Solar Watts : Daily AH Consumption

[sailinglegend]

Originally Posted by john61ct

I saw nothing in what you wrote that is in disagreement with what I know to be true.

Then either you didn't read my post properly or a64pilots post properly. I disagreed with this point that you agreed with!!!! And now you have agreed with my last posting.

Maybe you are just posting on too many threads at the same time.

Originally Posted by a64pilot

....After a very few minutes my 660 AH bank was accepting .5 amps, that is 1/2 an amp, al little over 7 Watts.
I’m going to boil out my several hundred pound bank of 6 batteries with 7 Watts of power?

No, you kill them by letting them go to much higher than absorption voltage and staying there, day after day....

[john61ct]

Originally Posted by a64pilot

He is correct on internally regulated Hitachi alternators that come with most Yanmar Marine Diesels, they are internally protected against overheating and do in fact derate themselves pretty quickly.
It’s likely one reason why the darn things can last for decades.

I would interpret derating as meaning current.

[john61ct]

Originally Posted by sailinglegend

Then either you didn't read my post properly or a64pilots post properly.

Sorry. Rather than such long posts containing background 101-level info not in dispute, you could succinctly state the two precise syllogisms you think are in conflict?

Thanks

[Stu Jackson]

Originally Posted by john61ct

I would interpret derating as meaning current.

john, as far as Hitachi alternators are concerned, MS has written repeatedly about these:


Hitachi/Yanmar Alternators: (by Maine Sail)

Some alternators though, such as those made by Hitachi and found on Yanmar diesels, are dumber than a pound of beetle poop. Actually, to the alternator, they are pretty smart but to your batteries and the speed of charging they are flat out stupid. Why?

Hitachi alts with dumb regulators, and some others, limit voltage but also reduce voltage based on alternator temperature. This is a self protective feature installed in the internal dumb regulator to prevent the alternator from cooking itself. Remember voltage is the pressure that allows more current to flow. So, if we reduce the absorption voltage, then we also reduce the current the alternator is supplying.. The battery simply will not accept the same current at 13.4V that it did at 14.4V and as a result the alternator will run cooler. What do you suppose this does to your batteries over time.......?

The problem is that when cold you will get 14.3V to 14.4V out of the Hitachi but as the alternator heats up the dumb regulator begins to reduce the CV/voltage limit based on the alternators internal temperature. It is not uncommon to find a Hitachi alternator at 13.4V when hot. This is REALLY, REALLY DUMB....

If you have a dumb regulator, and notice the voltage dropping, it is likely a temp compensated dumb regulator. Get rid of it or plan to buy new batteries more often.

If you have a temp compensated alternator or a Hitachi alternator on a Yanmar you really are in dire need of external regulation if deep cycling a larger battery bank.

This is from:

http://forums.sbo.sailboatowners.com...d.php?t=125392

and these, too:

http://www.cruisersforum.com/forums/...on-125843.html


http://www.cruisersforum.com/forums/...or-142083.html


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Also, I may have been wrong about the temp compen. I'll do more digging.

[john61ct]

Originally Posted by a64pilot

I have not yet seen a factory default setting that wasn’t overly conservative, dropping the bank into float way prematurely.

Yes, true for even the most sophisticated mains chargers and solar controllers as well.

The "damage" that comes from PSOC abuse is much less likely to be legally actionable than cooking a $4000 bank of GELs.

[sailinglegend]

Originally Posted by john61ct

Sorry. Rather than such long posts containing background 101-level info not in dispute, you could succinctly state the two precise syllogisms you think are in conflict?

Thanks

Sorry - not wasting any more of my time arguing with you - work it out yourself!

At least my posts contain concise facts that is what many readers want - not who knows best how a Victron Solar controller actually works.

Good night from the UK.

[john61ct]

Originally Posted by Stu Jackson

Also, I may have been wrong about the temp compensation I'll do more digging.

It's really a semantic issue.

Look at the temp comp charts from quality batt makers.

And **protecting batteries** from high-current overheating - which I am here distinguishing from the finer adjustments of voltage compensation

uses the same physical sensors and logic PLCs or whatever, just different conceptually.

The above applies to all charge source types.

Finally protecting **alternators** is unique to VRs (does wind power have any such requirement?) and that functionality as I said is most of the time done in such a way that the bank is in effect no longer charged at all.

Which for normal factory setups with Starter batts only, is not a problem.

But charging deep cycle House banks well - e.g. minimizing runtimes, dropping to Float when running all day - requires specialist aftermarket VRs.

[john61ct]

Originally Posted by sailinglegend

Sorry - not wasting any more of my time arguing with you - work it out yourself!

Wow.

OK, sorry if you interpreted our discussions here as "arguing".

I thought we were collaborating, trying to arrive at an informed consensus, helping each other to learn.

I realize some interpret my tone as overly assertive sometimes, but I certainly make no claim to know more than others here, and enjoy learning new stuff from y'all every day.

[john61ct]

If anyone else knows which data points s/he thought we were disagreeing about, maybe we can get that clarified without him/her.

[john61ct]

Originally Posted by Stu Jackson

john, as far as Hitachi alternators are concerned, MS has written repeatedly about these.

Yes, I've read that.

Is your point that he is conflating proper "temperature compensation" with the overtemp protection function?

As I said, just a syntax issue.

[a64pilot]

See, I would go so far as to say that my really Smart Balmar 614 seems to do its best to emulate the dumb Hitachi regulator, which if it were just a little less conservative, may have been the go to charge device.
Between me setting the belt manager to level 4 and me setting the alternator temp limit to 95c, I get at most seemingly about 80 amps continuous out of my 165 amp alternator. My alt temp sensor is mounted on the cold side of the alternator, I ought to move it to the hot side, one day I will. I have to remove the alt to do so.
However 80 amps is actually a lot of power out of something so small, and I’ll derate for long life any day, these things ain’t cheap.

However it’s my belief that a voltage regulator controls current (amperage) through voltage, it can’t separate the two.
There are of course power supplies that can, but I don’t think the average run of the mill alternator voltage regulator can, or needs to.
All that is needed is voltage control.

[a64pilot]

Originally Posted by sailinglegend

Sorry - not wasting any more of my time arguing with you - work it out yourself!



At least my posts contain concise facts that is what many readers want - not who knows best how a Victron Solar controller actually works.



Good night from the UK.

None of us mean to be confrontational, just sometimes we are thick headed.
For instance, I get your point on voltage, that high voltage and low current can damage a battery.
We don’t mean to offend, I apologize if it seems we are.

[sailorboy1]

I have both my alternator regulator and my solar controller set to absorption at 14.8V for 4 hours. They've been this way for 2 years and the batteries seem just fine and don't appear to have lost any capacity since (based on night time voltage and AH out). I just checked the water level (been over a month) and yes they needed some water, but were way away from the plates uncovering.

Now my sealed start battery is a different story. I may have cooked that last year because the 14.8V was too high for it (I now just leave it isolated most of the time). But since that battery was also at least 8 years old who knows.

[john61ct]

Originally Posted by a64pilot

See, I would go so far as to say that my really Smart Balmar 614 seems to do its best to emulate the dumb Hitachi regulator, which if it were just a little less conservative, may have been the go to charge device.
…
All that is needed is voltage control.

Well there are plenty of cheap dumb VRs out there, even seen one with a potentiometer knob to adjust volts output setpoint.

I'll swap it for your 614 8-)

Originally Posted by a64pilot

Between me setting the belt manager to level 4 and me setting the alternator temp limit to 95c, I get at most seemingly about 80 amps continuous out of my 165 amp alternator.

That sounds about right, if you don't have active cooling, diodes still attached to the alt etc.

Especially if you get that 80A continuously for extended periods at the right voltage.

> My alt temp sensor is mounted on the cold side of the alternator, I ought to move it to the hot side, one day I will. I have to remove the alt to do so.

Maybe move the diodes away from the body while you're at it?

> However 80 amps is actually a lot of power out of something so small, and I’ll derate for long life any day, these things ain’t cheap.

There ya go!

> However it’s my belief that a voltage regulator controls current (amperage) through voltage, it can’t separate the two.

No, internally VRs in general are controlling voltage by quickly varying current, internally.

From the Black Box POV, it is controlling Volts only, hence the name.

The small-engine and other Current de-rating features can be seen as "meta" to the normal process, similar to adjusting your Magnum to accommodate a shore pillar with only 10A mains to spare.

Protection against destructive heat has only become required with big deep cycle bank charging, especially with high-CAR chemistries like AGM and LFP.

[john61ct]

Originally Posted by sailorboy1

I have both my alternator regulator and my solar controller set to absorption at 14.8V for 4 hours.

And that may very well be within mfg spec for your bank, no one is saying that's high nor long for your setup.

Now if they were Lifeline, you'd get a shorter lifespan than if you adjusted V down.

But the Absorb Hold may be long or short, only you can tell, ammeter in hand when you drop to Float.