Trojan T105 6v Battery bank advice required !

[nicknorman]

2 minutes ago, WotEver said:

How long, Nick? Couple of hours? More?

Probably more. Mine have never been that low!  But the thing to do is to keep checking the sg every hour or so until it reaches ~1.277 or stops rising. You could just pick the worst cell and monitor that one. But I think the OP needs a more accurate measuring device. There is far too much scatter on that one.

[dmr]

3 minutes ago, WotEver said:

How long, Nick? Couple of hours? More?

It likely depends on how long the batteries have been sulphated for, the longer you leave them the more equalisation they need to sort them out (break down the sulphate).

The "official" approach is to check SG every hour till it stops increasing but as a wild guess I would say four hours. If things are really bad a bit of extra voltage might help. And your SG's are really not that bad, but are certainly saying equalisation is needed.

The optical hydrometers are nice to use but you loose the feature of stirring up the acid, so even if you go optical I would still do a few sucks and squirts with a turkey baster or moving dial device first.

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

[ditchcrawler]

11 hours ago, meerlaan said:

  Hoping to do an eq charge at the weekend and retest, any idea how long I should do this for ??

Thanks for all your help, Hopefully these results dont show my batteries to be ruined :/

 

 

Will you be discharging the batteries at all between now and then?

[nicknorman]

13 minutes ago, dmr said:

The optical hydrometers are nice to use but you loose the feature of stirring up the acid, so even if you go optical I would still do a few sucks and squirts with a turkey baster or moving dial device first.

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

Although whilst equalisation is going on, I would have thought there was enough stirring from the gassing.

[dmr]

25 minutes ago, nicknorman said:

Although whilst equalisation is going on, I would have thought there was enough stirring from the gassing.

Maybe, I was making a general observation about using the optical hydrometer.

When I equalise I see a few of bubbles gently rising to the surface (at any moment), I would not call it fizzing as some people do, and am not 100% convinced that this gives adequate acid stirring, but then again I don't think I can be bothered to properly investigate this.

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

[mross]

I notice that your technique improves from the early readings to the later ones!  The readings get more consistent.  The float can stick to the side of the hydrometer or bubbles can attach to the float.  A false reading can arise if you don't hold the hydrometer absolutely vertical.  But you seem to get pretty good consistency towards the end.  One technique is to take more than three readings, discard the highest and lowest and then average the remaining readings.  But if you get three readings all very close then don't bother.

[ditchcrawler]

If I ever plan to regularly check the SG of my batteries I will get a refractometer hydrometer as I think they are far easier to get constant results, the float type can stick or hold a bubble and I dont like the look of the dial type which I have been told can also stick. The line on the refractometer is easy to see and you are not worried about dripping acid out of a tube while you get it level to look at. I think someone found some at a reasonable price 

[smileypete]

Don't forget that tail current only works as intended provided the charge voltage is correct.

ISTR Trojans need 14.8 to 15.5V, add about half a volt if the batts are very cold.

At the end of charge the cells should be bubbling nicely, take great care with the usual precautions when checking as the gasses given off are highly explosive.

[meerlaan]

Thanks for all your responses !!

@Ditch Crawler yes I am liveaboard and continuous cruiser so batteries constantly in use! Specially with the miserable wather and dark days

Can anyone give me a link to a reliable SG tester please? I thought I had gone for a good choice but happy to get another one as really dont want to screw my batteries up!

@smileypete what does ISTR mean?? Is my voltage too low then?? I tried to keep notes of my volatge at various stages and mine seemed to be at 14.59v for most of the absorbption phase, wonder how I increase this!! Do I need a cable for my multiplus??

@mross yes think I was a bit shakey at the beginning, it was a little tricky down in my engine room. Think I may have been stiring a little more and more vigorous getting the acid in after the intial tentative ones, wasnt sure if this was right but seemed to give more reliable results, as you noticed

So my plan is to charge batteries back up to float mode today on a cruise and then stick my victorn into eq mode, think it switched of every hour so I plan on resetting this 2 or 3 times and checking my SG with the reader I currently have and see if I can get the results to improve.

Anyone know if my victorn will eq at 16v or I need to set this up? :/ I guess when it switches into this mode I can check the v on my BMV..? Feel like things might be making a little sense, thanks again for everyones help and adice.

Martin

[nicknorman]

25 minutes ago, meerlaan said:

Thanks for all your responses !!

@Ditch Crawler yes I am liveaboard and continuous cruiser so batteries constantly in use! Specially with the miserable wather and dark days

Can anyone give me a link to a reliable SG tester please? I thought I had gone for a good choice but happy to get another one as really dont want to screw my batteries up!

@smileypete what does ISTR mean?? Is my voltage too low then?? I tried to keep notes of my volatge at various stages and mine seemed to be at 14.59v for most of the absorbption phase, wonder how I increase this!! Do I need a cable for my multiplus??

@mross yes think I was a bit shakey at the beginning, it was a little tricky down in my engine room. Think I may have been stiring a little more and more vigorous getting the acid in after the intial tentative ones, wasnt sure if this was right but seemed to give more reliable results, as you noticed

So my plan is to charge batteries back up to float mode today on a cruise and then stick my victorn into eq mode, think it switched of every hour so I plan on resetting this 2 or 3 times and checking my SG with the reader I currently have and see if I can get the results to improve.

Anyone know if my victorn will eq at 16v or I need to set this up? :/ I guess when it switches into this mode I can check the v on my BMV..? Feel like things might be making a little sense, thanks again for everyones help and adice.

Martin

ISTR = I seem to recall.

This is the type of hydrometer I have, called a refractometer. You will also need a turkey blaster, which I used both for topping up the electrolyte and also for stirring up the electrolyte https://www.ebay.co.uk/itm/Glycol-Refractometer-Auto-Car-Fluids-Antifreeze-Battery-Acid-Engine-Tester/222610519335?hash=item33d49ef527:g:DnYAAOSwfLVZjlbU

Trojans do like a high charge voltage especially in winter. In summer your 14.6 will be OK but if this is from the Victron then it will be less in summer because the Victron has temperature compensation.

If you only ever charge from a generator then I would set the voltages in the Victron to be nominally 14.8v (it will become more in winter) including the float voltage. Float is only useful if you leave the boat plugged into shore power. When using a generator, float mode is a pain because it may well go to float earlier than you want. By making the float voltage the same as absorption, you effectively disable float.

personally I think the PC interface is well worth it, then you can effortlessly change the charging voltage on the Victron. You can’t do that for the boat’s alternator so easily, but doing most of the charging at say 14.4v is fine if in winter you finish off with some 14.8v or more from the Victron from time to time.

Edited December 1, 2017 by nicknorman

[mross]

@OP I think you have already realised this, but when you take SG readings it is a good idea to fill and empty the hydrometer several times and forcefully to stir up the electrolyte in each cell.  Durite make a very good hydrometer with a built-in thermometer but it is about £50 or even more.  On your Victron, is the temperature probe fitted?  It should beattached to one of the batteries so that the Victron can adjust its voltages to suit.   The refractometer ones are good but, as NN said, you need something else to agitate the liquid and to draw your sample.

[meerlaan]

Thanks, @nicknorman Think I need to bite the bullet and just buy the cable no point being tight there not cheap batteries!!

I have finally managed to get my multiplus into eq mode took quite a bit of fiddling with the switches, (off and on again) So for sure the batteries are as charged as they are going to be, the float mode went on twice, i switched off victron and let it go through the stages again. I will do a couple of hours and text the SG,

One thing I didnt understand (well another 1 thing) my BMV read 100% before my tail current was 1% even though I made a point of setting this perhaps I have my charge voltage wrong ? ( 13.2v )

Also, is it essential I have all 12v stuff turned off while running eq charge ?? I am currently writting this in candle light

The reading on my BMV currently is 15.33v and 12.3a so I am concerened the voltage is not high enough to eq, perhaps I should wait for the cable??

Thanks

Martin

 

[meerlaan]

its now reading 15.6v and 10a

 

[Tony Brooks]

8 minutes ago, meerlaan said:

Thanks, @nicknorman Think I need to bite the bullet and just buy the cable no point being tight there not cheap batteries!!

I have finally managed to get my multiplus into eq mode took quite a bit of fiddling with the switches, (off and on again) So for sure the batteries are as charged as they are going to be, the float mode went on twice, i switched off victron and let it go through the stages again. I will do a couple of hours and text the SG,

One thing I didnt understand (well another 1 thing) my BMV read 100% before my tail current was 1% even though I made a point of setting this perhaps I have my charge voltage wrong ? ( 13.2v )

Also, is it essential I have all 12v stuff turned off while running eq charge ?? I am currently writting this in candle light

The reading on my BMV currently is 15.33v and 12.3a so I am concerened the voltage is not high enough to eq, perhaps I should wait for the cable??

Thanks

Martin

 

Two points.

Meters such as the BVM are well known for overstating the percentage of charge so please learn to ignore it. Use Ah out and rested voltage to estimate the battery capacity and tail current to tell you when a adequately true fully charged has been reached. Best doen at around 14.2 to 14.5 volts. You may well have to turn the battery charge off and on a few times to prevent the float voltage giving an artificially low tail current. If you want to try to use the float voltage hen keep it charging until the current has stopped falling over an hour or so.

Basically your BVM 100% is almost certainly a lie.

13.2 volts is not enough to even charge the batteries, it may be the rested voltage of a fully charged battery or the rested voltage plus surface charge for a battery that has just come off charge. You need an absolute minimum of 13.6 volts plus lots and lots of time. while 13.8 is better, best of all anything between 14.2 to 14.5 volts.

The reason you ened to turn 12V stuff off while equalising is the high voltage may damage it but most "marine" LED bulbs are safe to 30 volts. I suspect the water pump will be OK as well. Not so sure about a 12V fridge. The 15v + may confuse it and persuade it that its on a 24 volt system.

15.33 volts will in my view equalise the battery but I think you are trying to reconvert sulphate so the higher the better. I would suggest you need to aim for about 15.5V unless Trojan say differently.

 

[meerlaan]

Great thanks @Tony Brooks

Sorry I meant to say

'charged voltage' - the charged voltage parameter should always be slightly below the end of charge voltage of the charger (usually 0.2v -0.3v below the 'float' voltage of the charger)

[Tony Brooks]

Just now, meerlaan said:

Great thanks @Tony Brooks

Sorry I meant to say

'charged voltage' - the charged voltage parameter should always be slightly below the end of charge voltage of the charger (usually 0.2v -0.3v below the 'float' voltage of the charger)

If you mean the voltage at the end of charging and without resting or a load being applied then I fear it means nothing. For the voltage to mean something other than a raw figure you need to remove the artificially high surface charge by allowing the battery to stand for an hour or longer or applying  a load like a water pump for several minutes. If you get more than about 12.8 volts then you still have surface charge. A fully charged battery will deliver between 12.7 and 12.8 volts so say 12.75V.

[nicknorman]

The issue for the BMV can be thus:

In order to work out when the battery is fully charged to the set tail current (say 1%) so it can reset to 100%, it needs to detect that the current has fallen to that low value of 1%. But of course that happens if you just switch off the charger - the current falls to <1%! So it has to know that the battery is still on charge and it does that by looking at the charging voltage - must be above the set value in the BMV. 13.2v apparently, in your set up. If the charging voltage parameter in the BMV is set quite low, and the batteries are being charged at a high voltage, and then the charger is turned off before reading fully charged ... well, the current falls to zero - tick! And the battery’s residual voltage only falls slowly and will linger in the mid to high 13v range, so above 13.2v - tick! So with both a very low (zero) current and still a highish voltage >13.2v, Lo and behold the criteria are met and the gauge resets to 100% early.

The answer is to increase the charge voltage setting in the BMV. 14v should be fine. Of course the problem with that is that if the charger decides to go to float before the 1% tail current is reached, the BMV will never get to 100%. But then if you adjust your charger so that it effectively doesn’t have a float mode, that won’t be a problem!

Edited December 1, 2017 by nicknorman

[rowland al]

Why is it that after I charged my new 12v Yuasa 75ah starter battery for 2 hours, and came back to the boat a day later, it read 13.0v? My Trojans got nowhere near that even when they were new. 

[meerlaan]

@nicknorman ok I can just about follow what your saying, i am not sure I follow why the victron would go into float early  (before reaching 1% tail current) but I see that I can set them up to be the same voltage so it wouldnt make a different, I might have to ask you some more questions when I get my cable

So only managed about 2 hours eq charge, I feel I may need to redo with a slightly higher voltage but here are my results :

Battery 1

[Front]  1.270

[Middle] 1.270

[Rear] 1.270

Battery 2

[Front]  1.280

[Middle] 1.280

[Rear] 1.280

Battery 3

[Front]  1.275

[Middle] 1.265

[Rear] 1.270

Battery 4

[Front]  1.270

[Middle] 1.275

[Rear] 1.265

Battery 5

[Front]  1.270

[Middle] 1.275

[Rear] 1.265

Battery 6

[Front]  1.280

[Middle] 1.275

[Rear] 1.280

Readings are still a little all over the place, I did as advised and mixed the batter water a bit and filled tester a few times before taking a reading and then took 2 or 3 to check for consistency. They definately seem better!!  

 

 

[nicknorman]

3 minutes ago, meerlaan said:

@nicknorman ok I can just about follow what your saying, i am not sure I follow why the victron would go into float early  (before reaching 1% tail current) but I see that I can set them up to be the same voltage so it wouldnt make a different, I might have to ask you some more questions when I get my cable

So only managed about 2 hours eq charge, I feel I may need to redo with a slightly higher voltage but here are my results :

Battery 1

[Front]  1.270

[Middle] 1.270

[Rear] 1.270

Battery 2

[Front]  1.280

[Middle] 1.280

[Rear] 1.280

Battery 3

[Front]  1.275

[Middle] 1.265

[Rear] 1.270

Battery 4

[Front]  1.270

[Middle] 1.275

[Rear] 1.265

Battery 5

[Front]  1.270

[Middle] 1.275

[Rear] 1.265

Battery 6

[Front]  1.280

[Middle] 1.275

[Rear] 1.280

Readings are still a little all over the place, I did as advised and mixed the batter water a bit and filled tester a few times before taking a reading and then took 2 or 3 to check for consistency. They definately seem better!!  

 

 

That’s looking pretty good!

[Phil.]

11 minutes ago, meerlaan said:

@nicknorman ok I can just about follow what your saying, i am not sure I follow why the victron would go into float early  (before reaching 1% tail current) but I see that I can set them up to be the same voltage so it wouldnt make a different, I might have to ask you some more questions when I get my cable

So only managed about 2 hours eq charge, I feel I may need to redo with a slightly higher voltage but here are my results :

Battery 1

[Front]  1.270

[Middle] 1.270

[Rear] 1.270

Battery 2

[Front]  1.280

[Middle] 1.280

[Rear] 1.280

Battery 3

[Front]  1.275

[Middle] 1.265

[Rear] 1.270

Battery 4

[Front]  1.270

[Middle] 1.275

[Rear] 1.265

Battery 5

[Front]  1.270

[Middle] 1.275

[Rear] 1.265

Battery 6

[Front]  1.280

[Middle] 1.275

[Rear] 1.280

Readings are still a little all over the place, I did as advised and mixed the batter water a bit and filled tester a few times before taking a reading and then took 2 or 3 to check for consistency. They definately seem better!!  

 

 

Did you compensate for temperature. Trojan state deduct .003 for each 10 degrees below 21c. Also what voltage were you using to equalise, should 16.2 volts for t105s

[nicknorman]

18 minutes ago, Phil. said:

Did you compensate for temperature. Trojan state deduct .003 for each 10 degrees below 21c. Also what voltage were you using to equalise, should 16.2 volts for t105s

The hydrometer used allegedly compensates for temperature. The voltage seems to have been adequate.

Edited December 1, 2017 by nicknorman

[Phil.]

Just now, nicknorman said:

The hydrometer used allegedly compensates for temperature.

Ah, better than my cheap old thing then.

[cuthound]

1 hour ago, meerlaan said:

@nicknorman ok I can just about follow what your saying, i am not sure I follow why the victron would go into float early  (before reaching 1% tail current) but I see that I can set them up to be the same voltage so it wouldnt make a different, I might have to ask you some more questions when I get my cable

So only managed about 2 hours eq charge, I feel I may need to redo with a slightly higher voltage but here are my results :

Battery 1

[Front]  1.270

[Middle] 1.270

[Rear] 1.270

Battery 2

[Front]  1.280

[Middle] 1.280

[Rear] 1.280

Battery 3

[Front]  1.275

[Middle] 1.265

[Rear] 1.270

Battery 4

[Front]  1.270

[Middle] 1.275

[Rear] 1.265

Battery 5

[Front]  1.270

[Middle] 1.275

[Rear] 1.265

Battery 6

[Front]  1.280

[Middle] 1.275

[Rear] 1.280

Readings are still a little all over the place, I did as advised and mixed the batter water a bit and filled tester a few times before taking a reading and then took 2 or 3 to check for consistency. They definately seem better!!  

 

 

That's now a fully charged battery.

After equalising you will rarely get all SG's exactly the same within a battery. As long as they are plus or minus 0.005 ish they are fine. 

Now is the time to reset the battery % SoC to 100% on your BMV by pressing the two range selection arrows (left and right) at the same time for 3 seconds. If you do this once a month or every full charge, then the SoC percentage will be as accurate as it can be.

Edited December 1, 2017 by cuthound
To add the last sentance.