge the batteries and you will almost certainly have a battery charger which runs off the shorepower. (if not - essential)

 

[PowerYachtBlog]

10% stays in anchor is not much, so you will not need it
you can always buy a portable Honda 1kw for 600 EUROS, if you decide to sleep more on anchor then that
today Fridges and LED lights and some caution can give you no need for this

I usually turn it just to make it work on the second night, with the batteries still being good

 

[Deleted User YDKXO]

I'm looking at a Galeon 325 - 34' sports cruiser that will be moored in the Med (South France). I will use it 90% for day trips (nav gear, stereo, water heater, fridges, cruising, lights on in the evening, some cooking etc..) and 10% for overnight stays and longer dashes (Italy, Corsica, Sardinia maybe Spain).

There is no AC, nor a generator. It has a shorepower socket. My question is if the onboard battery would have enough juice to support the above activities or if I should look into a generator or would a backup battery be enough? Do boats have equivalents of car alternators that charge up the battery while engines are on?

A generator would be v useful especially if you've got fridges going all day and we find having the anchor light on all night uses quite a lot of battery power too. We can't go much more than 12 hours without using the gennie to charge the batteries but then we're not careful about using power

 

[Medskipper]

Its all a matter of doing the maths! add up all the amps hours your equipment uses. The fridge, Water heater and cooker will use large amounts of current but I doubt that water heater and cooker are run on 12v?

Add up all the DC amp hours that you are burning and don't forget even the smallest bulb left on all night will burn a fair amount of amps. Add up all the 12v power you have and then divide by two! why? because you only have approx half usable power. i.e. 1 x 120 amp hour battery will only give you around 60 amps before its flat.

You then know how long you can be away safely from shore power. If your maths end up in minus figures you need a genny!

Cruising yachtsmen often away at anchor for weeks at a time will use a solar garden type lamp as an anchor light just to save them amps, the biggest concern of a cruising yachtmen is chasing amps! How good are your batteries? put a meter on them, if they are good you should get a reading of just under 13volts. if only around 12v or less your batteries are not in great shape and caution should be taken when anchoring all night without a genny.

All the best

Barry

 

[PowerYachtBlog]

Hello Mike
change the lights the most you use most to new generation LED Lights and it would work out for you
I changed the anchor, cockpit, and head, next is to be the reading lights for both cabins
when I put on anchor, cockpit and head togather consumption is near to zero now, with halogen used to be 10 amps plus if not more
but comparing a 32 footer with a 46 footer on consumption is always a hard call, I would say your boat consumes the double if not more
you may have three fridges alone if I am correct: galley, cockpit and fly...

 

[novanta]

If you can afford it: take the genny. Then you can cook when at anchor and if you later want to install an airco, you will need it anyway!

 

[MCNav]

If you can afford it: take the genny. Then you can cook when at anchor and if you later want to install an airco, you will need it anyway!

This is the boat guy said there's not really any 'space' to put in a generator later on. The boat has already dual Penta D4 engines.

 

[Renegade_Master]

wonder where you would put a genny on a 34ft stern drive SC

 

[MapisM]

Are generators normally needed when there's no shorepower at all for extended periods of in-operation of engines?
Or if something needs more juice than the battery provides (ie AC)?

The answer to first question depends on how extended those periods are and what you're using in the meantime, as explained by previous posters. But the answer to your 2nd question is definitely YES. You simply can't run AC out of batteries.

 

[oceanfroggie]

Geni - Need, want, nice to have, etc?

Once one has had an onboard diesel geni, one wonders what a boat would be like without it?