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nicknorman

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Everything posted by nicknorman

  1. Actually there is a small relay within the instrument panel. It is activated when the ignition is turned on, and connects the leisure battery + to the leisure alternator D+. But this is not relevant to your problem. No I don’t think the field current doesn’t come from the IGN terminal, I’m pretty sure it comes from the B+. The IGN is just a “logic input”. I think!
  2. It’s a sign of the times that you can get 1200ah of Li cells from the same place I got mine, for the same price as I paid for 600Ah 2 or 3 years ago - around £1600. But 1200 Ah - that will take a lot of charging! Why not though!
  3. I'm sure I saw you on a bus the other day? Rather than buying some "closed source" "drop in" Li batteries, I suggest it might be better to get some bare cells and add a commercial BMS such as JBD or Overkill. Then you have full control. Depending on your usage it might be better not to use FET based switching in the "emergency disconnect" switch, you can use eg a bistable relay like the Tyco BDS-A which obviously has a better ability to cope with large current surges than a FET based system - if you can find a BMS that drives it correctly (pulse on, pulse off).
  4. Yes that bit is a puzzle. I’m not clear if this was a one off thing, or a routine finding. If the former, perhaps it was just that eg worn brushes decided they would connect with the slightly higher system voltage. But if it is repeatable then yes it is definitely a puzzle. But still, if the voltages present on the alternator terminals are correct, it should charge, and if it doesn’t that points to a faulty alternator.
  5. The Beta 43 has been around for a while so it’s hard to be categoric, but for recent ones with twin alternators, the starter alternator is a 6 diode machine. It certainly is on our 2010 engine. So there is an “IGN” wire that wakes the alternator up when 12v is applied, and a separate warning light wire. The field current is initially obtained from the B+ wire. So it with the warning light being on, this suggests that both that wire and the IGN wire and the B+ are all connected, pointing to an internal alternator fault (intermittent, eg worn brushed). Before removing the alternator I would check voltages on the alternator terminals with ignition switched on, should be 12v on B+ (fat wire) and IGN (brown wire), and 0v on warning light wire (brown/yellow). If that is all satisfactory I can’t see another explanation other than a faulty alternator-
  6. A couple of years ago I noticed our (Shoreline compressor) fridge was running most of the time, even when the ambient temperature was average. I put an hour counter on it, discovered it was running about 70% of the time. In the end I got a gas kit from Amazon and added some “compatible” gas though not the original gas. Net result it now doesn’t run most of the time. I guess more like 25% of the time. So that might be one option, I think it cost around £50. Which is a lot less than a new fridge! Also we do have RGB LED tape running under the gunnels through the open plan saloon/dinette/galley which uses a surprising amount of juice, around 5A.
  7. I tried to send this by PM but I got the system response “IanD cannot receive messages”. Presumably there is an option to turn off receiving PMs which you have selected. So I’ll have to make it public. This is what I said in my PM: On the one hand you seem quite intelligent and knowledgeable. But on the other hand, sometimes incredibly childish. “Pot, kettle etc” is just so playground along with a total inability to recognise your own behaviour. I am going to stop interacting with you because you turn everything into an argument, even when we basically agree. Which is a shame because we both share a lot of knowledge and expertise and could have some interesting discussions. But I really can’t be bothered with the petty playground bickering. So you win, I’m out.
  8. It’s a shame you have to reduce every thread you contribute to, to personal conflict.
  9. It is not a theme of mine to repeatedly bang a drum about companies daring to sell stuff … blah blah. It is you making stuff up in order to make a personal attack on me. Everyone can see it, except you. What it is is me pointing out that the component cost is a small fraction of the retail price. I didn’t think we disagreed about that. But you will find any excuse to have a go of course. I also mentioned that when deciding on the retail price of a product, as well as deciding on a strategy to recover the development costs over a reasonable time, and make a reasonable profit, one would also look at the existing market to review competitor prices. If the other calculations revealed that you could sell the product at 50% the price of the competitors, it would foolish to do so. Selling it for 90% of the competitor price would be better, or even 110%, because in this sort of market people think cheaper is worse and more expensive is better, and there is no point in making less profit just for the sake of it.
  10. My comment was a statement of fact, not a complaint. A 4 paragraph rant from you is not going to alter my statement of fact.
  11. And then there is the “we should charge as much as the market will stand”. They will have looked at the pricing of the wakespeed and Balmar offerings.
  12. I recently have been messing about with Bluetooth BLE (Bluetooth Low Energy) modules. Whereas cooking Bluetooth just creates a single and permanent serial link, BLE is a much more intermittent, sending a “data available” advertisement which, if acknowledged, results in the data being sent in a burst. The rest of the time the transmitter is deactivated, hence the low energy bit. Anyway the BLE module in question is the HM-10 which uses the Ti CC2541 chip. As well as having the Bluetooth transceiver, this chip includes an 8051 microcontroller and exposes most of the port pins, and is loaded with peripherals including UARTs, SPI and I2C interfaces, counter/timers, A/D etc. I guess the thinking is that you need a microcontroller to manage the BLE protocol stack, but it is not processor intensive so you might as well expose the micro so the end application can make use of the spare processor resources. These modules are about £3 from China, and for that you get the BLE interface plus enough spare processor power to run an alternator controller. Remind me how the Zeus can cost £800+!?
  13. I don’t see how it could be clever enough to distinguish between a sense disconnect vs a heavy load coming from the boat (inverter etc). Max field current and (apparent) low voltage = maintain max field current. One can do something like diode OR the 2 voltage sources (sense wire and alternator output) such that a sense wire disconnect only creates a mild over-voltage of a diode drop’s worth. But whether the Zeus does that is probably unknown. Anyway my system uses same wire (not particularly thick) for controller supply/voltage sense/field current supply, without any ill effects.
  14. Presumably only one of the positive or negative wires is taking a lot of current, the return current path is via the alternator. Most alternators found on boats have a max field current of 4 to 5 amps. I think these regulators only have 10-12A max current in case you want to parallel 2 alternators from the one regulator. But anyway, why is it important to eliminate voltage drop so as to have an accurate measure of battery voltage by having separate near-zero current sensor wires? Li battery charge voltage is very flat and so the set voltage is not really of much relevance for 98% of the charging time, since the system is a current source and current limited. It only becomes relevant right at the end, or possibly during the float phase, both of which are periods when the alternator current and hence field current have fallen right off. I made a huge mistake when I first wired up my alternator controller (which sends a positive supply to the alternator rotor, the other brush being grounded) because I connected the wire which was the combined regulator power feed and voltage sense, to the battery + directly (via a fuse). Whereas the alternator output went via the Mastershunt (which has a 500A fuse) and the emergency disconnect relay before reaching the battery +. It all worked fine of course, but consider what would happen if the alternator B+ beinf connected to the boat supply systems, with the sense wire, measuring battery + voltage, became disconnected from each other eg due to the emergency disconnect relay opening or the 500A fuse blowing (or some other bad connection). The sense voltage would decrease below the regulated voltage which would cause the regulator to output maximum field current. Consequently there would be massive voltage coming out of the alternator catastrophically damaging the 12v appliances. Fortunately I realised my error before the catastrophe happened, and I moved the sense wire to the engine stud so that such a disconnect between alternator output and voltage sense, wasn’t possible. So now I sense more or less alternator output voltage, not battery voltage. But so what, highly accurate battery voltage is not that important when there is a lot of current flowing, because charging voltage will always be way below regulated voltage until the last few minutes after the current has fallen right off. And anyway, even at 150A charge the voltage difference is only about 0.1v. Inconsequential. Too much LA mindset going on!
  15. CANBUS is very good, highly robust and easy to implement. However it is just a hardware specification that moves bytes of data around. What the data means, is up to the system designer. So just because 2 devices have CANBUS in no way means they can necessarily talk to each other meaningfully. Apart from NMEA2000 I’m not sure that there is a standard protocol for boats or Li batteries. Maybe there is? Dunno.
  16. No it wouldn’t work, because there is likely an alternative current path from the starter negative lead that bypasses the shunt. If there isn’t such a lead and only one negative cable on the load side of the shunt, then all the starter current would pass through the shunt. Hundreds of amps. The shunt is there to track only the leisure battery state of charge, stuff happening with the starter battery needs to be kept separate. You just want one bonding point to hull, otherwise you create circuit paths through the hull. Because the engine is already probably connected to hull via the exhaust, prop shaft, control cables etc it is best to “properly” connect the engine to hull via a short lead. At the engine, the leisure and engine starter battery negatives are intrinsically connected together so any positive short from either starter or leisure battery will blow a fuse (if there is one). Yes this is more or less correct. If there are 2 possible current paths, one via a fat wire from engine to starter battery negative (connected direct to leisure negative) and one fat wire from engine to leisure battery negative via a shunt, the latter will have more resistance (the shunt) and so more than half the leisure alternator current will bypass the shunt. Meanwhile all the leisure battery discharge current will go through the shunt. Net result being that the indicated SoC decreases faster to zero after a short time, or bounces around between zero and 20% or somesuch. A friend’s boat was “professionally” wired like this when they got a battery monitor fitted. It didn’t work, as the indicated SoC was always extremely low no matter how much they charged it - for the reasons mentioned above. I was summoned to correct the wiring error made by the “professional” and the system now works properly.
  17. I’m on a ferry from Amsterdam to uk and about to lose signal, but just to clarify, connections to be as follows: From leisure battery to shunt (battery side). From shunt (load side) to engine/alternator negative - either via a connection to starter negative and thence on to engine/alternator negative, or direct to engine/alternator negative (both these options are the same from a circuit point of view. Nothing. Nothing. NOTHING to be connected to leisure battery negative, apart from the shunt. The alternator negatives are connected at the engine, so some of the leisure alternator negative current will flow via the shunt, some of the leisure alternator negative current will flow direct via the starter battery negative lead bypassing the shunt. Yes. Somewhere in your”junction box” you need a lead to the engine casing (alternator negative). From the engine casing a short lead to the hull.
  18. No. It creates an alternative current path for the domestic negative so the shunt only registers about 1/2 the charge current but all the discharge current.
  19. That is one way of doing it, but topologically it is exactly the same whether you have one connection to the engine going to the starter battery and with the shunt connected between starter and leisure battery, vs having one wire from shunt load side to engine and another wire from starter battery negative to engine. You just physically move the point where the two negatives are connected without any effect on the circuit. The two negatives are now connected at the engine instead of being connected at the shunt load side.
  20. You must have only one thing connected to the leisure battery negative, and that is the battery side of the shunt. The load side of the shunt is connected to the starter battery negative, the boat systems negative (for lights, pumps etc) and a single connection to hull. A connection to hull is likely to already exist via the engine (via exhaust, control cables, prop shaft etc) so in order to avoid current paths through the hull, just make a good quality connection between engine and hull. That is, unless the engine is isolated from starter negative, alternator negative (unlikely, but possible) when you can make a connection from eg starter battery negative to hull. No sorry this is wrong. If you link the battery negatives directly the shunt will not work properly. If you have multiple negative connections to hull, this creates a current path through the hull which can cause corrosion.
  21. I’ll take your lack of a cogent response as an admission that you got it wrong.
  22. But nothing was directed at you. You took it upon yourself to be rude to other people when they had not been rude to you, nor even communicated with you. That is unprompted rudeness.
  23. I presume this is your entry for “comedy post of the week”?
  24. Would you two mind getting a room, is a bit nauseous.
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