battery monitoring

[peterboat]

loafer i do not fill it very often its a 1 litre container that lives with the whispergen. i do not drain it down for winter either as the whispergen is on twice daily it warms the engine space up. as yet its not frozen but i suppose there will be a first time. i have 900 watts of solar on the roof so charging always happens on sunny days but on winter days the whispergen comes on twice daily for one and a half hours producing 72 amps per hour. if the batteries get above a certain point the whispergen ramps down the current. also i can set the whispergen to auto charge to make sure the batteries are well charged. i also take the boat out which means the 160 amp alternator does its stuff. i am not paranoid about charging and it seems to have worked

 

 

How often do you have to top up the header tank thingy? And closely allied to that, what is your charging regime? Just interested mate.

 

 

 

Simple answer Yes. You drain it for the winter

[WotEver]

Anyway to sum up I'd say the "experiment" (it wasn't really an experiment, just a report) was a success as it shows there is no clear answer. If there were a clear answer we would have nothing left to talk about!

 

Nicely done, Nick

 

However, I think that all you've shown (I can't say "proved" as you'd have to do hundreds of tests under varying conditions with a range of batteries of different types and condition to begin to 'prove' anything) is basically what we already knew.

 

Smartgauge will perform within its stated accuracy and when it experiences an 'unusual' event will learn from its experience. It gets more accurate with use. It is the best all-round tool for showing the battery's SoC. It shouldn't be used for determining when to stop charging.

 

An Ah counter, when all of the battery parameters are correctly entered, can accurately track the discharge curve of a bank. If the bank is not then recharged to 100% as determined by the monitor it will then almost certainly show an error in the calculated SoC which is cumulative over successive cycles. Its indicated SoC therefore gets less accurate with use. It is a good device to decide when to stop charging.

 

An Ammeter (depending on where it is positioned) can show charging current and discharge current. It's cheap and is the best tool for determining when to stop charging (because it is cheap).

 

The conclusions from the above are again what we already knew - a Smartgauge coupled with an ammeter are the best tools for an 'electrically naive' boater. An Ah Counter can give loads more information to the more technically minded boater but will give highly misleading results in the hands of the less experienced.

 

Tony

[WotEver]

... on winter days the whispergen comes on twice daily for one and a half hours producing 72 amps per hour.

 

I'm not being pedantic for the sake of it, but the above demonstrates the importance of correct terminology. Do you mean that the Whispergen generates (2 x 1.5 hours = 3 hours) at 72A, so a total of 216Ah? Or do you mean that over the space of the 3 hours it generates a total of 72Ah?

 

Tony

[nicknorman]

Nicely done, Nick

 

However, I think that all you've shown (I can't say "proved" as you'd have to do hundreds of tests under varying conditions with a range of batteries of different types and condition to begin to 'prove' anything) is basically what we already knew.

 

Smartgauge will perform within its stated accuracy and when it experiences an 'unusual' event will learn from its experience. It gets more accurate with use. It is the best all-round tool for showing the battery's SoC. It shouldn't be used for determining when to stop charging.

 

An Ah counter, when all of the battery parameters are correctly entered, can accurately track the discharge curve of a bank. If the bank is not then recharged to 100% as determined by the monitor it will then almost certainly show an error in the calculated SoC which is cumulative over successive cycles. Its indicated SoC therefore gets less accurate with use. It is a good device to decide when to stop charging.

 

An Ammeter (depending on where it is positioned) can show charging current and discharge current. It's cheap and is the best tool for determining when to stop charging (because it is cheap).

 

The conclusions from the above are again what we already knew - a Smartgauge coupled with an ammeter are the best tools for an 'electrically naive' boater. An Ah Counter can give loads more information to the more technically minded boater but will give highly misleading results in the hands of the less experienced.

 

Tony

Sure, its what we thought, but it doesn't hurt to demonstrate it practically. Anyway I'm retired and have nothing better to do!

 

My only disagreement with your comments above is where you say "shouldn't be used for determining when to stop charging". I'd say that whilst it is imprecise in this area, since there is no agreement about when one should stop charging, that it's reading is "close enough for government work". Certainly better than, for example, the folk who come on here and report that they stop charging once the charging voltage stabilises.

Edited January 27, 2016 by nicknorman

[Graham.m]

Smartgauge will perform within its stated accuracy and when it experiences an 'unusual' event will learn from its experience. It gets more accurate with use. It is the best all-round tool for showing the battery's SoC. It shouldn't be used for determining when to stop charging.

 

 

I am sorry I do not think that you can say that. The experiment without backup references and by being stopped at the point that that the sgauge reached 100% did not prove any accuracy in any phase of it. Neither you could say the Ahgauge used did not meet the requirements to show a reasonable level of accuracy whilst charging and discharging.

[nicknorman]

Oh and just to mention that I realise that I have a PC interface for the Masterbus and so I can set the laptop up to log and graph such parameters as charging current and MS SoC. I'll do that sometime (it will give smoother curves with less hassle for me) if I am still bored when next on the boat! I think it will be interesting to see the shape of the curve as it approaches zero / the minimum value and work out how many AH the last few % of tail current actually adds. That is if we can make the assumption that the final minimum represents the gassing current, the rest of the current goes to adding AH.

[Graham.m]

 

I'm not being pedantic for the sake of it, but the above demonstrates the importance of correct terminology. Do you mean that the Whispergen generates (2 x 1.5 hours = 3 hours) at 72A, so a total of 216Ah? Or do you mean that over the space of the 3 hours it generates a total of 72Ah?

 

Tony

 

Well interesting I think you are being pedantic, the poster wrote quite plainly the Whispergen produces 72 Amp per hour. Now if that continues for two hour that can only be 144Ahs

[WotEver]

Sure, its what we thought, but it doesn't hurt to demonstrate it practically. Anyway I'm retired and have nothing better to do!

 

Absolutely, it's your time

 

Of course, what most of us who've been on this forum long enough to remember Gibbo already 'know' won't be shared by some who refuse to accept reality.

 

Tony

[nicknorman]

Well interesting I think you are being pedantic, the poster wrote quite plainly the Whispergen produces 72 Amp per hour. Now if that continues for two hour that can only be 144Ahs

No, it is ambiguous and confusing since "72 amps per hour" is meaningless in this context, just as reporting one's speed along the cut as "3 miles per hour per hour" which is exactly the same error. If you are prepared to tolerate / think it is helpful not to correct the wrong use of units, where should it stop? Are we happy to be tacit about someone saying amps when they meant volts, even if it seems obvious what was intended? Ultimately it does the poster no favours.

 

In the same way I used to think that "its" was short for it is and "it's" was the possessive. Finally someone pointed it out and I was grateful because now I know the difference and take trouble to (usually) get it right.

[Graham.m]

Oh and just to mention that I realise that I have a PC interface for the Masterbus and so I can set the laptop up to log and graph such parameters as charging current and MS SoC. I'll do that sometime (it will give smoother curves with less hassle for me) if I am still bored when next on the boat! I think it will be interesting to see the shape of the curve as it approaches zero / the minimum value and work out how many AH the last few % of tail current actually adds. That is if we can make the assumption that the final minimum represents the gassing current, the rest of the current goes to adding AH.

 

I think that the amount energy input into a battery that gets used by the gassing process is often under estimated. I have often thought this is why a lot of chargers switch to float thus using a lower voltage which reduces or stops the gassing and that energy use.

[WotEver]

No, it is ambiguous and confusing since "72 amps per hour" is meaningless in this context, just as reporting one's speed along the cut as "3 miles per hour per hour" which is exactly the same error. If you are prepared to tolerate / think it is helpful not to correct the wrong use of units, where should it stop? Are we happy to be tacit about someone saying amps when they meant volts, even if it seems obvious what was intended? Ultimately it does the poster no favours.

 

Yep, I only posted because it confused me. I thought "Does he mean a total of 72Ah, or a total of 216Ah?" So I asked the question.

 

Tony

[nicknorman]

I think that the amount energy input into a battery that gets used by the gassing process is often under estimated. I have often thought this is why a lot of chargers switch to float thus using a lower voltage which reduces or stops the gassing and that energy use.

Do you think that near the end of the charging process (say last 5% SoC), and presuming a fixed voltage, the gassing remains the same, or increases, or decreases?

[peterboat]

Well all know now what he means just like we did about 6 posts ago. cant we let it go now or is the plan to jar every one off so the dont post

cheers, just stopped tiling now cleaning up. then pick up the better half and go to see strictly at sheffield does life get better.

[nicknorman]

cheers, just stopped tiling now cleaning up. then pick up the better half and go to see strictly at sheffield does life get better.

Aha now you're talking. We went to strictly last Sat in Brum. It's always a good night but I have say I was disappointed with Mel's compèring skills. Normally she is great on telly but not that night. Hopfully she will have improved with practice.

[peterboat]

Aha now you're talking. We went to strictly last Sat in Brum. It's always a good night but I have say I was disappointed with Mel's compèring skills. Normally she is great on telly but not that night. Hopfully she will have improved with practice.

we went to sheffield last year it was very good. i have a couple of celeb friends who could get free tickets to the real thing, and take us with them, would you believe they dont like strictly miserable sods

[Theo]

That is why I generally now simply ignore a certain poster.

 

Tony

Difficult one this. If a poster is posting misleading information/rubbish/tripe/dangerous nonsense then is it better to correc than to ignore lest less knowledgeable members are led from the paths of wisdom.

 

Nick

[WotEver]

we went to sheffield last year it was very good. i have a couple of celeb friends who could get free tickets to the real thing, and take us with them, would you believe they dont like strictly miserable sods

I can get free tickets to SCD too but we don't like it either, sorry

[nicknorman]

Bloody 'ell, cost us £45 each for crap seats. Mind you, Jeff was paying!

[WotEver]

I did use tickets to Dancing On Ice though a few years back.

[peterboat]

Bloody 'ell, cost us £45 each for crap seats. Mind you, Jeff was paying!

snap jayne is paying, i think our seats are fairly good but you know what thought did

[Tony Brooks]

Difficult one this. If a poster is posting misleading information/rubbish/tripe/dangerous nonsense then it is better to correc than to ignore lest less knowledgeable members are led from the paths of wisdom.

 

Nick

 

In this case both people posted what I consider suitably correct replies (109 & 110). The first was, again in my view, a perfectly acceptable statement for the majority of site users. The second was also technically correct BUT was likely to be misleading. It almost seemed as if my posts trying to clarify the apparent contradiction was of the nit picking over language variety as beloved here in certain topics rather than practical substance.

 

I find that I am getting this feeling more and more when I try to clarify a statement I think is misleading or just plain wrong.

 

The problem is how a newish member can easily find out who is likely to be correct, who is likely to be misinformed or lack experience and who really is nit picking.

[Theo]

 

In this case both people posted what I consider suitably correct replies (109 & 110). The first was, again in my view, a perfectly acceptable statement for the majority of site users. The second was also technically correct BUT was likely to be misleading. It almost seemed as if my posts trying to clarify the apparent contradiction was of the nit picking over language variety as beloved here in certain topics rather than practical substance.

 

I find that I am getting this feeling more and more when I try to clarify a statement I think is misleading or just plain wrong.

 

The problem is how a newish member can easily find out who is likely to be correct, who is likely to be misinformed or lack experience and who really is nit picking.

 

I hear what you are saying, Tony.

 

N

[WotEver]

As TC says an ammeter and a good voltmeter will do the job far more economically than the sgauge

More economically yes, but less accurately. A voltmeter whether good or bad isn't a tool that an unskilled person can use to estimate SoC under load.

 

Why not just throw everything out? That's even more economic.

 

Tony

[GUMPY]

As a skilled person I used to use a volt meter to estimate SoC, for a while I ran a prototype Smartgauge along side the VM it showed that I was overestimating discharge by some 15-20% so in fact my batteries never went below 65%.

Just me being cautious I suppose.

[WotEver]

As a skilled person I used to use a volt meter to estimate SoC, for a while I ran a prototype Smartgauge along side the VM it showed that I was overestimating discharge by some 15-20% so in fact my batteries never went below 65%.

Just me being cautious I suppose.

Better to be cautious than rash.

 

But yes, it proves my point that it's not easy to estimate on-load SoC with a voltmeter.

 

Tony