Generators needed on boat with solar and lithium.?

[Sailingnomad]

Why do boaters need generators with adequate solar panels and lithium batteries?

[Zanshin]

Because sometimes the sun doesn't shine enough. And I need my generator to power up the dive compressor. It is a good backup, although I have enough solar for normal use.

When I run the genset I turn on everything I can once the batteries (lead-acid) get close to 90% - watermaker, dive compressor, washing machine. That makes efficient use of the genset.

[Chotu]

Air conditioning

[Mike OReilly]

It’s the ultimate power backup.

Most seasons I might use the generator once or twice. Often I don’t use it all. But there have been a couple of seasons where we have extended no sun and inadequate wind (I also have a wind gen). That’s when the dino-generator comes out.

[flightlead404]

Originally Posted by Sailingnomad

Why do boaters need generators with adequate solar panels and lithium batteries?

I am struggling with this myself. Replaced 400 AHr AGM with 400 A Hr LiFePO4 and the proper charger. Added a 12v 30A DC-DC charger to charge from the alternator, have 630W solar.

I have a barely hanging on for dear life Fischer Pander 4.2 KW generator, but have not had to use it since going lithium. However, I put the lithium in in march, so maybe the picture would be different October - February.

I am considering adding an additional 400 AHr battery and removing the generator and putting a DC water maker in place. Maybe upgrading the alternator but not sure if I can get much more in a small frame (currently 85A) and may just go with an external regulator.

[noelex 77]

Waiting for generator parts and repair is a common frustration. If you can do without a generator it removes one significant error prone system and will leave you with more time for the joys of cruising. With a well designed electrical system many boats can enjoy most, if not all, the comforts (with perhaps the exception of air conditioning) without a generator. This is a worthwhile design goal.

[UYA]

They don't. At least we don't:
We moved to lithium (7.5kwh) and solar 1600W. We ditched our 40year old 3.5kw generator and never looked back.
Today we power everything with electricity except propulsion: cooking, water maker, dish washer, washing machine, toilet.
We are a family of 4 on a 42 foot monohull cruising full time in the tropics and subtropics being 100% at anchor. We dont charge the lithium batteries with our engine.
If there are a few days without sun (solar also works without sun but just not as good) we hold off on cloth washing, water making etc. This happens very rarely. Worse case you can use your engine to resupply some energy.
I think the magic sauce is the combo of enough solar (as much as you can) and lithium batteries.

[rslifkin]

Since adding solar (still AGM batteries) our generator sees a lot less use. If I could up-size the solar and battery enough to handle all cooking and hot water needs plus some more margin for bad weather, we could dump the generator. Only thing we'd lose is the (rarely used) ability to run air conditioning without shore power.

At the same time, the generator on our boat has been probably the most trouble free mechanical item we have. So unless I needed the space and weight for batteries, I'm not particularly inclined to remove it.

[Simi 60]

Originally Posted by Zanshin

Because sometimes the sun doesn't shine enough. .

It's as simple as that for us.

But we are a fairly heavy usage boat with multiple 240v household fridge/freezers
A mostly electric galley
240v watermaker
A 240v still that takes 6 hours to run off
240v washing machine
But no AC

840ah@ 24v of lifepo4

In full summer we keep on top of it with 2500watts of solar

In winter we need to run the Genset by day 3 to smash some amps back in.
And currently in the process of getting on engine charging - that will help a lot.

[SV Confianza]

We got rid of our generator after upgrading solar batteries and alternators. But on a cat, we already have two engines that can produce power if needed. On a mono it might be good to still have a backup generator, but could be a small Honda.

The A/C runs off the batteries.

[Simi 60]

Originally Posted by SV Confianza

We got rid of our generator after upgrading solar batteries and alternators. But on a cat, we already have two engines that can produce power if needed. On a mono it might be good to still have a backup generator, but could be a small Honda.

The A/C runs off the batteries.

Small Honda for small jobs

Real Genset for real jobs
We'd probably need 3 Honda's running to use our charger.
Vs our single 7.5kva diesel genset

[sailorboy1]

My diesel generator died years ago (hope it rots in hell). But I have a Honda and love it waaaaaaaaay more than I ever did that diesel generator. Yes it will not run all the AC loads at once, but not a big deal. It can run the battery charger at its max capacity when needed and can run the air conditioning, watermaker and the hot water heater. It just can only run 1 of those at a time and each is about 2/3 the capacity of the unit.

The cost of that Honda is way less that what it would take to add to my 640W solar and 400ah LFP batteries, which I also don't really have a place to install more of.

[smj]

Originally Posted by Simi 60

Small Honda for small jobs

Real Genset for real jobs
We'd probably need 3 Honda's running to use our charger.
Vs our single 7.5kva diesel genset

The Honda is a real generator used by those that don’t own a floating condo? Each to his own.

[Simi 60]

Originally Posted by smj

The Honda is a real generator used by those that don’t own a floating condo? Each to his own.

Yep
But I doubt it'll run our smallest charger 50amp @ 24v
It might run our watermaker
Therefore, in our eyes it's a small job generator.

[smj]

Originally Posted by Simi 60

Yep

But I doubt it'll run our smallest charger 50amp @ 24v

It might run our watermaker

Therefore, in our eyes it's a small job generator.

It’s all relative upon who’s eyes your looking through.