Victron Smart Sense

Wooie1958

Wooie1958

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I`ve just recently installed 2 x 110ah Expedition Plus Lead Carbon Gel batteries and fitted a Victron Smart Sense i already had.

www.alpha-batteries.co.uk

12V 110AH Expedition Plus Lead Carbon Gel Ultra Deep Cycle Battery (EXP12-110C) - Alpha Batteries

Ultra Deep Cycle Lead Carbon GEL Battery
www.alpha-batteries.co.uk www.alpha-batteries.co.uk

It`s linked to a Victron MPPT 75/15 with Bluetooth and i have it set as per the battery intructions i.e. 14.4v charge and 13.8v top up.


When it`s floating it`s now showing 14.0v and this is confirmed by the meter in the motorhome, the reading on the Victron app and a multimeter.

I know it`s only 0.2v but will it do any damage ?
 
st3v3 said:
It could be temperature compensation. It's fine to have a higher voltage when the temperature is lower.
Click to expand...

I was wondering that, the temperature is showing as 12C, it`s nowhere near that outside but they are inside under the seats in their own purpose built space, not sure whether that`s classed as cold or not.
 
Wooie1958 said:
I was wondering that, the temperature is showing as 12C, it`s nowhere near that outside but they are inside under the seats in their own purpose built space, not sure whether that`s classed as cold or not.
Click to expand...
Graham David advised me to fit one of these. It communicates with your MPPT giving it an accurate temperature to work with. This is particularly useful if your controller is a good distance away from your battery. This model has a 10m bluetooth range, there is a cheaper one but with a reduced range of three metres. Due to the fact this is connected directly to your battery it also gives a more accurate voltage reading.

 
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I bought one as it matched my Sargent controle setting, none adjustable no problems ,
 
Fisherman said:
Graham David advised me to fit one of these. It communicates with your MPPT giving it an accurate temperature to work with. This is particularly useful if your controller is a good distance away from your battery. This model has a 10m range bluetooth range, there is a cheaper one but with a reduced range of three metres. Due to the fact this is connected directly to your battery it also gives a more accurate voltage reading.

Click to expand...

Thanks Bill, in my post i already say that i have one of those fitted and i was wondering if it was that raising the voltages slightly.

It and the MPPT can see each other and are less than 12" ( 30cm ) apart and whilst i`ve had it a while i waited until i got these new batteries installed before i started using it.

The Victron MPPT controller i`ve had for sometime now and it`s far superior to my previous PWM controllers, it`s always previously charged at 14.4v and floated at 13;.8V but now it`s floating at 14.0v even though the settings say it`s 13.8v :unsure:
 
You can just lower voltage on blue tooth controller . save them settings as this date. My vans smart alternator charges at 15volts

I think of it this way untill battery is full it can charge a a higher rate as battery is say still only 13 volts not 14.4. so 15 volts in but battery is 13 .3v
Ie 14 4 is over charged / capacity.
 
Wooie1958 said:
Thanks Bill, in my post i already say that i have one of those fitted and i was wondering if it was that raising the voltages slightly.

It and the MPPT can see each other and are less than 12" ( 30cm ) apart and whilst i`ve had it a while i waited until i got these new batteries installed before i started using it.

The Victron MPPT controller i`ve had for sometime now and it`s far superior to my previous PWM controllers, it`s always previously charged at 14.4v and floated at 13;.8V but now it`s floating at 14.0v even though the settings say it`s 13.8v :unsure:
Click to expand...
I don’t think it’s a serious issue Graham, but David or Phil are the experts on here. Possibly one of them will advise. I sometimes think we get a tad too involved in such detail. But obviously you would like to feel you are getting the best from your system.
 
14V is too high for a float level even taking temp comp into account. The Solar mppt you have is very adaptable and 'intelligent' with the intention of doing it's best to keep a lead acid battery completely fully charged in order to avoid sulphation. The 14V level may be some sort of transition between bulk and absorption phase that the unit goes through when one/some of the particular charge profiles is chosen, if so and the battery eventually (after an hour or so) gets held at a correct float voltage of 13.6V then I wouldn't be bothered, if not though then changing the charge profile or setting would be better for the batteries long term.
Lead Carbons will tolerate a slight undercharge without issue and I'd lean that way rather than trying to get the last ounce of energy into the batteries and end up overcharging them.
 
Interesting this , let year I had 2
new leisure batteries fitted and a cheap Chinese controller. I took it back after 2 weeks because it was reading 20 + volts, I assume going into leisure battery ? The installers agreed it was a mistake and fitted (?) a new controller which showed around 14 volts. Just wondering if 2 weeks on the higher charge could damage the batteries ?
 
jacquigem said:
Interesting this , let year I had 2
new leisure batteries fitted and a cheap Chinese controller. I took it back after 2 weeks because it was reading 20 + volts, I assume going into leisure battery ? The installers agreed it was a mistake and fitted (?) a new controller which showed around 14 volts. Just wondering if 2 weeks on the higher charge could damage the batteries ?
Click to expand...
2 weeks at 20V would be catastrophic and kill the batteries, all the acid would be boiled out. However you'd know if the batteries were being charged to 20V, there would be an almighty stink of rotten eggs from the hydrogen sulphide gas!
More likely the display was a mile out. (y)
 
Wooie1958 said:
Thanks Bill, in my post i already say that i have one of those fitted and i was wondering if it was that raising the voltages slightly.

It and the MPPT can see each other and are less than 12" ( 30cm ) apart and whilst i`ve had it a while i waited until i got these new batteries installed before i started using it.

The Victron MPPT controller i`ve had for sometime now and it`s far superior to my previous PWM controllers, it`s always previously charged at 14.4v and floated at 13;.8V but now it`s floating at 14.0v even though the settings say it`s 13.8v :unsure:
Click to expand...
there are a few things here to consider and understand why the float voltage is 14.0V even though it is set at 13.8V ...

The most obvious one to check and probably quickest to dismiss is "Are there any another chargers that are active"? You could (unlikely, but only you will know) have another charger running and putting out 14V? The 14.0V that the MPPT is reporting is the voltage it is reading from the battery. it does not necessarily mean that is the voltage the MPPT itself is putting out.

Assuming the above is not the case, you need to look at the setting of the MPPT controller. The Victron Controller has an option to set Temperature compensation within the "Battery" configuration
The default is -16.2mV per 1 Celcius over 'Standard'.
tempcomp.png

This is what it will look like in the settings page

tempcomp2.png

What this means is for every 1 Celcius from 'Standard', the target outputs will vary from the configured values by 16.2mV - increased when temp is BELOW 'standard' and decreased when temp is ABOVE 'standard'.
The 'standard' battery temp is 20C. If for example, the battery temp is 8C (very possible at this time of year), the Float Voltage the Controller will aim to put out WILL actually be around 14.V, not 13.8V (will actually be 13.994V). So that 14.0V for float is perfectably possible.

Now there is another aspect to this as well .... You can see the temp the MPPT 'thinks' the battery is at in the Victron Connect. This is mine right now:
tempvalue.png

So if I have Temp Compensation enabled, my target voltages would be 0.11V higher than the values I set.
If you are using the Victron MPPT in standalone mode, then the temperature reported is NOT the battery temp, but the controller temp. Plus it is only updated at the time the controller wakes up first thing in the morning (this might have changed in some update, but I am not aware that it has). And first thing in the morning is usually pretty cold compared to the main part of the day.
What this means is you are compensating for a cold battery, and not only that but compensating for the same temperature level throughout the day. I would maybe turn off the temp compensation in the settings UNLESS you have a Victron SBS (Smart Battery Sense), in which case the MPPT will get real time updates of the actual battery temp and the compensation level will be accurate.

In YOUR case, you have the SBS so the temp compensation should be right.

HTH.
 
Thank you for the replies the compensate temperature is the same as shown above so i have gone into the setting and changed them manually to .2v lower than i actually want and i'll check it again tomorrow when the sun is hopefully up.
 
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wildebus said:
there are a few things here to consider and understand why the float voltage is 14.0V even though it is set at 13.8V ...

The most obvious one to check and probably quickest to dismiss is "Are there any another chargers that are active"? You could (unlikely, but only you will know) have another charger running and putting out 14V? The 14.0V that the MPPT is reporting is the voltage it is reading from the battery. it does not necessarily mean that is the voltage the MPPT itself is putting out.

Assuming the above is not the case, you need to look at the setting of the MPPT controller. The Victron Controller has an option to set Temperature compensation within the "Battery" configuration
The default is -16.2mV per 1 Celcius over 'Standard'.
View attachment 119217
This is what it will look like in the settings page

View attachment 119216
What this means is for every 1 Celcius from 'Standard', the target outputs will vary from the configured values by 16.2mV - increased when temp is BELOW 'standard' and decreased when temp is ABOVE 'standard'.
The 'standard' battery temp is 20C. If for example, the battery temp is 8C (very possible at this time of year), the Float Voltage the Controller will aim to put out WILL actually be around 14.V, not 13.8V (will actually be 13.994V). So that 14.0V for float is perfectably possible.

Now there is another aspect to this as well .... You can see the temp the MPPT 'thinks' the battery is at in the Victron Connect. This is mine right now:
View attachment 119218
So if I have Temp Compensation enabled, my target voltages would be 0.11V higher than the values I set.
If you are using the Victron MPPT in standalone mode, then the temperature reported is NOT the battery temp, but the controller temp. Plus it is only updated at the time the controller wakes up first thing in the morning (this might have changed in some update, but I am not aware that it has). And first thing in the morning is usually pretty cold compared to the main part of the day.
What this means is you are compensating for a cold battery, and not only that but compensating for the same temperature level throughout the day. I would maybe turn off the temp compensation in the settings UNLESS you have a Victron SBS (Smart Battery Sense), in which case the MPPT will get real time updates of the actual battery temp and the compensation level will be accurate.

In YOUR case, you have the SBS so the temp compensation should be right.

HTH.
Click to expand...
What a great post David, helpful as ever.
Hope you are enjoying Lochore. (y)
 
If i'm not happy with it tomorrow i'll disconnect the smart sense and see what happens.
It always matched the settings for charging and float with the previous batteries.
 
Be careful with the settings you choose because the temperature compensation value is less for lead carbon than it is for lead acid, the correct compensation level for your batteries is only 3mV/deg C.
Their permissible float voltage is quoted as 13.6-13.8V at 25DegC. With a float voltage latitude of 200mV there's no real point messing around with temp comp at just 3mV /deg. Scrap temp comp and set the float to 13.7V, check it with a multimeter and relax. You shouldn't be hitting 14V float unless the battery temp goes below -42 Deg!
 
Fisherman said:
Graham David advised me to fit one of these. It communicates with your MPPT giving it an accurate temperature to work with. This is particularly useful if your controller is a good distance away from your battery. This model has a 10m bluetooth range, there is a cheaper one but with a reduced range of three metres. Due to the fact this is connected directly to your battery it also gives a more accurate voltage reading.

Click to expand...
The control unit should be close to the battery.
 
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