Newbie...Trojan t105

[WotEver]

You have to admit the message for the newbie dummies is rather complex.

 

"Rely on the smartgauge - easy and simple to install and works just like a fuel gauge.

 

Oh except when you are charging, in which case you'll need to install an ammeter complete with shunt and a bit of hefty battery cable rewiring. Then keep an eye on it and when the tail current gets down towards 4%, or perhaps 2% or 1% depending on who is advising you, you're fully charged. Got that? Good!

 

Oh and another thing. When the smartgauge gets down to 50% you're empty. Obviously.

 

That's the one. Pin it!

[nicknorman]

You have to admit the message for the newbie dummies is rather complex.

"Rely on the smartgauge - easy and simple to install and works just like a fuel gauge.

Oh except when you are charging, in which case you'll need to install an ammeter complete with shunt and a bit of hefty battery cable rewiring. Then keep an eye on it and when the tail current gets down towards 4%, or perhaps 2% or 1% depending on who is advising you, you're fully charged. Got that? Good!

Oh and another thing. When the smartgauge gets down to 50% you're empty. Obviously.

I think you are forgetting that the alternative / previous state was zilch. The SG isn't perfect as we all know, and there are better devices at a cost or to be used in conjunction with a SG. But it comes back to the fact that an SG is reasonably priced, easy to install, easy to use and far better than nothing.

 

Oh and no, when the SG reads 50% you are not empty. It depends on th particular type of battery. At the worst, you are on reserve. At best, you have plenty to go. Trojans for instance give the best overall life when discharged to 40% SoC*. Proper deep cycle batteries probably lower.

 

*although it may depend on usage pattern - leaving them at a low SoC for long periods is probably detrimental.

Edited February 9, 2017 by nicknorman

[MtB]

Ok, when you get to 40% you're empty. Or nearly. Possibly.

 

Let's try to keep the message simple.

[WotEver]

Let's try to keep the message simple.

Fit a SmartGauge. Recharge when it reads 50%. Stop charging two hours after it says 100%.

 

Is it perfect? Absolutely not.

Is it simple? Yes.

Is it a vast improvement on charging for a couple of hours when the lights go dim...?

[MtB]

Or....

 

Fit a Smartgauge. It works just like a fuel gauge.

 

Except that... You must recharge before it says empty and carry on charging after it says full.

 

Very useful!

[rowland al]

Many thanks. Any help is so thankful. I will pop some pictures of what I have done to the boat on here.

Have you checked all of the battery connections are nice and tight yet?

[Gareth E]

I've never owned one but it seems to me, from reading this thread and others, that the Smartguage is a waste of money. The only benefit over a 3 quid voltmeter from China is that it disregards loads. With the cheapo though, you soon learn what loads reduce the voltage and by how much, so it does the same job.

[Richard10002]

Who are these 'experts' who recommend a SmartGauge without simultaneously mentioning an ammeter?

 

I don't know off the top of my head, but it's a message I recall many times from different people over the years.

 

My response was that, given the choice, I bought a NASA BM2, on the basis that i wanted to see instantaneous and cumulative amps.

 

Eventually I bought a Smartguage so as to have the best of both worlds, which was when I discovered its imperfections. I actually wondered if this was why Gibbo got upset with people eventually leaving, for some reason... but the manual is quite clear on what it shouldn't be used for... (a fuel gauge? ).

 

You could do some kind of search if you really want to know - I cant be bothered.

[Leon 12]

hi Rowland, removed all connections and cleaned followed by making sure all connections were good. When it comes to any equipment regardless of the purpose you shouldn't have to second guess it. if I buy a kettle and it don't boil at 100c then its not doing its job. The smartgauage website needs to be updated to these shortcomings. The BMV may fall sWort over time but at least it can give you more relevant info. I understand that over time it falls out but the smartgauge falls out before which to me is worse. what I need is info of going in. when I drop to 12.26 volts I recharge. people at Trojan said I could go to 12.00 volts but I don't want to run genny for 5 hours plus.....

[rowland al]

hi Rowland, removed all connections and cleaned followed by making sure all connections were good. When it comes to any equipment regardless of the purpose you shouldn't have to second guess it. if I buy a kettle and it don't boil at 100c then its not doing its job. The smartgauage website needs to be updated to these shortcomings. The BMV may fall sWort over time but at least it can give you more relevant info. I understand that over time it falls out but the smartgauge falls out before which to me is worse. what I need is info of going in. when I drop to 12.26 volts I recharge. people at Trojan said I could go to 12.00 volts but I don't want to run genny for 5 hours plus.....

Since doing that, and the other things you have tried, have you had a chance to see if it's made any improvement yet.

 

It does seem your usage is quite low (LED lights and a bit of TV). Similar to mine. It does make you wonder whether the Trojans suffered from being discharged after long storage.

 

You could try just runnung off 2 new batteries for a while to see of that makes an improvement. It works well for me. At least it's cheaper than buying 6 again. They will also reach a near 100% charged state quicker with less charging.

[MtB]

 

I don't know off the top of my head, but it's a message I recall many times from different people over the years.

 

My response was that, given the choice, I bought a NASA BM2, on the basis that i wanted to see instantaneous and cumulative amps.

 

 

The thing is, neither the Smartgauge nor the BM2 really gives you accurate information. Cumulative amphours out are not balanced by cumulative amphours in. And the state of charge displayed by the Smartgauge during charging cannot be relied upon according to the manual, in which case why display it?

 

The thing is, naive users approach batteries as though they are like a bucket. They expect to be able to keep track of battery charge status by counting out the AH, then counting them back in during charging. It doesn't really work like that as some of the AH in get consumed turning into hydrogen and oxygen and it varies according to how the charging is being done so you don't really know how many. Once they figure this out they then get seduced into thinking the Smartgauge is the answer.

 

AH counters like the BM2 need the user to interprete the data they capture and draw conclusions. The Smartgauge has been widely promoted on here as the better answer for battery monitoring but it too needs interpreting. I ended up with badly sulphated nearly new Trojan clones simply by assuming the Smartgauge would be roughly right when it said 100% charged, but on fitting my ammeter discovered it was WAY out, which is why I'm so pished off with it.

 

In addition the battery voltage my Smartgauge displays is wrong too. It displays 0.3V higher than every other instrument I use to check battery voltage (The BMV702, the Tracer, each of my several handheld multimeters). Now I know, I mentally adjust for it.

 

So in summary the info from both the Smartgauge and AH counters needs evaluating, interpreting and taking with a pinch of salt, despite what the marketing blurb might tell you.

[bizzard]

I've never owned one but it seems to me, from reading this thread and others, that the Smartguage is a waste of money. The only benefit over a 3 quid voltmeter from China is that it disregards loads. With the cheapo though, you soon learn what loads reduce the voltage and by how much, so it does the same job.

Hear, hear.

[WotEver]

... the battery voltage my Smartgauge displays is wrong too. It displays 0.3V higher than every other instrument I use to check battery voltage...

You've mentioned this before - why haven't you sent it back for recalibration or replacement? It's broken.

 

High voltage readings will result in a SoC reading that is higher than reality, which is your complaint.

 

"I have a broken kettle. It switches off before the water boils. Therefore all kettles are rubbish"

 

I've never owned one but it seems to me, from reading this thread and others, that the Smartguage is a waste of money. The only benefit over a 3 quid voltmeter from China is that it disregards loads. With the cheapo though, you soon learn what loads reduce the voltage and by how much, so it does the same job.

Yup, it's not aimed at you

If I told my wife to keep an eye on the voltage and start charging once it gets close to 12.2V but not if the TV is on, and if she's charging a laptop that might depress the voltage as well... her eyes would have glazed over before I was half way through the sentence.

 

edited for typos

Edited February 10, 2017 by WotEver

[WotEver]

 

Or....

 

Fit a Smartgauge. It works just like a fuel gauge.

 

Except that... You must recharge before it says empty

Yep, but there's no 'exception'. At what SoC to start charging is down to the battery chemistry, build quality and your choice. You might decide to never go below 70%, or you might like to exercise your traction batteries and take them down to 20% occasionally - the fuel gauge allows to to make that decision simply and quickly. As long as you don't have a broken one of course.

[MtB]

You've mentioned this before - why haven't you sent it back for recalibration or replacement? It's broken.

 

 

Must be nice to live in a world of black and white. It's not 'broken', its slightly out of calibration. I know how to fix it but I have better things to do with my time.

 

Actually I have another still in its box, bought about the same time as this one. Perhaps I'll plug that it and see how it fares. Will be interesting to see if this one also reads 0.3v high!

[WotEver]

Must be nice to live in a world of black and white. It's not 'broken', its slightly out of calibration. I know how to fix it but I have better things to do with my time.

Slightly? 0.3V on a 24V bank is a difference of >10% SoC. You know, like reading 100% when it's only at 90%.

 

I'm pleased that you have better things to do with your time than get your metering right.

[MtB]

Slightly? 0.3V on a 24V bank is a difference of >10% SoC. You know, like reading 100% when it's only at 90%.

 

I'm pleased that you have better things to do with your time than get your metering right.

 

 

I'll let you know if this other one is also broken, straight from the box.

[WotEver]

 

 

I'll let you know if this other one is also broken, straight from the box.

 

Please do, 'cos Gibbo had a right go at Merlin about it when Tommy had his broken one.

[MtB]

 

Please do, 'cos Gibbo had a right go at Merlin about it when Tommy had his broken one.

 

 

Ok. It will be a while, its in my other boat and I need to go and get it.

[Leon 12]

I find the bmv to be more accurate voltage wise, the SG just goes 12.55,12.60,1255,1260. Whilst the BMV gives a nice 12.67 or whatever it is. The tracer is always higher rounding up to the next ie...12.60.

I understand that more ah have to be replaced than used so now when it goes into float early I just turn the charger off and on again and it continues at absorbtion stage.

After doing the charge and equalization it is already showing signs of improvement. I will let the smartgauge run down to 69% and see how many amp hours were used....last time it was 58.5.

 

Voltage held true and good which im chuffed at too.

[WotEver]

I find the bmv to be more accurate voltage wise, the SG just goes 12.55,12.60,1255,1260. Whilst the BMV gives a nice 12.67 or whatever it is.

 

That would suggest that your Smartgauge is correctly calibrated. Just to be pedantic, that doesn't make the BMV 'more accurate' simply that it has a 'higher resolution'.

[MtB]

I find the bmv to be more accurate voltage wise, the SG just goes 12.55,12.60,1255,1260. Whilst the BMV gives a nice 12.67 or whatever it is. The tracer is always higher rounding up to the next ie...12.60.

 

 

That's interesting. Mine flutters about too. Its currently displaying 24.10v, 24.20v, and 24.30v. Mostly 24.20v.

 

The BMV reads a rock steady 23.96v.

[WotEver]

 

 

That's interesting. Mine flutters about too. Its currently displaying 24.10v, 24.20v, and 24.30v. Mostly 24.20v.

 

The BMV reads a rock steady 23.96v.

 

If the voltage is 23.98 then I would expect Smartgauge to display 24.00 most of the time with perhaps the occasional flick down to 23.90. With yours reading a consistent 0.3V high then that would be a reading of 24.20/24.30. If it's also sometimes reading 23.10 then that suggests even more that it's faulty.

 

To explain, on a 12V system it counts in increments of 0.05V. So 12.68 is higher than 12.65 but less than 12.70, so a voltage of 12.68 will result in a voltage reading which will alternate between those two figures to let you know that the voltage is higher than 12.65 but less than 12.70. As the voltage increases to 12.69V then Smartgauge will spend more time reading 12.70 with only the occasional flick down to 12.65. It should NEVER display 12.60, which is effectively what yours is doing.

[Richard10002]

I actually like the Smartguage for its simplicity. But I had a NASA BM2 first and was fully aware of tail currents, along with the fact that some of the Ah shown during charging are used to create heat and convert water into gases.

 

Generally, when my cumulative Ah reach zero, the current is higher than my desired tail current. I therefore wait until the tail current gets low enough, and zero the Ah display.

 

It's not rocket science when you have an idea of how these things work but, as said above, if I were to leave my wife on board for a week or so, I would have to leave a simple set of instructions for battery useage and charging.

 

e.g. when the Smartguage shows 50% or a bit less, start charging. When the NASA BM2 shows the current being drawn as 4A or less, (or it gets to 8pm), stop charging.

[WotEver]

It's not rocket science when you have an idea of how these things work but, as said above, if I were to leave my wife on board for a week or so, I would have to leave a simple set of instructions for battery useage and charging.

 

e.g. when the Smartguage shows 50% or a bit less, start charging. When the NASA BM2 shows the current being drawn as 4A or less, (or it gets to 8pm), stop charging.

 

Absolutely, and Gibbo actually designed it because his wife wanted something simple like a fuel gauge that she could read easily so that she could start charging when the batteries were half full.