Smartsolar max voltage

[magnetman]

So if it was 0.03v/'C and the batteries were 10'C the charge would be 0.45v higher? Is that how it works? 

 

It seems that this temperature compensation thing may be a bit pointless unless it is really cold. 

 

During summer does 0.1 or 0.2v extra charging voltage when it is a bit cool really make a lot of difference to the battery life? Given that it is solar. In winter solar won't do a lot unless they are tilted and aligned with the sun (I have only 30 years of experience with solar panels on my Boats). 

 

How much does it cost to do worthwhile temperature compensation and how much are the new batteries ? 

 

 

 

Edited July 12 by magnetman
double post and removed reference to gravel cleanliness

[Tony Brooks]

14 minutes ago, magnetman said:

So if it was 0.03v/'C and the batteries were 10'C the charge would be 0.45v higher? Is that how it works? 

 

It seems that this temperature compensation thing may be a bit pointless unless it is really cold. 

 

During summer does 0.1 or 0.2v extra charging voltage when it is a bit cool really make a lot of difference to the battery life? Given that it is solar. In winter solar won't do a lot unless they are tilted and aligned with the sun (I have only 30 years of experience with solar panels on my Boats). 

 

How much does it cost to do worthwhile temperature compensation and how much are the new batteries ?

 

And how much is the battery life reduced in real life use without temperature compensation, as long as you are not trying to charge at the maximum possible voltage.

[nicknorman]

13 minutes ago, magnetman said:

So if it was 0.03v/'C and the batteries were 10'C the charge would be 0.45v higher? Is that how it works? 

 

It seems that this temperature compensation thing may be a bit pointless unless it is really cold. 

 

During summer does 0.1 or 0.2v extra charging voltage when it is a bit cool really make a lot of difference to the battery life? Given that it is solar. In winter solar won't do a lot unless they are tilted and aligned with the sun (I have only 30 years of experience with solar panels on my Boats). 

 

How much does it cost to do worthwhile temperature compensation and how much are the new batteries ? 
 

Yes that is how it works. As you imply, in summer the change to charging voltage won’t be much but in winter it can make quite a big difference. Trojan lead antimony batteries in particular, don’t like to be charged at too low a voltage.

 

Although you might think that when the batteries are cold, there is no significant solar, in fact one should bear in mind that solar panel efficiency is highest at low temperatures and it can be quite cold in autumn and spring but still with reasonable solar energy, albeit for a relatively short day. The ideal is to charge the batteries in the morning with the engine (if necessary), and let the solar “finish them off” in the early afternoon with the specified 14.8v plus the temperature coefficient factor.

 

I think the Smartsense thing is under £100.

[magnetman]

I think this temperature compensation thing might be a way to sell more electronic boxes..

 

Microchips and all that is a massive industry. They want them everywhere. 

 

 

[nicknorman]

As usual we have the people who have not tried temperature compensation nor have experience of the batteries concerned, rubbishing it, whilst the people who have had the batteries concerned and have had temperature compensation in their charging, supporting it. Draw your own conclusions!

Edited July 12 by nicknorman

[magnetman]

Just now, nicknorman said:

Yes that is how it works. As you imply, in summer the change to charging voltage won’t be much but in winter it can make quite a big difference. Trojan lead antimony batteries in particular, don’t like to be charged at too low a voltage.

 

Although you might think that when the batteries are cold, there is no significant solar, in fact one should bear in mind that solar panel efficiency is highest at low temperatures and it can be quite cold in autumn and spring but still with reasonable solar energy, albeit for a relatively short day. The ideal is to charge the batteries in the morning with the engine (if necessary), and let the solar “finish them off” in the early afternoon with the specified 14.8v plus the temperature coefficient factor.

 

I think the Smartsense thing is under £100.

 

I know about solar being more efficient in the cold. Lower sun often means less solar because of shading unless one can find a very open location. Also there is the pollution effect when the sun is lower. 

 

Unless one is to significantly reduce power consumption then solar does not fulfil the requirements in winter unless it is a very large array. 

 

 

2 minutes ago, nicknorman said:

As usual we have the people who have not tried temperature compensation nor have experience of the batteries concerned, rubbishing it, whilst the people who have had the batteries concerned and have had temperature compensation in their charging, supporting it. Draw your own conclusions!

I am not 'rubbishing' it I am questioning the need for it. 

 

There is a difference draw your own conclusions !

[Tony Brooks]

Just now, nicknorman said:

As usual we have the people who have not tried temperature compensation or have experience of the batteries concerned, rubbishing it, whilst the people who have had the batteries concerned and have had temperature compensation in their charging, supporting it. Draw your own conclusions!

 

But so far no one has come up with a real life test of just how much difference to battery life, temperature compensation makes. Having shelled out for the necessary equipment, I can't see many claiming anything other than it is the bee's knees.

 

As you say pending the evidence draw your own conclusions.

[magnetman]

 

There will also be choice supportive bias associated with this kind of topic. Obviously. 

 

 

I love a bit of choice supportive bias. Its brilliant. Also known as post purchase rationalisation. 

 

Its a wonderful phenomenon. 

[Tony Brooks]

2 minutes ago, magnetman said:

 

I am not 'rubbishing' it I am questioning the need for it.

 

Exactly the same for me, so far no real evidence from everyday use.

[nicknorman]

52 minutes ago, magnetman said:

 

Unless one is to significantly reduce power consumption then solar does not fulfil the requirements in winter unless it is a very large array. 

 

I know. Which is why I explained about the finish charge thing. If you do you research and look at the manufacturer’s ideal graph of charge voltage vs SoC, it shows an uptick at the end to the 14.8v (compensated). In other words the 14.8v is only required near the end of the charge when the current is quite low. Solar is ideal to provide this in winter, if there is any sun.

[magnetman]

7 minutes ago, nicknorman said:

I know. Which is why I explained about the finish charge thing. If you do you research and look at the manufacturer’s ideal graph of charge voltage vs SoC, it shows an uptick at the end to the 14.8v (compensated). In other words the 14.8v is only required near the end of the charge when the current is quite low. Solar is ideal to provide this in winter, if there is any sun.

 

this seems to take us back to the OP where @blackrose  was worried that the voltage was around 15v. And this is in the summer. 

 

I did note that the total production on the Victron app was 21kWh so I wonder if these panels have been in place during winter previously 

 

Also if it is as you say 14.8v then why would this need to be temperature compensated? 

 

Surely one would just set the top voltage one wanted and leave it. 

 

The temperature compensation seems to me to be introducing an unnecessary extra element in the charging process. 

 

Edited July 12 by magnetman

[nicknorman]

59 minutes ago, Tony Brooks said:

 

But so far no one has come up with a real life test of just how much difference to battery life, temperature compensation makes. Having shelled out for the necessary equipment, I can't see many claiming anything other than it is the bee's knees.

 

As you say pending the evidence draw your own conclusions.

 The evidence comes from understanding the chemistry, and also from manufacturer’s charging recommendations, and from the fact that just about every quality marine installed battery charger or Combi manufacturer includes temperature compensation in the charge algorithm, as do decent alternator controllers.

 

My personal experience of having Trojan batteries mostly charged by a 14.5v alternator was that this was fine in summer, but in winter they accumulated sulphation quite quickly (as determined by looking at the Smartgauge vs the Ah counting Mastershunt). Fortunately I could give them an occasional a higher voltage charge via the Travelpower and the Combi to sort them out. Of course now I have Li, the challenge was to disable the temperature compensation because the chemistry is completely different.

15 minutes ago, magnetman said:

 

Also if it is as you say 14.8v then why would this need to be temperature compensated? 

 

Surely one would just set the top voltage one wanted and leave it. 

 

The temperature compensation seems to me to be introducing an unnecessary extra element in the charging process. 

 

I said 14.8(compensated). Later I said 14.8v and left out the (compensated) because with any lead acid battery charging profile, it is ALWAYS temperature compensated and so I don’t see a need to keep repeating the bleedin obvious.

 

You would not just set the top voltage and leave it, because the top voltage varies according to temperature. Did I mention that before? Has it been ubiquitously mentioned before in the few hundred years lead acid batteries have been around? YES. Jeez, can we have a new argument about the the length of a 1 metre piece of steel?

1 hour ago, Tony Brooks said:

 

Exactly the same for me, so far no real evidence from everyday use.

So presumably you think the battery manufacturer includes this data just out of devilment in order to make boaters’ lives unnecessarily complicated?

[magnetman]

I never realised lead acid batteries of the 12v type needed be charged above 15v in cold weather. 

 

 

Obviously there is the routine equalisation thing but it seems to me there must also be a water consumption question in this topic. 

 

Presumably the battery warranty has something to say about watering. 

[nicknorman]

Just now, magnetman said:

I never realised lead acid batteries of the 12v type needed be charged above 15v in cold weather. 

 

 

Well now you do. Although to be fair, it depends on the specific chemistry. There are many flavours of lead acid battery. This is why one looks at the manufacturer’s data sheets.

[magnetman]

 

 

If we are to argue about the the length of a 1 metre piece of steel it should be in French. 

[Tony Brooks]

32 minutes ago, nicknorman said:

So presumably you think the battery manufacturer includes this data just out of devilment in order to make boaters’ lives unnecessarily complicated?

 

No, I think for some applications it might be important - such as for example in BT exchanges where batteries have a very different use to those on narrowboats. So far the lack of real world evidence suggests to me that it is the manufacturer of electronic gizmos that make life difficult because despite you claiming it was all very simple in another topic Blackrose continued to have problems after that claim.

[nicknorman]

15 minutes ago, Tony Brooks said:

 

No, I think for some applications it might be important - such as for example in BT exchanges where batteries have a very different use to those on narrowboats. So far the lack of real world evidence suggests to me that it is the manufacturer of electronic gizmos that make life difficult because despite you claiming it was all very simple in another topic Blackrose continued to have problems after that claim.

Sorry Tony but this is just Luddite-ism. “We didn’t have it in my day, therefore it is pointless rubbish”. I have presented you with real world evidence but you choose to ignore it. There is no point in continuing to argue, it’s like trying to argue with the Jehovah’s witnesses!
 

I suspect that the only problem Mike has is giving credence to the history stats. There has been no actual evidence that the system has been charging at too high a voltage.

 

Edited July 12 by nicknorman

[magnetman]

The more complex a system gets the more there is to worry about. 

 

In terms of higher voltage presumably this results in water use in lead acid batteries. Do people always have a water topping up regime in place? 

 

How will the battery end up failing in this situation of high voltage charging? 

 

 

The fact the OP was concerned about it seems relevant. 

 

Its a bit like engine temperature worry gauges. In the old days engine manufacturers would coat certain parts of the engine with a paint which will begin to melt at a low temperature and alert the user to a problem using the olfactory nerves. 

 

The eyes are not the correct sensor when it comes to temperature. Its either got to be touch or smell or possibly the hearing. 

Edited July 12 by magnetman
too early

[nicknorman]

33 minutes ago, magnetman said:

The more complex a system gets the more there is to worry about. 

 

In terms of higher voltage presumably this results in water use in lead acid batteries. Do people always have a water topping up regime in place? 

 

How will the battery end up failing in this situation of high voltage charging? 

 

 

The fact the OP was concerned about it seems relevant. 

 

Its a bit like engine temperature worry gauges. In the old days engine manufacturers would coat certain parts of the engine with a paint which will begin to melt at a low temperature and alert the user to a problem using the olfactory nerves. 

 

The eyes are not the correct sensor when it comes to temperature. Its either got to be touch or smell or possibly the hearing. 

I am really struggling to understand the problem that (a very few) people are having with this. Battery manufacturers have been specifying a temperature coefficient on the optimum charging voltage for decades. Centuries, probably. Marine charger manufactures have been providing a temperature sensor and using that data to adjust the charge voltage for decades. Perhaps you are both just taking the piss to wind me up. Yes, that must be it, there is no other rational explanation. I’ll stop rising to the faux stupidity. 

 

[Tony Brooks]

9 hours ago, nicknorman said:

Sorry Tony but this is just Luddite-ism. “We didn’t have it in my day, therefore it is pointless rubbish”. I have presented you with real world evidence but you choose to ignore it. There is no point in continuing to argue, it’s like trying to argue with the Jehovah’s witnesses!
 

I suspect that the only problem Mike has is giving credence to the history stats. There has been no actual evidence that the system has been charging at too high a voltage.

 

 

So you are happy to level the charge of Luddite-ism, but appear unable to provide any evidence that temperature compensation provides any or any cost-effective REAL LIFE benefits from having it.

 

You claim the fact that battery manufacturers give such data proves it does provide a real life benefit, yet seem unable to back it up from practical tests or experience. Lead acid batteries have been happily used for probably 100 years with no temperature compensation and now, when consumer products start trumpeting it, it becomes something vital.

 

We come back to how much real life benefit it produces and how cost-effective it is. I suspect that the real life benefit is questionable, providing sensible maximum charging voltages are set. You seem to think it is vital, yet can't seem to evidence it apart from battery manufacture's data (that not all supply) and the availability of equipment that allows it. Neither of which show any economic benefit. In fact, the cost and extra complexity might suggest the opposite.

[jonesthenuke]

17 hours ago, blackrose said:

At the moment the battery temperature is 35C.

My limited understanding was that temp compensation increased voltage only when battery temp was below 25C.

I also assumed it decreased voltage when battery temp was above 25C but I might be wrong about that.

The compensation works for temperatures above and below 25C, higher voltage when temperatures are low and lower voltage when temperature is high.

With the cells at 21C, you should have increase in charging voltage of 4*30mV so 120mV. This assumes you have the compensation set to -30mV/C, can you confirm this?

[nicknorman]

39 minutes ago, Tony Brooks said:

 

So you are happy to level the charge of Luddite-ism, but appear unable to provide any evidence that temperature compensation provides any or any cost-effective REAL LIFE benefits from having it.

 

You claim the fact that battery manufacturers give such data proves it does provide a real life benefit, yet seem unable to back it up from practical tests or experience. Lead acid batteries have been happily used for probably 100 years with no temperature compensation and now, when consumer products start trumpeting it, it becomes something vital.

 

We come back to how much real life benefit it produces and how cost-effective it is. I suspect that the real life benefit is questionable, providing sensible maximum charging voltages are set. You seem to think it is vital, yet can't seem to evidence it apart from battery manufacture's data (that not all supply) and the availability of equipment that allows it. Neither of which show any economic benefit. In fact, the cost and extra complexity might suggest the opposite.

I already gave you real life evidence of why temperature compensation is beneficial. Presumably you either couldn’t be bothered to read it, or don’t understand it. Or maybe you are just wilfully ignoring it because it doesn’t suit your case. Whatever, some people simply can’t be convinced by hard evidence and will stick to their preconceived ideas regardless, so there is absolutely no point in me continuing to interact with you on the matter.

[Tony Brooks]

15 minutes ago, nicknorman said:

I already gave you real life evidence of why temperature compensation is beneficial. Presumably you either couldn’t be bothered to read it, or don’t understand it. Or maybe you are just wilfully ignoring it because it doesn’t suit your case. Whatever, some people simply can’t be convinced by hard evidence and will stick to their preconceived ideas regardless, so there is absolutely no point in me continuing to interact with you on the matter.

 

 

No, you just said battery manufacturers quote the data and gizmo manufacturers provide it - so in your view it must be of some benefit. I do not doubt that the maximum charging voltage can safely be adjusted up and down according to temperature, but I do question how much real world benefit this has for boaters and probably motor home users. So far you have avoided addressing this, preferring to blindly "follow the science", but no one has questioned the science, but two of us have questioned the actual benefit and if it is cost-effective.

 

You seem happy to brand people who ask for proven benefits of particular pieces of kit Luddites, but a similar charge of being a lover of complex systems with little consideration of cost can be levelled at you. I don't do that because what you do seems to work for you and it is your money and time.

 

My experience of over 55 years of working at the "black hand" end that more batteries, especially domestic ones, are destroyed by over cycling, sulphation, and loss of water than by grid corrosion. This does not mean I don't believe it happens, but I want evidence that temperature compensation makes a meaningful difference to the rate of battery failure, That is not Luddite - it is simply applying something close to peer-review of the claims made.

[magnetman]

I wonder if it is the more expensive batteries which tend to have data sheets mentioning temperature compensation. 

 

Rather than being a luddite I am just always questioning things. 

 

Might it be that by adding lots of extra information to a data sheet the consumer may feel that the product is better than the one without the data sheet. 

 

There is an awful lot of subliminal marketing going on with these things. It is business. 

 

 

[nicknorman]

49 minutes ago, Tony Brooks said:

 

 

No, you just said battery manufacturers quote the data and gizmo manufacturers provide it - so in your view it must be of some benefit. I do not doubt that the maximum charging voltage can safely be adjusted up and down according to temperature, but I do question how much real world benefit this has for boaters and probably motor home users. So far you have avoided addressing this, preferring to blindly "follow the science", but no one has questioned the science, but two of us have questioned the actual benefit and if it is cost-effective.

 

You seem happy to brand people who ask for proven benefits of particular pieces of kit Luddites, but a similar charge of being a lover of complex systems with little consideration of cost can be levelled at you. I don't do that because what you do seems to work for you and it is your money and time.

 

My experience of over 55 years of working at the "black hand" end that more batteries, especially domestic ones, are destroyed by over cycling, sulphation, and loss of water than by grid corrosion. This does not mean I don't believe it happens, but I want evidence that temperature compensation makes a meaningful difference to the rate of battery failure, That is not Luddite - it is simply applying something close to peer-review of the claims made.

I didn’t just say that manufacturers quote data - although for most people, this would be a pretty strong argument - I also described my own personal experience with this particular type of battery and how in winter they definitely needed a higher charge voltage, otherwise they rapidly sulphated. But it seems you didn’t bother to read that bit. I’m not going to repeat it, it is still there for you to read if you can be bothered.

 

Oh and regarding your last para, when I had these batteries they lasted about 7 years of hard use including lots of things that would make you wince such as routine use of the electric kettle and the washing machine. After 7 years I swapped them for Li batteries but there was still plenty of life left in them.

17 minutes ago, magnetman said:

I wonder if it is the more expensive batteries which tend to have data sheets mentioning temperature compensation. 

 

Rather than being a luddite I am just always questioning things. 

 

Might it be that by adding lots of extra information to a data sheet the consumer may feel that the product is better than the one without the data sheet. 

 

There is an awful lot of subliminal marketing going on with these things. It is business. 

 

 

Yes I would say it is the more expensive batteries that have data sheets showing the charge profile including temperature compensation. Cheap “dual purpose leisure” batteries are absolute rubbish and will die quickly unless you only use them to power a dim and flickering bulb to supplement the candles, regardless of how you treat them. They don’t even mention anything about a charge voltage. And of course they are often “no maintenance” and of the lead calcium variety which are slightly different beasts.

 

Better quality semi-traction lead antimony batteries are more expensive but can still be trashed quickly eg by sulphation unless they are charged properly. And of course they do use water. But water is pretty cheap!
 

They are not more expensive as some form of marketing scam, they are more expensive because they have more active material and are properly designed for deep cycling, not just rebadged starter batteries.

 

In my case, about 18 months for cheapo leisure batteries vs 7+ years for semi-traction, the latter costing about twice as much. So more expensive, and yet less expensive!

Edited July 13 by nicknorman