Boats with 12v and 24v systems on board.

[JayDomK]

I don't necessarily see it as a problem, but something I've not worked with and am ignorant of the day to day operation of a bi voltage DC system boat.

Seems like most have agreed with you that it's not a problem and I shouldn't be put off the purchase...

Of course, that's not a problem. You'll get used to it, I assure you.

 

[melvynpatrick]

I agree. I have only recently bought my boat and I had no previous experience of 24v. All of my older raymarine (c80) and b and g electronics run on 24v. All the led lights are 24v. Fridge also. For the more modern 12v stuff including vhf, element plotter and ais, I run off a victron 24 to 12v 70 amp converter. I do not have any power issues. I have 4 12v agm batteries at 125 amps each which wired together gives 24v at half the amps. I would like lithium but funds do not allow yet. What makes it easier is the two alternators. I do not have to worry about split charging and suchlike. Then it might be more complicated, for me at least. I am on a swinging mooring so I have two 12v 80 w solar panels wired to give 24v. They keep the batteries topped up just fine.

 

[JayDomK]

I agree. I have only recently bought my boat and I had no previous experience of 24v. All of my older raymarine (c80) and b and g electronics run on 24v. All the led lights are 24v. Fridge also. For the more modern 12v stuff including vhf, element plotter and ais, I run off a victron 24 to 12v 70 amp converter. I do not have any power issues. I have 4 12v agm batteries at 125 amps each which wired together gives 24v at half the amps. I would like lithium but funds do not allow yet. What makes it easier is the two alternators. I do not have to worry about split charging and suchlike. Then it might be more complicated, for me at least. I am on a swinging mooring so I have two 12v 80 w solar panels wired to give 24v. They keep the batteries topped up just fine.

Personally, solar panels are usually enough for me. But sometimes I have to use a alternator. Especially if I need to cook food on an electric stove. It consumes a lot of power, much more than a fridge.

 

[Parabordi]

I went to have a second viewing of a boat today. Something I missed first time around was the boat has both a 24v and a 12v system on board.

I get why one may want a 24v system; amp draw for given wattage being lower, lower voltage drop, smaller cables etc.

Question I have is how does that work in Practice? Would you expect to have engine start battery, 24v domestic bank and then a third 12v bank of batteries? That feels an awfy lot of batteries!

Alternatively do you just take the 12v load off one of the batteries in the middle of the 24v bank?

Or would you have a 24v to 12v dc-dc charger going from 24v bank to a 12v busbar?

Thanks.

I have both, mainly cos the original ENgines were 24v and we re-engined to new ones which are 12V.

Engines run 12V (old engine battery banks switched from series to parallel) and voltage-sensitive relays which then liven up Victron Orion 12v to 24V chargers (x2) which charge the Domestic 24V bank.

I kept the domestics at 24V as there were several expensive systems i didn't want to replace eg Loo, Eberspacher.

System works well, recommend Victron kit.

 

[melvynpatrick]

Personally, solar panels are usually enough for me. But sometimes I have to use a alternator. Especially if I need to cook food on an electric stove. It consumes a lot of power, much more than a fridge.

Yes. In the winter i run a honda eu2 if the batteries are getting low. i know generators can be annoying to others but the honda is very quiet and i use it responsibly

 

[geem]

Yes. In the winter i run a honda eu2 if the batteries are getting low. i know generators can be annoying to others but the honda is very quiet and i use it responsibly

We come across plenty of Honda generators on yachts in anchorages. I assure you they are not quiet to boats anchored nearby. Sound travels across water very well. They are super annoying and can ruin a perfect anchorage. Especially bad in the evening when you are having a meal in the cockpit and some idiot has the generator on his sugar scoop so HE doesn't have to listen to it

 

[melvynpatrick]

thats why i use it responsibly

 

[JayDomK]

We come across plenty of Honda generators on yachts in anchorages. I assure you they are not quiet to boats anchored nearby. Sound travels across water very well. They are super annoying and can ruin a perfect anchorage. Especially bad in the evening when you are having a meal in the cockpit and some idiot has the generator on his sugar scoop so HE doesn't have to listen to it

Yes, it can be annoying. Sometimes it even interferes with sleep.

 

[melvynpatrick]

I have watched this forum for a while and seen some good advice. I thought i ought to join as it was unfair to take and not give. i have only posted few times and already someone has fallen out with me. I did not realise running my generator in a deserted bay in England could annoy someone dining in their cockpit in the sunny Caribbean sea.
Consequently I will no longer be posting or watching or having anything to do with this forum. People are always looking for an argument and i have enough of that at work.

 

[Parabordi]

I have watched this forum for a while and seen some good advice. I thought i ought to join as it was unfair to take and not give. i have only posted few times and already someone has fallen out with me. I did not realise running my generator in a deserted bay in England could annoy someone dining in their cockpit in the sunny Caribbean sea.
Consequently I will no longer be posting or watching or having anything to do with this forum. People are always looking for an argument and i have enough of that at work.

 

[fisherman]

12/24 is the norm on many FVs, inc mine, now sold. 12v to run anything that needed it, like VHF, computer monitor. Separate fusebox from a 24/12 convertor, plus I had an extra one dedicated to one emergency VHF with very few connections. The idea being to bypass anything that might suffer unexpected failure, like a distribution board/fusebox. I reluctantly ran it off the main isolator switch, should really have been permanently connected to the battery bank with an inline fuse, but I would have left it on all night and the harbourside cottages would have to listen to fisherman early hours chat.

 

[sfellows]

We've 24v primarily with a few 12v circuits. No real issues, but you must remember for wiring circuits you can go from 12v to 24v with the same wire circuit but you MUST NOT go from 24v to 12v using the same wire circuit.

 

[MontyMariner]

but you MUST NOT go from 24v to 12v using the same wire circuit.

If the 24v circuit hasn't been over speced