Solar and alternator charging on passage observations and questions

[Stu Jackson]

Originally Posted by Salina

I just noticed on the yanmar site that the standard alternator on the 4JH5CE 54 HP engine is now 125 A. I recall it used to be 60 or 80 A. Does anyone know if other changes have been made (belts?) and what brand of alternator they are now using? I was in the middle of planning an upgrade to a balmar or mastervolt alpha alternator. But have stopped to get more details on this first.

Don't know about the Yanmar alts, but spending $$ on a Balmar may not always make sense, UNLESS you're interested in their 6 series with internal and external regulation. Leece Neville, IIRC, makes the Balmar alts. You can buy LNs here for good prices via internet orders (not phone). For example: Leece Neville*110-603 - 12V 90 amp ALTERNATOR

Are you aware of the built-in temp sensing of Yanmar (Hitachi) alternators?

[rabbi]

Depending on your setup you may also look at battery-2-battery chargers. Sterling for example Have big ones called b2b chargers.
They simply connect to the engine starter battery, take whatever amps they can get from there at a specific voltage and convert it into a three stage charge for the house batteries.

The original alternator is not touched, it will sense the load on the starter battery and increase the output to the maximum it can deliver.


i have one on my boat that is made by a german company Votronic. It comes with separate voltage sense lines to adjust for voltage drops in the wires, temperature compensation, adjustable voltage levels and draws nothing when the engine is off. Its too small for your needs at 45A maximum but it really does these 45A without getting hot. Cost was 250 euro, installation took two hours to run the wires.
Certainly enough for my setup with only 300Ah of batteries. Our twin Volvos come with 110A alternators so more than enough to feed the b2b charger.

[Dauntlessny]

Originally Posted by monte

Thanks for the input and feedback and no problem with thread hijacking. It's good to have lots if different experiences in one place.

Monte,

You have gotten tons of good advice. But at a certain point, too much is simply too much.

Your system, solar and bb, is about the same as mine. I am also very conscious about cost. I actually have an Hitachi alternator as my emergency backup, as I got it at an alternator shop and as other's have said, it is an alternator made to charge a start battery, not a battery bank. (If I actually needed to use it, I would have to run my generator concurrently).

So, now, your first goal has to be getting an alternator and external regulator that will keep your battery bank up. That will cost some money, but you will ruin your batteries, if you continue this way, and that will cost more.

Get that fixed first.

Your rested voltage does indicate the state of the batteries and I have found that for my battery bank, 980 amp-hours AGM, that with NO load or charge going on, the rested voltage will be within a 0.2 v within minutes and within 0.1v after 10 minutes.

I don't know what battery monitor you use, but they do get out of sync. Mine is the Victron BMV 600 and the solar panels confused it. I asked Victron and they recommended new settings bc of the solar panels (I have 440 watts)

I changed the Charged Voltage to 13.8v, and increased the Tail Current and the Charged Detection time. That solved my issue.

Lastly, my simple controllers that I got with the solar panels are 30 amps each. therefore I have two, two panels to each controller.

Everything works well now.

I hope this helps.

[nimblemotors]

Originally Posted by DeepFrz

What everyone seems to be missing is the input voltage. The MPPT tracking range of that controller is 26 - 75 volts. The OP has stated he is getting 19 v. at the input to the controller. Some of his panels should be in series to increase the input voltage.

Or get two of the miniMPPT controllers to up the panel voltages to '30v' so they don't have to be put in series and have better shade tolerance in parallel.

[rabbi]

Originally Posted by Dauntlessny

So, now, your first goal has to be getting an alternator and external regulator that will keep your battery bank up. That will cost some money, but you will ruin your batteries, if you continue this way, and that will cost more.

Get that fixed first.

I don't think its that urgent. Monte talks about issues when doing a longer passage. I guess now he is still in the Caribbean doing the right thing: nothing at all
I suppose his huge solar array can easily keep the batteries charged at anchor, and the BM should be in sync after a few full charge cycles.


Whatever he does to solve his issues should be cost effective, because its something that he only really needs during longer passages.

I had similar needs (just way smaller: cut all numbers in half at least) and cost and simplicity drove me to the b2b solution. To balance engine use on a cat you'd have to buy two external regulators and modify both alternators. At least in my boat using a single b2b charger was easier and less than half the cost.

[monte]

Thanks guys, Still keeping track of everyones input here. Indeed we have no charging issues sailing the caribbean or any passages up to a week, but still looking at solutions for longer passages. The B2B looks interesting. We have a year till we are likely to undertake any extended passages so will likely look at a good soulution during thet time. Sterling seem to make quite a few products to extract the most from the standard alternators. One unit would be enough as we can balance engine hours out easily enough after a passage and would likeley need less than 1hr/day anyway. All the sterling products seem to work on tricking the alternator that the battery voltage is lower and requires a full load, but as mentioned above this can lead to overheating and damage to the alternator not designed to run hot, so I will be taking that into consideration as well...

[rabbi]

Originally Posted by monte

All the sterling products seem to work on tricking the alternator that the battery voltage is lower and requires a full load, but as mentioned above this can lead to overheating and damage to the alternator not designed to run hot, so I will be taking that into consideration as well...

The sterling B2B comes with a temp sensor for the alternator to reduce current when its running too hot.

The Votronic does not have this capability but in our case it's not an issue as we have oversized alternators (well, oversized in relation to our needs... 2x 110A for a smallish 45A B2B charger). I could still touch the alternator with bare hands after 30 minutes @ 45A

[Time2Go]

Still being in a learning state I simply love reading real world scenarios.
This thread has been very educational for me. Thanks all
Battery technology is not my thing but I think I'm gonna build a 50w
solar system in my yard just to get a feel for it.
Sorry I can't add much here But, and excuse me in advance
If these questions are off the mark or just plain stupid
In this situation would adding Wind Generators help?
What about a towed hydro generator?
Can Cats be fitted with Wind Vane self steering?
It seems to from reading this thread that the electronics, sensors
and monitors are the real key to getting a system to work as
Speced and desired?
Just trying to get my head around all this battery stuff,
When I recently bought my daysailer, one of the requirements was no
batteries on board. I wanted to concentrate on sailing skills and
Hull and Rigging Maintaence.
So much to learn

[Time2Go]

Should have put controllers in after electronics

[rabbi]

Originally Posted by Time2Go

In this situation would adding Wind Generators help?
What about a towed hydro generator?
Can Cats be fitted with Wind Vane self steering?

Just one word: cost. Show me a cheap and working hydro / wind gen or windvane

Originally Posted by Time2Go

It seems to from reading this thread that the electronics, sensors
and monitors are the real key to getting a system to work as
Speced and desired?

For us te main battery draw is the fridge, followed by the AP when on passage.
Electronics are way less.

[monte]

In this situation would adding Wind Generators help?
Yes, it would have probbaly added 200Ah/day during that passage, cost around $1500
What about a towed hydro generator? yes good option again around 200Ah but over $3K initial cost
Can Cats be fitted with Wind Vane self steering?
Not really, there are options but nothing that will reduce power consumption by more than a few amps anyway..

Honestly we would have been fine with solar only had we taken some measures to reduce energy consumption, like turning off the second fridge and running less appliances, using gas instead of the electric kettle etc

[Dockhead]

Just for another data point --

We have the separate high output (110 amps x 24v), so-called "hot rated", externally regulated school bus alternator on the main engine.

We do not particularly economize on power on passage -- lots of electronics going and we often cook with microwave and electric kettle under way.

We charge by shortening sail if necessary to get heel down to 10% or so (the Yanmar hates being run on a heel -- spews oil) and motor-sailing at low speed (2000rpm or less) every day or so for an hour or so. The bus alternator will comfortably put out a couple of kWH per hour. This works fine and we are never short of power. At the same time, we can make a tank of hot water for showers.

We even run the washer/dryer off the inverter from time to time, if it's calm enough. A hot shower every day and clean clothes makes an enormous difference to crew morale on a long passage, I'll tell you.

Alternatively, if we're sailing well downwind and just don't want to motorsail, we run the generator, with the same care about avoiding heel angles.

My father was a power-nazi on his boat (and a water-nazi), and I grew up vowing that I would have enough water and enough power some day on my own boat not to have to be like that.

[rabbi]

Originally Posted by monte

In this situation would adding Wind Generators help?
Yes, it would have probbaly added 200Ah/day during that passage, cost around $1500

Downwind passage means low apparent wind. Something like 200Ah might be a bit too optimistic.

Originally Posted by monte

What about a towed hydro generator? yes good option again around 200Ah but over $3K initial cost

I like this one. Should be good for 200Ah/d @ 1375 €

However, this is a lot of money for an ugly addition to the boat that is good only for passages. Optimizing the engine charging regime makes more sense in my opinion.

Originally Posted by monte

Honestly we would have been fine with solar only had we taken some measures to reduce energy consumption, like turning off the second fridge and running less appliances, using gas instead of the electric kettle etc

[goboatingnow]

As Mainsail says a "Charge Controller" in its absorption or float stage is a Constant Voltage charger or a "voltage limiter". This voltage on the battery is what governs the current the battery can take. If the battery "wants" 30 amps at a certain State of Charge (SoC), then a 500 amp charger will not deliver any more current than a 50 amp charger. In this situation The battery decides what current it will take for a given SoC, not the charger.

The battery voltage at the end of bulk stage and the beginning of absorption stage will be a constant 14.4v and yet the SoC will be rising from 80% towards about 95%. The battery voltage is only based on the SoC when the battery is not under charge OR discharge.

Leaving aside the fact that this isn't germane to the OPs issues, cwyckham is absolutely completely correct, A little itty bitty charger controller connected to a large bank is totally determined essentially by the electrical characteristics of the battery

unless you have a charging source that is significantly greater power capacity then the battery, its primarily the battery bank that is determining the terminal voltage and operating current point. The electrical model of a real lead acid battery is actually quite complex

Battery voltage is always related to state of charge , however its a complex non linear relationship, and there cannot be used to easily determine SOC under charge or discharge conditions, under rest conditions battery voltage has a more " direct" i.e. linear relationship with SOC and therefore mere mortals can use it to " estimate" SOC.



just bear in mind that the english we use ( and engineers are terribly guilty of semantic shortcuts) , to talk about voltage and current sources and charging etc, is often a convenient " shorthand" and is often not what actually happens.



to get an idea, imagine replacing a charge controller with a variable resistance and a human brain watching a amp meter and a volt meter, and capable of responding in millisecs. imagine how you would adjust the resistance to do bulk, absorption and float modes of charging

Everything is interrelated , but these discussions are useful to EEs, they dont really help the OP

Dave

[Wild Bird]

We also crossed the Atlantic this winter. We don't have a problem with battery charge but we operate the boat a little differently.
We have 420w of solar. The majority of the panels are adjustable to point at the sun. We use an electric autopilot, a small super insulated fridge freezer, but we also have a Duogen. This is a towed generator on a pole rather than a rope. It also converts to wind power whilst at anchor in about 2 mins. We have two power hungry chartplotters but we turn them off most of the time. We switch them on occasionally if we see a ship. We didn't track squalls with radar as you can see the ones that matter approaching you from behind even in the dark. We would simply reduce sail and go a little faster in a squall. No big problem. We left the ais transponder on 24/7.
We have 800 amp hr of domestic battery capacity and a 4.5kva genset. We only run the genset for making water not battery charging. The Duogen does most of the work on our boat as it gives us about 10 amps most of the time 24/7. The solar adds up to 25 amps during full sun.


Sent from my iPad using Cruisers Sailing Forum