1st step: auto industry switching to 48v

[Mako]

Just read about how Tesla is not only switching to 48vdc as its system voltage, but that Musk has been writing to other vehicle manufacturers with a white paper as well.

It’s wonderful to see this. We know that the switch to the 12v standard was also driven by autos many decades ago, and this is what we need to help push 48v forward in the marine industry, which will eventually lead to more commonly available components of all sorts, with lower prices as well.

It will be a great sign when you see 48v bilge pumps and affordable alternators becoming available.

https://insideevs.com/news/656775/tesla-switch-48v-voltage-system/amp/

 

[SteveK]

I don't understand the cheaper part. Maybe you are saying current overpriced 48v parts will be cheaper when there is more demand, I dunno.

 

[Comodave]

I don’t see it making much, if any, impact during my lifetime.

 

[Mako]

Parts aren't overpriced. They are expensive. Simple supply and demand economics.

48v house banks for boats will become more prevalent as the industry evolves in the coming years. It won't take "lifetimes" however. Of course that really only affects new build boats, or those making major upgrades to their systems, not the millions which already exist with 12v or 24v systems.

 

[mvweebles]

I agree with you Mako. There are a lot of advanced in DC power controls and storage being driven by the off-grid solar industry, not just for cabin owners, but there are s ton of remote site industrial applications too. There are some super cool rack systems and all-in-one inverter/MPPT/charger systems that are well into the adoption phase. Whereas Victron has taken an approach of separate devices for every component feature, EG4, Schneider, and others have combined these into single, compact chassis that are super simple to install and cable vs the Victron wall of blue boxes connected by red/black wires and cables.

Mind you, these all-in-one chassis's are less than half the price of Victron components.

If I were to buy a new boat, would definitely have space for a smaller server rack for house/inverter loads. Would it be 48v? Might be a bit early for 48v, but would be my preference. There are 48v alternators available. A second 24v alternator and a relatively small 24VDC system for standard boat loads.

I see there is a perennial thread on Helmsman - wonder if anyone has approached a builder like them to proble art-of-possible?

Peter

 

[Nick F]

Some years ago I was crawling around behind the helm panel in a 58LRC. I had my shirt off and was sweating (we were off the central american coast). All of a sudden, I got quite a shock.

The boat system was 32 volts and with salty-wet skin you get a very noticeable shock. I would be concerned about 48 volt boat systems.

 

[tiltrider1]

I do not think the auto industry will be around long enough for 48v accessories to make it to the boating world. I could be wrong but as Comodave said, not in my life time at least.

 

[mvweebles]

I do not think the auto industry will be around long enough for 48v accessories to make it to the boating world. I could be wrong but as Comodave said, not in my life time at least.

I read the OP differently - I don't necessarily see 12v autos going to 48v (or even 24v for that matter). But I definitely see where 48vdc systems to drive LFP battery based inverters makes a ton of sense. Over the last 5-10 years, all cruise-capable boats power and sail (especially catamarans) have added a ton of 120vac appliances and applications. These are ripe for 48v base systems as that's the system of preference for the off-grid applications that are driving the advances. I think the transition will occur fairly quickly.

In short, the big change "Killer App" that could give transition to 48v is desire for 120vac (or even 240vac) appliances. Appetite has increased that the use cases are effectively at far end of what a 12vdc can easily support. Rather than create some sort of hybrid 12v (or 24v) system that expands off a boats DC system, it is making sense to build a more robust DC system that is dedicated to providing VAC support.

Peter

 

[tiltrider1]

I read the OP differently - I don't necessarily see 12v autos going to 48v (or even 24v for that matter). But I definitely see where 48vdc systems to drive LFP battery based inverters makes a ton of sense. Over the last 5-10 years, all cruise-capable boats power and sail (especially catamarans) have added a ton of 120vac appliances and applications. These are ripe for 48v base systems as that's the system of preference for the off-grid applications that are driving the advances. I think the transition will occur fairly quickly.

In short, the big change "Killer App" that could give transition to 48v is desire for 120vac (or even 240vac) appliances. Appetite has increased that the use cases are effectively at far end of what a 12vdc can easily support. Rather than create some sort of hybrid 12v (or 24v) system that expands off a boats DC system, it is making sense to build a more robust DC system that is dedicated to providing VAC support.

Peter

I certainly see 48v banks and inverters for supporting 120v windlasses and cranes. I don’t see 48v bilge pumps in our future.

As you said, there is a lot of 48v development coming from the off grid folks.

 

[Mako]

48vdc house banks are gaining in use, both for high energy needs on trawlers and on electric propulsion conversions in sailboats. This is where I currently see most (marine) uses.

Component availability is the issue in the marine market. It is slowly coming along, with 48v windlasses now available. I asked Rule a year ago and they had no thoughts of offering bilge pumps, but don't be surprised if that changes within a couple of years. Alternators are the problems. They are limited in availability and currently cost around $1500+ which is about 3X what a typical large frame HO 24v alternator can be sourced for.

BTW, you can source 48vDC split unit air-conditioners from the telecom industry. I've checked them out and unfortunately they are not particularly energy efficient, not even close compared to digital inverter VAC mini-splits.

 

[painlessone]

There are lots of advantages to 48 volt systems. Much smaller wire harnesses, less weight, more efficient, less cost because of less copper in the wiring. All PoE (Power over Ethernet) is already 48 volt. The white paper Musk sent also diagramed how much simpler all the components of a car or boat would be using PoE rather can independent CanBus systems for directing engine temps, oil pressure, navigation, radar, etc. to your MFD....maybe not in our lifetime (I'm 79)

 

[nwboater]

Mako, I've installed an all-in-one 48V lithium battery with a built-in 3000 watt inverter in my American Tug 34. It stores 4.5Wh of capacity. It has worked flawlessly for the past 2 summers. The unit powers the electric cooktop, coffeemaker, ice maker, and other AC appliances on the boat. I have also used it to charge the 12V house bank when we woke up to low batteries and didn't want to run the generator Info on this "power station" is available at Hysolis.com

 

[Mako]

Richard, that's a great product and install. For smaller boats with modesty needs, it's fantastic to have an all-in-one. Question though, have you noticed the closed cabinet getting particularly warm during times of heavy draw? A 3kW inverter is putting out about 300 watts of heat during full power.

 

[nwboater]

It can get warm during the summer months. I installed a small 12V circulation fan that plugs into the unit’s DC USB port. In addition to a built in 120V charger, the Hysolis also has an MPPT solar charge controller.

 

[Delta Riverat]

I'm all in favor of 48 volts. Same power with 4 times less copper. Especially now with high power inverters and solar. No more 2/0 cables!

 

[kthoennes]

Some years ago I was crawling around behind the helm panel in a 58LRC. I had my shirt off and was sweating (we were off the central american coast). All of a sudden, I got quite a shock.

The boat system was 32 volts and with salty-wet skin you get a very noticeable shock. I would be concerned about 48 volt boat systems.

I agree. Boats, cars, and a very elaborate, multiple transformer landscaping and outdoor lighting system at the house, including the koi pond, and security cams - all 12 volt. Heavily invested in the staus quo, but more than that, I don't have to worry about getting killed if my boys and I get wet and do something stupid. Heck, I've even kept a collection of 12v cordless power tools at home and the boat because I can use the batteries as testers. Dinghy bilge pump - everything. All interchangeable.

 

[Max1]

It stores 4.5Wh of capacity.

Thats not much. Unless you meant 4.5KWh

 

[Circumnavigator]

All three of our recent boats have 12 and 24VDC systems because while there are 24V Solas VHF radios, they cost three times as much as a high end 12V VHF. Also, N2K runs on 12V, so you have to have both. On the other hand, the copper saving is real, so 24V is worth it.



I don't see having 48VDC aboard until I can get a bow thruster and windlass using it -- they are the only loads where there is a significant saving in wire size.


Jim


Sweetwater - Swan 57 sloop - circumnavigated 1995-98
Fintry - x Royal Navy Fleet Tender 2003-22 20k miles including x-Atlantic The Fleet Tender Fintry
Morning Light -- Webbers Cove 42 trawler 2021- 23
Going back to sailing now that Morning Light is sold.

 

[Xlantic]

I'm all in favor of 48 volts. Same power with 4 times less copper. Especially now with high power inverters and solar. No more 2/0 cables!

And even less copper: the power loss along a conductor is inversely proportional to the square of the voltage.

 

[SteveK]

And even less copper: the power loss along a conductor is inversely proportional to the square of the voltage.

interesting stuff. once upon a time there were 6 volt vehicles.

 

[Mako]

I don't see having 48VDC aboard until I can get a bow thruster and windlass using it -- they are the only loads where there is a significant saving in wire size.

Those both exist now. 48vdc motors are available for being adapted. Just generally not through West Marine. Just takes some effort.

 

[diver dave]

And even less copper: the power loss along a conductor is inversely proportional to the square of the voltage.

assuming you design for constant waste power in the feeder: 2/0 turns into AWG11. really AWG10 since that is available. yes, that is economically very significant!

 

[socalrider]

I don't see having 48VDC aboard until I can get a bow thruster and windlass using it -- they are the only loads where there is a significant saving in wire size.

What about 120/240AC windlass and thruster? Do these exist?

I still like the idea of a 48V house bank charged by solar and 48V alternator(s), driving a 12VDC bus via DC-DC converter that manages all the standard house loads, LED lighting, bilge pumps, electronics, start battery, etc. Then a couple of inverters running all the heavy loads: HVAC, reefer, cooktop, water heater, thruster, windlass, davit crane, etc.

All the low power stuff stays at the 12V industry standard, all the high power stuff uses AC motors which are cheap, efficient, and super reliable. The missing pieces are reasonably priced 48V alternators (which seem to be coming along), and possibly the AC windlass & thruster; everything else is already there.