Electroquest 30 Amp Charger difficulties - Maximum Battery Bank Size?

[cuthound]

8 hours ago, Mike the Boilerman said:

3% of what though? 3% of its badge capacity or 3% of its much reduced actual?

As the tail current tends to increase as batteries age I would say original badged capacity.

[nicknorman]

9 minutes ago, cuthound said:

As the tail current tends to increase as batteries age I would say original badged capacity.

I agree, especially as most people don’t know what the actual capacity currently is.

[Dr Bob]

With the huge number of posts saying how good the SG is, it sort of suggests you are a muppet if you dont have one. This, supported by the fact that a large number of you seem to have an orgasmic love relationship with the device, must persuade an ill informed reader to order one immediately. Only MtB and Richard seem to question the combined knowledge of the forum!

I am questioning the point of having one.

Bear with me. Split us up into 2 groups. The first who know how to manage batteries. The second who dont. For the first group, we will all have ammeters and monitor amps out and tail current to guess (SoC). Why spend £160 on a gauge that doesnt really give us any more info? Voltage and amps in/out are all that is needed for someone who knows what they are doing.

For the second group, they should be advised how to look after their batteries properly hence buy an ammeter. Ok installing a shunt is not as easy as the SG but if you want to know if you are fully charged then tail current is important. This second group can be easily led by duff information. Yes if you read the SG manual you may find the info that says what the displayed results mean and can be relied upon. However, the guys in the second group will not read it cover to cover, and if they do, and listen to the info here, they will buy an ammeter. The group who dont read the manual will read info like the following – posted on Force 4's web page:

The Smartgauge provides at-a-glance information about your batteries. It remains highly accurate as, unlike many other battery monitors....etc

https://www.force4.co.uk/merlin-smartgauge-battery-monitor.html#.WgAzBIZpE0p

This is in the first paragraph of the description of the SG. “It remains highly accurate....”!!! How can +/-10% be highly accurate? +/-10%  is not even 'accurate'. The reader would be convinced that the SG is all he needs and when it says 100%- it means the batteries are 100%. The word “remains” suggests it is always highly accurate. Charging to 95% SoC and never doing the last 5% will mean sulphation of that last 5%, then another 5%, then another 5% etc.

For the second group then, spend £160 on an ammeter rather than a SG.

If my battery monitor fails, I will surely get a new ammeter rather than an SG. Maybe I am a muppet?

[alan_fincher]

11 minutes ago, Dr Bob said:

Why spend £160 on a gauge that doesnt really give us any more info?

 

12 minutes ago, Dr Bob said:

For the second group then, spend £160 on an ammeter rather than a SG.

Just for the record, they can currently be bought here at  £109.96, so you are not awsting as much as you suggest if you buy a lemon.

[alan_fincher]

15 minutes ago, Dr Bob said:

Only MtB and Richard seem to question the combined knowledge of the forum!

Not really so.
 

The jury is still out for me.

In my current situation, I don't think, (indeed I sincerely hope!) mine isn't telling me the truth.

However I'm not exactly minded to run my bank below 75% for no other purpose than trying to get the SmartGauge to tell me something more accurate.

OK, I'm on a mooring on a land-line at the moment, but if I do get regular boating again, I'd still actually prefer never to be taking the bank below an indicated 75%, unless stopping somewhere for multiple days, (unusual for us).

If the device can't learn your actual situation unless you do this, then it is significantly less useful than I might have hoped when buying.

At the moment I'm ignoring it, because I hope the fact it indicates my charger can never take the bank above about 90% without going into a very slow trickle charge float is a lie.

[smileypete]

Having a quick google last night on something related I found some more Smartguage skepticism on a lumpy water site:

http://www.cruisersforum.com/forums/f14/smartgauge-real-life-experience-170104.html

[nicknorman]

56 minutes ago, Dr Bob said:

With the huge number of posts saying how good the SG is, it sort of suggests you are a muppet if you dont have one. This, supported by the fact that a large number of you seem to have an orgasmic love relationship with the device, must persuade an ill informed reader to order one immediately. Only MtB and Richard seem to question the combined knowledge of the forum!

I am questioning the point of having one.

Bear with me. Split us up into 2 groups. The first who know how to manage batteries. The second who dont. For the first group, we will all have ammeters and monitor amps out and tail current to guess (SoC). Why spend £160 on a gauge that doesnt really give us any more info? Voltage and amps in/out are all that is needed for someone who knows what they are doing.

For the second group, they should be advised how to look after their batteries properly hence buy an ammeter. Ok installing a shunt is not as easy as the SG but if you want to know if you are fully charged then tail current is important. This second group can be easily led by duff information. Yes if you read the SG manual you may find the info that says what the displayed results mean and can be relied upon. However, the guys in the second group will not read it cover to cover, and if they do, and listen to the info here, they will buy an ammeter. The group who dont read the manual will read info like the following – posted on Force 4's web page:

The Smartgauge provides at-a-glance information about your batteries. It remains highly accurate as, unlike many other battery monitors....etc

https://www.force4.co.uk/merlin-smartgauge-battery-monitor.html#.WgAzBIZpE0p

This is in the first paragraph of the description of the SG. “It remains highly accurate....”!!! How can +/-10% be highly accurate? +/-10%  is not even 'accurate'. The reader would be convinced that the SG is all he needs and when it says 100%- it means the batteries are 100%. The word “remains” suggests it is always highly accurate. Charging to 95% SoC and never doing the last 5% will mean sulphation of that last 5%, then another 5%, then another 5% etc.

For the second group then, spend £160 on an ammeter rather than a SG.

If my battery monitor fails, I will surely get a new ammeter rather than an SG. Maybe I am a muppet?

Yes it isn’t perfect. Yes the same can be achieved with an ammeter and voltmeter and an ability to switch off loads on a whim to be able to check the rested voltage. The same can also be achieved by measuring the specific gravity of the cells. But all these things are a hassle compared to jus pressing a button and seeing a number that is a pretty good - though not perfect - measure of SoC.

It purely depends on whether £160 (or £110) is a significant amount for you, or whether it’s a trivial amount to give the convenience mentioned. Whether you are confused between volts, amps, amp hours etc and don’t really understand the difference between A, AH, SoC etc and can’t be bothered to learn. Whereas you do understand a simple display of %.

As to its accuracy, it is accurate to within 5% during discharge. That doesn’t mean it is always 5% out, sometimes it will be spot on, mostly it will be within 3% or so, and rarely it will be 5% out.

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

Sticking with accuracy, it’s key attribute is that its errors are not cumulative, in other words whilst it may be 5% out from time to time, the errors tend to self-correct. Compare this with an AH counting gauge that integrates current, isn’t sure of the instantaneous charge efficiency factor, and thus suffers from integration errors. If you know anything about integration you will know that over time, errors can increase without limit. The saving grace of an AHcounter is that its errors can be reset under one known condition - when the batteries are fully charged as indicated by low tail current under charging voltage. Fine if you routinely get there, not fine if you don’t. And anyway, it is reporting the SoC relative to a notional capacity. It has no idea what the actual capacity is.

For me, who does know something about A, AH, V etc, I still find it a convenient and instantaneous means of determining the actual SoC within a reasonable accuracy. If it say 80% I don’t really care if it’s actually 83% or 77% and anyway, there is no other feasible way to get the value with greater accuracy.

People who “dis” it tend either to not have one, to have it badly installed, incorrectly calibrated (not their fault) or some other issue with their charging system /batteries that the SG is telling them, but they are in denial about.

48 minutes ago, alan_fincher said:

Not really so.
 

The jury is still out for me.

In my current situation, I don't think, (indeed I sincerely hope!) mine isn't telling me the truth.

However I'm not exactly minded to run my bank below 75% for no other purpose than trying to get the SmartGauge to tell me something more accurate.

OK, I'm on a mooring on a land-line at the moment, but if I do get regular boating again, I'd still actually prefer never to be taking the bank below an indicated 75%, unless stopping somewhere for multiple days, (unusual for us).

If the device can't learn your actual situation unless you do this, then it is significantly less useful than I might have hoped when buying.

At the moment I'm ignoring it, because I hope the fact it indicates my charger can never take the bank above about 90% without going into a very slow trickle charge float is a lie.

But you installed it when the batteries were fully charged. You didn’t set the SoC to 100% as per the instructions, you lazily left it at 75%. You haven’t cycled the batteries yet so it has no real chance of getting itself into sync. Apparently it doesn’t make coffee either, so clearly it’s completely useless.

[Dr Bob]

11 minutes ago, nicknorman said:

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

For me, who does know something about A, AH, V etc, I still find it a convenient and instantaneous means of determining the actual SoC within a reasonable accuracy. If it say 80% I don’t really care if it’s actually 83% or 77% and anyway, there is no other feasible way to get the value with greater accuracy.

People who “dis” it tend either to not have one, to have it badly installed, incorrectly calibrated (not their fault) or some other issue with their charging system /batteries that the SG is telling them, but they are in denial about.

Other method to greater accuracy? I think it is clear from my post that V and A in/out is better for the same price.

I find V & A very convenient. I look at the V, I look at the A and I can in less than a second compute in my head whether I am happy or not. Once you get in the habit of looking at data, it is very quick. If you want to manage your batteries, you need an ammeter. Why invest in something that tells you nothing more?

11 minutes ago, nicknorman said:

... in other words whilst it may be 5% out from time to time....

The marketing blurb says "it remains highly accurate". 5% out is not highly accurate. I fully agree you dont need to be that accurate for this application but it is totally misleading to say 'remains highly accurate'.

Edited November 6, 2017 by Dr Bob

[Dr Bob]

48 minutes ago, smileypete said:

Having a quick google last night on something related I found some more Smartguage skepticism on a lumpy water site:

http://www.cruisersforum.com/forums/f14/smartgauge-real-life-experience-170104.html

I come from a lumpy water background. That link is typical of posts on the ybw forum as well (although there are may SG supporters there).

[koukouvagia]

1 hour ago, Dr Bob said:

Bear with me. Split us up into 2 groups. The first who know how to manage batteries. The second who dont.

I think there’s a sub-group to your first group (and I include myself in this): those who rely on a voltmeter and an ammeter and a table which relates voltage to percentage charged, but who don’t really understand the arcane art and all the minutiae of battery management. Empirically I know that I need to turn the fridge off at night; I have LEDs everywhere, I don’t allow daughter in law to use things like hair straighteners etc. and we can never bother setting up the TV when we’re travelling. I keep the charger on all the time I’m on the mooring and have found that a day’s boating when we’re out will keep the batteries charged. I know I need to wait a while after charging before I note the voltage but I certainly don’t worry about SoC etc. I’ll just get new batteries when the present ones give up the ghost.

I must be doing something right since my last lot of batteries lasted seven years – and they we very ordinary ones.

[WotEver]

11 hours ago, smileypete said:

Me too possibly but it doesn't invalidate the point to Tony that a fixed level of 1% may not cover all situations well enough.

I’ve never suggested that it did. Only in the example of Nick’s installation which you posted. 

I have always said aim for 2% or less (at absorption voltage of course). Check it after 30-45 mins and if it’s reasonably stable stop wasting fuel. If you can’t get that low then start saving up for new Batteries. 

[WotEver]

1 hour ago, smileypete said:

Having a quick google last night on something related I found some more Smartguage skepticism on a lumpy water site:

http://www.cruisersforum.com/forums/f14/smartgauge-real-life-experience-170104.html

Someone else who hasn’t read the manual. He writes that he bought the SmartGauge to tell him when to stop charging. He should have bought a five quid ammeter instead. 

[alan_fincher]

33 minutes ago, nicknorman said:

But you installed it when the batteries were fully charged. You didn’t set the SoC to 100% as per the instructions, you lazily left it at 75%. You haven’t cycled the batteries yet so it has no real chance of getting itself into sync. Apparently it doesn’t make coffee either, so clearly it’s completely useless.

How do/can I know the batteries were 100% charge when I installed it?

[smileypete]

6 minutes ago, WotEver said:

I’ve never suggested that it did. Only in the example of Nick’s installation which you posted. 

I have always said aim for 2% or less (at absorption voltage of course). Check it after 30-45 mins and if it’s reasonably stable stop wasting fuel. If you can’t get that low then start saving up for new Batteries. 

OK then what's your definition of 'reasonably stable'?

[WotEver]

1 minute ago, smileypete said:

OK then what's your definition of 'reasonably stable'?

From 2% to 1.9% is pretty stable

[Dr Bob]

A question.

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

[smileypete]

11 minutes ago, WotEver said:

From 2% to 1.9% is pretty stable

So you're looking for a fall of a tenth over one hour...

[cereal tiller]

10 minutes ago, alan_fincher said:

How do/can I know the batteries were 100% charge when I installed it?

Had to disconnect the Smartgauge recently during Maintenance,did not get around to resetting it .

After reconnection it read 75%,(at that time the Batteries were definitely 100%),the next morning it had reset itself to 100%(Boat was on Shore charge)

 

 

The SG Does learn battery behaviour, just allow it time to do so.

[WotEver]

Just now, smileypete said:

So you're looking for a fall of a tenth over one hour...

I’m not looking to put a figure on it at all, that’s what you’re doing. 

I think it’ll be pretty obvious to anyone when the reduction has slowed down so much that it’s not worth using any more fuel. 

[Richard10002]

1 hour ago, WotEver said:

Someone else who hasn’t read the manual. He writes that he bought the SmartGauge to tell him when to stop charging. He should have bought a five quid ammeter instead. 

I fell into exactly the same trap. Having spent a few years with a NASA BM2, watching tail current, and resetting the Ah counter when "full", I was also reading on a regular basis, (both here and elsewhere), that the Smartgauge is a simple fuel gauge which could tell you the SoC at a glance. If I had looked hard, I may have discovered the truth, but nothing dissuaded me of my perception over 2 or 3 years of interest in it.

I didn't read the manual before buying it and, after fitting it, I read enough of the manual to get it going, not reaching page 30 - RTFM you might say, and you would be right, except that, Who Does?? I didn't actually read the whole of the manualuntil I read MtBs battery destruction saga and discovery.

I didn't choose a Smartgauge over an Ammeter/Ah monitor, (I actually did the opposite). I just liked the idea of glancing at it and knowing my SoC, particularly when it was down to 50%, and I should definitely start charging, and when it was at 100%, so I could stop charging. I still checked tail current from time to time, so my battery killing tendency probably wasn't wholly due to the Smartgauge.

I agree in part with NN.

It doesnt matter if it isn't accurate when reading 50% or so - even if 5% out, it's good enough to give a guide as to when you ought to start charging.

It doesnt matter too much if it's wholly inaccurate down to about 80% SoC... as somebody quoted Gibbo as saying, "Who Cares?".

It matters a lot if it reads 100% hours before the batteries would be deemed full, (enough), by the tail current method, as this can cause a situation where sulphation is allowed to build up, and batteries lose capacity long before they should do.

If all Smartgauges were as accurate as NNs Smartgauge, there would be no need for warnings of any kind, and no need for the paragraph on page 30 of the manual.

In an honourable world, there ought to be a warning in a prominent place on all marketing material that Smartgauge should not be used to tell you that your batteries are full.... rather than it being stated but "hidden" on page 30 of a small print manual.

ETA - I paid £125 for my Smartgauge a few years ago.

Edited November 6, 2017 by Richard10002

[nicknorman]

1 hour ago, alan_fincher said:

How do/can I know the batteries were 100% charge when I installed it?

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.

[nicknorman]

1 hour ago, Dr Bob said:

Other method to greater accuracy? I think it is clear from my post that V and A in/out is better for the same price.

I find V & A very convenient. I look at the V, I look at the A and I can in less than a second compute in my head whether I am happy or not. Once you get in the habit of looking at data, it is very quick. If you want to manage your batteries, you need an ammeter. Why invest in something that tells you nothing more?

The marketing blurb says "it remains highly accurate". 5% out is not highly accurate. I fully agree you dont need to be that accurate for this application but it is totally misleading to say 'remains highly accurate'.

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.

[Iain_S]

2 hours ago, alan_fincher said:

(snip)

At the moment I'm ignoring it, because I hope the fact it indicates my charger can never take the bank above about 90% without going into a very slow trickle charge float is a lie.

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!

[nicknorman]

33 minutes ago, Richard10002 said:

I fell into exactly the same trap. Having spent a few years with a NASA BM2, watching tail current, and resetting the Ah counter when "full", I was also reading on a regular basis, (both here and elsewhere), that the Smartgauge is a simple fuel gauge which could tell you the SoC at a glance. If I had looked hard, I may have discovered the truth, but nothing dissuaded me of my perception over 2 or 3 years of interest in it.

I didn't read the manual before buying it and, after fitting it, I read enough of the manual to get it going, not reaching page 30 - RTFM you might say, and you would be right, except that, Who Does?? I didn't actually read the whole of the manualuntil I read MtBs battery destruction saga and discovery.

I didn't choose a Smartgauge over an Ammeter/Ah monitor, (I actually did the opposite). I just liked the idea of glancing at it and knowing my SoC, particularly when it was down to 50%, and I should definitely start charging, and when it was at 100%, so I could stop charging. I still checked tail current from time to time, so my battery killing tendency probably wasn't wholly due to the Smartgauge.

I agree in part with NN.

It doesnt matter if it isn't accurate when reading 50% or so - even if 5% out, it's good enough to give a guide as to when you ought to start charging.

It doesnt matter too much if it's wholly inaccurate down to about 80% SoC... as somebody quoted Gibbo as saying, "Who Cares?".

It matters a lot if it reads 100% hours before the batteries would be deemed full, (enough), by the tail current method, as this can cause a situation where sulphation is allowed to build up, and batteries lose capacity long before they should do.

If all Smartgauges were as accurate as NNs Smartgauge, there would be no need for warnings of any kind, and no need for the paragraph on page 30 of the manual.

In an honourable world, there ought to be a warning in a prominent place on all marketing material that Smartgauge should not be used to tell you that your batteries are full.... rather than it being stated but "hidden" on page 30 of a small print manual.

ETA - I paid £125 for my Smartgauge a few years ago.

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.

[GUMPY]

1 hour ago, Dr Bob said:

A question.

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

Me and I know I  have managed my batteries well for the last 25 years.

I did have one of the first smart gauges and have one ever since. The secret is not to be a towpath shuffler but to actually go boating. Before I had solar I was limited to a one day stop, now with 400w it's a couple or three at a push. It's more about understanding how your system works than about meters