12V from 24V house?

[jdege]

I've tossed essentially all the DC components of my boat, including battery, alternator, etc., so I'm starting from scratch.

I've been bouncing between 12 and 24V. Nearly everything I might need is available in 24V, but there are a couple of odd things that only run on 12V.

Now I could install a second 12V battery for them. Or I could install a Victron 24V-12V converter, and run 12V to where it's necessary.

But there are really cheap 24V-12V stepdown converters on Amazon, cheap as in $12. And they claim to be IP-68 rated.

So would it make sense to, rather than installing a single converter and running 12V wire throughout the boat, to just run 24V and to install a small, cheap, stepdown converters at point of load?

 

[chrisski]

Why swap to 24 volts?

My swap from 12 volt to 24 volts was to keep amperage down on a 3000 watt inverter.

If you do go 24 volts, I would go with the Victron converter. The smaller, cheaper multiple converters could come with an idle draw a little too high.

 

[jdege]

Everything that was 12V I'm throwing away.

Why 24V? Lower currents means cheaper wiring. And, like you said, currents get very high, at 12V, for a sizable inverter.

I'll pick up one of the cheap converters, and see what kind of loss it shows.

 

[chrisski]

Everything that was 12V I'm throwing away.

Why 24V? Lower currents means cheaper wiring. And, like you said, currents get very high, at 12V, for a sizable inverter.

I'll pick up one of the cheap converters, and see what kind of loss it shows.

I used one cheap converter connected to a 22 VDC panel to charge USB off solar input with no battery.


I stopped using this after a couple of days afraid this wouls fault out and ruin my phone I was charging.

 

[jdege]

I stopped using this after a couple of days afraid this wouls fault out and ruin my phone I was charging.

You need to use cheaper phones

 

[TimE]

My boat was built as a 24v boat. We have a 24v engine with 24v starting and alternator. Th engine uses a 24v to 12v dropper to power the control panel.
The Raymarine electronics run from a 24v to 12v dropper. Another dropper runs 12v USB chargers in the nav station. Another one runs 12v chargers in the saloon. The VHF has its own dropper and the cockpit has another for USB charging and a second VHF. None of these droppers are Victron. There are lots of sources of reiiable 24v to 12v droppers available for little money. I like using numerous droppers as I get built in redundancy. In an emergency I can just run a wire to a device from an existing dropper or hook up to a spare 40A dropper I have in the engine room on a switch should I need it. This keeps my distribution panel all at 24v with a device powered by a local dropper where needed

 

[JoeHam]

But there are really cheap 24V-12V stepdown converters on Amazon, cheap as in $12. And they claim to be IP-68 rated.

So would it make sense to, rather than installing a single converter and running 12V wire throughout the boat, to just run 24V and to install a small, cheap, stepdown converters at point of load?

Know that the cheap converter will be consuming power 24/7/365 unless you only use it intermittently.

Personally I’d add a cheap 12V battery just for the 12V loads.

 

[TimE]

Know that the cheap converter will be consuming power 24/7/365 unless you only use it intermittently.

Personally I’d add a cheap 12V battery just for the 12V loads.

A cheap 12v battery that you will need to keep charged using continuous power. What's the difference? The energy consumption of my 24/12v droppers is negligible. They use so little power. You can tell that as they don't get warm. The inefficiency can only be via heat if no current Is flowing to the load.