2021/2022 Updates on 48v for main system bus

[codingparadox]

Our boat was a 2008 boat with all original electronics when we got it at the beginning of this year, so we had to build a new system from scratch anyway. I'm a big fan of being able to run multiple A/C units at the same time for hours straight on anchor, with under 100 amps being drawn from the batteries, and hence very little heat in the equipment cupboard.

We have a 48V windlass on order since our current one is a bit undersized for the ground tackle we're now using (also had to upgrade from original undersized stuff). We're looking at thruster systems and deciding between the 48V Ventus thrusters or going with a jetthruster setup (also 48V natively).

48V is lovely, and we're at the precipice of it taking off in much more mainstream fashion. Once I get the windlass off the 12V system, the last big draw will be the swim platform, which I can just run off the start battery and have the entire house 12V system just run off a simple DC-DC converter.

[mako]

@AlaskaV, I was just reading through that 2019 thread and searched up this new one. Thanks for starting it as it's great to update discussions based on today's technology, not from 2 years ago.

Just as electric vehicles are now taking off and are becoming accepted by the conservative consumers (versus 2 years ago when Tesla was the only viable player in town), the same can be said for 48VDC primary systems.

What is available in 48VDC
It was mentioned that now the boating market can buy 48V windlasses and thrusters. Also, as electric scooters and small vehicles are exploding worldwide (but not so much in America, which is way behind the times), various sized 48VDC motors are readily available. Just check Alibaba for example.

LEDs (residential style E216 base) are readily available in 48V, they are just sorta expensive.

Water heater elements 48VDC at 900 watts are available. Typical American residential water heaters have 2 elements, so you could leave one at VAC and the other replace with 48DC to power directly from your solar, or batteries.

Mini-split airconditioners (if you can accommodate the condenser and hide its ugliness) are available from the telecom industry in 48VDC. They're just not very energy efficient compared to the new digital-inverter residential units, which are really, really wonderful!

What is not readily available in 48V
Bilge pumps. Solution is either stick with a secondary voltage, or install 48V centrifugal pumps wired to float switches.

Electronics. No problem, just run 12V through a B2B to a bridge battery. Hell, even VHF radios are practically not available even in 24V, very expensive if you do find them.

So I think a new build can be had with just 3 different voltages onboard: 12VDC (bridge), 48VDC (house), 50hZ/60hZ VAC.

[mako]

BTW, I love the idea of building a watermaker with a 48VDC motor, thereby bridging the difference in water production between typical 12V and 120/230V systems.

Same to be said for a scuba compressor.

[GordMay]

Originally Posted by mako

...So the question is "what is not readily available in 48V?"
Bilge pumps. Solution is either stick with a secondary voltage, or install 48V centrifugal pumps wired to float switches...

Fafeicy Power Converter Module, Buck Converter DC36V/48V Step Down to 24V 480W*, Waterproof Power Converter
$50.29 ➥ https://www.amazon.ca/Fafeicy-Conver...NsaWNrPXRydWU=

Cllena DC 36V 48V to 24V Converter Voltage Reducer 30A 720W* Waterproof DC Step Down Converter Buck Transformer
$72.99 ➥ https://www.amazon.ca/Cllena-Convert...0701566&sr=8-5


* Bilge pumps typically draw less than 200 Watts, or ±400W for the very largest.

[codingparadox]

Most of our boats have a ton of basic 12 or 24V stuff floating around them. Without a brand new build in the next few years, after more stuff like LEDs are readily available, I don't see a world in which you aren't multi-voltage (48V and 12 or 24, depending on boat build) for retrofits like ours. I'm going to move the big loads over to 48V where I can (i.e. windlass/thruster), but definitely will be keeping a 12V circuit for everything from kitchen lights to helm electronics. Heck, even N2k needs a 12V line, and that isn't going anywhere any time soon.

[alaskanviking]

I'm still curious about this. I see more and more signs that a multivolt system is the way to go for future proofing. The DC to DC converter will be the key piece it looks like. I think I need to do a full DC Elec system analysis and verify what equipment needs what voltage and what can be modified or swapped out with 48v native.

Right now my projects (mast refit, AC install) have all gone over time and over budget. Sucking up all my time and energy, and money. New plan of action is to rewire the AC system first and skip the 48v inverter/chargers for now. I have a 24v system now so I am thinking of replacing the 6v golfcart batteries with a small 24v Lithium bank, as a buffer bank for the 24v system. Call it the navigation bank.

I don't nessesarily like multiple banks this way, however the current 24v victron inverter charger and the sterling alternator regulator can be programmed for lifepo. So immediate conversation to lifepo, get rid of the lead acid, and partially rewire the DC side, while letting me use most of the stuff I already have. In theory this makes the system easy to add a 48v and DC to DC charging system. If there are any issues with BMS the separate bank will still have power.

That lets me concentrate on fabricating the house bank box in the bilge, installing conduit, ordering batteries, at my convenience. I can either wire the bank 24v/48v as things change. Use a cheap charger to start, and a small DC to DC charger to top off the 24v bank. Order the new inverter 48v chargers once everything is connected. Although i suppose I can get 48v inverter chargers as part of the AC rewire and just have them limited in use untill the other dc charging equipment (alternator ect) is changed over. Regardless the theory is to push the 48v change to the right but set things up to easily change to and support 48v.

[ArranP]

I'm currently caught between installing 24v inverters or 48v inverters with 48v-24v buck converters.

Existing equipment i.e. windlass and winches are all 24v.

As yet I have not bought the battery bank nor the inverters.

[mako]

@ArranP, honestly the answer is a no brainer. You have little to gain on an existing boat with existing wiring and systems. Save the 48 for your next new-build or total reconstruction

[ArranP]

Hi Mako, Thank you responding....

At this point I plan to keep the existing 24V system and equipment ( winches / windlass etc ) However I am caught between installing 24v or 48v inverters and battery bank ?

If I were to go the 48v route with the inverters / battery bank then this would require
DC-DC buck converters (48V -> 24V ) to power the 24V bus from my 48v bus.

Something similar to the Wakespeed 3000 or the Calex 3000 that were mentioned in an earlier post in this thread. https://www.cruisersforum.com/forums...ml#post3472897

With several of these buck converters connected in parallel ( and one on the shelf as a spare ), I am assuming this is enough to power to the 24V bus and cope with the surge from the 2KW winches & windlass ?

Instead, If I were to go the 24V route for the inverters / battery bank, I would need twice as many inverters ( 4x 3KW instead of 2x 5.5KW ), 2/0 AWG battery cable instead of 4 AWG cable, and twice as large BMS ( 200A instead of 100A ) for each of the 4 10KW batteries.

[alaskanviking]

Originally Posted by ArranP

Hi Mako, Thank you responding....

At this point I plan to keep the existing 24V system and equipment ( winches / windlass etc ) However I am caught between installing 24v or 48v inverters and battery bank ?

If I were to go the 48v route with the inverters / battery bank then this would require
DC-DC buck converters (48V -> 24V ) to power the 24V bus from my 48v bus.

Something similar to the Wakespeed 3000 or the Calex 3000 that were mentioned in an earlier post in this thread. https://www.cruisersforum.com/forums...ml#post3472897

With several of these buck converters connected in parallel ( and one on the shelf as a spare ), I am assuming this is enough to power to the 24V bus and cope with the surge from the 2KW winches & windlass ?

Instead, If I were to go the 24V route for the inverters / battery bank, I would need twice as many inverters ( 4x 3KW instead of 2x 5.5KW ), 2/0 AWG battery cable instead of 4 AWG cable, and twice as large BMS ( 200A instead of 100A ) for each of the 4 10KW batteries.

Your in the same spot I am. I fluctuate on this every day it seems.

The problem is the only thing I found with enough DC to DC amperage that can supply enough power to charge and run things when the 24v bank is drained is the wakespeed and they aren't selling it yet. That means I would have a hard time charging the 24v bank away from the dock, or charging sources would have to be connected directly to the 24v bank. On the same note120v to 25v charger only devices don't usually have large charge amperages ~20 amps so when you drain the batteries it will take some time to recharge.

I think the wakespeed may be the last critical piece to push me.

Found out yesterday the new refrigerator units I want that were listed as 12v only, will work or have option with 24v. So there will be little to no 12v equipment on the boat. Just the nmea2k and fans I think.

Found the starter motor for my engine that is 24v. Was about to give up. Will rewire everything when I dig into the engine later

[resistor]

I'm working on a 48v + 12v design for a major electrical refit our our catamaran. I'm similarly very anxious to get the Wakespeed WS3000 as the missing piece. I've been in touch with them, and it sounds like they're badly impacted by supply chain problems to the point that a critical subcomponent is just completely unavailable.

We're planning to go ahead with some Victron Orion 48->12 converters instead, and use the start batteries as a buffer for heavy 12v loads. The only one that'll be a real issue is our power winch, as we'll almost always have the motors running when operating the windlass.

[codingparadox]

That approach works fine, as long as you have some way to charge back up to the 48V direction in emergencies. We have a WS3000 prototype unit and I have the 30A 48->12V Orion-Tr as a backup. But I installed my whole system based on the Orion-Tr (with no way to charge the 48V bank from the engines) for a few months until the WS3000 prototype was ready.

[resistor]

Yup, I plan to install an as-yet-undetermined number of 12v->48v converters as well behind a manual breaker that is normally open (as well as breakers to disable 48v->12v converters) to enable reverse-charging in a pinch.

[ArranP]

There are these 1500W ( 48v > 24v ) buck converters currently available on Alibaba... I am contemplating maybe 4 in parallel, but as yet I have not yet approached the manufacturer to pose the question are there any issues with operating these in parallel.

https://www.alibaba.com/product-deta...822145204.html

[codingparadox]

FWIW, you're rarely using that much power. I'm currently running my 12V house as my port start battery. I'm getting some annoying effects from the preheaters (which pull 200 amps per motor!) when starting up, with voltage drop across the rest of my house setup, so I'm going to be putting in a cute little U1 AGM battery as my 12V house, ACR'd to the start batteries. With that there, you have some watt-hr sink for high level transient loads, which will charge back up again rapidly by a single dc-dc converter (even the orion-tr at 30A peak), but stay disconnected from your start batteries while they're cranking/etc. I'm going to a 48V windlass (it's in the hold, just haven't put it on yet) and a 48V bow thruster, so I won't have any big sustained loads on the 12V system after that. I'm already running the hydraulic swim step off the port start battery since it's so close to it, leaving only much smaller and more sustained loads on the 12V "house" setup.