Boat Battery Charge Systems.

[AdamB]

Hi all no been on here in a while. hope this is in the right thread area. 

Are any of you lot up on boat charge wiring. I've only got 1 battery bank for start and house. And I'm getting problems starting. So I'm looking at rewiring. 

I've got 2 engines. And 2 thrusters. 

Can't seem to get a plan without batteries been linked though the charge circuit on either the 12v alternator side or the shore power charger.

Don't want the bow thruster trying to run off the stern thruster battery through the charging wires. 

Any help would be great thanks. 

[CambridgeCabby]

Details of boat and type of engines and a photo if possible if the wiring / batteries would be a good starting point 

[AdamB]

Hi mate. 

The boat is a birchwood. With twin mercruiser 180hp. 

Don't have any pictures of current system. But I'm not sure how this would help if I'm starting again?

 

[mikeyboy1966]

How much do you want to spend

[mikeyboy1966]

This is my new installation,still a work in progress.

I recon I’m at £3k to date.

that’s without any labour as I’m doing it myself.

[Vaughan]

10 hours ago, AdamB said:

Can't seem to get a plan without batteries been linked though the charge circuit on either the 12v alternator side or the shore power charger.

I don't think you will, unless each battery bank has its own alternator.

I understand your thinking about the thrusters running via the charging circuit but if they are wired to the starter battery this should not be a problem as they are only in use while the engines are running, and therefore on charge.

We can't tell you much more without some photos, and more of a description of the layout you have at the moment.

[annv]

Hi Adam You need a large 11/13 plate Automotive battery (Car) for starting and thrusters charged by one of the engines, Then bank of leisure batteries for your domestics, two or four being ideal wired parallel these being charged by your other engine, trying to start your engines from a leisure battery is only going to be trouble, they dont have the power! you will only damage your starter motors.Having a advanced regulator on the leasure bank alternator is also a ideal option, Battery's that are constantly being discharged wont have a very long life. There is a combined regulator from Sterling that combines both alternators and charges and sorts the correct charging for all the battery's for the most economical charging BUT! they do have a cost, but the best way for max return.Sterling also provide wiring diagrams for there products, you can't wire both alternators to charge one battery bank just using there built in regulators, one alternator for one bank, or use a Sterling  Combiner.  John

[annv]

Hi Adam If you would like me to provide a new wiring diagram i need more info 1= how many batteries do you have and what type. 2= where are they positioned. 3= what are you aiming to achieve and how much do you have to spend. 4= what type of battery charger do you have and is it wired to shore power through a Galvanic Isolator. you dont have to have a battery for each thruster but you do need welding cables to carry the power from a battery to the thruster, so one battery can provide power for both thrusters, or from starter battery which is the best way as you only use the thrusters when the engine is running so power is replaced . John

[MargeandParge]

Have a look at Argofet from  victron with a three out put shore charger along side 

 

After all you have to start somewhere.

Kindest Regards Marge and Parge 

[scaniaman]

Hi Adam. You need to be on Youtube to get ideas for your boat. Victron energy have a good site, for marine use. journey with Johno did a narrowboat vlog whilst many van lifers  have also done some good systems. See Greg Virgoe, Gadget John, Lukes van life for ideas.

What you will need is some idea of budget, number and types of battery and how many charge inputs you will use, ie mains, solar, wind, alternator. A good start would be to look at Victron`s B2B battery management system. Good hunting.

Paul

[Smoggy]

I'd go for a charge splitter fed from both alternators of your choice, one start battery as you don't start both simultneously, thrusters fed from start battery as said before you only use while engines are running, most multi use batteries are good enough for engine starting nowadays as they are not proper deep cycle batteries anyway but a regular start battery would be better.

And as many domestic batteries as you can fit in wired to only stuff used while engines are not running, and a starter solenoid to a button on the dash across both banks in case of a starter issue.

If all else fails you'll have to push start it....

[Karizma]

Can I hijack this thread to ask a similar question regarding house battery banks (hope you dont mind AdamB).

I currently have 3 battery banks (2x sealed lead acid for house, 2x AGM for inverter and 1x sealed lead acid for engine). All these battery banks are charged by 2 x alternators, going through 2x 70 amp shore power multi battery isolators (these have 3 output terminals).

I've decided to upgrade the above to 2 battery banks; combining the house and inverter banks into 1 bank of 4 batteries and the one engine battery, charging all via 2 x Argofet 100-2 battery isolators.

Now I know you're not suppose to mix battery types (Sealed lead acid and AGM), or old and new batteries in the same battery banks - so before I go and buy 4 x new batteries (lead acid or AGM); what, if anything, would happen if I combined my AGM and sealed lead acid batteries (in the sort term) so I can wire up the 2 new Argofet 100-2 battery isolators (which only have 2 outputs)?

Is it just a case of the bank will not be 'balanced' and the charging profiles won't be 'optimised' for the different battery types connected together? or is there more of a safety risk by connecting these together?

I'm trying to decide if I can go ahead with the installation of the Argofets, prior to laying out more money on batteries, or if the advice is don't do one without the other?

Any boating electricians that can advise would be appreciated.

Steve

 

[Vaughan]

I see no comments to this so far, so I shall have a try!  For a start I am not sure what a shore power multi battery isolator is, but I can perhaps help with some basics :

I agree with having an inverter powered by two separate batteries, especially if they have their own dedicated alternator and you may well be better off to stick to this set up.  Use of an inverter usually means quite a high current draw but only for short periods, which is why you need 2 batteries for it.  Domestic use is normally less current draw but for longer periods, such as running a fridge overnight.

I have googled the Argofet and it seems to be a conventional charge splitter, on the blocking diode principle, which connects the batteries when charging but separates them when the engine is stopped.  It does not equalise them, as the diode only allows current to flow in one direction. NOT to be confused with a battery combiner, which is often used in caravans but doesn't have much application in a boat unless you have twin engines.

Shore power is a separate matter.

Shore power is normally connected to a battery charger and marine ones will have 2 or more outputs.  In this case they are doing the charge splitting for you and can be connected to the batteries, usually at the master switches.  Shore power will normally have a second circuit of 220v plug points in the boat, for plugging in microwave and TV direct to the shore. The inverter will have its own circuit of plug points, for use when you are not on shore power.  You can still use the inverter when on shore power, since the shore power is charging its battery bank.

The starter battery is not normally connected to the shore power charger as in theory, it is only supplying circuits which are in use when the engine is running, such as horn, nav lights and wipers.  The starter battery should therefore be fully charged at all times, in the same way as a car.

Hope this is helpful in terms of the basics!

[Karizma]

Hi Vaughan, thanks as always for replying to questions posted on here ..... much appreciated.

Ref: Shore power multi battery isolators - yes these are the 'old' diode type battery isolators, with the Argofet 100-2 battery isolators being the modern, more efficient battery isolators, and your summary of how they work is how I understand it as well.

Shore power inverter - At the moment, when the inverter is connected to shore power it has a single charge output, that chargers all 3 battery banks through 3 battery combiners (trust my boat to have these as well !!) 

 

[oldgregg]

4 hours ago, Vaughan said:

Shore power will normally have a second circuit of 220v plug points in the boat, for plugging in microwave and TV direct to the shore. The inverter will have its own circuit of plug points, for use when you are not on shore power.  You can still use the inverter when on shore power, since the shore power is charging its battery bank.

The modern inverter / chargers fitted to more recent boats tend to blur the lines a bit here as you'd potentially only have one set of 240v sockets, with the magic blue box handling where the power is coming from (batteries or shore power).

It's great in terms of simplicity, but bad in terms of helping users understand where the power is currently coming from and the need to manage usage - If an applicance is plugged into an 'inverter' socket then there's some realisation that there's a 12v battery on the other end and capacity is finite.

[Vaughan]

1 hour ago, oldgregg said:

The modern inverter / chargers fitted to more recent boats tend to blur the lines a bit here

They do indeed!

To my simple mind, an inverter is converting 12v DC to 220v AC to supply power to certain appliances, such as a TV.

Shore power is converting 220v AC via a charger, to provide 12 DC battery charging.  Said batteries, will then provide 220v AC via an inverter, for the TV.

If the inverter is now also considered as the charger, this seems to me like the rare Japanese Oozlum Bird.  For those who don't know the old rugby song ; it flies around in ever decreasing circles until it dis-appears up its own circuit breaker!

One thing I would definitely emphasise : VENTILATION.

These ever more complicated voltage converters give off a lot of heat (which is why they are inefficient) and you must install them in an open space near to a hull vent. If you hide them away in a little cupboard, or under the helm seat, they will overheat and burn out.  This is the most common cause of failure.

 

 

[annv]

Hi Karizma Lead acid battery's are the most cost efficient BUT do require maintained and storage outside the living area, if you combine the lad acide and the AGM set the charging rate to the lower type battery's they my be wont last as long but you will get some use from them. John

[Cheesey69]

1 hour ago, Vaughan said:

They do indeed!

To my simple mind, an inverter is converting 12v DC to 220v AC to supply power to certain appliances, such as a TV.

Shore power is converting 220v AC via a charger, to provide 12 DC battery charging.  Said batteries, will then provide 220v AC via an inverter, for the TV.

If the inverter is now also considered as the charger, this seems to me like the rare Japanese Oozlum Bird.  For those who don't know the old rugby song ; it flies around in ever decreasing circles until it dis-appears up its own circuit breaker!

One thing I would definitely emphasise : VENTILATION.

These ever more complicated voltage converters give off a lot of heat (which is why they are inefficient) and you must install them in an open space near to a hull vent. If you hide them away in a little cupboard, or under the helm seat, they will overheat and burn out.  This is the most common cause of failure.

 

 

This is my solution and I entirely agree with you.

To me, this is the simplest solution. When on shore power, my Victron charger tops up all my 12volt batteries (including starter). From the invertor I run a select set of sockets which is mainly the tv. For more power hungry stuff I only run on shore power with their own dedicated sockets live only when on shore power. The rest just runs on 12v topped up from the charger or the engines

[Karizma]

47 minutes ago, annv said:

Hi Karizma Lead acid battery's are the most cost efficient BUT do require maintained and storage outside the living area, if you combine the lad acide and the AGM set the charging rate to the lower type battery's they my be wont last as long but you will get some use from them. John

thanks John, just what I was looking for guidance on. cheers.

tbh the way they are all wired up at the moment, once on shore power the inverter charger (and old sterling 'modified' sine wave inverter) charger all 3 batteries (through 3 battery combiners wired together) and the inverter is currently set to charge AGM batteries (set up before I bought her), so I think some batteries are already loosing out on their most optimised charging profiles.

saying all that, the sealed lead acid batteries have a sticker on them saying installed in early 2019 and they are still doing ok.

 

[annv]

Hi Karizma Battery's will last longer if kept fully charged when out of use and the electrolyte level kept to the correct level (A solar panel is very useful for this along with running the fridge, which is the biggest user of power overall.A nother trick for long geverty is to set the charging rate a little lower if using a advanced charger.Shore power is 240 volts Ac this is used directly for fridge Tv Micro wave and any other 240 Volt appliances plus it charges your battery's, When!! it is disconnected and your appliances revert to 12Volt Dc,  If you have a inverta this will convert Dc to Ac to run your 240 Volt appliances when there is no shore power. There are several ways you can do this from the completely Automatically to owner having to remember to switch between units. Needless to say their is a cost between which system/way you decide to use. Sterling Power Products has a very good site plus a telephone help line service  John