Electrolyte specific gravity anyone?

[Loafer]

Should be 3mm below bottom of the filler well when fully charged.

Thanx, I was just about to stir myself, to go find the page! Was that from Trojan?

 

If that's true, then all 24 of my cells are in need of drying out a little. Even after a month! There's only one of them that isn't touching the bottom of the filler hole. Some of them are higher than 'just touching', but not enough to alarm me about overflow. All closely examined today under charge.

 

I should add that all this nonsense is just 'interest'. I'm sure that, if I was a complete electrical numpty, I would never have bothered checking and would probably have been happier as a result!!

 

Still, the story seems to have been interesting so far, and has distracted a few of us from issues of licensing, moorings, Sec 8's and certainly toilets. Excellent!

[nicknorman]

Thanx, I was just about to stir myself, to go find the page! Was that from Trojan?

 

Yea, from here, page 10 http://www.trojanbattery.com/pdf/TRJN0109_UsersGuide.pdf

[Loafer]

Yea, from here, page 10 http://www.trojanbattery.com/pdf/TRJN0109_UsersGuide.pdf

 

Ta chum. There's obviously more to Trojan's 'capacity will improve over the first 30 charge cycles'* then.

 

I'm going to relax over it for a little while, and then attack the subject again after a few more cycles.

 

*Can't remember where I read that, or even if I actually did. I may have dreamt it!

[mad dog n' Englishman]

On page 18 of users guide Trojan state "Trojan's batteries take between 50 -- 100 cycles to work up to giving full, peak capacity.

With these wise words from the horses mouth, relax and they will improve.

Garry.

[Loafer]

On page 18 of users guide Trojan state "Trojan's batteries take between 50 -- 100 cycles to work up to giving full, peak capacity.

With these wise words from the horses mouth, relax and they will improve.

Garry.

 

Yep. That has been in my mind from the start, and has been mentioned here. I couldn't remember the 50-100 bit though. That is encouraging.

 

It should be re-worded! If it said 'Your electrolyte SG will be relatively low until after 50-100 cycles, despite correct charging methods', then this post would never have been made!

[mad dog n' Englishman]

True, however we would all have missed a lot of informative and helpful information. I would treat the first 50 - 100 cycles almost as a bonus and start the "count down" from cycle No 101

Garry. (always look on the bright side)..

[Loafer]

True, however we would all have missed a lot of informative and helpful information. I would treat the first 50 - 100 cycles almost as a bonus and start the "count down" from cycle No 101

Garry. (always look on the bright side)..

 

 

I will definitely be watching after that.

[dmr]

I don't think the capacity should be massively reduced during the first 100 cycles, just a bit.

I saw a graph somewhere on the www, I will try to find it again.

A recent Firefox update has lost all my bookmarks, these open source geeks are even worse than microsoft.

 

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

[nicknorman]

I don't think the capacity should be massively reduced during the first 100 cycles, just a bit.

I saw a graph somewhere on the www, I will try to find it again.

A recent Firefox update has lost all my bookmarks, these open source geeks are even worse than microsoft.

 

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

 

IIRC it goes from about 80% capacity to 100% in the 100 cycles. Mine were nearer 50% but improve rapidly.

 

Oh and whilst we are on about this sort of thing, I am still unclear whether a "cycle", for this purpose, is a 100% cycle equivalent (ie taking it down to 50% and back, twice, counts as 1 cycle) because if not, what is a cycle? 100% to 99% and back? Surely not!

[smileypete]

I don't think the capacity should be massively reduced during the first 100 cycles, just a bit.

I saw a graph somewhere on the www, I will try to find it again.

A recent Firefox update has lost all my bookmarks, these open source geeks are even worse than microsoft.

 

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

 

Might be in a file called bookmarks<date something>.json. A search utility called 'Everything' can find stuff like that easily.

 

In any case it's good to do daily drive image backups, this sort of thing is where they come in handy.

 

cheers, Pete.

~smpt~

Edited February 4, 2015 by smileypete

[dmr]

 

Might be in a file called bookmarks<date something>.json. A search utility called 'Everything' can find stuff like that easily.

 

In any case it's good to do daily drive image backups, this sort of thing is where they come in handy.

 

cheers, Pete.

~smpt~

 

Daily Backups? that's a bit like giving up beer; a very good idea that just isn't going to happen.

I work on the concept of "phew, got away with it again".

 

Thanks, I have never heard of Everything, I am investigating now.

I doubt if Firefox has actually lost my bookmarks, I just can't find them after the latest user interface change.

Its something that I get irritated about, I see computers as tools and want to get on with my jobs rather than learning my way around a new user interface every few weeks. I write software and do sometimes have to make user interface changes and I really worry about it as I know some users will be frustrated about it. I could never justify it for "fashion" reasons.

 

rant over.......back to specific gravity.

 

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

[Loafer]

OK here we are today.

 

After a massive sunny day with the MPPT doing it's job, followed by a late afternoon engine run for hot water, me batts were drawing 1.5A. DEFFO fully charged! Right?

 

SG varied a little but they are all in the green now, although a few are 'only just'.

 

Having done my own legwork this time, Trojan say that at 10deg C (my battery temperature), fully-charged SG should be 1.277, less 0.012 for being at 10degC, which means 1.265.

 

The 'greenest' cell was more than that, at 1.275 on the scale of my hydrometer. I regard that as approximate, but good anyway.

 

Therefore I think my quest is over - they are ok and still improving on SG readings!

 

Noted also that you don't get full capacity at 10degC, but their scale is in degF and I couldn't be arsed to work it out.

 

 

So, I'm still hoping for some examples of your in-use voltage at your lowest SOC, for example first thing in the morning with the fridge going. Especially from those of you with T-105s.

 

Thanks guys.

[nicknorman]

OK here we are today.

 

After a massive sunny day with the MPPT doing it's job, followed by a late afternoon engine run for hot water, me batts were drawing 1.5A. DEFFO fully charged! Right?

 

SG varied a little but they are all in the green now, although a few are 'only just'.

 

Having done my own legwork this time, Trojan say that at 10deg C (my battery temperature), fully-charged SG should be 1.277, less 0.012 for being at 10degC, which means 1.265.

 

The 'greenest' cell was more than that, at 1.275 on the scale of my hydrometer. I regard that as approximate, but good anyway.

 

Therefore I think my quest is over - they are ok and still improving on SG readings!

 

Noted also that you don't get full capacity at 10degC, but their scale is in degF and I couldn't be arsed to work it out.

 

 

So, I'm still hoping for some examples of your in-use voltage at your lowest SOC, for example first thing in the morning with the fridge going. Especially from those of you with T-105s.

 

Thanks guys.

That sounds good. Although I am going down to the boat for a week on 13th, I'm not sure if I will be going out or whether remaining on shore power, but if the former I'll try to remember to look at the figures.

[Loafer]

IIRC it goes from about 80% capacity to 100% in the 100 cycles. Mine were nearer 50% but improve rapidly.

 

Oh and whilst we are on about this sort of thing, I am still unclear whether a "cycle", for this purpose, is a 100% cycle equivalent (ie taking it down to 50% and back, twice, counts as 1 cycle) because if not, what is a cycle? 100% to 99% and back? Surely not!

 

I've wondered about that. It is well known that keeping a high SOC forever, with very small discharges, extends the life of batteries for years.

 

Gotta be number of 50% cycles, I reckon, but I don't know how many '10% cycles' equates to a '50% one'. Good question.

[dmr]

Well done, but I may have to deliver a little bad news.

That temperature correction goes the other way.

It makes sense, at low temperatures the acid shrinks so is denser, so the fully charged SG should be 1.277 + 0.012.

 

But don't worry about the details, its all a bit approximate and you have massively improved things.

As you too are now becoming a boaty battery expert why don't you get a Smartgage?

With both a Smartguge and your amp-hour meter you can make some serious measurement of battery capacity and health.

 

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

[Loafer]

That sounds good. Although I am going down to the boat for a week on 13th, I'm not sure if I will be going out or whether remaining on shore power, but if the former I'll try to remember to look at the figures.

Don't lose any sleep mate!

[Loafer]

Well done, but I may have to deliver a little bad news.

That temperature correction goes the other way.

It makes sense, at low temperatures the acid shrinks so is denser, so the fully charged SG should be 1.277 + 0.012.

 

But don't worry about the details, its all a bit approximate and you have massively improved things.

As you too are now becoming a boaty battery expert why don't you get a Smartgage?

With both a Smartguge and your amp-hour meter you can make some serious measurement of battery capacity and health.

 

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

 

'Ang abaht Dave! I think I was right - see this:

 

7.3 Specific Gravity Testing (continue from pg 19)

• î Correct specific gravity readings for temperature by adding 0.004 for every 10°F (5°C) above 80°F (27°C) and subtract 0.004 for every 10°F (5°C) below 80°F (27°C).

 

Mine were 10degC, which is 17deg below 27, therefore 0.004x3 = 0.012 to be subtracted.

 

No? Yes?

[dmr]

I do struggle with this, and the various sites on the www do conflict with each other..

 

Your acid is cold and hence extra dense so will have a higher SG, so I still reckon you need to Subtract the correction factor from your readings.

 

or you need to ADD the correction to the figures provided by Trojan.

 

This is probably the source of the confusion.

 

Lets see what the others say?????

 

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

Edited February 4, 2015 by dmr

[nicknorman]

 

'Ang abaht Dave! I think I was right - see this:

 

7.3 Specific Gravity Testing (continue from pg 19)

• î Correct specific gravity readings for temperature by adding 0.004 for every 10°F (5°C) above 80°F (27°C) and subtract 0.004 for every 10°F (5°C) below 80°F (27°C).

 

Mine were 10degC, which is 17deg below 27, therefore 0.004x3 = 0.012 to be subtracted.

 

No? Yes?

 

 

It means subtract 0.004 for every 5degC below 27 deg C FROM THE READING OF THE HYDROMETER, not from the theoretical optimal SG value. So unfortunately Dave is right and I missed it first time!

 

Still, it seems a good improvement.

Edited February 4, 2015 by nicknorman

[Loafer]

I do struggle with this, and the various sites on the www do conflict with each other..

 

Your acid is cold and hence extra dense so will have a higher SG, so I still reckon you need to Subtract the correction factor from your readings.

 

or you need to ADD the correction to the figures provided by Trojan.

 

This is probably the source of the confusion.

 

Lets see what the others say?????

 

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

 

 

You're right.

 

I just HATE it when that happens.

 

(Thankful I didn't take the piss!)

[dmr]

 

 

You're right.

 

I just HATE it when that happens.

 

(Thankful I didn't take the piss!)

 

Thank you for accepting your error with dignity.

I am sometimes wrong but often right.

When I'm wrong my wife reminds me that I am wrong.

When I'm right she tells me I'm an infuriating smug Bstrd.

 

Your batteries are a bit full and this will reduce your SG a bit so things are even better than they look.

I tried to work it out today but I need to know the volume of acid in a Trojan Cell and the www failed to tell me.

 

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

[nicknorman]

Your batteries are a bit full and this will reduce your SG a bit so things are even better than they look.

I tried to work it out today but I need to know the volume of acid in a Trojan Cell and the www failed to tell me.

 

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

 

It depends why they are too full. Maybe too much acid was put in to start with? It seems unlikely that additional water has been added at so young an age.

[Keeping Up]

 

It depends why they are too full. Maybe too much acid was put in to start with? It seems unlikely that additional water has been added at so young an age.

 

Two major battery suppliers have each confirmed to me, separately and independently, that they always supply their batteries with far too much water added. They each said that they get fewer warrantee returns that way because the user can boil away a lot more water before they are too low to work properly and this normally takes them outside the guarantee period.

[Loafer]

 

Two major battery suppliers have each confirmed to me, separately and independently, that they always supply their batteries with far too much water added. They each said that they get fewer warrantee returns that way because the user can boil away a lot more water before they are too low to work properly and this normally takes them outside the guarantee period.

 

That's useful. At least it's only water that there's too much of. No problem there.

 

If it was too much 'proper mix', then some would have to be removed! Not good.

[nicknorman]

 

Two major battery suppliers have each confirmed to me, separately and independently, that they always supply their batteries with far too much water added. They each said that they get fewer warrantee returns that way because the user can boil away a lot more water before they are too low to work properly and this normally takes them outside the guarantee period.

Could be, although it comes back to my earlier question of at what point is the acid added. I've certainly bought motorbike batteries where the acid was either added by the dealer, or even in a pack for you to add yourself. It seems to me to make sense to add the acid as late as possible in the supply chain.

Edited February 4, 2015 by nicknorman