Hi EveryoneI'm about to replace my 8yo 500ah AGM house battery bank and at the same time, I'm looking to improve some of the electrical systems on my boat, which, like most boats, isn't amazingly efficient. I'm in the process of looking at what fuses are missing where and how I can add some more protection in.
I have two solar systems - a 200W and a 130W with separate charge controllers (I have upgraded to MPPT for the 200W and will do the same for the 130W panel). I also have a 400W AirX wind generator. The alternator currently only charges the starter battery
My partner and I live aboard and we run a fridge, 3000W inverter that we use to power laptops, but not much else apart from the regular lighting, instruments, windlass etc.
My question is about the best way to organize the charging devices. At the moment, it's a bit of a mess, the wind generator goes to a 1-2-both switch as it can be used to charge either the starter or house banks and is wired to the load distribution panel. The 200W solar panel is fused before the MPPT controller then directly to the battery terminals. The 130W solar panel is fused before the controller and then to the distribution panel. The wire between the house bank and the distribution panel has an on/off switch, but no fuse. Here's a diagram
So with this set up, when I switch off the load, power is still available in the system through the solar and wind and I need to have the generator off and the fuses pulled out of the solar. I don't really like this - it hasn't been dangerous so far, but it's just annoying.
So, is it much more sensible to set up a charging busbar that would have all charging systems wired to the battery terminals and isolated from the load distribution panels? Or is this set up ok?
Any help would be fantastic, thanks in advance
This is my opinion only & I am not an electrician!!
If I were you I would run the two panels through a Redarc Dual Input Multi-Stage 12V Battery Charger BCDC1250D (I have one of these & it has greatly improved my system (www.redarc.com.au/dual-input-50a-in-vehicle-dc-battery-charger) straight to the house bank via a circuit breaker.
Put a circuit breaker before the BCDC charger - this way you can turn off the panels if needed.
Run the wind through a circuit breaker to a controller then through another circuit breaker to the house bank.
I'm guessing the distribution board has fuses running to all the different loads.
The BCDC charger looks after the solar, alternator, start & house batteries & keeps them all charged - not real cheap but worth the $$.
I am running a similar system & very happy with it.
Hi Pat, I'm a bungling amateur when it comes to electrics, but I think I would be inclined to do as you suggest, run all charging sources to a busbar and then route both house bank and motor bank charging from there. Then take your load from the house bank to the distribution panel as shown in your diagram. I'm assuming you have some kind of regulator on the wind generator? As long as you have good MPPT controllers and a good regulator on the wind genny, then your battery banks will just get what they need automagically won't they?
What output is your alternator, would a dc to dc charger be worth considering in order to maximise what the alternator is doing in the mix?
Select to expand quote2bish said..
Hi Pat, I'm a bungling amateur when it comes to electrics, but I think I would be inclined to do as you suggest, run all charging sources to a busbar and then route both house bank and motor bank charging from there. Then take your load from the house bank to the distribution panel as shown in your diagram. I'm assuming you have some kind of regulator on the wind generator? As long as you have good MPPT controllers and a good regulator on the wind genny, then your battery banks will just get what they need automagically won't they?
What output is your alternator, would a dc to dc charger be worth considering in order to maximise what the alternator is doing in the mix?
OK thanks heaps for the advice. Yep I was thinking about a dc-dc charger either wired from starter to the house bank or after the alternator with house bank and started connected to DC-DC on separate circuits. How do you have yours set up?
For the wind genny, I don't have a wind charge controller, which made me worry! However, the AirX has an internal voltage regulator that manages the load in the same way that a wind charge controller does. They only really suggest a wind charge controller when combining multiple wind generators and in systems with large changes in temperature.
I definitely need more circuit breakers, but the vast majority of circuits are fused.
Lazz thanks for the BCDC advice, I'll do some research and see if it suits.
I had 3 primary circuit breakers for the charging/storage of the DC cabling. One on the + side of the house battery, a second on the + of the engine battery and a third for the - negative side of both. The intent being for current overload protection and also to isolate them from any charging source and loads in case of a fire or for long term storage.
I had all Blue Sea systems for the circuit breakers, relays, fuses etc, it was really nice kit to work with but expensive.
I'm a huge fan of bus bars. Go big for convenience! I had two tapped 10" x 1" bars at the back of the engine bay as pos and neg bus bars which were overkill for a 12mtr boat. But they were just awesome for maintenance and to work with, test stuff and make moves/adds/changes as you go along. Bus bars are good for tidying up all your cables too as it normally gives you natural cable routing just through the design. Everything is accessible....they just keeps ticking all the boxes.
So yes, use bus bars and get big ones for the sheer joy they will bring you when you have to do something 
.
Cheers!
SB
You probably know this already, but make sure you keep all the battery cables the same length, don't be tempted to cut any shorter than the longest run.
I should point out that I am in no way affiliated with Redarc - I just like the improvement the DC-DC charger made to my battery system!!
Which is 1200W of solar + Wind Gen feeding 780Ah of house batteries + start battery. I only have 550w of solar running through the BCDC50 & the rest runs through a 80a MPPT controller with the wind running through another 40a MPPT controller.
I'm also a fan of Bus Bars 
This is wiring for the Redarc Dual Input Multi-Stage 12V Battery Charger BCDC1250D that I have - thought it might help explain things:
Not a sparky either but what the guys said run to bus bars instead of battery terminals you can then set up a shunt and battery monitor to see what you are using and what you are generating also i would set up a dc to dc charger
Hey Pat, another amateur here.
Does your circuit look more like this, or do I have it wrong?
ie. the regulated feeds to your dist panel would come via either battery, and not direct from your wind and 130W panel?
This is always the way i've seen and done in the past.
Happy to be wrong though :)
I reckon electrical is one of hardest boat systems for us mere mortals . So drawings become my go-to to understanding electrical stuff. To minimise big screwups I have to start with a spreadsheet and detail out the important bits like what do I want each of my voltage sources to provide power to. Then I try and think whether I want it to be protected or isolated, etc.
I clipped some columns out of the screenshot, but there are columns for bypasses, device ID's, termination points etc etc. Then I have to draw it all out (like the ones exampled upthread) before I can get my head around it.
On the last boat, my memories of which bit did what from the commissioning turned out to be wrong on many aspects. The language barrier and information overload were partly to blame, but equally I was lacking a true understanding of which bit did what and why. So drawing it all out became my 'get out of jail' clause as well as slowly filling in my lack of knowledge. It took me weeks drawing it out on paper to get my head around it and a good year poking about. But it was a great feeling when I finally got to that point where you understood;
-- what everything did;
-- in what order the various devices go;
-- how it did it; and
-- where is it and where does the &*%$ cable go!
Select to expand quotecrustysailor said..
Hey Pat, another amateur here.
Does your circuit look more like this, or do I have it wrong?
ie. the regulated feeds to your dist panel would come via either battery, and not direct from your wind and 130W panel?
This is always the way i've seen and done in the past.
Happy to be wrong though :)
Yeah nah I wish it were a little more like this! The previous owner didn't use the boat much and relied on the wind generator to keep the starter battery topped up. He also had a really small maybe 20W PV panel to do the same thing, but was well dead by the time we came into the picture. I just think there wasn't much overall thought put into it and was patched together piece by piece. He had tried to set it up to live aboard, but he didn't actually have that lived experience of spending months at sea. So, a small overhaul is in the making.
@lazzz, I have just found out that my alternator is a Bosch K1 rated to 50A (meant for a Ford Laser, yeeha!) the guys at Bosch said it will output ~55A @6000rpm @25degC and have 2/3 output at 2200, which is basically the max that I run my old girl. So I guess I'm looking at a max 25A output. What do you all think about this in terms of output to charge a 500ah house bank (I understand we go by a rule of thumb of 10% capacity ~50A to get a proper charge that keeps the batteries healthy)? @Lazz what size is your alternator? The guys at Enerdrive recommended going for more power and an external regulator.
@shaggybaxter this is a great idea - i've mapped most of the system out and spend a considerable time sitting, reading, looking, watching and thinking about it all. I also don't mind the odd spready, so I might have a crack.
@2bish - the battery cables are a problem too - the 4th 125ah battery has connecting cables maybe triple the length of the others, i guess due to space issues. I need to work this all out too.
Thanks again for all the wise words. I'll send a couple of pics for you all to marvel at my wonderful world
Select to expand quotePatSiesta said..
OK here are a couple of photos of the mess! I'm sure there have been worse...
Yep, that looks pretty normal for a boat.
If you take the time to chase the wires, buy yourself a little cable labeller like a Brother P touch, it'll pay for itself in no time just for your sanity!
At the end of the day, you have two networks you want to try to connect, sinks and sources.
Sinks are all your field, or 'edge' equipment like wind sensors, lights, radios, fridges etc.
Sources are all your head end equipment, like batteries and your PC or chartplotter and charging systems.
When drawing it out, I always start with listing my sources on the left hand side and my sinks on the right hand side of the paper. I then draw a line from each source to the related sinks I want it to power/communicate to. Do this for every source. Then take all that horrible scrawled mess you've just created and enter it all into a spreadsheet. The cabling will start to sort itself out into some form of order and logic.
A device can be a source and a sink. For example, batteries gets listed in both the source and the sink columns. It is a source for field equipment, but they are also a sink in relation to your charging systems (which is another source). So it gets an entry in both columns.
This approach can also help sorting out your protection systems. Head end devices get circuit breakers and isolation switches. Field devices get fuses and no isolation.
There will be some edge equipment that is high current, like windlasses and electric winches. These are still edge devices in the spreadsheet but might get some special treatment like increased cable gauge and circuit breakers rather than a fuse.
If you think of it like sources and sinks, how to re-terminate and patch cabling gets a lot simpler. This is where your bus bars comes in, what termination and where to use it will usually become apparent after thrashing out which source/s is needed for which sink.
With the charging sources, don't just connect them to the battery banks. For example, rigging shore power to not only connect to batteries but also to the fuse/distribution panel for powering systems can be super handy.
Best of luck with it!
Ok Guys
Thanks again for all the support
Im almost ready to get in there. I decided not to upgrade the alternator and provide engine charing of the house ban just yet (that may be a future stage though)
We are replacing the batteries, ensuring each batter has the same cable length (wasnt the case), splitting the electrical system into sources and sinks via added busbars and adding more overcurtent protection.
My question now is about grounding. Our current grounding source is a single cable from the load distribution panel to the engine block. I have read it is best to direct to ground in this way through one source. Thinking about splitting the system into sources and sinks... will this system suffice? Or do I need another route to ground e.g. between sources and battery bank.
Also, we have a 3000w inverter which has been connected directly to the battery bank at opposite ends. Continue? Or hook it up to the load distribution panel?
Thanks!
Select to expand quotePatSiesta said..
Hi EveryoneI'm about to replace my 8yo 500ah AGM house battery bank and at the same time, I'm looking to improve some of the electrical systems on my boat, which, like most boats, isn't amazingly efficient. I'm in the process of looking at what fuses are missing where and how I can add some more protection in.
I have two solar systems - a 200W and a 130W with separate charge controllers (I have upgraded to MPPT for the 200W and will do the same for the 130W panel). I also have a 400W AirX wind generator. The alternator currently only charges the starter battery
My partner and I live aboard and we run a fridge, 3000W inverter that we use to power laptops, but not much else apart from the regular lighting, instruments, windlass etc.
My question is about the best way to organize the charging devices. At the moment, it's a bit of a mess, the wind generator goes to a 1-2-both switch as it can be used to charge either the starter or house banks and is wired to the load distribution panel. The 200W solar panel is fused before the MPPT controller then directly to the battery terminals. The 130W solar panel is fused before the controller and then to the distribution panel. The wire between the house bank and the distribution panel has an on/off switch, but no fuse. Here's a diagram
So with this set up, when I switch off the load, power is still available in the system through the solar and wind and I need to have the generator off and the fuses pulled out of the solar. I don't really like this - it hasn't been dangerous so far, but it's just annoying.
So, is it much more sensible to set up a charging busbar that would have all charging systems wired to the battery terminals and isolated from the load distribution panels? Or is this set up ok?
Any help would be fantastic, thanks in advance
My only critique would be to have all charging sources run to batteries, with an appropriate fuse at or as close to the battery as possible.
This is the advic proffered by both of the solar controller manufacturers that I have had anything to do with.
Thanks mate, im combining the charging sources at a bus bar and then straight to the batteries through a circuit breaker.
Select to expand quotePatSiesta said..
Thanks mate, im combining the charging sources at a bus bar and then straight to the batteries through a circuit breaker.
I would use individual circuit breakers/fuses sized to the individual devices, not one sized for the combined output.
Just to referring to your schematic, my looks similar, but both solar controllers going to bat. bank directly. Controllers takes care of charging.
Bat. bank has master switch.
Believe, wind gen. had own switch. Distribution panel with flick of the master switch is fully oscillating.
After re wiring one solar, test and updated if any more improvements needed.
OK Thanks @Bob all charging sources are already fused so it makes sense that I wont need to add more protection, maybe I was over doing it :D
Hi Everyone
Just finished stage one of thr upgrade with an unswitched distribution for charging sources and a new battery bank.
Here are a couple of photos
I've left some space in case I want to upgrade our little ford laser alternator to charge the battery bank, but I thibk it will be more likely that we would add more solar first if we need to.
Temps in the engine room while underway have been in the 40s so I added some heat shields and Im also going to connect a couple of computer fans to keep air moving
Next jobs are to connect the bilge pumps to the unswitched distribution, install those fans, test the new batt banks output and label everything! It never stops, hey?
Thanks for all the help getting my head around the options and making a plan!
Cheers
Pat
