Solar Capacity

[David Mack]

2 hours ago, Gra73 said:

I guess my next question is then how do I power it during the bleaker days?

 

Don't.

 

Empty the fridge and freezer when you leave the boat (for longer than a day or two), turn them off and leave with the doors ajar to stop mould.

 

Or run the risk of wrecked batteries and thawed food.

[Sea Dog]

4 hours ago, Gra73 said:

Thanks Mike the Boilerman,

I guess my next question is then how do I power it during the bleaker days? If I plug into shoreline power this is just for 240v and as the fridge (whether it has a separate inverter tbc) is 12v or runs off the batteries, then how does this all work.

Please be gentle with answer, I am about to short circuit with all the amps running around my non inverted mind!

If you already have a shore power connection, chances are you also have a mains powered 12V battery charger.  This should keep your batteries fully charged whilst your 12V powered stuff is happily being fed from your 12V distribution system powered from the domestic battery bank.  This is a pretty standard configuration, but not all boats are pretty standard!  If you're going to leave shore power connected, you'll need a Galvanic Isolator (or an isolating transformer) - so there's another question for you!

[Gra73]

Right Sea Dog! You’ve done it now!

I have heard about these galvanic isolators! But to recap on what you said! So yes, I have mains via shoreline connection. On the boat I have 12v and 240v (when the inverter is turned on, not that I’ve used it yet) and I (as you know!...) have the solar which trickle charges the batteries and hopefully takes care of the 12v ‘stuff’

So, when I plug into mains (activating the 240v ‘stuff’ on the boat) is this charging the batteries also? (I do have a separate plug in car battery charger, which is wired into the batteries) 

[Sea Dog]

9 minutes ago, Gra73 said:

So, when I plug into mains (activating the 240v ‘stuff’ on the boat) is this charging the batteries also? (I do have a separate plug in car battery charger, which is wired into the batteries) 

 

Well it would if your inverter was an Inverter/Charger and you switched it to "Charge" when you leave the boat.  I suspect it isn't and I suspect the existence of the plug in charger means this is how previous owner kept his batteries topped up. It might just be wired to a plug as the supply rather than hard wired in a switch to the shore supply panel, or it could be a spare, or you may find another permanent fit charger hard wired in which, if you don't have an Inverter/Charger, is ideally what you need if you're leaving the boat on shore supply with a 12V fridge running (when solar isn't reliable).  Your charger should be happy also to be a power supply in these circumstances,  so an old fashioned dumb car charger isn't gonna cut it.

 

Where are you? It might be useful if you're near someone here who knows what they're looking at who could pop round to help you identify what you have, then you will be in a better p,ace to know where to start. 

[MtB]

3 hours ago, Gra73 said:

Right Sea Dog! You’ve done it now!

I have heard about these galvanic isolators! But to recap on what you said! So yes, I have mains via shoreline connection. On the boat I have 12v and 240v (when the inverter is turned on, not that I’ve used it yet) and I (as you know!...) have the solar which trickle charges the batteries and hopefully takes care of the 12v ‘stuff’

 

 

Except that you also have a hidden inverter turned on and running 24/7/365. We know this because your 240Vac fridge still works with your 'main' inverter turned OFF.

 

And the solar will only take care of the 12v stuff in summer. Come September it will stop working with the shortening and duller days, like a switch has turned it OFF. 

 

 

Edit to add:

I'm not sure you fully grasp the massive difference between 12 volts DC (direct current) and 240 Volts AC (alternating current).

 

12Vdc is what a car or leisure battery puts out. Inherently safe mixing with water as the voltage and power available is low. 240Vac is 20 times more powerful 400 times more dangerous. It is AC because rapidly reversing voltage gives you repeated chances to let go between muscle spasms if you get a shock. With DC your muscles lock and you can't release yourself from a shock. 2240Vac needs treating with utmost care in a boat, and is actually quite inappropriate in my personal opinion. 

 

 

 

 

Edited June 15, 2018 by Mike the Boilerman

[cuthound]

10 hours ago, Alan de Enfield said:

 

It is always handy to know what systems you have on board, and how they work, so, when the time comes you can repair or replace them.

It would be worth pulling the FF out and have a look what the lead is connected to, and, follow the supply back - it could be that there is another inverter 'tucked away' that is 'always live' & it is not wired thru your master switches, it could be that it is 'hardwired' directly into your 'main' inverter and you have not noticed.

 

 

It is definitely Not connected directly to the battery source.

 

 

Its not a good idea to have mains voltage floating about that you do not know how to disconnect.

This is not a criticism of you (or the boat) but just a concern for your on-going safety.

 

Another problem with having two inverters on board is that they will be out of phase. This means that if you accidentally touched the outputs of both at the same time you could get a shock voltage of over 400 volts.

 

To mitigate this the terminals of each inverter should be at least 2 metres (more than a man's stretched arms) apart.

[Gra73]

Many thanks again for all the feedback, concerns and advise.

Attached is a bad picture of the inverter, and as suggested I need to get someone close by to physically explain the mechanics of the charging system etc. 

I do kind of understand most of it, it’s just the how does the 12v stuff get charge when there is no solar option come the autumn and winter, same goes for the batteries (without running the engine of course) 

[MtB]

14 minutes ago, Gra73 said:

Many thanks again for all the feedback, concerns and advise.

Attached is a bad picture of the inverter, and as suggested I need to get someone close by to physically explain the mechanics of the charging system etc. 

I do kind of understand most of it, it’s just the how does the 12v stuff get charge when there is no solar option come the autumn and winter, same goes for the batteries (without running the engine of course) 

 

There is quite likely no way other than running the engine. This would be perfectly normal. In winter you would keep the batteries charged by plugging a battery charger into the electricity bollard byyour mooring in the marina and connecting it to the batteries.

 

If you are off-grid, then boat electrics and battery charging rapidly gets VERY complicated and expensive. If you want it all to totally look after itself then you can easily spend a sum approaching the value of the boat in generators, automation and charging equipment. Far better empty the fridge and turn it all OFF in winter, and leave the solar to trickle charge the batteries. 

[Gra73]

OK Thank you 

[Richard10002]

At the bottom of the second picture is something which has “Master Charger” on it - I can’t read anything else. Could that be a battery charger? If not, what might it be?

 

If you don’t know what it is, a better pic would help.

[Gra73]

That is the battery charger that was on the boat when I purchased it,’it is wired into or down to the batteries.

[MtB]

15 minutes ago, Gra73 said:

That is the battery charger that was on the boat when I purchased it,’it is wired into or down to the batteries.

 

Please don't plug it into your inverter!!

[Richard10002]

16 minutes ago, Gra73 said:

That is the battery charger that was on the boat when I purchased it,’it is wired into or down to the batteries.

Aha! So it’s portable, rather than permanently connected?

[Gra73]

Yes, well in as much that you can plug it in or not, but the charger is connected to the batteries.