Smartgauge

[smileypete]

We have already removed 10Ahrs. That figure of 10Ahrs cannot be changed retrospectively. We have had that energy and used it. So it now has 70Ahrs remaining (the new capacity of 80Ahrs minus the 10Ahrs already used). It has therefore dropped from 90% SoC to 87.5% SoC just by dropping the temperature.

OK, say you have a fully charged 100Ah battery and after being made much colder it's total capacity drops to only 80Ah.

 

Now what is its SoC? It must still be 100%!

 

cheers,

Pete.

Edited September 16, 2010 by smileypete

[WotEver]

OK, say you have a fully charged 100Ah battery and after being made much colder it's total capacity drops to only 80Ah.

 

Now what is its SoC? It must still be 100%!

 

cheers,

Pete.

Yeah - Gibbo stated that way back in post #34

In a normal wet cell at 100% SoC temp coefficient is zero.

 

Tony

[smileypete]

Yeah - Gibbo stated that way back in post #34

OK, then next question is, if you take 8Ah out of the cold battery, how many Ah remaining, and what's its SoC?

Edited September 16, 2010 by smileypete

[Gibbo]

OK, say you have a fully charged 100Ah battery and after being made much colder it's total capacity drops to only 80Ah.

 

Now what is its SoC? It must still be 100%!

 

Deleted. Can't be arsed. I've given you references, I'm not doing your homework for you as well.

Edited September 16, 2010 by Gibbo

[smileypete]

OK, say you have a fully charged 100Ah battery and after being made much colder it's total capacity drops to only 80Ah.

 

Now what is its SoC? It must still be 100%!

Deleted. Can't be arsed. I've given you references, I'm not doing your homework for you as well.

 

Well what would a Smartguage say, 80% or 100%?

 

cheers,

Pete.

[alan_fincher]

The truth is that the Smartgauge is a very clever piece of kit and, provided it is properly installed as per the instructions, it will help you to prolong the life of your batteries and it will save you money. Those people that are sceptical will tell you that you don't need it and can manage without one but they are invariably people who have not installed one on their own boat.

 

It is not surprising that the biggest critics of this product are those that: have not tried it; do not understand it; or both.

 

I'm not a critic of Smartgauge, and have already conceded for a lot of people it will be useful, (and for some very useful).

 

However the above generalisations are not, I still believe, true for all boaters.

 

Anyone with low battery usage when not moving, who routinely puts in a lot of boating hours, can easily meet their full charging needs just by the fact that the engine is running for enough hours a day that anything used since it last ran gets replenished long before the next cruising day ends.

 

I can see from the fact that my ammeter indicates only minimal charge going to my battery bank long before I tie up for the night, that no benefit, or added longevity to my batteries would be gained by continuing to run the engine when I'm moored.

 

I understand how it works, but have no need to try it, or spend around £150 on a bit of kit that for me would be no more than a novelty gizmo.

 

If I were in your situation, I would almost certainly fit one, but it is wrong to say generically to all boaters "it will help you to prolong the life of your batteries and it will save you money"

 

For me it would not, and I don't think even Gibbo would necessarily make the case that it would benefit me greatly. (But he is very welcome to try!....)

[Gibbo]

Well what would a Smartguage say, 80% or 100%?

 

cheers,

Pete.

 

Well, as it's designed specifically to tell the user how much energy they have left as a percentage of their actual battery capacity as it stands right now which do you think?

 

It wouldn't be much use if it told them the available energy left as a percentage of what they might have if they did something to their batteries like increasing/decreasing the battery bank size, or warming the battery up. That would make it as useless as an amp.hour counter.

 

For me it would not, and I don't think even Gibbo would necessarily make the case that it would benefit me greatly. (But he is very welcome to try!....)

 

I've never even tried to sell one to someone who wants one, let alone someone who doesn't!

[alan_fincher]

I've never even tried to sell one to someone who wants one, let alone someone who doesn't!

Very drole!

 

But (genuine question!), could you actually make a case to someone like me, who puts in a lot of hours boating every day, and has low power demands when not boating, that a Smartgauge could be useful.

 

I really can't see ways it would save me money, (Graham's claim), but perhaps I've genuinely missed something.

 

To state my current position - I actually think it's a good product, but not automatically right for everybody that happens to own a narrow boat. (Bit like a bow-thruster ? - No - don't go there!....)

[Gibbo]

Very drole!

 

But (genuine question!), could you actually make a case to someone like me, who puts in a lot of hours boating every day, and has low power demands when not boating, that a Smartgauge could be useful.

 

 

I'd struggle. I'm sure a salesman could try, but I wouldn't.

 

To clarify, on our boat, when moored up for a few days, with the fridge going, and the kids on board using X-Boxes and such like we'd seriously struggle without it. It would be either guesswork or a lot of faffing around trying to guesstimate the SoC. On the other hand, if we're cruising every day, BBQing outside at night therefore not much lighting going on and little or no TV, no kids aboard etc, we know we don't have a power problem therefore we don't even look at it. We only really use it when we're marginal on power. And under those circumstances it's worth its weight in gold.

 

I guess you fit into the second useage pattern so your money is probably better spent on beer.

[alan_fincher]

I guess you fit into the second useage pattern so your money is probably better spent on beer.

Or at least two leisure batteries when they finally next need replacing, (or presumably up to 6 if bought from Vince!)

 

I think your answer is honest, and about what I would assume.

 

I think you are agreeing that not everybody would save money in the long run just because they had bought one. (And to be clear, I accept that for many they are the best thing they can buy to try and help manage batteries where keeping them fully charged is a potential issue...)

[WotEver]

I also think they're an essential item for anyone who says "I bought some new batteries x months ago but they don't appear to be holding their charge...". How often do we see that in one form or another on this forum?.

 

Tony who has very modest electrical demands and only one (knackered) 7 year old leisure battery.

 

I'm awaiting Vince's next stock

[nb Innisfree]

Don't know if this is the recommended procedure but when using a hydrometer I never take the first reading in case there is stratification, instead I gently squirt the electrolyte back and forth a couple of times to mix it up.

[Gibbo]

Don't know if this is the recommended procedure but when using a hydrometer I never take the first reading in case there is stratification, instead I gently squirt the electrolyte back and forth a couple of times to mix it up.

 

Yes that's good practice. If you keep doing it you can actually see it rise with each suck ( )

[Gibbo]

I think you are agreeing that not everybody would save money in the long run just because they had bought one. (And to be clear, I accept that for many they are the best thing they can buy to try and help manage batteries where keeping them fully charged is a potential issue...)

 

It really comes down to one simple question:-

 

Do I always have loads of surplus power because my cruising pattern can easily replenish what I use and I don't discharge them much anyway? If the answer is yes, then any form of battery monitoring is a waste of time and money. On the other hand if people are running engines and generators purely to charge batteries, or if they moor up until they need to move again because they need to charge batteries then its indispensible.

 

But on another hand, how many people think they are charging plenty and not using much power (how many times have we heard: "Oh not much, a few lights, a hairdryer, a fan heater, a washing machine" !!!!????) but then come on here asking questions after a few months because their batteries are knackered due to undercharging and overdischarging? As Tony said, it's a very common problem because a lot of people don't know anything about batteries. Even more aren't even interested in knowing about them.

 

But (and remember I've sold it now, I have no financial interest in it whatsoever) if someone needs a battery monitor and is only interested in "How much power have I got" I honestly believe it is the best one available. I don't think anything else comes even remotely close.

 

But it's only needed by those people who really don't know whether they have enough power available to do what they want to do. If you really know you have loads, you don't need one.

 

Does a multimillionaire need to keep checking his bank statements? (bet Chris W hasn't looked at one for years )

[alan_fincher]

Don't know if this is the recommended procedure but when using a hydrometer I never take the first reading in case there is stratification, instead I gently squirt the electrolyte back and forth a couple of times to mix it up.

Yes....

 

Emphasis on gently!

 

In my youth I had far too many clothes, and even a pair of my mother's curtains, (don't ask!), caused by lack of care when handling battery acid.

 

My worst nightmare on the boat is that usually however careful I am, I manage to get some residual drips from the bloody thing on something I should not.

 

Whilst a useful tool, anyone not familiar with what battery acid can do to objects, let alone (say) your eyes should treat with extreme caution. If you do manage to drop one when it's got acid in, don't grab for the bulb - better to let let it drop, (please don't ask me why I think this is good advice, now..... )

 

At least SmartGauge can only burn a hole in your wallet, not your clothing, I'll admit!

 

Does a multimillionaire need to keep checking his bank statements? (bet Chris W hasn't looked at one for years )

Oh, I don't know about that!

 

He might delight in telling us impoverished types just how much richer he is than us!.......

[mayalld]

It really comes down to one simple question:-

 

Do I always have loads of surplus power because my cruising pattern can easily replenish what I use and I don't discharge them much anyway? If the answer is yes, then any form of battery monitoring is a waste of time and money. On the other hand if people are running engines and generators purely to charge batteries, or if they moor up until they need to move again because they need to charge batteries then its indispensible.

 

 

We have reasonably middle of the road electrical demands (TV/DVD combi, fridge, mini freezer, don't use the lights mutch). We tend to have long cruising days, 400Ah of domestic bank, and have a sterling battery bolier fitted.

 

Observing the volt meter on the Vetus panel during the day;

• When we first set off in the morning it shows around 12.7 volts
• Over the course of the first 1-2 hours it creeps up to 14.2 volts
• By early afternoon, it drops to about 13.5 volts and stays there

From this, I conclude that;

• we are discharging the batteries a fair bit, to the extent that when we first start, the alternator is current limited.
• we are doing enough cruising during the day to allow the battery boiler to drop back to float, and as such we are probably pretty close to full charge.

My impression, from reading what has been said about Smatgauge is that it is a damned useful bit of kit. The question is "Will it actually tell me anything that I'm not already working out fior myself from the VM"

[smileypete]

Well, as it's designed specifically to tell the user how much energy they have left as a percentage of their actual battery capacity as it stands right now which do you think?

 

It wouldn't be much use if it told them the available energy left as a percentage of what they might have if they did something to their batteries like increasing/decreasing the battery bank size, or warming the battery up. That would make it as useless as an amp.hour counter.

Well I'd expect Smartgauge to say 80% when in fact the SoC of the cold battery is still 100%!

 

I think this is why Smartgauge can be inaccurate during charging. Charging can heat the battery some which makes it read the % higher than it should do, so it can indicate 100% before the battery is fully charged.

 

 

I can see from the fact that my ammeter indicates only minimal charge going to my battery bank long before I tie up for the night, that no benefit, or added longevity to my batteries would be gained by continuing to run the engine when I'm moored.

Exactly, and if the voltage doesn't remain below about 12.2V while moored up then the batts won't be run down too much to harm them.

 

cheers,

Pete.

Edited September 17, 2010 by smileypete

[bottle]

I think this is why Smartgauge can be inaccurate during charging

 

Taking that one sentence, probably out of context, you are correct.

 

In fact it says that i n the manual.

 

Quote:

 

During charging this is not possible due to the presence of the charger preventing SmartGauge ever getting

an opportunity to actually measure the charge status. In effect, if it tried, it would be attempting to measure

the charge status of the charger. During charging, SmartGauge only shows the calculated charge status as

does an amp hours counter however SmartGauge, because it operates on a different principle, calculates a

charge status that is much more accurate. For this reason, it is possible that, during the charge cycle, the

charge status displayed may not be totally accurate. It will be within 10% of the actual battery charge

status. This may seem like nothing (and is infinitely more accurate than an amp hours counter may show

which could be literally hundreds of amp hours adrift), but it can have certain consequences.

 

Unquote

[nb Innisfree]

 

I can see from the fact that my ammeter indicates only minimal charge going to my battery bank long before I tie up for the night, that no benefit, or added longevity to my batteries would be gained by continuing to run the engine when I'm moored.

 

 

Just to add to that, when we hook up to a shoreline our Victron takes at least 24 hours for the charge rate to bottom out so there would be some benefit to batteries to keep engine running though of course it would be an expensive way to maximise battery life.

Edited September 17, 2010 by nb Innisfree

[Gibbo]

Well I'd expect Smartgauge to say 80% when in fact the SoC of the cold battery is still 100%!

 

I think this is why Smartgauge can be inaccurate during charging. Charging can heat the battery some which makes it read the % higher than it should do, so it can indicate 100% before the battery is fully charged.

 

And...................

 

You'd be wrong on both counts. Congratulations.

 

We have reasonably middle of the road electrical demands (TV/DVD combi, fridge, mini freezer, don't use the lights mutch). We tend to have long cruising days, 400Ah of domestic bank, and have a sterling battery bolier fitted.

 

Observing the volt meter on the Vetus panel during the day;

• When we first set off in the morning it shows around 12.7 volts
• Over the course of the first 1-2 hours it creeps up to 14.2 volts
• By early afternoon, it drops to about 13.5 volts and stays there

From this, I conclude that;

• we are discharging the batteries a fair bit, to the extent that when we first start, the alternator is current limited.
• we are doing enough cruising during the day to allow the battery boiler to drop back to float, and as such we are probably pretty close to full charge.

My impression, from reading what has been said about Smatgauge is that it is a damned useful bit of kit. The question is "Will it actually tell me anything that I'm not already working out fior myself from the VM"

 

Your conclusions are about right. But you don't seem to have any idea how deeply you are discharging the batteries.

[smileypete]

And...................

 

You'd be wrong on both counts. Congratulations.

So Smartguage will read a 100Ah battery which is fully charged but at reduced capacity of 80Ah due to cold, as 100%, yes? Very good!

 

cheers,

Pete.

Edited September 17, 2010 by smileypete

[bottle]

As a complete numpty on this, I would think the answer is yes because the state of charge is 100% of its capacity at that time.

 

As I understand it the Smartgauge measures SOC not capacity.

 

or have I got it totally wrong. (quite possible)

 

Edit: that's not fair you edited whilst I posted

Edited September 17, 2010 by bottle

[Gibbo]

So Smartguage will read a battery which is fully charged but at reduced capacity due to cold, as 100%. Very good!

 

You seem to have learning difficulties.

 

You have tried, over about 5 years, on at least 100 occasions to catch me out or prove me wrong. You have failed every single time, and yet you continue with this futile effort. When will it sink in that you're never going to succeed?

 

And in answer to the above question, that is exactly what it will do. Because that way, it tells the user how much power he has left as a fraction of his batteries being fully charged now. What is so difficult to understand about that?

 

Telling someone how much power they have left as a fraction of what they might have had if the batteries were in a different condition, or at a different temperature, or if the bank was a different size, or if they were newer is dead easy. Any old pillock can do that. That is what amp.hour counters do, it is totally and utterly useless and is why SmartGauge does so well.

 

As a complete numpty on this, I would think the answer is yes because the state of charge is 100% of its capacity at that time.

 

Spot on.

[smileypete]

You seem to have learning difficulties.

 

You have tried, over about 5 years, on at least 100 occasions to catch me out or prove me wrong. You have failed every single time, and yet you continue with this futile effort. When will it sink in that you're never going to succeed?

 

And in answer to the above question, that is exactly what it will do. Because that way, it tells the user how much power he has left as a fraction of his batteries being fully charged now. What is so difficult to understand about that?

Fair enough, as I understand it Smartgauge measures the conductance of a battery and converts it to a %.

 

Also as I understand it, conductance varies with temperature eg (clicky)

 

'Just as battery performance is significantly affected by temperature, conductance also varies with temperature in a predictable manner due to the change in conductivity of the electrolyte. This is especially true at cold temperatures. Conductance factors are thus temperature sensitive and require temperature information for correct assessment.'

 

So I just wondered how Smartgauge handled it.

 

 

Anyway, in future if you post anything that I feel is worth a question, I won't bring it up.

 

I'm not trying to catch you out, just get some answers.

 

cheers,

Pete.

[Gibbo]

I'm not trying to catch you out, just get some answers.

 

In the same message as.............

 

 

.... as I understand it Smartgauge measures the conductance of a battery and converts it to a %.

 

Also as I understand it, conductance varies with temperature eg (clicky)

 

 

Good job SmartGauge doesn't rely on conductance then eh?

 

You really will have to get out of bed much earlier.