Tony Brooks

Because I do not fully understand how your boat is wired there are several things I don't understand here. What was this isolator switch that got replaced with a simple on off switch. All pure isolator switches are simple on off switches. Maybe we have found who got rid of a 1,2,both, off switch, Typically the70 Ah battery in a split system would be the start battery and the 90 Ah one the domestic battery, each with a dedicated simple isolator switch, The start battery would have NO alternator connection, but thick leads between the start battery and main stater terminal and also between the start battery negative and the ground point on the engine. The engine electrics would get their feed from either start battery + or the main starter terminal. All negtaive back to the start battery negative. The domestic battery would have bond between its negative and the start negative. The positive internal would feed the domestic distribution board and all domestic negatives could return to either the engine bond point or the domestic battery negative. The alternator B+ would run to the DOMESTIC battery positive (this is to minimise current through the split charged relay for optimum life) The main terminals of the split charge relay would run to the two battery positives and one of the small terminals to any negative and the other to the D+ terminal on the alternator (this will vary if it is a VSR). So apart from a degree of rewiring I don't see why your system is not suitable for a split bank with relay option, but remember, I have no seen or tested the boat.

Yes You seem to have two batteries and one alternator, and if so it would be normal to designate one the start battery and one the domestic battery, but you seem to have one disconnected from the system for some reason. Some (older?) boats may use two batteries to form one one large bank for both duties, but that risks the domestic and navigation equipment flattening the batteries so you are unable to start it, so what you want to do an how to connect the system means you need to make decisions, but if you want a two bank solution you will probably have to buy more equipment. It is possible that your boat had a bat1, bat2, both, off switch fitted at some point so one of the batteries, at your choice could supply all the loads. This means that if you switched to (say) bat 1 when stopping the engine, bat 2 would not be discharged so it would start the engine when you set the switch to bat 2, then, once the engine is running you switch to both, so both batteries get charged. Again a decision to make and possibly buy such a switch. I do wonder if your boat had this system and for some reason the switch was removed and one battery's positive connection was left to dangle in the bilge. Author Posted 37 minutes ago HI Tony,I'm 24 hours away from having the engine lifted back into the boat so quietly panicking over the complexity of what Im undertaking (more of that later) In preparation for the lift, I was reading back through pretty much every post I have made and the responses to them that others have posted, when I came across this one where you were obviously advising me regarding the electrics and it sparked a thought in my head. I have had an auto electrician go over the wiring onboard in an attempt to sort out the issue of the batteries not charging. He has tested everything, cleaned connections, replaced terminals and generally done everything he knows to sort the issue but still the alternator was not charging. I've had a new ammeter and alternator fitted, the alternator has been back to the suppliers and tested in case it was faulty. Then once the engine had been lifted, I identified this large black cable (picture 1) laying loose in the bilge. Looking at photos I took of the batteries, I can see it is connected to the positive terminal of the leisure battery (picture 2) He explained that this was almost certainly the problem, there is no positive feed direct from the battery to the starter motor, connect both the large black cable and the red feed from the loom (presumably comes from the ignition switch) to the same post and the circuit is complete and it will charge. There has never been a problem with cranking the engine over (he said it had been supplying power through the panel and it was a miracle it had not burnt the wires out) and I can get that as the starter would be drawing power from the panel in the absence of the heavy duty feed direct from the battery that you discuss, Im now hopeful that this will finally solve the charging issues. . SO have I understood things correctly. There should be a feed (about 4 mm red) from the ignition through the loom to the post on the small cylindrical thing on the side of the starter motor. Bolted on to the same post should be a connection directly from the positive side of the starter battery (huge black cable previously laying loose in the bilge) to the same post and a third smaller wire (from the loom also) with a spade connection fitted to the blade adjacent to the post where the two heavier cables are already attached. BUT another friend says "if that cable is connected directly from the positive terminal to the starter, the motor will fire up and run permanently, making me doubt myself. To complicate matters even more, someone from the yard say they recall disconnecting an earth cable that I had missed when the engine was lifted and identified it as the large black cable left laying in the bilge. So I'm thoroughly confused now. Your post seems to confirm that Mark (auto electrician) is correct, in that there needs to be a direct connection from the starter battery positive terminal connected to the same post as the feed from the ignition switch which runs through the loom. Have I got that right? Im certain that the thick black cable was NOT connected to that post when the engine came out but if it was the positive from the battery would it have not caused problems of shorting out in the water and oil slopping about in the bilge No, water is not a very good conductor of electricity, and as yours is a GRP, rather than metal boat, I am not surprised that no damage appears to have been done. Now if this was a steel boat the whole charging problem would have been resolved after the fire. BUT another friend says "if that cable is connected directly from the positive terminal to the starter, the motor will fire up and run permanently, making me doubt myself. Towpath, marina bar, and friends are not the best source of good advice - especially, as in this case they don't seem to understand pre-engage starters. Unless by attaching that black lead to the starter SOLENOID main stud terminal (B+) you accidentally allow it to contact the connection that comes from start/ignition switch, the motor can not run all the time. SO have I understood things correctly. There should be a feed (about 4 mm red) from the ignition through the loom to the post on the small cylindrical thing on the side of the starter motor. Bolted on to the same post should be a connection directly from the positive side of the starter battery (huge black cable previously laying loose in the bilge) to the same post and a third smaller wire (from the loom also) with a spade connection fitted to the blade adjacent to the post where the two heavier cables are already attached. BUT another friend says "if that cable is connected directly from the positive terminal to the starter, the motor will fire up and run permanently, making me doubt myself. To complicate matters even more, someone from the yard say they recall disconnecting an earth cable that I had missed when the engine was lifted and identified it as the large black cable left laying in the bilge. So I'm thoroughly confused now. Your post seems to confirm that Mark (auto electrician) is correct, in that there needs to be a direct connection from the starter battery positive terminal connected to the same post as the feed from the ignition switch which runs through the loom. Have I got that right? NO, there should be a feed from the start position on the ignition switch or start switch to the SINGLE 6mm or SMALL stud connection on the starter solenoid. This tells the solenoid to connect the main battery connection to the actual motor. There should also be a heavy duty cable from battery positive to the larger stud connection on the solenoid. That stud connection on the solenoid is often used as a junction box for a feed to the instrument panel and on a single battery bank boat all the electrics. Following the comment from the yard guy about "the earth" they had disconnected, I did some research and the dreaded Google suggests that both batteries should be earthed, is this necessary or is a single earth sufficient? Until I know how you intend to use the batteries I can not comment. If it is just one bank of two then you will only have a single earth point on the engine, with both battery negatives joined and both positives joined at the batteries. If you have a two bank solution then you keep the negatives joined as I have just described, but the positive wiring is altered. I am far from clear what is going on with the boat, but on the face of it - which may well be wrong - the simplest and easiest way for you to get afloat is to connect that large black cable to the main STUD terminal on the starter solenoid and then join the two batter positives together using a similar cable at the batteries, But be aware that if you flatten them at sea you will not be able to start the engine. As you seem to have had a number of "experts" offering different opinions on what is wrong I can't be responsible for my advice, which is given on the basis of what you have posted and my understanding, from your posts, of the situation. If you want to discuss either a split charging system or using a 1,2,both, off switch please let me know.

Depends on make of gearbox, but it has a screw in filler plug with the dipstick fixed to it, then you have to screw the plug in to get the correct level OR in many cases rest the plug on the top of the case and treat any minimum mark as maximum and the bottom of the dipstick as minimum. This is true of PRMs and probably others. So if you did not screw the plug in then the level may be correct.

That is NOT a mains cable. Mains do not use cigarette lighter plugs. It is a 12V? power supply for the TV that will/should stabilize the supply. You do not have to use the plug fitted, you could fit whatsoever type of plug you wanted to get the 12VDC into the magic box.

Note what you were advised a way back in the topic. The boat electrical system can have voltages present of (say) between 11v and 15V, plus voltage surges. Your 240V to 12V TV plug provides a stabilized 12V supply so using an stabilized 12V (nominal) boat supply MIGHT (not will) eventually damage the TV. You may be better looking at stabilized 12V, car, computer supplies, many of which allows the selection of variable output voltages.

More likely signs of cackhanded terminal tightening, and as long as the post is still attached to the plate group and it is treated properly, unlikely to indicate impending failure. Go a bit gorilla and it could fail instantly.

Any way, how is the OP getting on with his high voltage - if it is now a high voltage. As I said before, some regulator suppliers quote 14V regulator, but then say 16V regulation, and guess what, the last two images he has posted show 16V - assuming I understand what the images are saying.

The radiators and calorifier in parallel with each other using a two pipe system, The calorifier closest to the boiler, although with a two pipe system it should not make much difference.

No, because I knew it was differential expansion so without a total strip out and refit with suitable expansion gaps and cover trims in the fit out it would have been a waste of effort. If you did not leave sufficient expansion gaps in the fit out and glued the battening to the hull it is possible that contraction of the steel may have broke some glue lines.

It is an old style Lucas relay and almost any modern 4 terminal, or 5 terminal and ignore one terminal "square box" type relay will do as long as it is rated at 10 amps plus. It may well be a starter terminal, but at that age of boat it may have had or still have a Lucas 10 or 11AC alternator, and if so it could be related to the charging system.

Do they not have a base at the bottom end of the Shropshire Union canal.

What KIB said above, but it does not sound good - throw the problem back at the re-conditioners to sort out.

But I have seen that at least some do, and cars, vans and trucks only have one battery so in the vast majority of vehicles other equipment is always drawing some current, even if it is only the engine electrics. For the cost of the parts, I think it is worth trying to load the battery and see what happens. I agree it should not happen, but his latest reading gives 14.6v which is listed on some sites selling A127 regulators as the actual voltage where astthey are listed as 14V.

It took me ages to grasp that he was charging the lithiums from an A127 that has a maximum output of 70 at most, and less than that if it needs to be derated for heat.

I think that most use the engine battery as the buffer battery, so it will be slightly discharged when starting and also there will be a current draw supplying the gauges while the engine is running. My suggestion is to try to replicate this. On a car there will often be a load from the heater/air con blower, flashers, ICE system, and the ECU system(s). I would not want to join the start and buffer batteries if it involved parallelling the alternators because we already know that can cause odd symptoms with well charged batteries. Try a load on the buffer before doing much else.

I am not sure if they are still available in different voltages. You need someone with knowledge and suppliers catalogues that give such info. Where is @Sir Nibble when you need him. Maybe your chap in the shed will know. I think the problem is that you are trying to operate the alternator way outside its design criteria. Is there any way that you can use the "turn off the B2B" signal to turn on (say) a headlamp bulb to see if that load makes much difference. Better still, make up a clip lead to a 55W headlamp bulb and clip it across the buffer battery when the charge to the Lis is turned off, as a test. I think the main and dip headlamp bulbs come with three 6mm blade connections, so 2 x pos. one for each beam and one negative. If it works, it would be time to think up a more elegant solution.

In that case, if they are "standard" BMC 1.5 SENDERS (not switches) with no adaptors between them and the block I am 98% sure that you will need EU standard gauges, rather than US standard.

To be clear, the buffer battery is NOT the starting battery so should spend all it's time absolutely fully charged. If that is the case I suspect it is just the effect of a fully charged battery drawing all but zero current. I suspect the only thing you can do now is get a 14.2 to 14.4 regulator fitted and see how that works. I can't see how bad brushes/slip rings can cause over voltage and have never experienced it, but who knows.

Tacho - do not make the mistake of buying one for a petrol engine. You need one that takes pulses from the alternator W terminal, not the coil 12V lead. I am sure a maximum of 4000 rpm will be fine unless you intend to take the engine to maximum revs out of gear. The way propellors react with torque and BHP means that a boat is likely to never reach the maximum revs in the automotive manual because torque (what the prop needs to twist it) starts to fall off at higher revs although BHP will continue to climb. Virtually any oil pressure gauge that goes to at least 70 psi will be fine, the actual oil pressure is more likely to be around 60 when cold and revving and 40 psi when hot, maybe as low as 10 to 15 psi when hot and idling. Temperature gauge. Your engine cooling system may or may not be pressurised, so a maximum of around 120C should be fine. Remember, the gauges and senders have to be matched, and you may well need adaptors to fit them into a BMC. If they are not matched, they will either read abut twice what they should or about half.

Yes, who posted something that appeared designed to "Unwarranted antagonism and provocation", to use Mr Ho's own words from yesterday, when he claimed to have run to mother. Perhaps a number of us should follow his example. Thank you for behaving in a civilised manner. Hopefully this thread has taught you that there are a number of very experienced members who try to offer good advice, but there are also a few, very few, who seem to think that are vicariously experienced from third parties, who's motives may be more to do with promoting themselves and making money than offering genuine useful help. The trick is learning who is trying to help and who needs treating with caution. I hope that your visits to the brokers work out well.

I was about to post something similar, plus the fact that I have never seen Alan claim to be a "master mariner", he just claims considerable sailing experience. Seems to me that Mr Ho is exhibiting a certain lack of intellect at the least.

Mine used to do it, and creak all by itself. Usually it needed sun shining on the boat and no engine vibrations.

So another new and so far non-contributing member gets nasty and throws an insult when the forum does not, for whatever reason, give him the answer he demands. I spent maybe 15 minutes trying to find a DEFINITIVE answer to the question, although I suspected the last three figures were the length, there is no way I would tell you that without confirmation. The "normal" 33C type cables were traditionally labelled in feet, so 2.?? feet seemed an unlikely cable length. If it was so easy, then I ask you why the supplier you talked to could not or would not tell you. To add, in the original post you gave no information like boat type, engine type/make model, gearbox type/make model, control make/model, what each cable was for, or where the control is located relative to the engine and gearbox, so we could try to work out a typical run length and work from there. My guess was that you have a mechanical gearbox, so need a heavier duty cable, but I did not know for sure. You also gave no indication of your practical and boating knowledge and experience, so one had to assume, given the lack of relevant information, that you had little knowledge or experience. Yes, as you seemed to think that you needed that information so urgently AND a suppler could not tell you, then doing that work would be necessary for you to get that information, given that it seems it was too difficult for you to get a semi-accurate length by measurement in situ. I note that this is the first time you talk of tie wraps and tape, I would suggest that this is not a typical installation method. Usually they are put loosely in place and then the odd clip or tie wrap is used to keep them in place, keep the bends and bows from getting too tight, and keep the cable away from potential damage, so there is not normally much effort in removing them. If you have a boat yet can't afford or carry a ball of string, then I feel sorry for you, I can see major problems ahead.

If you have access to most of the cable run, I don't see why it would be so difficult to disconnect it, tie string to one end and pull it out leaving the string where the cable ran. then you can straighten the cable and measure it. Use the string and a good deal of wriggling, twisting, pushing and shoving to put it back. As long as you don't go messing with the adjustment at each end and put the ends fittings and outer clamps back exactly where they were, there will be no adjustment needed. If you can't do it, maybe a fellow boater will help you.