Highest Volatge advisable

50 cents... and really seal it good. In other words to get at batteries you have to cut the box open. Normally the hydrogen will come up the ventilation and you can inject carbon dioxide into it to keep oxygen out. It should never explode or catch on fire then.

 

Its not something I would do and im not sure the insurance surveyor would be too impressed either.

 

I agree with you Frosty. I need at all times access to those batteries. Waterproof with rubber pipes going to outside ventilation is a brilliant suggestion from him, but fiddling with gasses is out.

 

a defribillator is for stopping fibrillation i.e. stopping the hearts irregular beatings
only in the movies does it start your heart

 

I remember that and like the idea as alternators are getting very big and cant produce enough at idle to support a car these days.
I heard the emergency services killed it off thinking the 42v and water in an accident is dangerous?
Now we have Toyota Prius running around with 280volt battery pack and no complaints?

 

I was managing the initial engineering design of new vehicles at the time. My understanding is the primary reason the 42 volt systems were not adopted was a combination of factors including more efficient 12 volt components and the use of "smart" components which reduces the need to run as many heavy wires.

One negative with 42 volt systems in automobiles is the short life of 42 volt incandescent light bulbs due to the filaments being much thinner than 12 volt bulbs combined with vibrations and shock loads. For a while at least it looked like a dual voltage system would be needed with 12 volts for the incandescent bulbs as well as "legacy" plug in accessories.

 

Well I dont remeber it or even hearing of it and I was in the motor trade at that time .. was this USA.

Only benefit would be absolute necessity of purchasing manufacturers spare parts. No copies would be bothered and finance raise its head once more.

 

Yes was in the technical press
I think BMW did a 7 series at 42volt?
There are many SAE papers on it ( you are a member right?) as they were also looking at brushless flywheel starter generators.

http://en.wikipedia.org/wiki/42-volt_electrical_system
http://www.popularmechanics.com/cars/news/4226979
http://www.eetimes.com/electronics-news/4166019/Car-makers-turn-toward-42-volt-systems
http://lees-web.mit.edu/public/in_the_news/a new 42-volt standard.htm

 

BMW yes I could guess at. No after market nothing--- bulbs ,radio , Cd player, you name it. No accessories at all --BMW would love that.

And what,--- 4 x 12 V battery or 1 huge 48,-- again at massive market expense.

 

The purpose of using 48v in a vehicle is to save weight /wiring/starter/battery etc and for the US its only a 2x inverter for the 110v they want to give out on a pick up for tradesmen

 

1 cell is 1,5 V your still going to need a lot of them to make 48. Where is the weight saving there then.

How much would a BMW 48volt batt cost --I shudder to think Or a BMW quarts halogen head lamp bulb. Talk about getting hold of the short and curlies,-- Sorry not for me

 

I(f you look at RING products who I always regarded as cheap you will see they have the full range of 48v bulbs for vehicles..
The idea is to run the starter as a three phase brushless motor and also to use it as the generator as well . a lot of its to do with the auto stop/start on the modern cars and currents at 12 v have reached there realistic limit.
Of course 48v will in fact be 58v on the charged lead acid battery

 

The way they keep water out of gearboxes /axles /distributers on vehicles for wading is to presurise them to a few psi with a small pump...dont think any of this underwater battery stuff is practical unless its a submarine !!

 

Oh give me a break --your showing your ignorance. all of the above is open to atmospheric.

God help the poor kids you've been teaching.

You ever seen a gearbox or diff without at breather.

 

The arc produced when opening and closing relay and switches with DC current is destructive to the point contacts. So lower voltage is better than high voltage. Too bad cause higher voltage means you can use smaller gauge wiring. When you pump up the DC voltage, switches wear out quickly. AC has a self extinguishing arc due to the cyclical polarity, the voltage drops to zero. 12 volts is a decent enough way of doing things. 6 volts was too low. 24 volts is likely a little better than 12, but so many things are designed around 12, the 24 volt stuff will cost more. For example, LectraSan electrode pack is $300 for 12 volt system, ~$600 for 24 volts.

I have a few wires in the lower bilge area for the bilge pump. Whoever installed the boat AC ran a 120 volt wire thru the lower bilge following the copper refrigerant lines for a fan in a split AC cruiseair system. Which I dont like much they way they did that. Salt bilge water even in the air has been eating the copper lines on the outside.

I plan to clean them off and coat them with some PL Premium construction adhesive to seal out the water.
I have a lot of things I plan and not enough time.