Rickent Posted April 18, 2017 Report Share Posted April 18, 2017 Was down the engine hole today and had a quick look at battery connections and they are wired as in diagram 1. I have very limited electrical knowledge but is this correct or is diagram 2 correct or neither. Link to comment Share on other sites More sharing options...
WotEver Posted April 18, 2017 Report Share Posted April 18, 2017 Neither. See here: http://smartgauge.co.uk/batt_con.html Note that whichever method you use, ALL positive connections should come from ONE point, and ALL negative connections should come from ONE point. Link to comment Share on other sites More sharing options...
Robbo Posted April 18, 2017 Report Share Posted April 18, 2017 (edited) 2; I'll have to dig out the quote from Nigel Calders book for the advantages of that layout. However I use the method wotever linked to, and if you have a shunt it's the only method. Edited April 18, 2017 by Robbo Link to comment Share on other sites More sharing options...
Rickent Posted April 18, 2017 Author Report Share Posted April 18, 2017 Are the batteries not better balanced in 2? Link to comment Share on other sites More sharing options...
Chewbacka Posted April 18, 2017 Report Share Posted April 18, 2017 If rewiring then there is no reason not to follow best practice as linked to above, but if the wiring is in place will it make a big difference in the real world to battery life if you don't use the optimum? I think the bigger the currents the more benefit, but if you have big cables and rarely pull big currents I am not convinced it is worth the cost to change it. Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 18, 2017 Report Share Posted April 18, 2017 (edited) It looks to me as if this boat probably has two domestic batteries and one engine battery. The OP need to clarify. If so then the solar can not charge both battery banks unless both banks are combined into one larger bank as I think has been done in diagrams 1 & 2. so if I am right both are wrong unless the OP only wants one bank. If that is the case then option 2 seems to have the batteries balanced for both discharging and solar charging but in an unconventional way. If it were my boat I would alter diagram 2 so both the solar supply cables are on the same terminal and diagonally opposite corners. that is 2 pos leads on one end and the two neg leads on the other. However the OP must clarify if this is a 3 battery domestic bank or two battery domestic bank plus one engine battery. If its the latter the op is asking for ending up being unable to start the engine to recharge the domestic bank. Edited April 18, 2017 by Tony Brooks Link to comment Share on other sites More sharing options...
Rickent Posted April 18, 2017 Author Report Share Posted April 18, 2017 Sorry Tony, it is a bank of 3 domestics. The starter is seperate. They have already been wired as in diagram 1, but this doesn't seem right as the method of wiring in 2 seems to be the more logical and balanced way. Link to comment Share on other sites More sharing options...
Robbo Posted April 18, 2017 Report Share Posted April 18, 2017 42 minutes ago, Robbo said: 2; I'll have to dig out the quote from Nigel Calders book for the advantages of that layout. However I use the method wotever linked to, and if you have a shunt it's the only method. Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 18, 2017 Report Share Posted April 18, 2017 You are right, method one is not best balanced and I can see no reason why it was done that way. As I said method two is balanced but so everyone knows what is going on I would move the solar inputs to the other end of the batteries so they connect on the same terminals as the main pos & neg. Link to comment Share on other sites More sharing options...
Rickent Posted April 18, 2017 Author Report Share Posted April 18, 2017 Is the middle battery in 1 still acting as part of the bank as it isn't connected at the positive terminal to the end battery, as you say even I with my very limited knowledge didn't think this was right. Link to comment Share on other sites More sharing options...
Flyboy Posted April 18, 2017 Report Share Posted April 18, 2017 Yes it's still part of the bank but not very well balanced. Link to comment Share on other sites More sharing options...
Rickent Posted April 18, 2017 Author Report Share Posted April 18, 2017 Cheers all, will be tidying up the wiring and putting it right in the next couple of weeks. Link to comment Share on other sites More sharing options...
Sir Nibble Posted April 18, 2017 Report Share Posted April 18, 2017 Real world. You will never ever notice any difference. Even a liveaboard whe zealously monitors battery performance will never notice a difference. Link to comment Share on other sites More sharing options...
WotEver Posted April 18, 2017 Report Share Posted April 18, 2017 49 minutes ago, Robbo said: Calder doesn't half write some rubbish. The above is a good example. I wonder if he could explain how this 'battery filter' acts differently with the charger being connected to different terminals. Actually I don't wonder. He couldn't. Link to comment Share on other sites More sharing options...
Rickent Posted April 18, 2017 Author Report Share Posted April 18, 2017 Tony Brooks has stated that the charger connections need to be connected to the same terminals as the main pos and neg, that's good enough for me. Link to comment Share on other sites More sharing options...
WotEver Posted April 18, 2017 Report Share Posted April 18, 2017 29 minutes ago, Rickent said: Tony Brooks has stated that the charger connections need to be connected to the same terminals as the main pos and neg, that's good enough for me. So did I in the first reply. 1 Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 19, 2017 Report Share Posted April 19, 2017 13 hours ago, Rickent said: Tony Brooks has stated that the charger connections need to be connected to the same terminals as the main pos and neg, that's good enough for me. Actually I did not say that. I said that diagram 2 was balanced for both solar charging and the main circuits but it would be better to alter it. 14 hours ago, WotEver said: Calder doesn't half write some rubbish. The above is a good example. I wonder if he could explain how this 'battery filter' acts differently with the charger being connected to different terminals. Actually I don't wonder. He couldn't. I wondered last night if you would say something like this especially as Gibbo said much the same thing. Just because something is in a book/on the net dies not make it correct. Lets assume the batteries do tend to damp surges but then we need top ask the most likely sources for such surges and unless the mains gets a spike or the battery charger/solar regulator is faulty in the Calder diagram the most likely source of surges is from switching inductive circuits within the boat. In other words the surges are most likely to arrive at the main pos and neg connections, not the charger connections. This means the domestic equipment will be subjected to the surges while (if the book is true) the charger which should be designed to cope with normal and expected surges would be protected. In my view a totally unimportant thing to worry about. Interesting that Payne does not even consider what Calder says./ Link to comment Share on other sites More sharing options...
Robbo Posted April 19, 2017 Report Share Posted April 19, 2017 6 minutes ago, Tony Brooks said: Interesting that Payne does not even consider what Calder says./ Payne? Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 19, 2017 Report Share Posted April 19, 2017 5 minutes ago, Robbo said: Payne? The Marine Electrical and Electronics Bible by John C Payne. Published by Adlard Coles, ISBN 0-7136-5724-3 Also my copy of the 12 Volt Bible for Boats (second edition) says nothing about wiring batteries to damp surges. Its a non-issue. Link to comment Share on other sites More sharing options...
Robbo Posted April 19, 2017 Report Share Posted April 19, 2017 4 minutes ago, Tony Brooks said: The Marine Electrical and Electronics Bible by John C Payne. Published by Adlard Coles, ISBN 0-7136-5724-3 Also my copy of the 12 Volt Bible for Boats (second edition) says nothing about wiring batteries to damp surges. Its a non-issue. Cheers, I actually have the Payne book as well,although it I've not read it yet (no electronic version!) Link to comment Share on other sites More sharing options...
WotEver Posted April 19, 2017 Report Share Posted April 19, 2017 2 hours ago, Tony Brooks said: I wondered last night if you would say something like this especially as Gibbo said much the same thing I wasn't aware that he had but it doesn't surprise me, it's total rubbish. Link to comment Share on other sites More sharing options...
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