Newbie...Trojan t105

[Alan de Enfield]

At 11:30 the current was still dropping so they were probably not yet at 100%.

Ideally you should have retested at 12:30, and again at 13:30, .......repeat, until the current does not change.

 

I have 1300Ah (6x 230Ah) of batteries and charge until I get under 10 amps charge rate for over an hour, then consider them fully charged.

[Leon 12]

As others have said above the smartgauge is flawed. If you go by what it says during charge and in reality that is false ie ..out but then it rectifies during discharge then initially it's wrong whatever the final outcome is. No one wants to second guess something that tells them 100%. I am in no way putting smartgauge down but in my opinion it is a flawed piece of kit.

[Leon 12]

Surely temp affects gravity....so at 70 degrees it would be 12.75 however at lower temps specific gravity is lower but still fully charged. All specs are at lab conditions not in the real world my hydrometer said deduct 12 points for the temp it's at so that would indicate 12.63 fully charged. Am I wrong with this assumption. Trojan specs are at 80 degrees f. Deducting 0.004 for every 10 degree drop so today it was 10 degrees so at test it would mean 0.028 deduction in reading and that would be 100%.

[cuthound]

Virtually all lead acid batteries will increase signal in capacity over the first few charge/discharge cycles, because the plates are deliberately not fully formed during manufacture.

 

The Smartgauge is a clever voltmeter, it does not measure resistance.

 

As Phil says, specific gravity readings and charge voltages require adjusting for temperatures, most are specified at 25°C and compensation is required if the temperature is different from this.

[Leon 12]

1.277 for trojan batteries at 80 degrees

A clever voltmeter..........lol

[mrsmelly]

At 11:30 the current was still dropping so they were probably not yet at 100%.

Ideally you should have retested at 12:30, and again at 13:30, .......repeat, until the current does not change.

 

I have 1300Ah (6x 230Ah) of batteries and charge until I get under 10 amps charge rate for over an hour, then consider them fully charged.

 

1300 ah..............jeeeeeesus.............do you sell some off to the national grid? How much does a replacement set cost? My paltry 440ah feel all belittled and pathetic now bless em

[Alan de Enfield]

 

1300 ah..............jeeeeeesus.............do you sell some off to the national grid? How much does a replacement set cost? My paltry 440ah feel all belittled and pathetic now bless em

 

No - just means don't have to worry about moving every couple of days - also powers the microwave, toaster, freezer and fridge + all the usual 12v stuff) without worrying.

A good days run (12 hours) with twin alternators puts most of it back in and the Solar tops up the last bit.

 

230Ah batteries around £150 - £200 each

Decent brand around £200 but get £25+ each back from the scrap man.

 

http://www.ebay.co.uk/itm/lfd230-varta-625-230ah-deep-cycle-battery-930230115-2-yr-warranty-/122004814394?hash=item1c680dba3a:g:Cg4AAOSwQupXUVAM

 

Similar to mine but I have 'unsealed' ones that can be topped up.

[dmr]

The Smartgage is an instrument designed to show state of charge during discharge, and is, I think, most accurate towards to 50% point. It struggles a bit to be accurate immediately after a charge, but you would also struggle to do it manually by reading the off load voltage.

 

The state of charge approximation during charge should be seen as an added bonus rather than an indication that the instrument is flawed.

 

................Dave

[Phil.]

Surely temp affects gravity....so at 70 degrees it would be 12.75 however at lower temps specific gravity is lower but still fully charged. All specs are at lab conditions not in the real world my hydrometer said deduct 12 points for the temp it's at so that would indicate 12.63 fully charged. Am I wrong with this assumption. Trojan specs are at 80 degrees f. Deducting 0.004 for every 10 degree drop so today it was 10 degrees so at test it would mean 0.028 deduction in reading and that would be 100%.

Yes you are correct, the lower the temp the lower the specific gravity. It is the equalisation voltage that may be a bit low. For example, my solar charger is set to absorption at 14.8 volts. However in these lower temperatures it is actually charging during the absorption phase at 15.3 volts.(Temp. Compensated). I would think that to equalise the voltage should be up towards 16 volts or just over depending on what temp your batteries where at.

 

 

Edit to add.... having just looked at the Trojan info, it seems equalisation should be at 16.2 volts so definitely on the low side.

 

http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf

Edited February 9, 2017 by Phil.

[Leon 12]

I have altered the tracer to compensate for temp and what trojan states but until I can find a suitable charger, one that I can input charge voltages I am kinda stuck. The sterling inverter charger on lead acid setting is 14.813.3 and 15.5 in equalization mode. Are there any other brands that let you use a user setting?

[nicknorman]

Yes you are correct, the lower the temp the lower the specific gravity. It is the equalisation voltage that may be a bit low. For example, my solar charger is set to absorption at 14.8 volts. However in these lower temperatures it is actually charging during the absorption phase at 15.3 volts.(Temp. Compensated). I would think that to equalise the voltage should be up towards 16 volts or just over depending on what temp your batteries where at.

Edit to add.... having just looked at the Trojan info, it seems equalisation should be at 16.2 volts so definitely on the low side.http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf

No, the specific gravity for a given SoC will be higher at lower temperature. But it is a little confusing since when you take the gravity of a cell at low temperature, you have to subtract the compensating value to get what the gravity would have been at 25C or whatever.

[WotEver]

The Smartgage is an instrument designed to show state of charge during discharge, and is, I think, most accurate towards to 50% point. It struggles a bit to be accurate immediately after a charge, but you would also struggle to do it manually by reading the off load voltage.

 

The state of charge approximation during charge should be seen as an added bonus rather than an indication that the instrument is flawed.

 

................Dave

^^^^ this.

 

SmartGauge should not be used to accurately indicate SoC when charging. The documentation states that clearly yet folk still do it.

[nicknorman]

As others have said above the smartgauge is flawed. If you go by what it says during charge and in reality that is false ie ..out but then it rectifies during discharge then initially it's wrong whatever the final outcome is. No one wants to second guess something that tells them 100%. I am in no way putting smartgauge down but in my opinion it is a flawed piece of kit.

The Smartgauge is flawed. Every other type of device for measuring SoC is flawed. Smartgauge's flaws are minimal during discharge which is when the reading is most important - well I suppose fully charged is important too but there is no definition of 100% SoC so it's kind of hard to make a gauge that reads it! An ammeter to tell you when to stop charging, plus a Smartgauge, is a pretty good setup. Especially if the ammeter is in fact something like a BMV 700 series meter that shows you AH consumed as well - then you can easily see what capacity your batteries have. This is what you have, isn't it?

 

It is merely a question of working out the best way to interpret the information presented!

Edited February 9, 2017 by nicknorman

[WotEver]

I have altered the tracer to compensate for temp and what trojan states but until I can find a suitable charger, one that I can input charge voltages I am kinda stuck. The sterling inverter charger on lead acid setting is 14.813.3 and 15.5 in equalization mode. Are there any other brands that let you use a user setting?

You could (in these temperatures) use the Equalization setting as a 'standard' charge for your Trojans while you await a better charger. As a CCer you never want to feed them 13.3 unless they are already at 100%, and 14.8 is still a bit low.

[Leon 12]

Would that be ok to do so? Made me gulp

Hi nick, because of the nature of the Trojans with increasing capacity until its achieved I have no way of inputing the ah in the settings of the victron, I am gestimating the capacity. Which is pretty futile.

[nicknorman]

Would that be ok to do so? Made me gulp

I'm not familiar with the Sterling equalisation mode but the Mastervolt one is current-limited to about 15A IIRC.So you might have to charge at the normal voltage and then switch to equalisation voltage to finish off. But if the Sterling is capable of putting out 15.5v at high current you could go for it. The voltage probably won't actually rise to 15.5v until the current has subsided to a fairly low value anyway.

 

Presumably you've had a look at the Trojan user guide? Page 19 for charging voltages.

 

http://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf

Edited February 9, 2017 by nicknorman

[Leon 12]

On equalization mode it kept a steady 15.5 volts and 10 amps, would it still tail off as in normal charge mode.

[WotEver]

On equalization mode it kept a steady 15.5 volts and 10 amps, would it still tail off as in normal charge mode.

Yes. The batteries demand the current, not the charger (although of course the charger sets the maximum).

... I have no way of inputing the ah in the settings of the victron, I am gestimating the capacity. Which is pretty futile.

When you get the batteries nominally to 100% (it doesn't appear that you've yet done so) you can discharge to 50% on the SmartGauge and note Ah supplied to do so as indicated on the Ah counter. Multiply that by 2 and you have your capacity. Edited February 9, 2017 by WotEver

[Leon 12]

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

[nicknorman]

Yes. The batteries demand the current, not the charger (although of course the charger sets the maximum).

When you get the batteries nominally to 100% (it doesn't appear that you've yet done so) you can discharge to 50% on the SmartGauge and note Ah supplied to do so as indicated on the Ah counter. Multiply that by 2 and you have your capacity.

However from the sound of it, your batteries aren't yet properly "run in" so you'll need to repeat the process after more cycles as the capacity will increase. I still think they would benefit from a deep cycle down to 30% or so. Mine certainly did - they were rubbish when I first got them.

[MtB]

I think you are being a little unfair. It is not possible for a device that only measure voltage to be very accurate during charge, since it only "sees" the charger, not the battery voltage.

 

 

I don't think I'm being unfair at all. The Smartgauge is promoted as a battery monitor for dummies.

 

If it cannot determine the state of charge during charging it should say so on the display. "Indeterminate" perhaps.

 

It should not incorrectly, confidently and misleadingly say 100%, whilst burying the fact that 100% doesn't mean 100% somewhere in the manual (which few dummies will either have to hand, or read and understand).

Edited February 9, 2017 by Mike the Boilerman

[dmr]

 

 

I don't think I'm being unfair at all. The Smartgauge is promoted as a battery monitor for dummies.

 

If it cannot determine the state of charge during charging it should say so on the display. "Indeterminate" perhaps.

 

It should not incorrectly, confidently and misleadingly say 100%, whilst burying the fact that 100% doesn't mean 100% somewhere in the manual (which few dummies will either have to hand, or read and understand).

 

A good old rule of thumb for Liveaboards was "run the engine for two hours every day, and 8 hours on Saturday".

 

In my case 100% on the Smartgage usually corresponds to a little bit more than 2 hours so maybe this is what Gibbo was aiming at, and if it is an instrument for dummies then this would sort of make sense. This logic is a bit dodgy though because you would then have to charge to much more than 100% on Saturdays.

 

but I still stand by my comment somewhere above that the charge reading really should update in a non linear way.

 

...............Dave

[Richard10002]

 

 

I don't think I'm being unfair at all. The Smartgauge is promoted as a battery monitor for dummies.

 

If it cannot determine the state of charge during charging it should say so on the display. "Indeterminate" perhaps.

 

It should not incorrectly, confidently and misleadingly say 100%, whilst burying the fact that 100% doesn't mean 100% somewhere in the manual (which few dummies will either have to hand, or read and understand).

The fact is that novices ask what to get for battery monitoring and "experts" suggest the Smartguage on the basis that it is as simple to use as a fuel guage. Given that they are novices, how likely is it that they would even read, never mind understand, the small print of a fairly comprehensive manual.

 

So it is no wonder that novices using a Smartguage soon complain of problems with their batteries.

 

I would agree that the display could be different, or there could be a big warning on the box, and the front of the manual, and on the Smartguage itself to the effect that "DO NOT RELY ON THE READINGS OF SMARTGUAGE WHEN CHARGING! "

[WotEver]

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

[MtB]

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

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.

 

Edited February 9, 2017 by Mike the Boilerman