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Peter Sloe roamin

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  • Gender
    Male
  • Location
    Liveaboard
  • Occupation
    Retired
  • Boat Name
    Sloe Roamin
  • Boat Location
    Continuous cruiser

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  1. Well, a whole list of questions so - 1. I measured across each battery when it had no load - because I disconnected cables on one post - so I could see if there was an imbalance, and there was. I am a liveaboard so there is a continuous cycle of use and recharge, either from the 512w solar or from the engine alternator (100a). 2. I said 'apparent' good state of charge because I could only use the voltage indicated on an MT50 monitor unit. With no charging going on from the alternator or the solar I wold expect 12.6 - 12.7v to indicate a good state of charge and I used to see it quite often but in the last 3 months it became rarer. 3. Since I bought the boat two years ago I have tried to keep the non-charging voltage above 12.1v at all times, but over the last 3 months this was very difficult, in the morning it would be down to 11.8 or even 11.6v. In the winter of 2017-2018 the boat was left moored at a broker until I picked it up in mid-March and I suspect there was little or no charging of the batteries in that time which won't have helped their longevity, the old ones were at least 4 years old, perhaps older. I had an electrician look over the system last year and the charger was OK then. He had me run the engine at 1100rpm for 3 hours and at the end the MT50 was showing 14.6v. I tried the same thing recently and only got to 14.3v. Because of the rewiring I got a professional in again to swap the batteries, test the starter battery, and check the system was working right for the AGM batteries and he gave it the thumbs up. So far I don't use shore power at all but I'm aware I don't have built-in battery charging if the boat is plugged in to a shore unit so I am considering swapping out the 17 year old Sterling 3000w inverter for a combi inverter/charger with lower output, say 2000va, and add a proper monitoring unit like one of the Victron BMV range to give me a better idea of what is going on.
  2. An update to my original question - and thanks to everyone for their input - after several instances when an apparent good state of charge dwindled away rapidly I put a voltmeter across each of the four batteries in turn and found batteries 1, 2 and 4 at 12.2v and no3 at 12.5v. That convinced me to make some changes so a few days ago the 4 x 115ah batteries were swapped for 4 x 130ah AGMs, the starter battery was moved to the end of the row, and the wiring was replaced so all loads are across the whole bank and the inter battery links are all the same length. Of course new batteries are always better than old ones but the extra capacity feels great.
  3. Thanks to everyone for commenting on my odd battery connections, I feel I know my boat a lot better after going through this exercise. I couldn't see any good reason to have the starter battery in the middle of the leisure and it's good to see no-one can think of one either so I'll look at the implications of moving it. At least I can then move the inverter -ve feed to the end of the bank without adding any cable. I also can't see why two batteries are rotated 180 degrees to the rest, as you say Tony, just confusing. As to the value of the calculations in the article, they make sense to me as someone who did a three year electronic engineering apprenticeship (a very long time ago but I believe the electrons still move the same way) and with a 100amp load the imbalance is startling. Of course most of us aren't pulling 100a most of the time but I di when I'm microwaving a ready meal and that's enough to make want to balance the load better. Thanks again for helping my thought process.
  4. Here is the layout. The starter battery is in the middle of the row of leisure batteries. I show some with positive at the top and some with negative uppermost because that's how they are installed. Thanks for asking for the picture by the way - it forced me to learn how to do it!
  5. I didn't mention a specific method, however my batteries are connected in parallel group of four - with no division into groups. The previous owner got Onboard Solar to fit a pair of panels and they are connected right across the bank as shown in smartgauge article method 2. The inverter (which I assume was an original fit) is connected to +ve on battery one and the -ve on battery three and the +ve feed to the distribution point comes off the positive terminal of battery two. As you say, some work needed there. My boat is a 2003 John White build and fit out and I assume they set up the wiring like that.
  6. I'm considering replacing my leisure batteries (4 x 115ah) so I've been looking around to check the validity of the wiring system in my boat. I found this interesting article smartgauge.co.uk/batt_con.html about the pros and cons of various connection methods, including calculations. It looks like you can get quite big differences in individual battery load using the first method even with fat cables. I was told today that one way to get max life from a bank connected like that is to shuffle the batteries occasionally - like I'll ever get round to that ? It looks like I need to get some rewiring done on my boat even if I keep the batteries, the solar is connected bottom negative to top positive as per the plan but the main distribution point and the inverter feed come off two different points along the battery chain, which according to the article will result in uneven loading. I will do some more research before getting the spanners out though.
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