SHETLAND OWNERS ASSOCIATION

Was starting to get bored with this lockdown, so took it out on the boat, and want to get her refurbished for the spring and summer.I´ll keep you posted, but at the same time I have loads of questions, and need the help of you Shetland lovers, and many thanks in advance.

1. The Accu Trim unit was just lying around, but the two tubes going to the Trimblades left and right are still there, obviously the previous owner
didn´t use them. I believe they work hydralically. ANYONE USE THIS SYSTEM ON THEIR BOAT?. As the boat is in the water, I have no idea as to how the blades look.

2. The electrics are a mess, and there is only one battery. My plan is to put in a House battery, along side the starter battery using the Blue Sea Systems. Add a battery. https://www.bluesea.com/products/7650/A ... Kit_-_120A
HAS ANYONE THIS SYSTEM OR SIMILAR ON THEIR BOAT? WHICH Amp/Hour DO YOU USE, AND DOES THE STARTER AND HOUSE BATTERY HAVE TO BE THE SAME?.
Well I´d be grateful and thankful for lots and lots of info. Again many thanks in advance from Northern Germany. Sean

Looks like a good boat and project. Sorry, can't answer your questions thought.

I am also embarking on a 570 project myself.

Hi, regarding the electrics I use a similar system on my 535, except the battery switches are individual units.
Your start battery should be at least the capacity recommended by the engine manufacturer, though if your trip involves short distances and frequent restarts a larger capacity may be advantageous. This battery will be similar to a car battery in that it will be designed for infrequent heavy but short duration loads. The house battery can be of the leisure style, i.e. designed for lower discharge rates over longer periods. Its size can be calculated by figuring out the expected loads and their duration. My own boating involves perhaps five hours cruising followed by overnighting using anchor, cockpit, and cabin lights and the GPS (anchor drift warning) and for this I use a 120 ampere hour battery.
The ACR (sometimes called a Voltage Sensitive Relay) works by monitoring the start battery voltage. After start up the voltage rises until a certain point, at which the relay closes and the house battery is paralleled to the start battery and both charge together. After engine switch-off they stay paralleled until their voltage drops to the set point whereupon the relay opens and the batteries are disconnected from each other, thereby preventing the the start battery going flat.
A point to consider is that if you are using a small capacity motor (river cruising maybe) then the engine alternator may also be of low output and therefore insufficient to keep the batteries charged.
Hope this helps.
Paul

Hallo Paul, Many thanks for your splendid reply. I have just checked my instructions for my motor, a Honda BF 45A. In there it say´s " use at least a 70Ah starter battery" Connected is only a 36Ah no idea why. I plan to do weekend or weekly run outs in the summer. (The advantage being a pensioner ) So would I be right, and okay with a 70Ah - 80Ah Starter and a 100Ah to 120Ah House connected with the ACR and Switch. I´ll be using lights, fish finder, radio, and maybe bits of this and that in 12v sockets.
Many thanks for a reply, also to anyone regarding my thoughts. Sean

You should be OK with those sizes if your trips involve long enough periods of mid to full throttle cruising. Your engine alternator apparently produces 22 amps of which about 18 is available for battery charging. This will be considerably reduced at low RPM. Provided your lighting is all LED and your other loads are intermittent there should be no problem.
It may be useful to buy a cheap multimeter and check your battery voltages at the beginning and end of your first few trips to ensure the system is providing enough power. There are several useful books on small boat wiring and electrics available which will give far more information and could prevent a mistake if you are uncertain of some aspect of the system.
Paul
PS if anyone spots an error or omission in my response please say so, won't be the first time I've made a boo boo.