Solar charging voltage

[david lloyd]

Our 2013 Mercedes based Autosleeper Worcester is equipped with a (standard glass) 120W solar panel wired directly to the leisure batteries (2 X Varta LFD90) via a Votronic Duo 165 MPPT controller. In recent days there has been some good sunny spells with the panel producing as much as 6 - 7 amps but, despite that the State of Charge reading on the Sergent control panel has decreased by about 10% a day and not increased.

 

Two days ago we stayed on a site with EHU and the State of Charge went back up to 100% over 24 hours with the solar computer showing, at times, a charge voltage of 14.4v reducing back to 13.3v which is pretty much what I would expect to see.

 

However, previous to having that hookup and also in the past two days, the charging voltage has not gone above 13.4v even when it showed the panel producing up to 7 amps. I would have expected the solar charge rate to go up to 14.4v just like the mains charger.

 

So far, I have disconnected the temperature sensor from the Votronic but nothing changed so I swapped the Votronic for a Victron 75/10 MPPT controller that I had fitted previously. Still no change. The voltage at the panel input to the regulator is between 17.7 and 18.05v on my multimeter.

 

So, any thoughts? Am I correct in believing that the SofC will not rise if the charge voltage doesn't get up to 14.4v and, if so, what are the probable causes

.

 

David

[spirou]

Am I right in assuming you're only seeing the voltage and solar amps but not EHU amps or consumption?

 

And is it possible that your consumption is somehow even greater than the 6-7 amps coming from the votronic/victron? From the looks of things that's my first thought.

[david lloyd]

Thanks for your thoughts spirou - during the day most 12v use is not used (TV, lights etc) and even at night there is little lighting and no heater fan so certainly during the day I am not using all the solar input. The Sergent panel confirms as little as 0.5 amps outgoing.

 

The readings are from the Votronic solar computer which is connected to the controller and measuring the voltage at the battery terminals - so off EHU even with the computer showing up to 7 amps coming in the battery (charging) voltage is not going higher than 13.4v. As soon as the mains charger is on the voltage reading goes up to 14.4v until it reaches the time to return to float charge.

 

David

[Wortho]

I have the Votronics 165 but with EBL system and have observed voltage as high as 14.7v (AGM setting) but then it drops to around 13.4v which I assumed normal and just moving from absorption/bulk charge to maintenance charge. Like you however if I plug mains in I can see voltage increase again beyond 14v so wonder if perhaps the solar reg has gone into maintenance/float mode to early. I assume the solar reg determines which charge profile to use based on battery resistance increasing as the battery charges, however i'm not sure and perhaps it is also time or is voltage based. I guess a test would be to disconnect the feed from the solar reg when at float voltage and see if it moves to the higher absorption voltage and how long it stays in that mode.

[spirou]

Float mode and 7amps don't make sense. No ideas right now

[plwsm2000]

Most if not all "State of charge" indicators, calculate the SoC by measuring the current in and out of the battery and factor in the size (Ah) of the battery you have set. They don't try the measure the SoC directly from the battery voltage.

Given that your solar controller is connected directly to the battery and not through the EBL, your EBL will not see the solar charge current and so will not increase the SoC display. To me, what you are seeing with your setup is to be expected.

 

The Votronic, when set for Lead acid batteries, will only apply its main (bulk) charge for a set time from sunrise (or as soon as there is sufficient voltage on the panel). On a good day, this can occur up to 10-20 mins before sunrise.

The main 14.4V charge will only last 4 hours and at this time of year, it will end around 9-10am. Obviously there is small amount of solar POWER early morning so the main charge will be limited. This is the biggest downside of the Votronic (and most other solar regulators) IMO.

If you were to cover or disconnect the panel at midday for about 20 seconds, the controller will restart the 4 hour timer and you should see the full 14.4V charge.

 

[mikefitz]

If the solar controller is wired direct to the batteries any current flow into the batteries will not be recorded by the Sargent electronics, ( if the Sargent calculates state of charge based on power in/power out).

Solar at 7 amps with a voltage not exceeding 13.4 and the controller in bulk state, ( the Victron will indicate charge mode), should charge the batteries in a few hours given the light use.

 

Could there be some electronics 'clamping' the voltage to this 13.4 level, perhaps the Sargent charger? There may be a conflict caused by the Sargent system and the 13.4 level activates other systems, (engine battery charging?, fridge in 12v mode?).

 

I suggest a test with nothing connected to the batteries except the solar charger, perhaps just use one of the batteries for this test. This will confirm that the charger is indeed going through bulk, absorption and float.

 

Mike

[david lloyd]

plwsm2000 - 2019-08-24 10:26 AM

 

Most if not all "State of charge" indicators, calculate the SoC by measuring the current in and out of the battery and factor in the size (Ah) of the battery you have set. They don't try the measure the SoC directly from the battery voltage.

Given that your solar controller is connected directly to the battery and not through the EBL, your EBL will not see the solar charge current and so will not increase the SoC display. To me, what you are seeing with your setup is to be expected.

 

The Votronic, when set for Lead acid batteries, will only apply its main (bulk) charge for a set time from sunrise (or as soon as there is sufficient voltage on the panel). On a good day, this can occur up to 10-20 mins before sunrise.

The main 14.4V charge will only last 4 hours and at this time of year, it will end around 9-10am. Obviously there is small amount of solar POWER early morning so the main charge will be limited. This is the biggest downside of the Votronic (and most other solar regulators) IMO.

If you were to cover or disconnect the panel at midday for about 20 seconds, the controller will restart the 4 hour timer and you should see the full 14.4V charge.

 

Thanks for the advice. Just to confirm, my supply system is not. An EBL but the Sergent EC500 with a Sergent EC328 control panel.it could well be as you say though as this originally had a 30 W panel wired direct to a built in PWM controller that was replaced earlier this year with the Vitronic wired direct to the batteries. The SOC indicator on the panel shows a decrease in % daily but on EHU will go back up when fully charged to 100%. However, when the Vitronic is fitted this has a Batt Full LED which has not been lit since being off EHU. Similarly, it has the solar computer connected with a sun symbol to show a charge is there but this should turn to a flashing symbol once fully charged which it has not done since being off EHU.

 

I have done as suggested and covered the panel from 12.00 to 12.30 with the following results.

 

Using the Victron controller the figures on the Smartsolar app showed that with the panel off the solar voltage was initially 17.7v and the current was 0.0 amps. On the battery it showed voltage as 12.87v, current as 0.0 amps and the State as 'Off' just before removing the cover I noted these readings again and the solar voltage has slowly risen to 17.36v whilst the battery voltage had slowly dropped to 12.71v

 

Once uncovered the readings were showing the the solar voltage fluctuating between 16 and 17v with the current around 4.0 amps. The battery voltage reads 13.3v and the current 4.9 amps - the State is 'Bulk'

 

I have just noticed that the Load output state is 'On' and shows a current of 0.1 amp

 

I am just about to try the next suggestion of switching off all the 12v connected to the batteries.

 

David

[david lloyd]

mikefitz - 2019-08-24 10:37 AM

 

If the solar controller is wired direct to the batteries any current flow into the batteries will not be recorded by the Sargent electronics, ( if the Sargent calculates state of charge based on power in/power out).

Solar at 7 amps with a voltage not exceeding 13.4 and the controller in bulk state, ( the Victron will indicate charge mode), should charge the batteries in a few hours given the light use.

 

Could there be some electronics 'clamping' the voltage to this 13.4 level, perhaps the Sargent charger? There may be a conflict caused by the Sargent system and the 13.4 level activates other systems, (engine battery charging?, fridge in 12v mode?).

 

I suggest a test with nothing connected to the batteries except the solar charger, perhaps just use one of the batteries for this test. This will confirm that the charger is indeed going through bulk, absorption and float.

 

Mike

 

Thanks mikefitz,

 

OK, so second test done. Covered solar panel and switched regulators to Votronic then uncovered panel with all 12v switched off. This gave the following readings. Solar voltage 17.3v and 4.5amp. Battery voltage 13.2v.

With the 12v system back on the readings were Solar panel 17.6v, 4.3 amp and the battery voltage 13.2v.

 

I checked the EC328 display which showed the following information, Voltage (leisure batt) 13.1v, capacity (leisure batt) 82%, solar input 0.0 amp, Batt amps 0.3 amps.

 

This confirms no solar input going through Sergent system (as expected) and that it is reading the same battery voltage as that on the Votronic solar computer and at the terminals on the regulator. The capacity has not gone up though from this morning and this is confirmed on the Votronic equipment as the solar computer sun system is not flashing and the LED's for MPP and Charge are lit on the regulator but the Batt Full and >80% are not lit.

 

My two Varta LFD 90 batteries are less than one year old with good charging regimes at home etc. The starter battery was new in May when the old one gave up in France and is an Exide L5 EFB 95ah. Could it be that neither regulator is big enough to handle these three batteries? A total bank of 275ah. Or is the panel itself not giving enough voltage (around 17.5) to get the charge rate up?

 

David

 

PS just another thought, the Sergent system allows you to change the size of the batteries and mine is set at 180ah - should this be set at the sum of leisure and starter batteries - ie 275ah and would that have a 'clamping' effect?

[plwsm2000]

Sorry - I used "EBL" as a generic term for the system that controls and monitors the 12V side.

 

I am not 100% certain, but the "Batt full" and ">80%" LEDs on the Votronic can be misleading and only relate to the status of the Votronic controller and not from the actual battery voltage or state of charge.

 

The Votronic manual description for the LEDs is -

“Batt. Full“: Battery fully charged, green

If it is lighting: Battery (batteries) has(have) been charged to 100 %, trickle charging U2, finished.

If it is lighting dimly: Main charging process is still effected in the charging phase U1.

Off: Main charging process is still effected in the charging phase I.

 

>80 %“: green

If it is lighting: The solar controller is in the charging phase U1, the battery will be charged fully.

 

So I read this as "Batt full" is on when the solar controller ends the charging phase U1 (absorption) and is now trickle charging. So if it has been fully charged by some external charger, the LED may still be off.

Also ">80%" means solar charger is still in charging phase U1 and is getting the maximum charge from the available solar power.

 

On the Votronic (not sure about the Victron), the solar panel voltage must drop below 11V for at least 20 seconds (MPP LED flashes every couple of seconds) before it will restart.

 

Re: Your other other post, the capacity should just be for the leisure batteries (180Ah in your case) so don't include the starter battery capacity.

 

I assume your Votronic switches are set correctly? (switch 3 up for lead acid)

 

Nothing happens particularly fast with solar controllers and you might need to wait for several minutes (sometimes hours) for things to happen.

 

 

 

 

[david lloyd]

Thanks again my friend especially for the explanation of the LED status.yes the battery switch (3) is in the up position - it was the first thing I checked and hoped that ‘up’ was on rather than the switch being down and all the other three up!

 

I have put everything back as it was wired to the Votronic regulator and solar computer. Although the sun is falling a bit now the charge voltage is up over 18v so I guess you are right about things taking a bit of time to settle down. Will see how it looks tomorrow after it has shut down overnight.

 

I suppose the one thing really confusing me is, although the LED’s indicate it is in the main charging phase, it is just not reaching 14.4v but, as yet, the batteries are holding up.

 

Any thoughts on the possibility that either the panel or the regulator (or both) are simply not up to charging the three batteries fully?

 

David

[BruceM]

I’m not familiar with the Sargent EC500 but having read the posts my thoughts on this issue are

 

1. We’ve established that the SoC is a red herring as it’s bypassed by the solar regulator. I note from one of Allan’s old posts ( https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/help-with-solar-electrics/51076/ ) that the EC500 is designed to accept the output of an external solar regulator so you might want to consider wiring the solar regulator habitation output through the EC500 if you would like your SoC readings to be meaningful.

 

2. Are you confident that when you installed the Votronic it was all wired in correctly and securely– ie hab supply to hab batteries and starter supply to starter batteries? I say this having just today tracked an under voltage measuring fault on the van's hab control panel down to a poor connection at one of the hab batteries.

 

3. Diagnostically, with the all habitation 12v turned off, I’d pull the solar master fuse – or cover the solar panels with blankets, disconnect the solar regulator from the habitation batteries to totally power it down, then reconnect the solar regulator and then reconnect/uncover the solar panels. Assuming that it’s daytime I’d use a multimeter to check the voltage at the habitation batteries and then check the voltage on the regulator hab output terminals. Naturally the voltages should be the same and initially over 14v. If that voltage is achieved, then I’d leave well alone for four or five hours and check the voltages again. If they’re down to about 13.1v then everything is fine. At this point I’d expect to see the solar regulator’s 'battery full' led lit and possibly the 'AES' led lit. You’ll note that I’ve ignored the solar computer throughout – that’s an extra variable we can do without.

 

Incidentally, I have the Votronic Duo 250 (because I have 200W of solar) with twin Varta’s for habitation and it copes just fine and kicks out the required charging voltage when the batteries require it.

 

[david lloyd]

BruceM - 2019-08-24 4:34 PM

 

I’m not familiar with the Sargent EC500 but having read the posts my thoughts on this issue are

 

1. We’ve established that the SoC is a red herring as it’s bypassed by the solar regulator. I note from one of Allan’s old posts ( https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/help-with-solar-electrics/51076/ ) that the EC500 is designed to accept the output of an external solar regulator so you might want to consider wiring the solar regulator habitation output through the EC500 if you would like your SoC readings to be meaningful.

 

2. Are you confident that when you installed the Votronic it was all wired in correctly and securely– ie hab supply to hab batteries and starter supply to starter batteries? I say this having just today tracked an under voltage measuring fault on the van's hab control panel down to a poor connection at one of the hab batteries.

 

3. Diagnostically, with the all habitation 12v turned off, I’d pull the solar master fuse – or cover the solar panels with blankets, disconnect the solar regulator from the habitation batteries to totally power it down, then reconnect the solar regulator and then reconnect/uncover the solar panels. Assuming that it’s daytime I’d use a multimeter to check the voltage at the habitation batteries and then check the voltage on the regulator hab output terminals. Naturally the voltages should be the same and initially over 14v. If that voltage is achieved, then I’d leave well alone for four or five hours and check the voltages again. If they’re down to about 13.1v then everything is fine. At this point I’d expect to see the solar regulator’s 'battery full' led lit and possibly the 'AES' led lit. You’ll note that I’ve ignored the solar computer throughout – that’s an extra variable we can do without.

 

Incidentally, I have the Votronic Duo 250 (because I have 200W of solar) with twin Varta’s for habitation and it copes just fine and kicks out the required charging voltage when the batteries require it.

 

Thanks bruceM that’s very helpful. Just to confirm though my Votronic Regulator is the 165 Duo (hence

the question regarding it being man enough for the job) and doesn’t have the AES facility of the 250.

 

During the tests described above I did, in fact, remove the regulator in addition to covering the solar panel before restarting with the results as shown. The voltages shown are taken by multimeter at the solar regulator terminals (right next to the leisure batteries) as I cannot get full access to the battery terminals under the passenger seat. Upon restart the voltages never reach 14 v which remains my main concern.

 

David

[plwsm2000]

The voltage will only get to 14.4V if there is sufficient current available to charge the battery beyond the bulk phase (see attached pic from Votronic manual).

A partly discharged battery will try to draw quite a large current initially, and if there is not enough solar energy, the voltage will take some time to reach this voltage. Also attached is a plot that I recorded at the end of May on my system that has a Votronic 250W, a similar size panel (for now) but only one hab. battery There would be little difference between a 160W and 250W controller with the same size panel, but having twice the hab. battery size will take longer to charge up.

 

The Votronic only puts out 1A maximum to the starter battery so is not a major factor. I rarely see my starter battery take more than 0.3A just sitting on the drive.

 

Your panel size vs battery capacity is probably on the small side but on a good day, the battery should get fully charged (depending of course how much you have taken out of them beforehand) .

 

 

(edit - Just to add the current plot corresponding to the voltage plot)

[spirou]

The question is whether the batteries were so discharged after the last EHU charge, that the solar panels didn't get to finish the entire bulk phase. But if you start with >12.8V in the morning I don't suppose the solar charge should have a problem getting up to 14+

[david lloyd]

spirou - 2019-08-24 9:12 PM

 

The question is whether the batteries were so discharged after the last EHU charge, that the solar panels didn't get to finish the entire bulk phase. But if you start with >12.8V in the morning I don't suppose the solar charge should have a problem getting up to 14+

 

Hi spirou - fortunately I have kept a record (albeit just from the Sergent panel) since leaving the hookup with following results taken roughly at 2pm then 10pm.

 

Thursday - 2pm - 99% capacity 14.4v 10pm - 90% capacity 12.7v

Friday - 2pm - 90% capacity. 13.4v. 10pm - 82% capacity 12.4v

Saturday - 2pm - 82% capacity 13.3v 10pm - 76% capacity 12.4v

Sunday - 2pm - 76% capacity 13.2v

 

So, when we left the site on Thursday the voltage was up at 14 4v falling to 12.7 by nightfall then each day, despite the seemingly falling capacity, the voltage never gets above 13.4ish and at night is down to 12.4v.

 

Following on from bruceM's post I have had more advice to check that the incoming amps are not being misdirected to the starter instead of leisure battery so I am hoping to give that a try next.

 

David

[david lloyd]

OK so another test completed. With +3amps from the solar I checked the starter battery which was at 12.5v and the hab batts were at 13.2v so it doesn't look like the incoming amps are going to the starter battery. Just as another test that was suggested I put the ignition on and turned on the headlights then took the readings again. The starter battery fell to 11.8v but the hab batts stayed at 13.2v - then, with the engine running, the starter battery went up to 13.8v and the hab batts stayed at 13.2v.

 

I had little or no idea to start with but have tried various good ideas suggested by others to no avail .......maybe, there's nothing wrong?

 

David

[plwsm2000]

Do you have access to a DC current clamp? Something like this [url=] https://www.ebay.co.uk/itm/UNI-T-UT210E-Digital-Handheld-Clamp-Multimeter-Tester-DMM-Voltmeter-AC-DC-Meter/392118967556 [/url] has been discussed on this forum before. It is a very useful item for fault finding.

 

If you have a DC clamp, measure the current on the positive cable between the solar reg and the battery + and check it agrees with the displayed solar current.

Then put the clamp on the cable from the battery + to the Sargent charger. With all your 12V consumers off, this should be quite a low current. The difference between the two readings is the actual current going into (or out of) the battery. If they are similar, most of the solar current is going somewhere other than into your battery, and so it will not get fully charged.

 

Your EHU charger can deliver much more current than the solar regulator and will drive the other loads with a bit to spare to put a reasonable charge into the battery to acheive the 14.4V.

 

I don't suppose your EC500 could be clamping the battery voltage? (it would be a pretty poor design if it did). I am thinking that the Sargent unit is working in a unusual mode in that it has no EHU power or internal solar, so you are back driving the Sargent unit when it has no input power of its own. Does anyone else have a similar setup (solar connected direct to the battery)? I can't believe they would do this but worth asking the question as I am running out of ideas.

 

 

[david lloyd]

plwsm2000 - 2019-08-25 6:53 PM

 

Do you have access to a DC current clamp? Something like this [url=] https://www.ebay.co.uk/itm/UNI-T-UT210E-Digital-Handheld-Clamp-Multimeter-Tester-DMM-Voltmeter-AC-DC-Meter/392118967556 [/url] has been discussed on this forum before. It is a very useful item for fault finding.

 

If you have a DC clamp, measure the current on the positive cable between the solar reg and the battery + and check it agrees with the displayed solar current.

Then put the clamp on the cable from the battery + to the Sargent charger. With all your 12V consumers off, this should be quite a low current. The difference between the two readings is the actual current going into (or out of) the battery. If they are similar, most of the solar current is going somewhere other than into your battery, and so it will not get fully charged.

 

Your EHU charger can deliver much more current than the solar regulator and will drive the other loads with a bit to spare to put a reasonable charge into the battery to acheive the 14.4V.

 

I don't suppose your EC500 could be clamping the battery voltage? (it would be a pretty poor design if it did). I am thinking that the Sargent unit is working in a unusual mode in that it has no EHU power or internal solar, so you are back driving the Sargent unit when it has no input power of its own. Does anyone else have a similar setup (solar connected direct to the battery)? I can't believe they would do this but worth asking the question as I am running out of ideas.

 

 

Thanks Phil, I don't have access to a DC current clamp at the moment although this has been suggested to me from elsewhere and, assuming I'm not going to find an answer anytime soon, it is something I will try to get hold of who we get home early September.

 

I'm certainly not sure what effect bypassing the Segent EC500 has had. Initially, when the built in PWM controller failed in the spring,I had the Victron 75/10 fitted temporarily in its place, directly through the EC500. This was working well but the installer felt it would be far more efficient if it were wired directly to the battery - something generally supported by Allan Evans of aandncaravans. When we returned from the France trip I had decided (as the vehicle battery had failed whilst on the trip) to do that but change the Victron for the Votronic Duo to charge both leisure and stater battery. It does seem that since making that change (to Votronic wired direct to batteries) the charge controller has not been able to get up to the desired 14.4v needed to achieve full charging mode.

 

David

[spirou]

Going from the SOC chart Allan usually posted

http://www.aandncaravanservices.co.uk/resources/Battery%20Yuasa%20state%20of%20Charge%20Chart.jpg

 

Your reading of 12.4 (possibly even lower in the morning) leads me to think the LFD batteries are quite discharged, possibly quite a bit below 50%. The drop to 12.7 on the first evening and the high solar amps you're seeing without expected rise in voltage further lead me down that road. Since you're dealing with a 180Ah bank you're talking a deficit of around 90Ah or more and that will take a very long time to recharge on 120W of solar alone. And we already know the SOC display is off as it doesn't count everything going in and out.

 

Without any further ideas, I'd park the MH somewhere on EHU and leave it plugged in for at least 2 days or at least until sargent unit switches to float charge for several hours.

[Brambles]

Just a quick note on the EC500. It incorporates Smart charging. From what I understand about this it checks the vehicle batt and if below 12.4 volts sends the charge current to it for 4 hours before reverting back to the leisure battery. Hence why maybe it is recommended to connect the votronic (or other dual output solar regulators) directly to the batteries bypassing the EC500 so there are no conflicts.

 

Might be worth setting the EC500 via the control unit to disable smart charging and select the leisure battery and see if it makes a difference. Thing is this also means EHU will not maintain the vehicle battery.

 

Reading through the EC500 system manuals it mentions frost protection for water tanks. Could this be drawing the power applying additional load on the batteries the solar power cannot keep up with. Worth checking it is disabled if fitted. Long shot as not being reflected in computer displaying current drain from batteries - but I am now at the clutching of straws to find what may be wrong.

 

I agree about purchasing/borrowing/stealing a DC clamp meter... makes life a lot easier to trace where current is flowing and is a very useful tool to have when tracing faults.

 

Jon.

[david lloyd]

spirou - 2019-08-25 9:03 PM

 

Going from the SOC chart Allan usually posted

http://www.aandncaravanservices.co.uk/resources/Battery%20Yuasa%20state%20of%20Charge%20Chart.jpg

 

Your reading of 12.4 (possibly even lower in the morning) leads me to think the LFD batteries are quite discharged, possibly quite a bit below 50%. The drop to 12.7 on the first evening and the high solar amps you're seeing without expected rise in voltage further lead me down that road. Since you're dealing with a 180Ah bank you're talking a deficit of around 90Ah or more and that will take a very long time to recharge on 120W of solar alone. And we already know the SOC display is off as it doesn't count everything going in and out.

 

Without any further ideas, I'd park the MH somewhere on EHU and leave it plugged in for at least 2 days or at least until sargent unit switches to float charge for several hours.

 

Thanks again spirou. Certainly think the low readings now are to be expected after 4 nights/5 days off hookup with (apparently) nothing going back into the batteries. We are due to leave here tomorrow and will be on a site for a few days so will get the charge required then back to monitoring what is happening back home.

[david lloyd]

Brambles - 2019-08-26 12:30 AM

 

Just a quick note on the EC500. It incorporates Smart charging. From what I understand about this it checks the vehicle batt and if below 12.4 volts sends the charge current to it for 4 hours before reverting back to the leisure battery. Hence why maybe it is recommended to connect the votronic (or other dual output solar regulators) directly to the batteries bypassing the EC500 so there are no conflicts.

 

Might be worth setting the EC500 via the control unit to disable smart charging and select the leisure battery and see if it makes a difference. Thing is this also means EHU will not maintain the vehicle battery.

 

Reading through the EC500 system manuals it mentions frost protection for water tanks. Could this be drawing the power applying additional load on the batteries the solar power cannot keep up with. Worth checking it is disabled if fitted. Long shot as not being reflected in computer displaying current drain from batteries - but I am now at the clutching of straws to find what may be wrong.

 

I agree about purchasing/borrowing/stealing a DC clamp meter... makes life a lot easier to trace where current is flowing and is a very useful tool to have when tracing faults.

 

Jon.

 

Hi Jin - thanks. The SMART function was still selected so have turned that back to LEISURE and the charging type to NORMAL.

 

The water tank heaters are selected on a separate switch in the control panel (rather than through the settings) and they have always been off so don't think they have been involved.

 

Just because we are due to leave tomorrow I will have the vehicle running a while later today to empty/fill tanks etc. Spent the evening wondering if I should reconnect the Votronic back through the EC500?

 

David

[Brambles]

Just a note to say smart charging is desirable for long lay ups though to maintain the engine battery if you are on hook up and there is no sun for solar charging.

 

and..of course it could just be you are using much more power than you realise and solar is just to not up to replacing it all. Much easier to check once you are back home.

 

 

[david lloyd]

It's all pretty much guesswork on my part Jonathan, if the SOC reading is anywhere near true I'm guessing I'm using 10% capacity per day - about 18amps, which would mean being down to about 50% DoD by now - that's if there is nothing much going back in - and pretty much what I am seeing. Am I right in thinking that, in order to get a good bulk charge, the voltage does need to be around 14.4v? And therefore, if it is only ever reaching 13.4v (for whatever reason) there will hardly be any charge going in?

 

Hence my recent question about whether the panel and/or regulator are man enough to cope - which is something you seem to be hinting at?

 

Thanks for all the help so far.

David