House / Start Battery Separation Techniques - Best Practice?

[ilana]

I see a problem to connect batteries minus switch in cases where the product has two input +plus connections.
one fixed + connection to keep the memory and second +plus connection after the main switch is intended to activate the product.
The best example I can remember at this moment is my FM radio in my boat.
Ilan Arbel F

[Wotname]

Originally Posted by ilana

I see a problem to connect batteries minus switch in cases where the product has two input +plus connections.
one fixed + connection to keep the memory and second +plus connection after the main switch is intended to activate the product.
The best example I can remember at this moment is my FM radio in my boat.
Ilan Arbel F

Please note that in the drawing in the original post, the negative of ALL house loads are always connected to the house battery. The only aspect that is switched of the house battery is the negative for starting and running the engine.

[ilana]

Originally Posted by Wotname

Please note that in the drawing in the original post, the negative of ALL house loads are always connected to the house battery. The only aspect that is switched of the house battery is the negative for starting and running the engine.

So FM radio always reset when you close the main switch.

[deblen]

Originally Posted by ilana

So FM radio always reset when you close the main switch.

As Wotname said-In his original post & diagram,the Pos of house dist panel is always connected to Pos & the Neg of house panel is always connected to Neg. Your FM radio(both feeds to it) will always be live,if you don't turn Dist.Panel breaker off. Or,as in a car,you could source the memory Pos from any always live Pos as you would do for an automatic bilge pump,fume alarm,etc.

In my proposal(later post) I suggest a new swx installed in ground source of the existing 1,2,All swx,that would be used to remove all Neg from system--a Master Off / On. That would disable the dist panel ckts.
I also suggested a re-location of the Main Neg Bus source of Neg from permanent conn. to bat Neg to wiper of existing 1,2,All swx.

I didn't add that another source of Neg would be required for Always On ckts such as Auto bilge pump,Alarms,your FM radio memory,etc.

/ Len

[deblen]

"Stole" this diagram from YBW forum-posted by pvb.

Good setup!
Eliminates bridging of House & Start bats. while Emergency Starting from House bat.

https://www.dropbox.com/sh/bj4c5q4o4...9XQRIuUEa?dl=0

[ilana]

Probably not so important what electrical system you are building
What is important is to keep accurate electrical diagram of the ship within reach.

[UNCIVILIZED]

Looks like a topic definitely worth digging into, once properly caffeinated for the day.

[Maine Sail]

Originally Posted by deblen

"Stole" this diagram from YBW forum-posted by pvb.

Good setup!
Eliminates bridging of House & Start bats. while Emergency Starting from House bat.

https://www.dropbox.com/sh/bj4c5q4o4...9XQRIuUEa?dl=0

That is a very standard three ON/OFF switch design that many of us have been installing for many years. Blue Sea even makes a three switch pre-made panel which I install quite a few of..... This owner used to have 5 switches and one of them was a 1/2/BOTH. it was a MESS.... He wanted "simple"..



The only difference is that in the US we generally feed all charging sources to the house bank and in Europe Charlie Sterling has scared everyone into believing that the start battery gets fed first (essentially marketing for one of his products that created a "need" where there was none)....

One of the key points for battery isolation, in case of a failure, is that the emergency parallel switch goes on the load side of the house and start switches.

If you have the room for three switches I generally prefer the three ON/OFF design to most others due to its simplicity and ability for isolation of a bad bank and its limp home redundancy by powering all systems from either bank while also having the ability to isolate the other....

[Bill Seal]

Since the starter relay control is usually part of the engine panel, what about the charging circuit, instruments and such.
The reason I went with the simplistic is from camping with a Ford 7.0L diesel which had both batts paralleled (factory wiring) and I just pulled one terminal when on the beach. When we ran one batt dead, I could always get it started. Sometimes simpler is better.
The boat came with a shore power charger that has 3 isolated outputs, one of the few things the PO did right.

[deblen]

Originally Posted by Maine Sail

That is a very standard three ON/OFF switch design that many of us have been installing for many years. Blue Sea even makes a three switch pre-made panel which I install quite a few of..... This owner used to have 5 switches and one of them was a 1/2/BOTH. it was a MESS.... He wanted "simple"..



The only difference is that in the US we generally feed all charging sources to the house bank and in Europe Charlie Sterling has scared everyone into believing that the start battery gets fed first (essentially marketing for one of his products that created a "need" where there was none)....

One of the key points for battery isolation, in case of a failure, is that the emergency parallel switch goes on the load side of the house and start switches.

If you have the room for three switches I generally prefer the three ON/OFF design to most others due to its simplicity and ability for isolation of a bad bank and its limp home redundancy by powering all systems from either bank while also having the ability to isolate the other....

Thank you for info!
Especially your point of putting the Emerg Combine swx on Load side.
I will make that improvement on my boat.

Regarding charging :

I'm nervous about having a readily accessible on/off swx in alternator out put wire because of possible blown alt. if someone opens swx while engine running. I could live with one of the key operated bat swxs. in the alt. o/p,& keep key stashed somewhere handy.

Reason for conn charging to house over start bat ? I had never given any thot to this,as my existing engine wiring harness took alt. o/p to starter bat term,as most do. Plus my start bat is always up,cause that is all it does. I rely on VSR to quickly bridge Start & House. I can guess your reasons,but I will let you answer.

Re-the English gent. I have noticed "self interest" prevailing in posts from different posters & on different topics. One must keep an open mind at all times.

Cheers / Len