plwsm2000 Posted May 23, 2019 Share Posted May 23, 2019 As we have had a good few days of sun, I decided to take a look at some data that was logged over this week. I found a couple of minor issues with my Votronic MPP controller that might be of interest to others. I haven't used the van since last Sunday and it has been sitting on my drive with just the solar controller keeping the battery topped up. Apart from the EBL, nothing else has been switched on. My first observation is that at very low light levels, the Votronic controller actually takes MORE current from the battery than it puts in. It seems to take about 100mA when there is sufficient light on the panel to start up the controller, but not enough to generate any useful power. I have noted this on the first graph below. In normal usage, this extra current should not be that noticeable, but I was wondering what would happen if you were parked up during the day under very heavy shade? My second observation is that the Votronic starts its main charge phase immediately at startup (in my case at around 5am). Obviously there is very little solar power about at this time in the morning - just when the battery needs it most from the overnight usage. The first 2-3 hours of the main charge is therefore limited by the available solar energy rather than what the battery is demanding. Even doubling the panels wouldn't make a vast difference at this time of day (two times not much is still not much!) On the gel setup, the main charge will last a maximum of 6 hours (finished before 11am at this time of year). It would be better if the Votronic delayed its main charge phase for a couple of hours, and just started up in a float charge mode. Even in this float charge mode, I would guess that the charge would still be restricted due to the low light levels at this time in the morning. On the second day, I temporarily disconnected the panel from the controller so that the Votronic restarted in main charge in the early afternoon just to see what happens. You can see the results on the 4 day plots. To see what happens when the van is occupied, last night I rigged up a 2 amp constant current load that switched on for 4 hours overnight (see plot over 4 days below). With the EBL current, this is equivalent to about 9Ah overnight usage (about normal for me). The 6 hours main charge ended at 11:17am today and even at dusk, the battery is still not quite fully charged (but almost!). If the main charge had been delayed a couple of hours, the battery would have been fully charged early afternoon. I only have one 80Ah gel and a 110W panel which I think is a good match. We seem to be "wasting" available solar energy by starting the main charge early. I also include plots for the habitation and started battery voltages for reference. Hopefully this might be of interest to someone. Link to comment Share on other sites More sharing options...
spirou Posted May 23, 2019 Share Posted May 23, 2019 Just wondering what you're recording this with and how you power it? I used an RPi to do the same and it used around 0.16A. Not much in summer but quite significant in winter. Link to comment Share on other sites More sharing options...
aandncaravan Posted May 24, 2019 Share Posted May 24, 2019 plwsm2000 - 2019-05-23 8:19 PM As we have had a good few days of sun, I decided to take a look at some data that was logged over this week. I found a couple of minor issues with my Votronic MPP controller that might be of interest to others. I haven't used the van since last Sunday and it has been sitting on my drive with just the solar controller keeping the battery topped up. Apart from the EBL, nothing else has been switched on. My first observation is that at very low light levels, the Votronic controller actually takes MORE current from the battery than it puts in. It seems to take about 100mA when there is sufficient light on the panel to start up the controller, but not enough to generate any useful power. I have noted this on the first graph below. In normal usage, this extra current should not be that noticeable, but I was wondering what would happen if you were parked up during the day under very heavy shade? My second observation is that the Votronic starts its main charge phase immediately at startup (in my case at around 5am). Obviously there is very little solar power about at this time in the morning - just when the battery needs it most from the overnight usage. The first 2-3 hours of the main charge is therefore limited by the available solar energy rather than what the battery is demanding. Even doubling the panels wouldn't make a vast difference at this time of day (two times not much is still not much!) On the gel setup, the main charge will last a maximum of 6 hours (finished before 11am at this time of year). It would be better if the Votronic delayed its main charge phase for a couple of hours, and just started up in a float charge mode. Even in this float charge mode, I would guess that the charge would still be restricted due to the low light levels at this time in the morning. On the second day, I temporarily disconnected the panel from the controller so that the Votronic restarted in main charge in the early afternoon just to see what happens. You can see the results on the 4 day plots. To see what happens when the van is occupied, last night I rigged up a 2 amp constant current load that switched on for 4 hours overnight (see plot over 4 days below). With the EBL current, this is equivalent to about 9Ah overnight usage (about normal for me). The 6 hours main charge ended at 11:17am today and even at dusk, the battery is still not quite fully charged (but almost!). If the main charge had been delayed a couple of hours, the battery would have been fully charged early afternoon. I only have one 80Ah gel and a 110W panel which I think is a good match. We seem to be "wasting" available solar energy by starting the main charge early. I also include plots for the habitation and started battery voltages for reference. Hopefully this might be of interest to someone. Plwsm2000, that is how all good Motorhome chargers work, they need power to run the electronics to make the MPPT operate. It is well documented that no battery charger, Solar/Mains/Alternator is 100% efficient, they all take power from the source. Same with PWM regulators, but the time a good Solar Panel will stay in this intermediate state should be very short as the sun rising just a little should switch things around. Also all the best motorhome chargers are timer based. The LAS1218 charger module in your EBL, depending on year of manufacture, could be one with just a 1 hour timer, 4 hour timer and the latest EBL 30/119 range, a 16 hour timer. You will see some examples of charger timers on the web page 'How does a charger work' : http://www.aandncaravanservices.co.uk/how-does-a-charger-work.php including the EBL 119 chargers profile. The web page shows why it is so important to match the battery bank size to the charger otherwise very extended charging times result. That applies to Mains chargers and Solar chargers. Some of the Solar Regulators have just a 1 hour timer, but 4 hours is more typical. The Votronic's 6 hours is longer than most. Some of the the Victron range has a shorter timer 'out of the box' but has the advantage that you can alter the timers, but it gets complicated for most. This behaviour has been documented a long time along with the work around to get the best from the unit. It is very easy to restart the timer on any mains charger, just isolate it from power and it will restart the timer from the beginning to give you another 6 hours. Same applies to a Solar charger. If you look at our many posts you will see we repeatedly try to point out that just because the charger has dropped to 13.8v 'Float' charge doesn't equate to the battery being fully charged. As the 'How does a charger work' web page point out, depending on the battery bank size they may not even be half charged. You should also bear in mind that a Gel battery can take twice as long to charge as a modern wet battery. Link to comment Share on other sites More sharing options...
Charles Posted May 24, 2019 Share Posted May 24, 2019 Well it's been cloudy here all day and the solar has just been managing about 1.7 amps. The sun came out 2 minutes ago at 4.58pm and the charge rate went up to 5.6 amps so it looks like our Votronic duo 250 stays on bulk charge until it's work is done. B-) Edit 7.5 amps now :D Link to comment Share on other sites More sharing options...
Guest pelmetman Posted May 24, 2019 Share Posted May 24, 2019 aandncaravan - 2019-05-24 10:47 AM plwsm2000 - 2019-05-23 8:19 PM As we have had a good few days of sun, I decided to take a look at some data that was logged over this week. I found a couple of minor issues with my Votronic MPP controller that might be of interest to others. I haven't used the van since last Sunday and it has been sitting on my drive with just the solar controller keeping the battery topped up. Apart from the EBL, nothing else has been switched on. My first observation is that at very low light levels, the Votronic controller actually takes MORE current from the battery than it puts in. It seems to take about 100mA when there is sufficient light on the panel to start up the controller, but not enough to generate any useful power. I have noted this on the first graph below. In normal usage, this extra current should not be that noticeable, but I was wondering what would happen if you were parked up during the day under very heavy shade? My second observation is that the Votronic starts its main charge phase immediately at startup (in my case at around 5am). Obviously there is very little solar power about at this time in the morning - just when the battery needs it most from the overnight usage. The first 2-3 hours of the main charge is therefore limited by the available solar energy rather than what the battery is demanding. Even doubling the panels wouldn't make a vast difference at this time of day (two times not much is still not much!) On the gel setup, the main charge will last a maximum of 6 hours (finished before 11am at this time of year). It would be better if the Votronic delayed its main charge phase for a couple of hours, and just started up in a float charge mode. Even in this float charge mode, I would guess that the charge would still be restricted due to the low light levels at this time in the morning. On the second day, I temporarily disconnected the panel from the controller so that the Votronic restarted in main charge in the early afternoon just to see what happens. You can see the results on the 4 day plots. To see what happens when the van is occupied, last night I rigged up a 2 amp constant current load that switched on for 4 hours overnight (see plot over 4 days below). With the EBL current, this is equivalent to about 9Ah overnight usage (about normal for me). The 6 hours main charge ended at 11:17am today and even at dusk, the battery is still not quite fully charged (but almost!). If the main charge had been delayed a couple of hours, the battery would have been fully charged early afternoon. I only have one 80Ah gel and a 110W panel which I think is a good match. We seem to be "wasting" available solar energy by starting the main charge early. I also include plots for the habitation and started battery voltages for reference. Hopefully this might be of interest to someone. Plwsm2000, that is how all good Motorhome chargers work, they need power to run the electronics to make the MPPT operate. It is well documented that no battery charger, Solar/Mains/Alternator is 100% efficient, they all take power from the source. Same with PWM regulators, but the time a good Solar Panel will stay in this intermediate state should be very short as the sun rising just a little should switch things around. Also all the best motorhome chargers are timer based. The LAS1218 charger module in your EBL, depending on year of manufacture, could be one with just a 1 hour timer, 4 hour timer and the latest EBL 30/119 range, a 16 hour timer. You will see some examples of charger timers on the web page 'How does a charger work' : http://www.aandncaravanservices.co.uk/how-does-a-charger-work.php including the EBL 119 chargers profile. The web page shows why it is so important to match the battery bank size to the charger otherwise very extended charging times result. That applies to Mains chargers and Solar chargers. Some of the Solar Regulators have just a 1 hour timer, but 4 hours is more typical. The Votronic's 6 hours is longer than most. Some of the the Victron range has a shorter timer 'out of the box' but has the advantage that you can alter the timers, but it gets complicated for most. This behaviour has been documented a long time along with the work around to get the best from the unit. It is very easy to restart the timer on any mains charger, just isolate it from power and it will restart the timer from the beginning to give you another 6 hours. Same applies to a Solar charger. If you look at our many posts you will see we repeatedly try to point out that just because the charger has dropped to 13.8v 'Float' charge doesn't equate to the battery being fully charged. As the 'How does a charger work' web page point out, depending on the battery bank size they may not even be half charged. You should also bear in mind that a Gel battery can take twice as long to charge as a modern wet battery. I'm still on the fence Solar cost wise seeing as we full time mostly on campsites :-S ........... That said our leccy bill is increasing in Spain 8-) .......... I blame her hair dryer......she blames my yacking on here :D ........ I'm aware that solar wont be able to provide the necessary when it comes to her hair dryer or my hoover :-| ........ So seeing as we only have a single leisure battery and rarely spend more than a few days off grid does the financial cost weight installation add up yet? :-S ........ Link to comment Share on other sites More sharing options...
Charles Posted May 24, 2019 Share Posted May 24, 2019 pelmetman - 2019-05-24 5:54 PM aandncaravan - 2019-05-24 10:47 AM plwsm2000 - 2019-05-23 8:19 PM As we have had a good few days of sun, I decided to take a look at some data that was logged over this week. I found a couple of minor issues with my Votronic MPP controller that might be of interest to others. I haven't used the van since last Sunday and it has been sitting on my drive with just the solar controller keeping the battery topped up. Apart from the EBL, nothing else has been switched on. My first observation is that at very low light levels, the Votronic controller actually takes MORE current from the battery than it puts in. It seems to take about 100mA when there is sufficient light on the panel to start up the controller, but not enough to generate any useful power. I have noted this on the first graph below. In normal usage, this extra current should not be that noticeable, but I was wondering what would happen if you were parked up during the day under very heavy shade? My second observation is that the Votronic starts its main charge phase immediately at startup (in my case at around 5am). Obviously there is very little solar power about at this time in the morning - just when the battery needs it most from the overnight usage. The first 2-3 hours of the main charge is therefore limited by the available solar energy rather than what the battery is demanding. Even doubling the panels wouldn't make a vast difference at this time of day (two times not much is still not much!) On the gel setup, the main charge will last a maximum of 6 hours (finished before 11am at this time of year). It would be better if the Votronic delayed its main charge phase for a couple of hours, and just started up in a float charge mode. Even in this float charge mode, I would guess that the charge would still be restricted due to the low light levels at this time in the morning. On the second day, I temporarily disconnected the panel from the controller so that the Votronic restarted in main charge in the early afternoon just to see what happens. You can see the results on the 4 day plots. To see what happens when the van is occupied, last night I rigged up a 2 amp constant current load that switched on for 4 hours overnight (see plot over 4 days below). With the EBL current, this is equivalent to about 9Ah overnight usage (about normal for me). The 6 hours main charge ended at 11:17am today and even at dusk, the battery is still not quite fully charged (but almost!). If the main charge had been delayed a couple of hours, the battery would have been fully charged early afternoon. I only have one 80Ah gel and a 110W panel which I think is a good match. We seem to be "wasting" available solar energy by starting the main charge early. I also include plots for the habitation and started battery voltages for reference. Hopefully this might be of interest to someone. Plwsm2000, that is how all good Motorhome chargers work, they need power to run the electronics to make the MPPT operate. It is well documented that no battery charger, Solar/Mains/Alternator is 100% efficient, they all take power from the source. Same with PWM regulators, but the time a good Solar Panel will stay in this intermediate state should be very short as the sun rising just a little should switch things around. Also all the best motorhome chargers are timer based. The LAS1218 charger module in your EBL, depending on year of manufacture, could be one with just a 1 hour timer, 4 hour timer and the latest EBL 30/119 range, a 16 hour timer. You will see some examples of charger timers on the web page 'How does a charger work' : http://www.aandncaravanservices.co.uk/how-does-a-charger-work.php including the EBL 119 chargers profile. The web page shows why it is so important to match the battery bank size to the charger otherwise very extended charging times result. That applies to Mains chargers and Solar chargers. Some of the Solar Regulators have just a 1 hour timer, but 4 hours is more typical. The Votronic's 6 hours is longer than most. Some of the the Victron range has a shorter timer 'out of the box' but has the advantage that you can alter the timers, but it gets complicated for most. This behaviour has been documented a long time along with the work around to get the best from the unit. It is very easy to restart the timer on any mains charger, just isolate it from power and it will restart the timer from the beginning to give you another 6 hours. Same applies to a Solar charger. If you look at our many posts you will see we repeatedly try to point out that just because the charger has dropped to 13.8v 'Float' charge doesn't equate to the battery being fully charged. As the 'How does a charger work' web page point out, depending on the battery bank size they may not even be half charged. You should also bear in mind that a Gel battery can take twice as long to charge as a modern wet battery. I'm still on the fence Solar cost wise seeing as we full time mostly on campsites :-S ........... That said our leccy bill is increasing in Spain 8-) .......... I blame her hair dryer......she blames my yacking on here :D ........ I'm aware that solar wont be able to provide the necessary when it comes to her hair dryer or my hoover :-| ........ So seeing as we only have a single leisure battery and rarely spend more than a few days off grid does the financial cost weight installation add up yet? :-S ........ Is your fridge on LPG? We're in Benidorm so usually have plenty sunshine for everything except hair dryer and fridge. The fridge is on LPG and when she needs the hair dryer I switch the changeover switch to EHU (40c/kwh) 12kg gas lasts 30 days. That's the problem with solar, you economise so you use less power, so it's then not worth getting solar for what you save. The fridge on gas saves us about €20 a month though. Link to comment Share on other sites More sharing options...
Guest pelmetman Posted May 24, 2019 Share Posted May 24, 2019 Charles - 2019-05-24 6:30 PM pelmetman - 2019-05-24 5:54 PM aandncaravan - 2019-05-24 10:47 AM plwsm2000 - 2019-05-23 8:19 PM As we have had a good few days of sun, I decided to take a look at some data that was logged over this week. I found a couple of minor issues with my Votronic MPP controller that might be of interest to others. I haven't used the van since last Sunday and it has been sitting on my drive with just the solar controller keeping the battery topped up. Apart from the EBL, nothing else has been switched on. My first observation is that at very low light levels, the Votronic controller actually takes MORE current from the battery than it puts in. It seems to take about 100mA when there is sufficient light on the panel to start up the controller, but not enough to generate any useful power. I have noted this on the first graph below. In normal usage, this extra current should not be that noticeable, but I was wondering what would happen if you were parked up during the day under very heavy shade? My second observation is that the Votronic starts its main charge phase immediately at startup (in my case at around 5am). Obviously there is very little solar power about at this time in the morning - just when the battery needs it most from the overnight usage. The first 2-3 hours of the main charge is therefore limited by the available solar energy rather than what the battery is demanding. Even doubling the panels wouldn't make a vast difference at this time of day (two times not much is still not much!) On the gel setup, the main charge will last a maximum of 6 hours (finished before 11am at this time of year). It would be better if the Votronic delayed its main charge phase for a couple of hours, and just started up in a float charge mode. Even in this float charge mode, I would guess that the charge would still be restricted due to the low light levels at this time in the morning. On the second day, I temporarily disconnected the panel from the controller so that the Votronic restarted in main charge in the early afternoon just to see what happens. You can see the results on the 4 day plots. To see what happens when the van is occupied, last night I rigged up a 2 amp constant current load that switched on for 4 hours overnight (see plot over 4 days below). With the EBL current, this is equivalent to about 9Ah overnight usage (about normal for me). The 6 hours main charge ended at 11:17am today and even at dusk, the battery is still not quite fully charged (but almost!). If the main charge had been delayed a couple of hours, the battery would have been fully charged early afternoon. I only have one 80Ah gel and a 110W panel which I think is a good match. We seem to be "wasting" available solar energy by starting the main charge early. I also include plots for the habitation and started battery voltages for reference. Hopefully this might be of interest to someone. Plwsm2000, that is how all good Motorhome chargers work, they need power to run the electronics to make the MPPT operate. It is well documented that no battery charger, Solar/Mains/Alternator is 100% efficient, they all take power from the source. Same with PWM regulators, but the time a good Solar Panel will stay in this intermediate state should be very short as the sun rising just a little should switch things around. Also all the best motorhome chargers are timer based. The LAS1218 charger module in your EBL, depending on year of manufacture, could be one with just a 1 hour timer, 4 hour timer and the latest EBL 30/119 range, a 16 hour timer. You will see some examples of charger timers on the web page 'How does a charger work' : http://www.aandncaravanservices.co.uk/how-does-a-charger-work.php including the EBL 119 chargers profile. The web page shows why it is so important to match the battery bank size to the charger otherwise very extended charging times result. That applies to Mains chargers and Solar chargers. Some of the Solar Regulators have just a 1 hour timer, but 4 hours is more typical. The Votronic's 6 hours is longer than most. Some of the the Victron range has a shorter timer 'out of the box' but has the advantage that you can alter the timers, but it gets complicated for most. This behaviour has been documented a long time along with the work around to get the best from the unit. It is very easy to restart the timer on any mains charger, just isolate it from power and it will restart the timer from the beginning to give you another 6 hours. Same applies to a Solar charger. If you look at our many posts you will see we repeatedly try to point out that just because the charger has dropped to 13.8v 'Float' charge doesn't equate to the battery being fully charged. As the 'How does a charger work' web page point out, depending on the battery bank size they may not even be half charged. You should also bear in mind that a Gel battery can take twice as long to charge as a modern wet battery. I'm still on the fence Solar cost wise seeing as we full time mostly on campsites :-S ........... That said our leccy bill is increasing in Spain 8-) .......... I blame her hair dryer......she blames my yacking on here :D ........ I'm aware that solar wont be able to provide the necessary when it comes to her hair dryer or my hoover :-| ........ So seeing as we only have a single leisure battery and rarely spend more than a few days off grid does the financial cost weight installation add up yet? :-S ........ Is your fridge on LPG? We're in Benidorm so usually have plenty sunshine for everything except hair dryer and fridge. The fridge is on LPG and when she needs the hair dryer I switch the changeover switch to EHU (40c/kwh) 12kg gas lasts 30 days. That's the problem with solar, you economise so you use less power, so it's then not worth getting solar for what you save. The fridge on gas saves us about €20 a month though. Kinda concur as we dont actually need to save money, but I've always been green :D....... although back then it was called being mean ;-) ....... We also got through a bottle of gas a month in the winter using the heating, cooking and the fridge on gas ;-) ....... But our fridge in the guest wing (Carlight Caravan) is a old fashioned small fridge with a tiny freezer that doesn't use as much gas or leccy as those new fangled stack fridge/freezers you posh folk have :D ...... So I get the feeling .......unless leccy in Spain becomes seriously expensive.......Or I need to live off grid for long periods?.......Or need to leave my camper parked up for weeks .........It's not required for my current circumstances? ;-) ....... BTW I must ask.......seeing as I'm being driven North by the heat.......is it not getting a bit warm down their? :-S ........ Link to comment Share on other sites More sharing options...
plwsm2000 Posted May 24, 2019 Author Share Posted May 24, 2019 spirou - 2019-05-23 9:12 PM Just wondering what you're recording this with and how you power it? I used an RPi to do the same and it used around 0.16A. Not much in summer but quite significant in winter. spirou, I designed this myself (both the hardware and software) at the component level (I am an electronics design engineer by profession and this is a hobby project). It is powered from the 12V habitation battery (Schaudt calls this the "lighting" power to the DT220 display unit but it is only used to power the DT220). The unit takes less than 1 milliamp (about 800uA) in normal operation and so is permanently on. The current goes up to about 3mA when connected to the Android app. over Bluetooth. pm me if you want any more details. Allan, Yes - I understand about the normal EHU charger mode, but with EHU, there is no restriction on available power in the same way as for solar. My issue is that for the 2-3 hours from sun rise (which comes off of the 6 hour main charge time), the solar controller will never be able to deliver anything like the current needed. That is why I suggested it would be better to delay the main charge for a couple of hours so you get the full 6 hours main charge when there is likely to be a reasonable amount of solar energy available. Having a switch to restart the solar main charge is a good idea, but I don't suppose many people would think about doing this?. It is only worth doing if your battery had heavy overnight use and the morning was a bit overcast (i.e little solar) Charles - 2019-05-24 4:02 PM Well it's been cloudy here all day and the solar has just been managing about 1.7 amps. The sun came out 2 minutes ago at 4.58pm and the charge rate went up to 5.6 amps so it looks like our Votronic duo 250 stays on bulk charge until it's work is done. B-) Edit 7.5 amps now :D Charles, From my test, the main (bulk) charge time is continuous (once it starts up at sunrise, the main charge will end 6 hours max. later irrespective of how lttle current is used). What is important is to check the voltage (rather than current) to see whether the solar controller is in main charge or float charge mode. Obviously if your battery is still some way off being fully charged, it will still take a decent amount of current even at the float voltage. Also any other consumers can draw current at any time from the solar (at any voltage) so this current may not all be going back into the battery. Link to comment Share on other sites More sharing options...
Bulletguy Posted May 24, 2019 Share Posted May 24, 2019 pelmetman - 2019-05-24 7:17 PM Charles - 2019-05-24 6:30 PM Is your fridge on LPG? We're in Benidorm so usually have plenty sunshine for everything except hair dryer and fridge. The fridge is on LPG and when she needs the hair dryer I switch the changeover switch to EHU (40c/kwh) 12kg gas lasts 30 days. That's the problem with solar, you economise so you use less power, so it's then not worth getting solar for what you save. The fridge on gas saves us about €20 a month though. Kinda concur as we dont actually need to save money...... Yet shocked at his rising electricity costs and wants to know if the "financial cost installation [of solar] adds up". Hardly the sign of someone who "doesn't need to save money". (lol) Link to comment Share on other sites More sharing options...
Charles Posted May 25, 2019 Share Posted May 25, 2019 Bulletguy - 2019-05-24 10:50 PM pelmetman - 2019-05-24 7:17 PM Charles - 2019-05-24 6:30 PM Is your fridge on LPG? We're in Benidorm so usually have plenty sunshine for everything except hair dryer and fridge. The fridge is on LPG and when she needs the hair dryer I switch the changeover switch to EHU (40c/kwh) 12kg gas lasts 30 days. That's the problem with solar, you economise so you use less power, so it's then not worth getting solar for what you save. The fridge on gas saves us about €20 a month though. Kinda concur as we dont actually need to save money...... Yet shocked at his rising electricity costs and wants to know if the "financial cost installation [of solar] adds up". Hardly the sign of someone who "doesn't need to save money". (lol) You could start an argument in an empty room (lol) Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.