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Broken battery isolator


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Damn! I broke the battery isolator (runs from battery selector 1-or-2 to main switch panel). One side of the housing cracked. It’s an unusual design: you pull the slider out to break the circuit. 

 

Any idea where I can find a replacement? 

 

Pic attached:

 

 

D8A4ED3B-2149-4D62-B3FA-581746B054DB.jpeg

Edited by dewshi
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It would help if we could see the rest of it. It looks like some kind of plastic "bracket" possibly identified by @philjw plus a home-made metal adaptor plate for mounting the switch on. I think most "cheap" key type switched would fit that plate so I would get a length of steel strip welded to it along the back edge so it can be screwed to the wood but as that wood is in place it would make an idea mounting for a more reliable face mount switch like one of Blue Sea offerings.

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52 minutes ago, philjw said:

I wonder if that hasn't been homemade by adapting a fuse holder. If that is the case then you won't get a like for like replacement.  

 

@philjw No it’s not home made, it’s embossed moulded plastic. Though in a Dutch sailing barge so prob hard to find an exact replacement :-// Would be happy with anything that works. 

 

31 minutes ago, Tony Brooks said:

as that wood is in place it would make an idea mounting for a more reliable face mount switch like one of Blue Sea offerings.

 

@Tony Brooks Thx. I’ll check out Blue Sea switches...

Edited by dewshi
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Whilst you are working around there, fix that tape bomb on the wiring which looks like an earth wire and a neutral joined together. What is all that about?

 

Blue Sea isolator is good, the cheap crappy ones with a red removable key are no good.

Edited by Tracy D'arth
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@Tony Brooks I’ve actually already got a decent 1-2-Both-Off switch (which you can see in the pic is hanging off the side of the battery storage box while I’m painting). So I only really need a way of connecting those heavy duty cables. Plus adding solar and inverter positive leads. Any suggestions on how to rig ? Thanks

B4DF5CCD-023F-4F6B-88C9-B07E71ACFAA5.jpeg

327C633A-F6F3-4780-9790-355B55D17E93.jpeg

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49 minutes ago, dewshi said:

@Tony Brooks I’ve actually already got a decent 1-2-Both-Off switch (which you can see in the pic is hanging off the side of the battery storage box while I’m painting). So I only really need a way of connecting those heavy duty cables. Plus adding solar and inverter positive leads. Any suggestions on how to rig ? Thanks

B4DF5CCD-023F-4F6B-88C9-B07E71ACFAA5.jpeg

 

 

Well, having looked inside a number of these bat1, bat2, both, off switches I would never describe them as decent, popular yes, but also too prone to human failure but that is by and by.

 

That 3 way switch complicates things in my view in two resects.

 

1. Unless it's a very modest inverter periods of inverter use at higher powers may well overheat and compromise the 4 way switch.

 

2. Although the solar is normally used to recharge just the domestic bank during periods like at present when the boat may be left unattended for months on end its no bad idea to also allow it to charge the engine battery. You could connect the solar to the alternator terminal of the 4 way switch but then solar would only charge the battery the switch is set to and if turned off will charge no batteries. You could connect the solar to the domestic battery terminal on the 4 way switch. That is allowed under the BSS. But then you could not charge the engine bank unless the switch is set to both.

 

The inverter needs to be connected to the batteries by the shortest and fattest wires possible while complying with best practice so the easiest way to do that is to run dedicated cables between the battery bank and inverter but then to comply with the BSS it needs a mater switch in the positive. It will also need a suitable fuse, close to the battery connection but not inside the battery box, to protect the cable. If the inverter is a combined inverter charger then although a  dedicated master switch  is a good idea it is not mandatory.

 

As I said, I do not like those four way switches, so if major rewiring is taking place I would do away with it and feed the alternator to the domestic bank or if a twin alternator engine one alternator direct to the relevant bank. The solar would also go to the domestic bank. If it's a single alternator boat I would then fit a dual  sensed VSR (voltage sensitive relay) between the domestic and engine banks. If it's a twin alternator boat the VSR is not needed for engine battery charging but if one were fitted it would allow the solar to charge the engine battery once the domestic bank was reasonably charged and also allow either alternator to charge both banks. It would also combine both alternator outputs for battery charging. There is a downside in that once the batteries were well charged one alternator may shut down and display the charge warning lamp or beep at you. That will not adversely affect the battery charging and the same can happen if the solar fully charges the batteries and you run the engine.

 

 

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14 minutes ago, Tony Brooks said:

2. Although the solar is normally used to recharge just the domestic bank during periods like at present when the boat may be left unattended for months on end its no bad idea to also allow it to charge the engine battery. You could connect the solar to the alternator terminal of the 4 way switch but then solar would only charge the battery the switch is set to and if turned off will charge no batteries. You could connect the solar to the domestic battery terminal on the 4 way switch. That is allowed under the BSS. But then you could not charge the engine bank unless the switch is set to both.

 

 

 

It may not be an 'approved' method but for Winter (Winterisation) I run a 'fat cable'** across from the positive on the domestic bank to the positive on the starter batteries, any solar (connected to the domestics) will therefore also charge the starter.

 

** It is normally a 'spare' battery lead, 2 metres long with a crimp ring terminal on each end.

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52 minutes ago, Alan de Enfield said:

 

 

It may not be an 'approved' method but for Winter (Winterisation) I run a 'fat cable'** across from the positive on the domestic bank to the positive on the starter batteries, any solar (connected to the domestics) will therefore also charge the starter.

 

** It is normally a 'spare' battery lead, 2 metres long with a crimp ring terminal on each end.

Works for me but for long term use it really should be fused at both ends.

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8 hours ago, Tony Brooks said:

 

Well, having looked inside a number of these bat1, bat2, both, off switches I would never describe them as decent, popular yes, but also too prone to human failure but that is by and by.

 

That 3 way switch complicates things in my view in two resects.

 

1. Unless it's a very modest inverter periods of inverter use at higher powers may well overheat and compromise the 4 way switch.

 

2. Although the solar is normally used to recharge just the domestic bank during periods like at present when the boat may be left unattended for months on end its no bad idea to also allow it to charge the engine battery. You could connect the solar to the alternator terminal of the 4 way switch but then solar would only charge the battery the switch is set to and if turned off will charge no batteries. You could connect the solar to the domestic battery terminal on the 4 way switch. That is allowed under the BSS. But then you could not charge the engine bank unless the switch is set to both.

 

The inverter needs to be connected to the batteries by the shortest and fattest wires possible while complying with best practice so the easiest way to do that is to run dedicated cables between the battery bank and inverter but then to comply with the BSS it needs a mater switch in the positive. It will also need a suitable fuse, close to the battery connection but not inside the battery box, to protect the cable. If the inverter is a combined inverter charger then although a  dedicated master switch  is a good idea it is not mandatory.

 

As I said, I do not like those four way switches, so if major rewiring is taking place I would do away with it and feed the alternator to the domestic bank or if a twin alternator engine one alternator direct to the relevant bank. The solar would also go to the domestic bank. If it's a single alternator boat I would then fit a dual  sensed VSR (voltage sensitive relay) between the domestic and engine banks. If it's a twin alternator boat the VSR is not needed for engine battery charging but if one were fitted it would allow the solar to charge the engine battery once the domestic bank was reasonably charged and also allow either alternator to charge both banks. It would also combine both alternator outputs for battery charging. There is a downside in that once the batteries were well charged one alternator may shut down and display the charge warning lamp or beep at you. That will not adversely affect the battery charging and the same can happen if the solar fully charges the batteries and you run the engine.

 

 

 

@Tony Brooks Thank you for this information, it’s super helpful. 

 

The inverter is 400W, so I trust not likely to overheat the switch. 

 

The boat originally came with two solar panels, each of which was charging one of the batteries only. But then the seller put the 4-way switch in and wired them both via a  MPPT controller to the switch output, so I could select which battery to charge. This was intended as an improvement. 

 

I hadn’t registered that if the switch is off no battery will be charged! Though I will be living aboard, so it is unlikely I shut down the batteries for an extended period. 

 

By by the way, is the output of the 4-way switch what you are referring to as the alternator terminal? Sorry I’m not completely up to speed with the wiring. I presume that it connects to the alternator, engine and the main switch panel?

 

it is a single alternator boat, so your wiring suggestion would mean I lose some voltage through the VSR, but I wouldn’t have to think about which battery to charge if moored or cruising etc, right? So without the vsr, the engine battery wouldn’t get a solar top up when moored, unless I selected both. But then it would also be drained by domestic use. Also if I’m cruising and have the switch set to 1, the domestic battery won’t get a top up from the engine. Is this correct?

 

I haven’t really got going yet, so haven’t figured the pattern of my needs. I think I will delay this decision until I know better how I use the boat. 

 

Please can you explain why the inverter fuse must be outside the battery box in order to satisfy BSS? How is that safer?

 

thanks again for these comments. 

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400 watts at mains voltage demands abut 40 amps from the battery so I am sure the switch will be fine. I was concerned it might be 2.5kW or more.

 

I doubt you would lose any more voltage through a VSR than your switch, the VSR is just a switch unlike passive split charge diodes. Its passive diodes that cause volt drop.

 

Those four way switches can be wired in a number of ways. It could be a charge selection switch from the alternator to battery or a battery selection switch between the whole boat electrical system and either battery bank. I am unwilling to advise on how to use it unless I understand exactly how it and the single alternator is wired. Typically, you would run the engine with the switch set to both.  I think you have the gist of what I was saying.

 

As far as the BSS is concerned the fuse could go in the battery box but if you site it there any acid mist is likely to cause corrosion and if the fuse blew while battery charging, even with a sealed battery, you might get a battery explosion.

 

Two ordinary master switches, one for the engine circuits and one for the domestic circuits, the alternator  wired to the domestic bank and a VSR joining both banks at voltages higher than about 13.6V makes the whole charging splitting form solar, battery charger, or solar automatic so you  never have to  remember t twist switches except when you want to isolate the electrics when leaving the boat.

Edited by Tony Brooks
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16 minutes ago, dewshi said:

@Tony Brooks Thanks!

 

I found this for joining my positive cables:  https://www.amazon.co.uk/gp/aw/d/B08S7G64TP

 

Rated at 300A. Is it enough for starting engine?

 

My starter draws 235 amps.

Different engines / starters will have differing requirements.

 

Have a look what your starter motor spec is, it should tell you.

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1 hour ago, dewshi said:

@Tony Brooks Thanks!

 

I found this for joining my positive cables:  https://www.amazon.co.uk/gp/aw/d/B08S7G64TP

 

Rated at 300A. Is it enough for starting engine?

 

As Alan says it depends upon your starter. I suspect you have a six cylinder Daf of similar engine and it might be 24 volt. If its 24 volt then it will draw half the amps for the same engine on 12V. Also starters only draw maximum current for microseconds as the run up to speed. Once up to speed the current falls. Although its not a bright idea to introduce volt drop into a start circuit I think that busbar will be OK.

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1 hour ago, Tony Brooks said:

 

As Alan says it depends upon your starter. I suspect you have a six cylinder Daf of similar engine and it might be 24 volt. If its 24 volt then it will draw half the amps for the same engine on 12V. Also starters only draw maximum current for microseconds as the run up to speed. Once up to speed the current falls. Although its not a bright idea to introduce volt drop into a start circuit I think that busbar will be OK.

 

It’s a Sole 34 / 4 cylinders. I think 12V, as that’s what all the other circuits are on. 

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5 minutes ago, dewshi said:

 

It’s a Sole 34 / 4 cylinders. I think 12V, as that’s what all the other circuits are on. 

 

That's not very large for a barge as in your photo so 12V is more likely but I still think the busbar will work well enough.

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