Buying a Smartgauge

[sailinglegend]

Originally Posted by Kenomac

..... for those of us who spend our time 100% in anchorages charging with solar panels and generators and using multiple systems including freezers, fridge, water makers and washing machines... it's not smart enough.....

I’m the same as you but in the Aegean. Every two weeks I find a restaurant or marina and fully charge with shorepower. My Lifeline batteries have lasted 13 years so I must be doing something right!

If you only have 450 W of solar and charge with a genset then you are probably never getting to anywhere near 100%.

I fear that you don’t like what Smartgauge is telling you - closer to the truth than your Mastervolt system. When your new Mastervolt shunt is installed to measure return amps and you have finally done tests and comparisons, then any further comments will be very interesting and very welcomed.

[Kenomac]

Originally Posted by sailinglegend

I’m the same as you but in the Aegean. Every two weeks I find a restaurant or marina and fully charge with shorepower. My Lifeline batteries have lasted 13 years so I must be doing something right!

If you only have 450 W of solar and charge with a genset then you are probably never getting to anywhere near 100%.

I fear that you don’t like what Smartgauge is telling you - closer to the truth than your Mastervolt system. When your new Mastervolt shunt is installed to measure return amps and you have finally done tests and comparisons, then any further comments will be very interesting and very welcomed.

We charge up to 100% every two to three days or so without difficulty. Bulk charge in the morning while electric cooking using the generator, then solar the rest of the day. Our Trojan battery bank is now 7 years old.

Just because I'm not a Smartgauge Fanboy like the rest on this thread, doesn't mean the thing is hooked up wrong or defective.... I don't like it.

Why don't some of you ask Noelex why he's chosen NOT to become a Fanboy of the Smartgauge monitoring system on their new Bestevaer 49? Me thinks you'll hear the same answers coming from him as me... it's woefully inadequate to serve his/our needs. And yes... we can afford to install something better, so Why not?

The Smartgauge stinks during the charging stage, then is all over the place when a larger load is first placed on the battery bank. Peel back the fancy marketing hype, and it's nothing more than an expensive voltmeter. I feel like the boy in the story "The Emperor's New Clothes" who's the only one calling it as I see things.

I'm not so sure the Smartgauge fanboy club will be interested in any real-life testing, as it seems their minds have already been made up. BUT I'll post the results and probably put up with the abuse.

[a64pilot]

I have had mine exhibit similar symptoms to what Ken was having.
In particular it was when we were anchored out, the generator was having fuel delivery issues and Solar hadn’t been hooked up yet, so I was running the engine every few hours to charge batteries and it was before my Balmar 614 was installed so it would trip to float way prematurely, so of course when it would I would shut down, your not charging enough to matter in float by running the engine, but I was partial charging the bank only a little, really just getting a surface charge on and no real decent charge, reason I had to start again in just a few hours.
Anyway I theorize I was pretty much putting in a surface charge and confusing things. See I am of the opinion that the SG is just a very smart voltmeter, nothing else and it can determine SOC by voltage changes over time, somehow ignoring voltage sags from high amp loads, and by artificially raising the voltage with a surface charge, which of course doesn’t add AH as much as just voltage, and then repeating, it was confusing the SG.

I believe if given several hours in discharge the SG gets its act back together, reason I believe it’s accurate late at night and early in the morning. If I’m right though, you need several continuous hours of discharge.
Now if I’m right, then I can see how for those with wind generators and regularly have good wind at night, it may never really get its act together.

This is all theory based on just observing the thing over a few years, and it could be way off base, sort of like cavemen determining that the Sun must be a God or something
If I’m correct then during charging, and especially if the charge rate sort of varies a lot that the SG just can’t get its act together as the voltage does not represent the actual bank voltage, and that does seem to correlate with what I observe.

[kenbo]

Originally Posted by a64pilot

I have had mine exhibit similar symptoms to what Ken was having.
In particular it was when we were anchored out, the generator was having fuel delivery issues and Solar hadn’t been hooked up yet, so I was running the engine every few hours to charge batteries and it was before my Balmar 614 was installed so it would trip to float way prematurely, so of course when it would I would shut down, your not charging enough to matter in float by running the engine, but I was partial charging the bank only a little, really just getting a surface charge on and no real decent charge, reason I had to start again in just a few hours.
Anyway I theorize I was pretty much putting in a surface charge and confusing things. See I am of the opinion that the SG is just a very smart voltmeter, nothing else and it can determine SOC by voltage changes over time, somehow ignoring voltage sags from high amp loads, and by artificially raising the voltage with a surface charge, which of course doesn’t add AH as much as just voltage, and then repeating, it was confusing the SG.

I believe if given several hours in discharge the SG gets its act back together, reason I believe it’s accurate late at night and early in the morning. If I’m right though, you need several continuous hours of discharge.
Now if I’m right, then I can see how for those with wind generators and regularly have good wind at night, it may never really get its act together.

This is all theory based on just observing the thing over a few years, and it could be way off base, sort of like cavemen determining that the Sun must be a God or something
If I’m correct then during charging, and especially if the charge rate sort of varies a lot that the SG just can’t get its act together as the voltage does not represent the actual bank voltage, and that does seem to correlate with what I observe.

What you're saying is fully supported in the SG documentation. During charging the SG only "sees" the charging source. It's during the discharge cycle that thing settle down and the SG can modify it's algorithm and offer a better result.

BTW what type or regulator were you using on your engine alternator before you installed the 614 that was going to float?

[Dockhead]

Originally Posted by john61ct

Running even a $150 generator for a finishing charge is just silly IMO.

. . ..

Not if you don't have solar, aren't on shore power, and aren't doing any long motoring trips.

I did this one winter when I spent a lot of time living aboard on my mooring and rarely going anywhere, and I think it was worthwhile. I'm fairly relaxed about battery management (as I have expressed in this thread), but one thing I am particular about is to not go too long without getting a good long finishing charge on. Followed sometimes by an equalization charge.

[Dockhead]

Originally Posted by a64pilot

I have had mine exhibit similar symptoms to what Ken was having.
In particular it was when we were anchored out, the generator was having fuel delivery issues and Solar hadn’t been hooked up yet, so I was running the engine every few hours to charge batteries and it was before my Balmar 614 was installed so it would trip to float way prematurely, so of course when it would I would shut down, your not charging enough to matter in float by running the engine, but I was partial charging the bank only a little, really just getting a surface charge on and no real decent charge, reason I had to start again in just a few hours.
Anyway I theorize I was pretty much putting in a surface charge and confusing things. See I am of the opinion that the SG is just a very smart voltmeter, nothing else and it can determine SOC by voltage changes over time, somehow ignoring voltage sags from high amp loads, and by artificially raising the voltage with a surface charge, which of course doesn’t add AH as much as just voltage, and then repeating, it was confusing the SG.

I believe if given several hours in discharge the SG gets its act back together, reason I believe it’s accurate late at night and early in the morning. If I’m right though, you need several continuous hours of discharge.
Now if I’m right, then I can see how for those with wind generators and regularly have good wind at night, it may never really get its act together.

This is all theory based on just observing the thing over a few years, and it could be way off base, sort of like cavemen determining that the Sun must be a God or something
If I’m correct then during charging, and especially if the charge rate sort of varies a lot that the SG just can’t get its act together as the voltage does not represent the actual bank voltage, and that does seem to correlate with what I observe.

Your theory is entirely consistent with my own observations.

[Exile]

Originally Posted by a64pilot

I believe if given several hours in discharge the SG gets its act back together, reason I believe it’s accurate late at night and early in the morning.

In other words, same as a basic voltmeter. So as Dockhead has pointed out, the SG becomes more of a convenience item, albeit a redundant one. We already know that the only reliable way of determining 100% SOC is by measuring amps going in (while charging source is in absorption mode). And we also already know that it doesn't really matter whether we re-charge at 50-55-60-70% or even below 50% on occasion. I suppose a SG might help if one desires more precision with the latter, but whether that precision results in longer battery life sounds questionable given all the variables.

[john61ct]

Originally Posted by Dockhead

Not if you don't have solar

But even one of those foldup backpackers solar chargers would be enough to save at least 3-4 hours of running the genny per time.

Side benefit of doing it much more often.

[john61ct]

Originally Posted by Exile

And we also already know that **it doesn't really matter whether we re-charge at 50-55-60-70% or even below 50%** on occasion. I suppose a SG might help if one desires more precision with the latter, but **whether that precision results in longer battery life sounds questionable** given all the variables.

No, that is not the case at all, as a glance at and DoD vs life cycles graph will dramatically illustrate.

Yes there are plenty of other variables, but on a given boat they will tend to be relatively constant; this is one of the handful we can control.

[Dockhead]

Originally Posted by Exile

. . . We already know that the only reliable way of determining 100% SOC is by measuring amps going in (while charging source is in absorption mode). . . ..

One other way -- the "crude but effective" way -- is to leave a good charger plugged in for a sufficient amount of time to remove any doubt about it, or to go motoring for a sufficient etc. with a well-regulated heavy duty alternator.

My Victron charger will definitely get my bank up to 100% in a 12-18 hour port call, and to remove any doubt, I can make it do an extra absorption cycle, or an equalization one.

Bit of thread drift, but my Leece Neville school bus alternator is regulated with an Adverc, and odd bird among regulators. Once absorption stage is reached, the Adverc will alternate between voltages just above and just under gassing voltage, turning the voltage down in time to prevent heavy gassing but then turning it back up again.

I have no idea whether this has been shown to be good or not, but it seems to work ok on my boat. I do need to be careful about watering the batteries, though, when I do a lot of motoring.

[john61ct]

Originally Posted by Dockhead

One other way -- the "crude but effective" way -- is to leave a good charger plugged in for a sufficient amount of time to remove any doubt about it, or to go motoring for a sufficient etc. with a well-regulated heavy duty alternator.

Sorry to keep harping on this, but instead of "good" charge source, that really needs to be

an adjustable charge source properly calibrated so as not to prematurely drop to Float

which needs to be done referencing endAmps.

The vast majority of charge sources, many costing thousands of dollars, latest fine technology, do not actually get a big bank to 100% Full even left running for 8+ hours.

Yes, I'm sure that does not apply to your setup, but my point is, just buying quality gear and hooking it up for a long time may be necessary, but it is not sufficient.

And yes this issue has little to do with SG.

[weavis]

Originally Posted by a64pilot

This is all theory based on just observing the thing over a few years, and it could be way off base, sort of like cavemen determining that the Sun must be a God or something

Everyone knows its the moon!

[Exile]

Originally Posted by john61ct

No, that is not the case at all, as a glance at and DoD vs life cycles graph will dramatically illustrate.

Sure, all things being equal discharging only to, for e.g., 80% vs. 50% every time will increase battery life. But as Rod pointed out in the last thread and nobody disputed (as I recall), that doesn't take into account the add'l energy provided by another 30% of usage prior to recharge. I think you need to compare total energy provided by your batts. over whatever length of time they wind up lasting. Different variables in play depending on how dependent your boat is on diesel vs. renewables, obviously.

Yes there are plenty of other variables, but on a given boat they will tend to be relatively constant; this is one of the handful we can control.

On any given boat, yes. But that's not what these threads are about. Boats being discussed run the gamut from DH's which has no solar, is plugged in a lot, and has very effective charging while running his engine, to Ken's which is rarely plugged in and often anchored, relies mostly on genset & solar, and has large loads running much of the time.

This is not a forum discussing electrical engineering theory, but one which tries to help mostly laymen better manage their batteries in pragmatic ways so that whatever is learned may be applied to a myriad of different boats.

[Exile]

Originally Posted by john61ct

Sorry to keep harping on this, but instead of "good" charge source, that really needs to be

an adjustable charge source properly calibrated so as not to prematurely drop to Float

which needs to be done referencing endAmps.

The vast majority of charge sources, many costing thousands of dollars, latest fine technology, do not actually get a big bank to 100% Full even left running for 8+ hours.

Yes, I'm sure that does not apply to your setup, but my point is, just buying quality gear and hooking it up for a long time may be necessary, but it is not sufficient.

And yes this issue has little to do with SG.

So are you saying that a boat left plugged in for a month will never reach 100% SOC if the charger has dropped to float prematurely?

[Dockhead]

Originally Posted by john61ct

Sorry to keep harping on this, but instead of "good" charge source, that really needs to be

an adjustable charge source properly calibrated so as not to prematurely drop to Float

which needs to be done referencing endAmps.

The vast majority of charge sources, many costing thousands of dollars, latest fine technology, do not actually get a big bank to 100% Full even left running for 8+ hours.

Yes, I'm sure that does not apply to your setup, but my point is, just buying quality gear and hooking it up for a long time may be necessary, but it is not sufficient.

And yes this issue has little to do with SG.

Sometimes "harping" performs a useful public service Good for you.

Yes, of course, what you say is absolutely correct. But a decently sophisticated charger like my Victron is easily set up to hold absorption voltage for long enough, and have battery temp sensors to catch you if it goes too far. Factory settings are always too conservative.

As I've written, I don't care about SOC to the nearest percent or even 10%, and I follow Sailorboy's battery management philosophy. BUT FIRST, get your charging sources set up right. I agree with you on this 100%.