Electroquest 30 Amp Charger difficulties - Maximum Battery Bank Size?

[alan_fincher]

3 minutes ago, Iain_S said:

It isn't a lie.

Our charger does the same, gong into float much too early. Doesn't really affect us, though, as the charger is seldom used.

Believe the Smartgauge; If anything, it tends to be optimistic, not pessimistic!

Which brings me back full circle to the reason I started this thread.

As described somewhere within it, I have established, both from the "documentation" and by actual observation, that the 30A charger named in the thread will go into float if charge current falls to 10% of its full capacit, so when charge current is at 3 amps. 

Unless I have is understood much of the discussion, that is surely a fairly low current into a total bank size of 550Ah.

It's my belief that there is no way you can set the charging voltage higher, (the only way I could get the charge current to stay above 3 amps for longer), and the charger it performing exactly as they state it will.

So, (back to post 1 again), is it actually an unsuitable charger for my needs, because it will not stay in absorption for longer, (and can't apparently be made to)?

[cereal tiller]

1 minute ago, alan_fincher said:

Which brings me back full circle to the reason I started this thread.

As described somewhere within it, I have established, both from the "documentation" and by actual observation, that the 30A charger named in the thread will go into float if charge current falls to 10% of its full capacit, so when charge current is at 3 amps. 

Unless I have is understood much of the discussion, that is surely a fairly low current into a total bank size of 550Ah.

It's my belief that there is no way you can set the charging voltage higher, (the only way I could get the charge current to stay above 3 amps for longer), and the charger it performing exactly as they state it will.

So, (back to post 1 again), is it actually an unsuitable charger for my needs, because it will not stay in absorption for longer, (and can't apparently be made to)?

I use the Electroquest 30 AMP. Charger and it will take the Smartgauge to 100%,on Float the Batteries are still taking Current

 

[alan_fincher]

19 minutes ago, nicknorman said:

Well if they have been on shore power for a while, it’s a pretty safe bet. Maybe you can’t tell the difference between 95% and 100%, but you could be pretty sure it wasn’t 75%. Not that it matters for most people. It only matters if you are only cycling the batteries between 95% and 100% such that the actual SoC never reaches the indicated SoC you set (or accepted) when you installed it. And if you are only cycling the batteries between 95% and 100% then the SGwas the wrong thing to get.

See above.

When I bought said SmartGauge I had a very much larger charger, with about 80 amps capacity, not 30 amps.

It was telling me the batteries were at 100% most of the time.  With the new one I get a different reult, hence partly my reason for starting the thread.

I don't actually know what SoC the bank is likely to be at now.  From my perception I am probably using more 12v than the charger wants to put back, but I have no way of proving that.

If I were to tell the SG that they are actually at 100%, not the current indicated 89%, what do you think would happen over time, assuming I don't go below this75% figure?  If I keep them on the charger whenever I'm using them, will it stay at 100%, or drop again to around the 90% figure, do you think?

3 minutes ago, cereal tiller said:

I use the Electroquest 30 AMP. Charger and it will take the Smartgauge to 100%,on Float the Batteries are still taking Current

 

So do you thin I have a bad one? (Charger that is, not SG).

[Richard10002]

5 minutes ago, nicknorman said:

Regarding the fully charged thing, once again I point out that the SG is fairly close, within the spread of what people consider to be fully charged. A BMV700 series out of the box resets to 100% when the tail current is 4%. The SG is no worse than that. And as I also said before, the comparison should be between the SG and having nothing, rather than between the SG and somone who has gone to the trouble to install a shunt meter and knows what it all means.

And, for the sake of good order and, once again, I point out that SG isn’t close enough at 100%. If it were close enough, Gibbo would not have inserted the warning on page 30 of the manual. If it were close enough, I would not have to continue charging for a couple of hours after it reads 100% to reach my 2% tail current.

How a BMV700 works is irrelevant, although one could argue that it should reset at 2% out of the box.

I could argue that the false sense of security engendered by a SG reading 100% when charging is actually worse than having nothing.

Knowing what I know now, I wouldn’t have bought one, and would suggest that it is probably a waste of money at best and, on its own, actually dangerous with respect to Battery life.

As a matter of interest, I wonder if you could message me with instructions for calibrating my SG. I’m reasonably sure that it’s voltage reading is accurate, compared with the NASA and a couple of volt meters I have, but it would be worth double checking.

[smileypete]

To be fair tail current is not without any pitfalls, it only applies for a healthy batt at the correct absorbtion voltage, people seem to overlook that sometimes....

Edited November 6, 2017 by smileypete

[bizzard]

''Some one had blundered.   Theirs not to make reply,  Theirs not to reason why,   Theirs but to do or die,   Into the valley of Smartgauge'', ''Into the jaws of inacuracy, Rode the Six Hundred''.

Flashed all their cables bare,  Flashed as they shorted in despair,  scorching the owners hair,  Charging an army of Smartgauges, while, All the worlds multimeters wondered. 

From The charge of the LED Light Brigade.

 

Edited November 6, 2017 by bizzard

[Dr Bob]

31 minutes ago, nicknorman said:

V and A is fine for determining when the batteries are fully charged. But not for determining an intermediate SoC. You have dodged the question slightly by changing it to “better for the price” but that wasn’t what you said before nor what my question was aimed at fleshing out.

So I ask again, what is a more accurate method than the SG of measuring SoC other than fully charged?

Here’s some examples: V=14.1, A=80. What is the SoC to within significantly better than 10%? You have 2 seconds to answer.

V=12.37, A = -12A. What is the SoC to within significantly better than 5%. You have 2 seconds to answer.

without looking at any other answers, based on my system and a 2 second answer:

Ex 1. This is typical of what I see when I have just started the engine after a night where I have used around 100/120Ahrs (660Ahrs bank). I am usually a little lower in Amphrs as I am usually 80Ahrs down (from full) and the charging starts at 70A so the 80A would suggest less SoC than normal overnight. Voltage correlates. I would guess on 80-85% under this scenario. (Charging via alternators 90A/50A via Sterling AtoB). It could be a different SoC if it was the shore power battery charger just switched on but I never look at V or A when I plug in shore power.

Ex2. This is typical of what I see in the morning before the solar kicks in. If the load was removed then I would expect the V to rise by 0.15 - 0.2V so again 85% ish but I would need some other info to know - ie is there a trickle of solar getting in? Temp of the bank (is it a freezing cold night or mid July?)

These are very frequently seen numbers (well -70A in Ex 1 is) for me.

[smileypete]

56 minutes ago, cereal tiller said:

I use the Electroquest 30 AMP. Charger and it will take the Smartgauge to 100%,on Float the Batteries are still taking Current

Need some tail current readings to make sense of that one.... in rare circumstances it could be a faulty battery.

Edited November 6, 2017 by smileypete

[MtB]

On 06/11/2017 at 11:15, nicknorman said:

Could you advise what other method you could use that will give you the current SoC to greater accuracy?

 

Why do yoiu need to know the SoC with any accuracy except when finishing a charge to 100% as close as practical? As we all now know, this is the one circumstance when the SG can specifically not be relied upon. 

Well that's what the manual says anyway, so I understand. I never got as far as page 30.

Edited November 6, 2017 by Mike the Boilerman

[nicknorman]

1 hour ago, Dr Bob said:

without looking at any other answers, based on my system and a 2 second answer:

Ex 1. This is typical of what I see when I have just started the engine after a night where I have used around 100/120Ahrs (660Ahrs bank). I am usually a little lower in Amphrs as I am usually 80Ahrs down (from full) and the charging starts at 70A so the 80A would suggest less SoC than normal overnight. Voltage correlates. I would guess on 80-85% under this scenario. (Charging via alternators 90A/50A via Sterling AtoB). It could be a different SoC if it was the shore power battery charger just switched on but I never look at V or A when I plug in shore power.

Ex2. This is typical of what I see in the morning before the solar kicks in. If the load was removed then I would expect the V to rise by 0.15 - 0.2V so again 85% ish but I would need some other info to know - ie is there a trickle of solar getting in? Temp of the bank (is it a freezing cold night or mid July?)

These are very frequently seen numbers (well -70A in Ex 1 is) for me.

So bearing in mind my original question asked what method of determining SoC is significantly more accurate than SG, and you said your volts and amps, it now seems that was unjustified because you are just saying “guess 80-85%” and “85% ish” which doesn’t inspire me with feelings of great accuracy!

So I would say that despite your volts and amps, despite you great familiarity with your particular setup and how it behaves, despite the lengthy period of time you have spent becoming familiar with it, you are still guessing and as you say, one needs to know the previous history as well as the instantaneous volts and amps. For example I can get 80A going into the battery an hour or so after starting charge from a lowish SoC when the SoC is now 80% ish, or almost instantly when restarting the engine following a linch stop when the SoC is 97% and I’m just putting back the surface charge.

I’d go further and say that it is quite impossible to determine the instantaneous SoC just by looking at instantaneous V and A. You need to know the circumstances, when charging was started or stopped etc. If you spend a lot of time thinking about all this then sure you can probably get nearly as close as a SG. But the alternative is to just spend you £120 or whatever, press a button, see a reading and then get on with your life.

[nicknorman]

1 hour ago, Mike the Boilerman said:

 

Why do yoiu need to know the SoC with any accuracy except when finishing a charge to 100% as close as practical? As we all now know, this is the one circumstance when the SG can specifically not be relied upon. 

Well that's what the manual says anyway, so I understand. I never got as far as page 30.

You don’t. However that doesn’t stop certain people banging on about how hopeless the SG is because it can only measure discharge SoC to 5% accuracy, and how there are so many much more accurate ways to measure it. Even though there aren’t.

[Dr Bob]

1 hour ago, nicknorman said:

So bearing in mind my original question asked what method of determining SoC is significantly more accurate than SG, and you said your volts and amps, it now seems that was unjustified because you are just saying “guess 80-85%” and “85% ish” which doesn’t inspire me with feelings of great accuracy!

So I would say that despite your volts and amps, despite you great familiarity with your particular setup and how it behaves, despite the lengthy period of time you have spent becoming familiar with it, you are still guessing and as you say, one needs to know the previous history as well as the instantaneous volts and amps. For example I can get 80A going into the battery an hour or so after starting charge from a lowish SoC when the SoC is now 80% ish, or almost instantly when restarting the engine following a linch stop when the SoC is 97% and I’m just putting back the surface charge.

I’d go further and say that it is quite impossible to determine the instantaneous SoC just by looking at instantaneous V and A. You need to know the circumstances, when charging was started or stopped etc. If you spend a lot of time thinking about all this then sure you can probably get nearly as close as a SG. But the alternative is to just spend you £120 or whatever, press a button, see a reading and then get on with your life.

Of course I look at the circumstances...DUH! Absolutely you need to know if you've just started the engine, or if its sub zero, or if the solar is charging. Do you think I am thick?

I say guess, 'the highly accurate' SG gives its best prediction. I dont think they will be any different. My 'guess' is well informed. No different from the SG. You do me a disservice suggesting otherwise.

The alternative is to not buy an SG for £120, take two readings by pressing one button and then get on with your life. This is not rocket science. It takes virtually no time to do and does not get in the way of enjoying life. Arguing about it here however does take time.

I dont even think about SoC when I check the numbers in the morning. I am looking for trends and if one or more numbers are not right then I will think harder viz your second case .....what the heck is drawing 12A? That's not right with only x,y and z running. To me the ammeter is far far more important than an SG.

 

[ditchcrawler]

5 hours ago, Dr Bob said:

A question.

How many of you on here dont have an ammeter yet think they are managing their batteries well?

Some people think that recharging when the inverter bleeps is looking after the batteries. I don't have a Smart Gauge but think I can interpreter the readings from my Sterling Battery Management panel well enough to give me the information I need. 

[Dr Bob]

1 minute ago, ditchcrawler said:

Some people think that recharging when the inverter bleeps is looking after the batteries. I don't have a Smart Gauge but think I can interpreter the readings from my Sterling Battery Management panel well enough to give me the information I need. 

Thanks Brian. I am interested to see how people are managing their systems.

[nicknorman]

26 minutes ago, Dr Bob said:

Of course I look at the circumstances...DUH! Absolutely you need to know if you've just started the engine, or if its sub zero, or if the solar is charging. Do you think I am thick?

I say guess, 'the highly accurate' SG gives its best prediction. I dont think they will be any different. My 'guess' is well informed. No different from the SG. You do me a disservice suggesting otherwise.

The alternative is to not buy an SG for £120, take two readings by pressing one button and then get on with your life. This is not rocket science. It takes virtually no time to do and does not get in the way of enjoying life. Arguing about it here however does take time.

I dont even think about SoC when I check the numbers in the morning. I am looking for trends and if one or more numbers are not right then I will think harder viz your second case .....what the heck is drawing 12A? That's not right with only x,y and z running. To me the ammeter is far far more important than an SG.

 

No I don’t think you are thick. But you are being irrational just to try to make your point. We both agree that with monitoring of V and A and being very familiar with the system and it’s behaviour and being aware of the history of the current charge or discharge run, you can make a guess at the present SoC. But no more accurately than the SG and much less so under circumstances you are less familiar with. So your earlier point about the SG not being accurate was an irrational one since as you secretly realise, but won’t admit, there is no more accurate way to measure it. It is disingenuous to dis something for being inaccurate if there is nothing more accurate.

your methodology as you describe it is fine, and clearly works for you. Unfortunately not everyone has the wherewithal or interest to do the same as you and those people can get just as good or better results by coughing up £120 for a gadget that doesn’t require them to think. You have to remember that some people really are incredibly thick, or plain just not interested in electrickery.

Edited November 6, 2017 by nicknorman

[Dr Bob]

55 minutes ago, nicknorman said:

No I don’t think you are thick. But you are being irrational just to try to make your point. We both agree that with monitoring of V and A and being very familiar with the system and it’s behaviour and being aware of the history of the current charge or discharge run, you can make a guess at the present SoC. But no more accurately than the SG and much less so under circumstances you are less familiar with. So your earlier point about the SG not being accurate was an irrational one since as you secretly realise, but won’t admit, there is no more accurate way to measure it. It is disingenuous to dis something for being inaccurate if there is nothing more accurate.

your methodology as you describe it is fine, and clearly works for you. Unfortunately not everyone has the wherewithal or interest to do the same as you and those people can get just as good or better results by coughing up £120 for a gadget that doesn’t require them to think. You have to remember that some people really are incredibly thick, or plain just not interested in electrickery.

....then we will have to disagree.

I do not think that a gauge that on one hand claims to be 'highly accurate' but has the following specification is any better than my limited skills.

• Accuracy For State Of Charge (Charge): +/- 10%
• Accuracy For State Of Charge (Discharge): +/- 5%
• Accuracy Voltage: +/- 0.5V DC

[WotEver]

2 minutes ago, Dr Bob said:

I do not think that a gauge that on one hand claims to be 'highly accurate' but has the following specification is any better than my limited skills.

• Accuracy For State Of Charge (Charge): +/- 10%
• Accuracy For State Of Charge (Discharge): +/- 5%
• Accuracy Voltage: +/- 0.5V DC

I disagree. 

I could look at the voltage and current flow and have a pretty good idea of where the SoC is sitting, just like you can. So I don’t ‘need’ one.  Neither do you.

My wife wouldn’t have a clue. She’s also not interested in learning. She CAN press a button and get a simple, clear number that she can understand though. She, and boaters of a similar mindset, is who the SmartGauge is aimed at. The stated accuracy (which you keep avoiding to mention is a self-correcting maximum error) is way more accurate than my wife guessing, or waiting for the inverter to squeal. 

[nicknorman]

49 minutes ago, Dr Bob said:

....then we will have to disagree.

I do not think that a gauge that on one hand claims to be 'highly accurate' but has the following specification is any better than my limited skills.

• Accuracy For State Of Charge (Charge): +/- 10%
• Accuracy For State Of Charge (Discharge): +/- 5%
• Accuracy Voltage: +/- 0.5V DC

Let’s hope the SG’s accuracy is better than your transcribing accuracy!

”highly accurate” is a qualitative term. But when the device in question is more accurate than any other method, it seems a reasonable assertion to me.

[Richard10002]

48 minutes ago, WotEver said:

I disagree. 

I could look at the voltage and current flow and have a pretty good idea of where the SoC is sitting, just like you can. So I don’t ‘need’ one.  Neither do you.

My wife wouldn’t have a clue. She’s also not interested in learning. She CAN press a button and get a simple, clear number that she can understand though. She, and boaters of a similar mindset, is who the SmartGauge is aimed at. The stated accuracy (which you keep avoiding to mention is a self-correcting maximum error) is way more accurate than my wife guessing, or waiting for the inverter to squeal. 

As a matter of interest, if she were alone on the boat for a few days, how would she charge the batteries, and how would she know when they are full?

I ask because my wife is probably in the same boat, “wouldn’t have a clue”, but she doesn’t spend much time on the boat, so it doesn’t really matter, to date.

i guess the instructions could be, charge until Smartgauge reaches 100%, then for another couple of hours. She would probably have to run the engine as she couldn’t manoeuvre the genny.

[WotEver]

Just now, Richard10002 said:

As a matter of interest, if she were alone on the boat for a few days, how would she charge the batteries, and how would she know when they are full?

I ask because my wife is probably in the same boat, “wouldn’t have a clue”, but she doesn’t spend much time on the boat, so it doesn’t really matter, to date.

i guess the instructions could be, charge until Smartgauge reaches 100%, then for another couple of hours. She would probably have to run the engine as she couldn’t manoeuvre the genny.

In this hypothetical situation she’d run the engine until the ammeter read circa 2% of capacity. (Or until 8pm  )

[MtB]

2 hours ago, Dr Bob said:

Accuracy Voltage: +/- 0.5V DC

 

Were did you get THAT from?

If you found this as part of the published SG specification, BOTH my SGs are within factory spec. Even though they disagree with one another by up to 20% SoC on the same battery sometimes.

[Dr Bob]

7 minutes ago, Mike the Boilerman said:

 

Were did you get THAT from?

If you found this as part of the published SG specification, BOTH my SGs are within factory spec. Even though they disagree with one another by up to 20% SoC on the same battery sometimes.

On the Force 4 web site.

https://www.force4.co.uk/merlin-smartgauge-battery-monitor.html#.WgCpQIZpE0o

Yes, that's why I was attempting to raise the awareness of how accurate the SG could be. When I look a the volts in the morning, I want to see it accurate to at least ten times better. Not checked any other sellers site though.

[MtB]

17 minutes ago, Dr Bob said:

On the Force 4 web site.

https://www.force4.co.uk/merlin-smartgauge-battery-monitor.html#.WgCpQIZpE0o

Yes, that's why I was attempting to raise the awareness of how accurate the SG could be. When I look a the volts in the morning, I want to see it accurate to at least ten times better. Not checked any other sellers site though.

 

I wonder if Merlin are aware of the outrageously misleading claims on the Force 4 website.

One of my SGs reads voltage 0.3V lower than actual, and the other 0.4V higher than actual. Given that I charge my batteries daily now (ok, nightly!) they never got down anywhere near 50% SoC.

And as the manual tells us the SG has no idea when the batts are 100% charged so cannot be relied upon. This is confirmed by one of mine confidently stating 100% for two hours while the other slowly climbs from 80% to 96% then stopping. So my SGs are pretty much redundant now, other than to confirm the SoC hasn't fallen below 60%. Or 75%, depending on which  you are.... ...oh you get the picture....

Edited November 6, 2017 by Mike the Boilerman

[MtB]

From the Force 4 website, describing the Smartgauge

• Accuracy Voltage: +/- 0.5V DC

Has this always been the case or is it new? I'm thinking now if I returned mine as faulty, I'd just get them back again stating they are within specification. 

If it is a recent slackening of the spec, I wonder if it is in response to an avalanche of returns. 

 

 

 

[WotEver]

26 minutes ago, Dr Bob said:

On the Force 4 web site.

https://www.force4.co.uk/merlin-smartgauge-battery-monitor.html#.WgCpQIZpE0o

Yes, that's why I was attempting to raise the awareness of how accurate the SG could be. When I look a the volts in the morning, I want to see it accurate to at least ten times better. Not checked any other sellers site though.

It appears that Force4 don’t understand the difference between 0.5% and 0.5V. 

(It’s a difference of 0.44V)

3 minutes ago, Mike the Boilerman said:

Has this always been the case or is it new?

Neither. It’s a mistake. 

Cactus, however, know how to type

http://www.cactusnav.com/merlin-smartguage-battery-monitor-p-11874.html

Edited November 6, 2017 by WotEver