Charge splitting

[Bill.H]

Hi all, new to the forum here, but I’ve been a member for a while reading and trying to take in the combined knowledge of the collective. It has probably been discussed before, but I can’t find any recent posts so here goes …

I am (or was pre Covid-19) in the middle of a major re-fit of my Moody 37, ready to move on board permanently in a couple of years time. Current priority job is getting a new engine in, and as part of this I am ripping out and re-doing the battery charging system. Everything is well over 30 years old and has been modified and bodged in varying measures by several previous owners. If this is going to be my long term home I want to know what is fitted and how it works.

I have pretty much decided on an automatic split charge system, but thought I’d throw the options out there to see what peoples reasoned opinions are. My engineer is not the most helpful with this, but then he is a marina bound motorboater, and so doesn’t get the need for optimised battery charging.

My first choice was a Sterling Pro Split R (Like this: https://sterling-power.com/products/...iant=882765499).

A second alternative is the Victron Energy ArgoDiode (Like this: https://www.kuranda.co.uk/product/ar...tery-isolator/) which comes in at a lower cost.

Of course to make these systems work at an optimum level I’ll most likely have to add an advanced alternator regulator into the system.

The batteries are likely to remain Lead Acid, but I’d like to keep the option for Lithium in the future should finances allow.

What do people think of these systems? Or are there better alternatives for a live aboard, full time cruiser? I am normally a great believer in the “Keep it simple” policy, but in this instance I have decided on the application of technology to simplify life, particularly as I sail with non-sailing friends quite often.

Thanks for the input.

Bill

[smac999]

Connect the alternator direct to the house battery. Then use a xantrax echo charger or the victron Orion smart to charge the engine batt from house batt.

Use an external regulator and take the voltage sense directly off house battery. This will give you best charging. It’s hard to get a proper voltage sense using the isolators.

[Bill.H]

Thanks smac, that's certainly not an option I'd thought of, but seems to keep everything simple. I'll have a look at the kit for this for sure

[YANDINA]

Connect the alternator to the house battery as mac suggests but use a Combiner to link to the other battery(ies). The splitters/diodes lose 1/2 a volt wasting energy and reducing maximum charge. The "Echo" charger systems have a 10 or 15 amp maximum while the Combiners at 100% efficiency can handle up to 500 amps with no cooling needed.