DC voltage conversion

[Hatteras58]

I am considering converting the DC electrical on my 58YF from 32V to 24V. Anyone on the HOF like to offer any 'lessons learned' or other advise/opinion?? Also, there is a long DC terminal block on the forward bulkhead of my port engine room. I do not have a wiring diagram for this block and I cannot find many of the wire numbers on other wiring schematics. Does anyone on the forum have the schematic for this block?

Thanks in advance for any feedback.

 

[SKYCHENEY]

Before you do it, make a list of what has to be changed out and price it. The list gets pretty long:
Windlass motor, toilet motors, vent fans, lights, autopilot pump, water pumps, bilge pumps, chargers, inverters, any step down converters, starters, alternators, etc, etc, etc....................................

 

[Pascal]

There is indeed a lot of things to convert and replace which gets pricey. Is it worth it? Depends...

I converted my 53 to 24v but that was because I was repowering and rewiring the whole boat. Almost 50 years old with questionable untinned wiring... it was time. Let me just say that the hatteras wiring quality left a lot to be desired back in 1970... I knew it worked almost 50 years but it was a way past time to re do it all. I found things like port and stbd shorepower connections made with a crimped copper tube and a lot of electrical tape

Now Hatteras greatly improved the electricals throughout the 70s So your wiring is likely better

Wiring for lights isn’t much of an issue since you ll likely switch to LEDs. Concern is bulge pumps but not too hard to rewire

An option to consider is keep the engines 32v and go with 24v for house with a new battery bank. Saves replacing the alternators, starters, gauges etc. my factory remans Cummins are 12v so I have an 8D for each engine, a house bank and G31 for the generator. You need to add a 24v alternator to one of the mains to charge the house bank if the genset fails though.

Bottom line, I sleep much better at night with a new elecrical system...

 

[oscarvan]

An option to consider is keep the engines 32v and go with 24v for house with a new battery bank. Saves replacing the alternators, starters, gauges etc. --------------- You need to add a 24v alternator to one of the mains to charge the house bank if the genset fails though

This is my plan, with the exception of utilizing a B2B instead of an additional alternator.

 

[Glory]

I changed my YF to 12 volts, 9, maybe 10 years ago. One of the best things I have done to the boat. About $6,000 to $7,000 in parts. Every thing from adding starter relays, changing heads, alternators, starters, bilge pumps, the list goes on and on.

I did it over a winter, started on the must have and worked my way down to incendentals.

I will never carry a 8V 8D all of my batteries are G31s including the inverter.

I remember some pushback when I did the battery refit. The only thing not 12 is the windlass, it's 24 with a dedacated charger.

8 8 volt batteries are now $3,000+, I call replace all 19 batteries for $2100, and I don't need help.

Like others said, it is a big job. If you have questions on me I will send you my number.

Hope this helps

 

[SKYCHENEY]

8 - 8v Rolls can be had for less than $2000, but your point regarding the weight of moving them is well taken.

 

[jmooney]

Where did you get 8V Rolls for $2000 for eight batteries?

 

[SKYCHENEY]

I've posted it here several times. I'll have to look it up. Its a railroad supply company out of Pennsylvania.

 

[jmooney]

Thanks,Jim

 

[stimmy]

While Hatteras seems very conservative in their wire sizes, reducing from 32 to 24 volts may cause some undersize wiring problems. Ampacity, not voltage, determines proper wire size. To do the same amount of work, a 24 volt source needs 33% more amps than a 32, possibly overheating the wire.
Of course, all circuit breakers will have to be upsized to handle the additional current, again possibly causing a problem if the existing wire is not sufficient for it.

 

[davidwigler]

I was amazed when I installed a Victron battery monitor and saw how many amps the DD starters draw. I think it was in the thousands at 32 volts. Maybe they are not accurate at those loads.

 

[Captain Ralph]

Not sure if it's the money, time or just to lazy. My 42 year old, Bertram is still a 32Vdc Bertram.
I keep spares and keep eyes open at used part shops. Sell 32Vdc parts all over.

My new windlass is 24Vdc. It is not a constant use devise, so it can tap off the top of the third 8V battery for 24Vdc with no problems.

Don't let 32V scare you. There are some 48V boats and options still out there.

 

[Glory]

I was amazed when I installed a Victron battery monitor and saw how many amps the DD starters draw. I think it was in the thousands at 32 volts. Maybe they are not accurate at those loads.

In a 12 volt system it is about 1800 CCA to start an 8-71.