42 V electrical systems?

Any guess on how long it will take boat manufacturers to switch over? Who do you think is going to be the first?

I would say a long long time if ever. All the accesories in a boat are or at least based off of a car system. Think of all the people who have bangin systems in their boat as well as integrated balast with pumps. Also, manufaturers would have to spend a ton of money in r & d, as well as new componsets. Sorry mark, not gunna happen. What are the benifits of a 42 volt system anyway?

Chevy is supposedly doing it on their new hybrid trucks, so it may trickle down someday.

To fill everybody in, ALL cars, yes ALL cars in the not so distant future will switch to 42V. Chevy, Ford, GM and the rest already have 42V models far past R&D, I believe Mitsubishi even has one out right now...or maybe it's a Ford, I dont remember off the top of my head. But the point is everything is going to go towards it because of the huge strain put on 12V systems. look around on the net and you would be suprised at how much stuff is out there about this.

Mark is right. Because of the high amp's in the cars, the manufactures gonna switch to 42V (because power = Amp's x Volt , Volt 3x higher = Amps 3x lower and thus better controlling in cables and power loses).
We're designing pretty much car electronics and all of our IC's are at this moment bi-voltage (so can be connected to 42V and 12V). It's a matter of time when they switch to 42V . And if it's in the car industry I think the boat industry is gonna follow..

Whoah! Sorry guys. I guess I was out of the loop. Makes sense to me. I think the transition is going to suck though, but stereos are going to be a lot louder and a lot more efficent. The question is are they going to make 42V batteries or wire 7 six volt batteries in series?

im sure it will just be 21 smaller cells in one battery about the same size as before but it still doesnt make wire size any smaller. Wire is rated for a certain power and even if you up the voltage and drop the current you are still required to use the same amount of power to do the same amount of work IE: turn the motor over??

Are you sure Bob? I thought the problem with 12V systems is you don't have a lot of head room for voltage drop, with higher voltage systems you can drop 5-10 volts without a major problem.

Bob is incorrect about wire sizeing. 10 amps times 12 volts = 120 watts, 10 amps times 42 volts = 420 watts! A 10 gage wire is rated about 35 amps up to 600 volts.

I think the reason they are changing is that you can draw alot more current on a smaller wire. It's the same reason they use 277 volt lighting in commercial buildings instead of 110 volt, copper aint cheap!

I disagree with Bob, wire is sized by the amperage it carries, and rated by voltage and temperature.

A few random thoughts on this:

1) The higher voltage would certainly make the wiring for high power things easier. Higher voltage means lower current, and wire size is based on current.

2) In conceptthe battery is just a larger number of smaller cells. Unfortunately, each cell requires separation, so the effective useable space of the battery is significantly reduced. The end result is that the battery would be a lot larger.

3) At 42 volts you are at the point where it is a shock hazard. 42 volts and a wet environment is not sounding good. Add salt water to that mix and it could become a significant problem.

4) It shouldn't really make a difference to the amps what the input voltage is. Whatever the voltage is the amp will need to convert it to something else and regulate it. It is a little easier to start with a higher voltage but it isn't that much harder (or expensive) to work with a lower voltage as input.

The higher voltage would certainly make wiring easier, but I am not sure that it would be worth it on a boat.

Rod

Rod-
The 42 volt threshold was chosen because it is less than it takes to stop a human heart.

I stand corrected, i thought marine/automobile wire was not rated for high voltage but just checked and found it is good to 600 volts.


Mark it only takes approx 10 milliamps or .010 amps across your heart to stop it. The thing people always say is that the current kills not the voltage...guess whats pushing the current through your body---voltage is and the higher it is the easier it is to push .010 amps through you. 13.5/ .010 = 1350 is the resistance or impedence your body would have to drop to in a 12-14 volt system and in a 42 volt system it would then be 42/ .010 =4200 ohms or 3 times less??????? Lets see your out in the boat---WET--- and your boat wont start so you go back and start working on your 42 volt battery ...thats gonna leave a mark. Anyone ever feel what a 12 volt battery can do when your wet, can you imagine three times that??

see if this loads

Don't count on seeing 42-volt marine systems anytime soon, and probably not before the end of the decade at the earliest.

Several years ago they said we'd see the first 42V automotive systems in 2003. One main reason it hasn't happened yet is very relevant to marine applications: a 42V system is much more prone to arcing when circuits open and close. Designing components that address this problem is turning out to be a larger challenge than expected.

Plus, the first cars will have a dual system; 42V where a lot of power is needed (the starter, heated seats, and electric brakes, steering, and suspension systems) and 12V for radios, lights, small motors, etc. (and, yes, two batteries). There likely won't be sufficient components for exclusively 42V systems until about 2010.

BTW, the 42V systems will have 36V batteries. That's analogous to the situation today, where 14V systems (that's the charging rate) use 12V batteries.

Okay Bob, you right about that. So that's why we don't see 42V this decade in a boat. But people are already putting a second or a third battery in their boat, so their is a demand for a 42V system.

Jeff, we already see 42V systems in cars!! Alright it's 2004, but nothing is on time these days ;-) . But that has nothing to do with the Marine applications imho.
The most part (all as far as I know) of the car electronics (IC's not power electronics) are these days already designed for 42V systems. The new alternators (with built in starters) are gonna be 42V. The entire A/C, heated/cooled seats, lights, window motors and the IC's (CAN/LIN, MicroControllers) are already availeble in 42V. I don't know about navigation/DVD/radio but I cannot think that is a huge problem. But you right that it won't be mainstream before 2010, and the batteries will be 36V...

I agree that 42V systems are going to be great in cars. They will cost more, but the advantages are weight savings, better fuel efficiency, better steering, suspension, and brakes, and a wealth of new electronic options. None of these benefits apply much to small pleasure boats (well, except fuel efficiency, but I doubt we'll see hybrid boats or boats that turn off the motor when they're stopped at a signal).

You're right that a 42V system would be much more efficient for a sound system on a wakeboard boat, but such a change would drive up the cost of the entire boat line quite a bit while improving things for a very small number of boats. Plus, boat manufacturers don't even offer the kind of mega-amp sound systems that would really call for a 42V electrical system; those are after-market.

I'm aware that suppliers are ramping up with components that will work in 42V systems as well as 12V (14V) systems. AFAIK, however, there is only car with an actual 42V system. It's a hybrid, and it's available only is Japan at this time. I'm hearing that Ford may come out with a dual system (42V/12V) in an SUV next year, but we're still several years away from widespread, complete 42V systems in cars.

Yeah, I'm aware that the boat industry is not leading in this technology because the costs are to high. But when an engine (starter, bobine and computer) and stereo's are mainstream in 42V, the 42V will become cheaper. And thus the 12V become more expensive...
I think you right about it's not the near future for the boating industry... But ultimately (sp?) the boating industry has to follow, because it's cheaper..

Why do we talk about 12V and 42V instead of 14V and 42V?? Even in our designs we talk about 12V and 42V... Strange?!

http://www.cmcpower.com/html/electricity/why42volt.asp