nicknorman

This does seem a bit piss poor from a coding point of view. My code works out the max field current limit by looking at various issues, and then chooses the lowest one. The code for the max field current (max excite current = IEM) as a function of alternator temperature is pretty simple really (the max field current due to circuit resistance is 4.5A): IEM_temp = 4.5 -(((float)(Alternator_Data.Alternator_Temperature - 75))/8); So for every degree over 75, the max field current is reduced by 0.125A. It tends to stabilise at around 85 to 90 degrees (depending on ambient). There is no sudden switching between constant temperature and constant voltage regimes. Not rocket science! I don't see a problem connecting the Zeus to the BMV shunt. As you say, the impedances are massively different. But I would say that there is no particular issue with having shunts in series, I have the Mastershunt in series with the BMV. The max voltage drop is 50mV at 500A so it is not a big deal especially if you are careful with alternative ground paths (but don't tell IanD!) CANBUS can be quite fast (1mB/sec) but of course you need to take into account the processing speed at each end. And often it is implemented at 250kB/s which is still quite fast bearing in mind you only need a few bytes of data to give (eg) current. I would agree though, that voltage needs to be internal not dependant on some databus which might or might not be plugged in. Ditto the entire regulation loop. But slowly changing or less imporant things like battery & alternator temperature, charge current (used for the purposes of deciding when to go to float) can all be sent over a databus providing the code notices and makes safe allowances for when the data is lost (due to you unplugging the cables etc) No I strongly disagree. There is no elegance in throttling a power source by disspating lots of power. The elegance comes in working out how much power should be generated in the first place and limiting it to that. Think steam engines - boiler is fired at full power all the time and excess steam is blown off, vs boiler is fired at a rate appropriate for the present load. This almost sounds like a modulating gas boiler!

Yes the chap phoned me yesterday to say the booking system was working for him at least, and he made the booking on the system that I’d requested earlier. It is now showing in our list of bookings.

Yes I have. But the real question is how much effort did I put into interpreting them. A sort of “look vs see” situation.

However, if the fault were the resistor open circuit, the light would be on.

It may need the W wire connecting to make everything work properly - otherwise it can’t know how fast the alternator is spinning - or if it’s spinning at all! Can’t remember if you have already connected it? “Actually its correct....its assuming the field circuit is open circuit so not lighting up, just like a conventional alternator system.” NO NO NO!!! You are still thinking 9 diode machine. Wash your mouth out! Think 6 diodes!

Is the light staying on or off? My reg chip has a few error codes that are reported back to the micro, one being "mechanical failure" ie the thing is not going round (fast enough) and one for overtemp (of the reg chip) and one for electrical failure (which I think is a disconnect in the field circuit). But I just used the "mechanical failure" one to switch on the warning light. The Zeus probably follows a similar logic. If I may say so, just like when one switches from LA to Li, it is hard to shed the LA mindset and switch to the Li mindset, when you switch from a 9 diode internally regulated alternator, to a 6 diode externally regulated alternator (which is what you have done) there is some mindset shedding and switching to be done! Think 6 diode!

You should just set the "Feature out" to "Warning Lamp" which I think is the default anyway.

That is not my reading of the manual. It says The feature output lamp that can be configured in the app. This output acts like a switch between your load (light or fan) and the internal ground in the Smart Regulator. It can switch uo to 48V at 1 Amo. So I read that it's a switch to 0v. Other side of light should be to +12v, probably the IGN switch so it is off then the IGN is off. Maybe it is not working just because the reg isn't wired up correctly at the moment?

But with a reasonable system of solar and batteries and especially in the summer, there is no reason not to use a toaster. They are typically 800w which will take about 80A. But only for about 2 or 3 minutes. If we say 3 minutes, that is 4Ah. Not exactly going to break the bank!

While you are at it, connect the panel warning light wire that was on D+, to the Zeus "Output 1". Then the alternator warning light will work as normal, plus some fault code blinking.

I’m going to go upstairs and check on the big screen computer, but this sounds wrong to me. I would expect the field circuit to be: from B+ direct to the brush. From the other brush via the regulator to ground. The D+ and field diodes are not used. It becomes a 6 diode machine. The alternator warning light would be operated by the regulator. I certainly have a P type circuit on my setup, the other brush connected to ground. But I would still fuse the wire from the B+ to the regulator. I don’t think it makes much odds whether you use P or N. In my case, the reg chip was P only and one brush was already connected to case so it was a no-brainer.

My point is that if there is +12v on the D+ terminal, it means there is no circuit through the rotor, typically because the brushes are not connecting. If everything is working then the voltage would be around 1v, but then the light would be on. Which it isn’t.

Yes surely the device becomes a “6 diode machine” with the field current supplied from the B+ terminal, ie direct from the battery until the alternator is spinning and making its own juice. I would definitely have the w connected, otherwise the controller doesn’t know the speed. You want it to know the speed so you can have reduced max field current at low rpm, but allow max field current at high rpm (reduced if it gets too hot, of course). Are you sure you have wired it correctly?

Hmmm, you have never used an air fryer, have you?!

Air fryer.

Luddite! Just joking, but I think one should perhaps bear in mind the question being asked "which model of inverter do I need" rather than a different question "do I need an inverter at all". The answer to the latter question is of course no. We spent 20 years borrowing a friend's boat to go boating for a 2 week holiday every year. It didn't have an inverter. But, these days lots of people do have an inverter. Times move on! And if you have an inverter, there is of course no complusion to turn it on! It is helpful to answer the question asked rather than answering a question not asked. On Mike (Blackrose's) point, having a good inverter and a mains fridge is a perfectly valid alternative to a 12v fridge. The 12v fridges around at the moment seem to be very low budget (and hence low efficiency) mains fridges that have had a 12v compressor added. So if you look at the overall efficiency of a 24/7 quality inverter and a modern high efficiency mains fridge, vs a 12v fridge, there is not much in it and with the former you have the advantage of always-on mains power in the boat. Well yes but we had an always-on inverter right from the start, when we had ordinary Lead Acid batteries.

The Beta 43 at least, has a relay behind the panel. The ignition switch etc is powered from the starter battery. When it is turned on, it energises the relay which connects the leisure battery + to the alternator D+, via the warning light (and a resistor in parallel). So as a first step I would check that the relay is working properly and connecting the leisure battery + to the warning light when the ign is switched on. If not check the other side of the relay. If no +12v, could be an issue with the multi-way plug because the leisure battery + connection is via the domestic alternator B+ and up through the multi-way connector to the panel. Presumably the leisure battery isolator switch is on and working properly? Other causes for this issue is basically something else in the circuit from the leisure battery + to the alternator D+ via the relay, the bulb and resistor, the multiway connector and the D+ terminal, or a faulty alternator For fault finding I would start with the easiest things to reach. Having checked for 12v on the warning light, you could move to the D+ terminal on the alternator - if it has +12v on it when the ign is on, the alternator is faulty (brushes worn out etc) but if it is 0v then it is likely the mutli-way connector in the wiring loom. So just to clarify (because the above is a bit waffly!) and summarise your question "how is the alternator charge circuit arranged": There is a thinish green/yellow stripe wire from domestic alternator B+ on the engine, via the wiring loom and multiway connector, to a relay behind the panel, to the warning light, back down the wiring loom via the multiway connector as a blue/yellow stripe wire, to the domestic alternator D+. The relay is activated by current from the starter battery when the ignition is switched on.

Didn't anyone tell you it's not summer yet?

Blimey the luddites have got in first while I wasn't looking! I would get a Victron inverter, they seem to be the best bet at the moment. In terms of what size, you need to look at the most powerful device you plan to use. For example a toaster is probably under 1000 watts, whereas an electric kettle is more likely 2000 to 3000 watts. If you are looking at something with a motor, be aware that the initial surge of power required to start the motor, can be a lot more than the continuous power consumption. Sometimes as much as 5 or 10 times as much! You do have to be careful about how much power you take out of the batteries, and all the power you take out has to be put back, but as well as looking at the power consumption you also should look at the duration that device will be on. So for example a toaster, although using a fair bit of power, is only on for a couple of minutes, so the amphours taken from the battery is not that much. Same for the kettle, although the amphours will be more because it takes twice as much power and is probably on for longer. One solution to this is to only use these "thirsty" devices when the engine is running (and running a bit above idle). So it is fine to use the kettle while you are cruising, not a good idea to use the kettle in the evening when you are moored. The other thing is that with all this ability to use lots of power, it becomes more important to keep track of the state of charge of the batteries and to make sure they get fully charged regularly, otherwise you can kill them in a few months. I would recommend getting some sort of battery monitor fitted eg a BMV712 or a Smartgauge. Once you have the inverter and it is wired to the batteries with short fat cables, you will need to work out how to connect it to your boat's mains sockets etc. The rules are that you must not be able to have the inverter and the shore power connected at the same time, and the short socket must not be live when the inverter is on. So you need a mains changeover switch that is "break before make" ie when you move the switch, it disconnects the one source before connecting the other source.

And then you were weighed before flying back home again just to check how much weight you had put on whilst offshore!

The 6 diode machine just has the 6 main rectifier diodes. There is no internal supply for the field current, which is derived from the B+ terminal either from the battery (before and during start) or from the rectified alternator output (during normal running). All controlled by some electronics that switch off the field current completely and sends the circuitry to sleep when the IGN doesn’t have 12v. And when it does have 12v (ignition on) it sends field current and grounds the warning light circuit. Once the alternator is spinning fast enough it extinguishes the warning light. Voltage regulation depends on the voltage at B+ modified a bit by voltage on the IGN wire - hence the battery sensed bit.

My presumption is based on the description in the manual - leisure (9 diode) alternator is described as “machine sensed” whereas the engine alternator (6 diode) is described as “battery sensed”. Battery sensed via the IGN wire. So if the rather thin IGN a wire is to be used to measure battery voltage, you certainly wouldn’t want 4A or so of field current running from engine battery via ignition switch via fuse via thin wire back down to the engine. You would want the current in that wire to be minimal so there wasn’t any voltage drop.

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!

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!

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).