High power charging/output possible? (F200 MY2017)

[Yatagarasu]

I've been running this new boat with a F200 (4 cylinders, 2.785 liter, 4 stroke) this season and now I'm starting with a major upgrade to the electrical system. Quite much of my understanding of the issues comes from Nigel Calder's excellent book (4th ed, 2015).

The boat has started out with a dual battery system with the regular old fashioned open wet-cell lead acid cranking batteries, 2 x 100 Ah. I might stay up to 3 nights in one place without access to external electricity and few possibilities of charging, so capacity and charging become central issues. I understand Yamaha engines generally come with automotive style alternators/regulators, though newer ones have somehow "smart" versions. The base model of operation is constant voltage charging which will top off the batteries only very, very slowly while the boat is underway.

The idea is to replace/extend the house bank with a more capable AGM or lithium battery. Especially with the lithium option, I could connect a battery-to-battery charger to the circuit powered by the alternator and separately charge the house battery (naturally isolated from loads during charging). This would have the benefit of driving the alternator with a much higher output current and thus charging the battery system much faster than currently while the engine is running. The max alternator output is 50A - the charger would provide a charging current of 30A (some additional efficiency losses would need to be factored in). Sterling makes excellent chargers and I would probably use this one: https://www.svb24.com/en/sterling-pr...y-charger.html

Some issues, questions and notes:

1) Is this a good idea with Yamaha outboards? From some comments on this forum I understood that the alternators can be run for long periods at high output, but Calder notes that many alternators are designed to start with a high current which quickly becomes lower, thus a lower load and a lower amount of heat is generated over time. I understood overheating can be an issue with Yamaha alternators?

2) Sterling provides for temperature sensing, which could perhaps be installed at the regulator/alternator? There is a large duct going from the technical insides of the boat through the rear wall of a some kind of a cocpit to the engine - the wires could perhaps be routed via this duct like so many that already go to the engine, not sure if this would be a pain for the (professional?) installer?

3) Will it mess up the function of the Yamaha regulator. The charger as I understand would be no different from the other loads such as boat electronics, and is not very sensitive to input voltage, so the regulator can provide whatever voltage it feels happy with - only the current consumed would be quite high.

4) I might occasionally run the engine three hours in a row, possibly even longer. It is not typical to run for very long periods at high RPM, time to time it will drop below 2000 RPM, and sometimes will stay there for a while. Would sufficient output at low RPM be an issue, sometimes I'll run the engine at idle RPM (or off gear). The Sterling charger provides some handy functions such as automatically switching off when the input voltage is low, or the charge current can be set to 1/2 normal in case there are issues. Or the charger could just be disconnected in unusually problematic cases.

5) One post claimed that the rated alternator output is not provided to the electrical system as such, but a small chunk (10A?) goes actually back to the engine itself just to keep it running. (Makes sense, there's several electrical and electronic components inside modern engines.)

AGM and lithium (LiFePo) are attractive technologies for my needs because they tolerate deep discharge and can be charged rapidly, especially for lithium. LiFe batteries are also very light, which provides modest performance increases, means they are light to move around but above all help with fuel savings - it's a planing boat. Main disadvantages are the high cost and a short track record on the marine market. Technically the lithium batteries could pay themselves back in 20 years with just the fuel savings resulting from a lower weight.

[99yam40]

might want to re evaluate what you are trying to do, unless Yamaha changed their charging system, they are not like automotive systems.
along with they have a separate circuit to charge the house battery already. you just have to hook it up

good luck getting any battery to last 20 years

[panasonic]

Have you considered just getting a small portable generator for your boat to charge the batteries? They are very compact now and extremely quiet.Yamaha makes those as well..

[pstephens46]

What type of electronics are you running with the two batteries? Boscoe can confirm......I believe the alternator output is about 50 amps on that model. That should charge a good battery in short order.

[Yatagarasu]

might want to re evaluate what you are trying to do, unless Yamaha changed their charging system, they are not like automotive systems.

That might change a few things. You are very correct at least on the separate circuit for house batteries, shows up in a service manual I googled too. Not sure how the function is different. Is there any usable documentation for the charging system - the average boat owner might have no idea what it can do? Yamaha also don't seem to have any support contact beyond "contact your dealer". Now I vaguely recall reading that Yamaha also supports AGM (guess LiFe is way too new tech for most boaters) and any info on that would be very interesting, can imagine there would be a few additional issues...

The funny thing is, the boat itself has a charging diode/switch which to my understanding will connect the batteries in parallel when a charging voltage is reached. So probably they didn't bother connecting the house circuit (or rather, the cranking circuit... unless Yamaha requires that). So complex. I'll have a few questions when I talk to my dealer the next time

Most ironically, the boat is a Yamaha as well - they acquired the brand about 2 years ago. Not that much has changed - the model at least used to be sold with Mercury as well, but I guess there might be more pressure to sell with only Yamaha engines nowadays. At least the dashboard is nowadays integrated to the MFD/chartplotter.

And har har to 20 year batteries Yes there were a few caveats like that but you get the idea, hopefully. Wet cell cranking batteries seem to last about 6 years in my use; recall lithium was given a 10 - 15 years quote somewhere, should maybe recheck and calibrate the figures before I make decisions. Then again, lithium batteries of today are much more capable than they were just 10 years ago.

Have you considered just getting a small portable generator for your boat to charge the batteries? They are very compact now and extremely quiet.Yamaha makes those as well..

Actually I have that (it's a cheap Chinese clone but it's nifty) and it's a solution when things get too difficult, but it has drawbacks. At around 18kg it's a little bit bulky, a boat is always a little bit too small, and you're not supposed to transport it in too rough conditions, or you should at least empty the tank. Noise can be a bit of an issue, exhaust not in practice usually. But I think it is a good suggestion too.

For electronics, there's 2 x chartplotter and radar when underway, and one of the MFD/plotters also handles stereo, wifi etc. Off the 12V plugs I run plenty of stuff from coolboxes (eventually could upgrade to a compressor based model) to USB charging phones, LED torches and so on. All lights are LEDs, besides fixed searchlights which sometimes might get used when moored, and there's also a heater, which might practically be necessary in any month over here.

[Yatagarasu]

To summarize and reflect back a bit, assuming that correct charging circuits are currently connected, my current problems are due to

A) The wet cell cranking battery as a house battery not having much DoD capacity
B) It's a bit hard to tell if a wet cell is properly topped up, and I didn't record it that meticulously - in the absorption zone your pre-existing charge seems a bit mystical compared to lithium (I'm probably most used to that chemistry due to other hobbies) where you can just rely on the voltage if you've let the batteries sit a few minutes
C) Wet cell requires several hours of absorption charging to be really fully charged - maybe I never achieved that, or not when I would have needed it; still I'm not sure if the batteries got fully charged even when there was little use on the house battery and it was mostly just boating around

Nevertheless I need to find more info on the charging system...

[zenoahphobic]

I would do experimenting with your engines alternator output, simply measuring various loads at various revolutions. A bit of work recording.
This will determine the minimum revs required to get maximum output. You'll have to multiply your voltage with the current as the voltage will rise with revs before the inbuilt regulator holds the voltage. I presume there is no current regulator.
I would monitor the temperature of the regulator, if you can use a temperature gun. The charging coils will be harder to check. Presumably they are under the flywheel, and perhaps the flywheel and the general area can be measured, running the engine with load and without. Take a bit of time. What temps you find will require some judgement as to what might be too much, indicating a possible "meltdown ". You may find very little temp change and that their will be self limiting of the output of the coils at maximum current that does not burn the wires. But be careful here. The rectifier and regulator may also be overrated, this is why current regulators went out with DC generators because they required protection.
I suggest the above as you probably won't find out the rating from any official source, and it is always better to get direct performance figures than those that might be quoted in a book somewhere.
You could also go to the extent to tap the output before the regulator and upgrade with more sophisticated and higher rated electronics. Smart chargers and DC to DC chargers can get every last "drop" out of varying voltage sources.
Now you are right that batteries of the past require time to charge, and using excessive current simply is not only waisted energy, but reduces the life of the battery. So there is an optimum match with alternator output to battery optimum charging efficiency. This is usually achieved by having the optimum Amphour capacity of one or more batteries in parallel.
Modern lithium batteries reduce "time" to efficiently being charged. I would check with RV and c*****ner forum. These people seem to be very annul about these things so you could gleen from them what is actually happening in practice.
Now the use of a small portable generator, if not for the noise and fumes, can be far more efficient than running your outboard. There are some as light as 8kg that have the capacity, (at 14.5 volts 300 Watts gives you 20 amp, theoretically!), but unfortunately their output at 12v is little; most of it is at AC mains voltage. This then also requires this mains voltage to be converted to 12v. So an additional matched piece of electronics needs to be attached.
And solar panels, and/or even wind generators should be considered to add to a source of battery charging.

[boscoe99]

Yamaha outboard motors do not use what many call an "alternator". An alternator being in my mind a belt driven generator that outputs AC voltage that is converted to DC voltage either internally or externally.

Yamaha outboards use what is known as a PMG. Permanent Magnet Generator. Magnets in the flywheel are creating electricity as the pass coils that are part of a stator assembly. They are producing all of the electrical power of which they are capable of producing at any given engine RPM. Power that is not needed is wasted in the form of heat.

The regulators are constant voltage regulators. The output is maintained at X voltage (nominally about 14.6 volts). The amount of current that flows to a battery is a function of the voltage and internal resistance within the battery(s) being charged. If a battery is low then more current will flow. If the battery is charged then less current will flow. As stated earlier, maximum electrical power is being created all of the time. You cannot hurt the system by overloading it. The result will be that voltage might drop below normal levels.

Best results generally are seen when a large deep cycle lead acid battery (or batteries) is/are used to power stuff within the boat when the motor is turned off. I don't have any experience with lithium type batteries. From what I have read they need a special charging system output. Which a Yamaha does not provide.

[boscoe99]

To summarize and reflect back a bit, assuming that correct charging circuits are currently connected, my current problems are due to

A) The wet cell cranking battery as a house battery not having much DoD capacity
B) It's a bit hard to tell if a wet cell is properly topped up, and I didn't record it that meticulously - in the absorption zone your pre-existing charge seems a bit mystical compared to lithium (I'm probably most used to that chemistry due to other hobbies) where you can just rely on the voltage if you've let the batteries sit a few minutes
C) Wet cell requires several hours of absorption charging to be really fully charged - maybe I never achieved that, or not when I would have needed it; still I'm not sure if the batteries got fully charged even when there was little use on the house battery and it was mostly just boating around

Nevertheless I need to find more info on the charging system...

I think you are way overthinking the situation. Just get the largest lead acid battery that you can find and use the number of them that you need for whatever you are powering. The motor will either be able to recharge them on its own or it won't. If it won't then perhaps more batteries are needed that can be recharged while the boat is on shore via external power.

As noted, a Honda type of portable generator can be used. If the noise is not too objectionable. I have one and if it runs in the background for too long it starts to drive me crazy.

[rodbolt17]

hahahaah
the amount of mis information is simply staggering here.
\unlike a few other manufacturers Yamaha has never,yet,used a belt driven alternator. yet the Yamaha system uses ALL the same components as a belt driven unit.
it has a rotor same as grannys old chebby.
it has a stator just like uncle bubbas old bronco and a voltage regulator just like mom's old grocery getter station wagon.
just like ANY alternator it has physical limits.
speed of the rotor acrossed the stator affects output.
alternating current is not a new concept.
rotate a magnet past a coil or a coil past a magnent and you get an AC sine wave.
run that AC wave through a set of diodes allowing a full wave rectification and you now have a DC output.
run that output through a constant voltage regulator and you now have a modern charging system.
the only variable is rotor speed.
this system has to work with rotor speeds from 600 to 6000 RPM.
why idiots rig modern yamahas with VSR's and such is beyond me. they don't work well and you already paid for a battery isolator that is part of the engine.
but you do as you wish with the you tubes.
problem with li is two fold.
it requires a special charger and they do like to light up.

[boscoe99]

hahahaah
the amount of mis information is simply staggering here.
\unlike a few other manufacturers Yamaha has never,yet,used a belt driven alternator. yet the Yamaha system uses ALL the same components as a belt driven unit.
it has a rotor same as grannys old chebby.
it has a stator just like uncle bubbas old bronco and a voltage regulator just like mom's old grocery getter station wagon.

Where are the rotating field coil, slip rings and the regulator that is varying current through that field coil so as to control the amount of voltage that is being produced? I cannot find them.

[99yam40]

problem with li is two fold.
it requires a special charger and they do like to light up.

I can imagine a Lipo bat fire on a boat while out 100 miles from shore
I would not want to be in that situation holding a fire extinguisher and no where to go but in the water with jaws

[zenoahphobic]

Where are the rotating field coil, slip rings and the regulator that is varying current through that field coil so as to control the amount of voltage that is being produced? I cannot find them.

Good one, a good correction. I think both of you are somewhat smitten by Miss Information.
The relevent truth is that electricity is generated within a moving magnetic field; the "amount" of electricity generated is dependent on the rate of change (revolutions) and is limited by the amount of magnetism available. Ie bigger magnets produce more than little ones. The system starts at low output and then is "saturated" at some higher revolutions.
Going bigger and bigger with batteries will have a dependence on fully shore charging because the life of lead acid batteries is considerably reduced if they are in a constant state of below being fully charged.
Lithium batteries, or any new immerging battery technology, will mean batteries will have such capacity to release large destructive energy. How we safely live with this potential is going to be more and more challenging .

[rodbolt17]

trons don't care if you take them from the stator or the rotor.

[99yam40]

but how they are produced and con*****ed is different between outboards and automotive.