12v circuit refit - ideas/refinements?

[solent clown]

Might look cool, but I imagine it would be a nightmare if anything significant went wrong! The fuses and relays are just plug-in items, but there's a lot of electronic witchcraft there as well. From a DIY point of view, there's much to be said for being able to trace wires.

I didn't want to offend by saying so old chap, but I was thinking exactly that ;-) I was a lecturer in battle damage repair in one of my previous lives. Looking at that reminds me of the time I had a 43 series APC shot with a raden cannon for about 30 seconds, then after the pinging stopped sent the techs in to have a look at fixing the comms gear... Nothing doing, bits of circuit board everywhere. The Vehicle Mechanics however had the "tank" running again and jury rigged in minutes. there is lots to be said for simplicity, but some things are just not lent to that.

 

[solent clown]

Unless wires are routed poorly mechanical damage is very rare. The main risk is corrosion in the damp atmosphere, especially if salt water gets below (it takes ages to really dry compared to fresh water). Flooding and resultant corrosion is also a bit of a risk. I definite avoid the typical crimp connectors, preferring waterproof glued heatshrink ones, although some argue for the lucar type connectors as they are easier to inspect. Also try to keep the wiring a fair few inches up just in case you get a few inches of flooding.

Another non-auto risk is boiling of batteries from solar charging if the boat is left too long uninspected on a mooring, so make sure the charging regime is suitable.

We are well used to immersion, not with the added dimension of salt - but mud does a pretty good job of ruining anything not heatshrunk by holding moisture.

 

[<152587>]

Real fun can be had by making Boolean functions out of relays. Did this recently to control 3 wiper motors on big mobo. Controller £300 squidish, few relays £10.

 

[solent clown]

Real fun can be had by making Boolean functions out of relays. Did this recently to control 3 wiper motors on big mobo. Controller £300 squidish, few relays £10.

Lovely, now you are talking. BDR

 

[pvb]

I didn't want to offend by saying so old chap, but I was thinking exactly that ;-)

No offence taken! But the reality is that most modern boats have lots of inbuilt electronics, just as all modern cars essentially make DIY repairs no longer feasible.

 

[solent clown]

No offence taken! But the reality is that most modern boats have lots of inbuilt electronics, just as all modern cars essentially make DIY repairs no longer feasible.

yep, we use a lot of modern engines and gearboxes, so we either build our own ecus or use an emerald system - it's easier than trying to unpick the original loom most of the time, especially with transponder immobilisers and the like.
Out of interest, does that board run everything? And what would it cost to carry a spare?

 

[pvb]

Out of interest, does that board run everything? And what would it cost to carry a spare?

Yes, it supplies power to most on-board users. For my sort of sailing, a spare isn't necessary, and I've no idea of the cost.

 

[rogerthebodger]

Yes, it supplies power to most on-board users. For my sort of sailing, a spare isn't necessary, and I've no idea of the cost.

That is a very good point. Foe my kind of sailing I would not have a board like that to control the power to most on board.

I had a board like that control my remote control gates. The board failed and could not get a replacement. I ended up replacing the functions with a 3 standard 8 pin plugin relays that can be fixed with off the shelf items.

 

[pvb]

Foe my kind of sailing I would not have a board like that to control the power to most on board.

In that case, you wouldn't buy a modern production cruiser.

 

[rogerthebodger]

In that case, you wouldn't buy a modern production cruiser.

You are correct and I have not.

 

[solent clown]

it is a fascinating thing indeed, that we combine an ancient technology such as sailing, with hi tech modern electrics and living. All the more reason to see the many "shades" of sailing, and know we all do things on our own way.
I favour simplicity and ability to fiddle as much because my background and work have drawn me to that, as much as others want a sophisticated plug and play production solution, or all points inbetween. This thread has been fascinating for me to see those differing opinions, and approaches, and I hope our deviations have not offended the OP too much.

 

[pvb]

...and I hope our deviations have not offended the OP too much.

I suspect the OP may be immune to change.

 

[GHA]

That is a very good point. Foe my kind of sailing I would not have a board like that to control the power to most on board.

Agree a big number percent. Almost all the disagreements on this thread I think can be put down to systems for different styles of boats not being compatible, not sure how many if any really 'gets' how vitally important self sufficiency is on a cruising boat. Which was a main driver for the LX refit slowly going on - spare battery never touched plus very basic switching. I'd never have a board like that onboard either, more than fine on a normal weekend few weeks in the summer not too far away boat but cruising far too many chickens in one basket waiting to go wrong sooner or later.
Not that a bit of clever stuff is pure bad and nasty, I've raspberry pi doing lots of really handy stuff onboard and spitting out lots of things over wifi, but that that all goes down and a moment the boat can still carry on functioning safely on next to nothing.

 

[PaulRainbow]

Agree a big number percent. Almost all the disagreements on this thread I think can be put down to systems for different styles of boats not being compatible, not sure how many if any really 'gets' how vitally important self sufficiency is on a cruising boat. Which was a main driver for the LX refit slowly going on - spare battery never touched plus very basic switching. I'd never have a board like that onboard either, more than fine on a normal weekend few weeks in the summer not too far away boat but cruising far too many chickens in one basket waiting to go wrong sooner or later.
Not that a bit of clever stuff is pure bad and nasty, I've raspberry pi doing lots of really handy stuff onboard and spitting out lots of things over wifi, but that that all goes down and a moment the boat can still carry on functioning safely on next to nothing.

What happens if the 1-2-both switch burns out whilst motoring in heavy weather, being blown towards a lee shore ?

Oh yes, you die.

i just hit the emergency switch.

You keep referring tp "basic", nothing more basic than an on/off switch. You just cannot seem to grasp that the system i drew up has all of the functionality you asked for, but is simpler, more reliable and has greater redundancy.

You drew something that looks like a dogs dinner and is a fusing nightmare. Strip away the solar bits for a moment and all you have is the most rudimentary, olde worlde, 1-2-both system, with no added value at all. All it does is select which bank you use, you obviously have to select the main bank, because the other one is too small to run the domestics. You decry a VSR for split charging, but you'll happily fit a cheap Chinese DC-DC convertor and rely on that to keep your emergency battery topped up. Your emergency power supply relies on a single point of failure, the 1-2-both switch

 

[lpdsn]

I suspect the OP may be immune to change.

Looks like it.

 

[GHA]

What happens if the 1-2-both switch burns out whilst motoring in heavy weather, being blown towards a lee shore ?

Oh yes, you die.

i just hit the emergency switch.

You keep referring tp "basic", nothing more basic than an on/off switch. You just cannot seem to grasp that the system i drew up has all of the functionality you asked for, but is simpler, more reliable and has greater redundancy.

You drew something that looks like a dogs dinner and is a fusing nightmare. Strip away the solar bits for a moment and all you have is the most rudimentary, olde worlde, 1-2-both system, with no added value at all. All it does is select which bank you use, you obviously have to select the main bank, because the other one is too small to run the domestics. You decry a VSR for split charging, but you'll happily fit a cheap Chinese DC-DC convertor and rely on that to keep your emergency battery topped up. Your emergency power supply relies on a single point of failure, the 1-2-both switch

Getting all defensive like that it's obvious there's not really much point in trying any kind of further discussion.

You do it your way, I know what I need & I know my boat and what works- I'll do it mine. Chill.

Thanks for the input though, helped thinking deeper into things.

 

[GHA]

Looks like it.

Not at all, nothing was rejected out of hand, just that none of the comments come from a cruising boat perspective, Roger's the only one who knows what he's talking about.
Prime example is everyone getting into a big row about their favourite switch and no one person interested in how to keep lead acid in best condition.

Oh well so it goes

 

[GHA]

What happens if the 1-2-both switch burns out

Does that ever happen? Never heard of one burning out but would be nice to know if it's a common problem - any details of any incidents anyone?

 

[Daverw]

I had one on my last boat weld the contacts and just helped a friend replaced one where the contacts were starting to fail and needed switching a few times before they held. Checked the voltage across and had 0.5 v drop

 

[GHA]

I had one on my last boat weld the contacts and just helped a friend replaced one where the contacts were starting to fail and needed switching a few times before they held. Checked the voltage across and had 0.5 v drop

Thanks, good to know - what sort of load?


What about on/of switches - any failures there?