Seven days camping off the grid, batteries slowly winding down.
iana said
06:45 AM Jul 21, 2020
450 Watts of solar flat mounted, 2 x 120 AH batteries, and the system wired in series to an MPPT controller. Sun lower on the horizon, days beautiful and sunny, and a compressor fridge helping its self to the battery power, plus charging all of our gadget's. So still not enough capacity in either panels or batteries to stop the inevitable spiral down of battery charge. Now back on the grid, and the restrictions have gone. Probably need to invest in a portable panel, so I can angle it to catch the morning sun energy, but that's weight, can't win.
Aussie1 said
09:51 AM Jul 21, 2020
Never experience that problem. We have solar but the generator is always there as a back up. To easy. I just refuse to be inconvenienced. Weight not a problem for us fortunately.
Colin Penrose said
11:06 AM Jul 21, 2020
Hi mate. I had the same problem. Only 200w flat on the roof. I had just installed a fridge in my Hilux with a battery charged from the car. I added an Anderson plug to that set up plus one on the side of my caravan connected to the van charger. I then purchased a 160w folding panel (without the controller) to boost the charge on both, at different times of course. The Hilux battery normally just needs a top up with the morning sun. Obviously pointed east before I go to bed. I made a three metre wire rope to secure the panel to the a bar. Not had a problem since and even an overcast day gives you a dribble of power. Oh yes also I al total 12v now including van fridge but I Di have gas bbq and diesel heater. Hope this helps. Col
Noelpolar said
10:53 PM Jul 21, 2020
800w for me in winter down south....
Whenarewethere said
11:15 PM Jul 21, 2020
Are the panels clean, is the wiring heavy enough & do you get a tiny shadow anywhere on a single panel.
Peter_n_Margaret said
11:34 PM Jul 21, 2020
Did they used to do the job before and don't now or have they never done the job?
What max charge rate do you see in full sun?
Cheers,
Peter
iana said
07:35 AM Jul 22, 2020
Yes the panels are clean, shadows yes, cant help that, unless I remove the air-con and the skylights. The panels are wired in series, so while the wiring is a good size, wiring in series overcomes any voltage drop. During the summer we got over 30 amps coming in, but the passed few days only got a max of 17 amps.
I think that a portable 200 watt panel would help, so I can position it to follow the sun.
Peter_n_Margaret said
09:37 AM Jul 22, 2020
Any panel with shade will produce almost nothing. If that panel is in series with others they will all produce about nothing.
Having panels in parallel will mean that only the panel with shade will stop producing.
Cheers,
Peter
Noelpolar said
09:51 AM Jul 22, 2020
iana wrote:
Yes the panels are clean, shadows yes, cant help that, unless I remove the air-con and the skylights. The panels are wired in series, so while the wiring is a good size, wiring in series overcomes any voltage drop. During the summer we got over 30 amps coming in, but the passed few days only got a max of 17 amps. I think that a portable 200 watt panel would help, so I can position it to follow the sun.
I was up in the flinders a few weeks ago.... 20 amps was common.... maybe high 20's occasionally is all I got out of my 800w.... and mostly only for the few hours when the sun was up a bit..... say 10:30 to 2pm ish..... long shadows this time of year etc.
Whenarewethere said
10:09 AM Jul 22, 2020
Have a look at the bottom of this page for my notes on shadows.
I don't have bypass or blocking diodes. There are 2 panels in series & 3 sets of them. A very small shadow will bring that set in series to its knees, so 1/3 of my 120 watts gone. A tiny shadow on each of 2 sets, 2/3 of 120 watts gone.
What was interesting on my setup was a shadow of each of the 3 sets, is I still had about 1/3 of the 120 watts.
If you can't move the panels you really have to think very carefully how you park so any vehicle self shadowing is minimised, as well as trees!
Yes the panels are clean, shadows yes, cant help that, unless I remove the air-con and the skylights. The panels are wired in series, so while the wiring is a good size, wiring in series overcomes any voltage drop. During the summer we got over 30 amps coming in, but the passed few days only got a max of 17 amps. I think that a portable 200 watt panel would help, so I can position it to follow the sun.
I was up in the flinders a few weeks ago.... 20 amps was common.... maybe high 20's occasionally is all I got out of my 800w.... and mostly only for the few hours when the sun was up a bit..... say 10:30 to 2pm ish..... long shadows this time of year etc.
Hi
Let me say clearly that if you want to go free camping for a while you need to put in as much power every day as you use. You cannot go long on the batteries alone. So if they are getting lower each day you do not have enough charging. Perhaps the posters here already know that but others reading here may need this spelling out.
Soooo how to do that ! There are suggestion made here, all standard things for solar. MORE solar, check the solar has no shading, that it is working as well as it should, get portable panels to chase the sun better, cut back on usage, LED lights, etc. In winter down south the sun is lower and the days shorter so care will be needed to select your sites.
Then what alternative charging do you have. The first should be your engine alternator, the best charger you have. Dumb alternators will supply a high constant voltage at a high rate, so rig that up with good wiring and perhaps that is all you need. Smart alternators will need a dc-dc charger that is bigger than most people buy, to cut the run time to a reasonable short time. EG if 20 Amps it will take 6 hrs to put in 120Ahr. At 40 amps it will take 3 hrs to do that. Basic maths.
A generator is the other means of charging. But if you have a 240V AC generator then you also need a big DC charger to get the power in to the battery in a reasonable time. So do the maths there too just like above. A small charger that charges over night is not big enough. I have a 12Vdc generator/charger that does 50Amps. I must admit that I never take it but it is an expensive but lighter option(aussie made too)
-- Edited by Jaahn on Wednesday 22nd of July 2020 10:35:47 AM
Tony Bev said
11:35 AM Jul 22, 2020
Hi Ian
I have only got 300 watts of solar on the roof, I had more or less the same problem as you
I purchased a lightweight (3½ Kg), 160 watt portable solar panel
It came with a built in 10 amp solar controller/charger
I fitted two Anderson type plugs, a grey one from the solar controller, and a red one direct from the fold up panel
From the grey Anderson type plug, I can go direct to any battery
From the red Anderson type plug, I go to the input of my DC/DC charger
I have seen 6½ amps going into my DC/DC charger
It is very handy, for early morning, and late afternoon solar harvesting, plus overcast days
When I connect it, I usually leave it, (day and night), until I leave that camp
Noelpolar said
11:45 AM Jul 22, 2020
FWIW.... for winter down south ..... I go for 4x Solar watts to battery AH (ie some would say 200w of solar for 100ah of battery.... I go 400w of solar to 100ah.... I use about 100ah a day..... so went with 200ah battery to 800w on flat van roof). Off course.... I only generally see my battery at 70% discharge as some of the 100ah consumed is straight from solar during the day.... so always have 2 or 3 days of really bad weather winter reserve.
In summer.... can tolerate some shade because of solar over provisioning for summer conditions. I went with 6 panels.... 3 parallel strings of 2 panels in series.... so some series benefit (higher voltage, smaller cable, slightly longer mppt on time), with some parallel shading mitigation.
I also didn't want to manually handle panels.... just want to relax. Haven't used a 240v charger in 18 months.... so probally could have saved $260.
-- Edited by Noelpolar on Wednesday 22nd of July 2020 11:52:33 AM
Craig1 said
08:36 PM Jul 22, 2020
Maybe a hijack, hopefully better than yet another thread. Is there an easy or simple way to check if panels are in series or parralell ? Had a dealer fitted single panel, then bought a same second panel off dealer, both 120w, but second panel fitted by local auto elec who has gone bush somewhere. He connected wires on the roof. Van is under carport at the moment which catches a little afternoon sun onto panels and according to input display in the boot ( around 14.8v-15.2).
thanks Craig
Mamil said
10:01 PM Jul 22, 2020
Craig1 wrote:
Maybe a hijack, hopefully better than yet another thread. Is there an easy or simple way to check if panels are in series or parralell ? Had a dealer fitted single panel, then bought a same second panel off dealer, both 120w, but second panel fitted by local auto elec who has gone bush somewhere. He connected wires on the roof. Van is under carport at the moment which catches a little afternoon sun onto panels and according to input display in the boot ( around 14.8v-15.2). thanks Craig
Craig, with that kind of voltage they will be in parallel. In parallel the voltage stays the same and the current doubles, in series the current stays the same and voltage doubles.
Whenarewethere said
10:18 PM Jul 22, 2020
Have a look at the link in my post a bit above. You probably will be bored to tears with data.
I have 2 & also had tested 3 panels in series. The MPPT controller will adjust the voltage output to what the battery needs. 2 panels in series is about 33 - 35 volts out of the panels. About 9amps from the MPPT into the batteries.
Maybe a hijack, hopefully better than yet another thread. Is there an easy or simple way to check if panels are in series or parralell ? Had a dealer fitted single panel, then bought a same second panel off dealer, both 120w, but second panel fitted by local auto elec who has gone bush somewhere. He connected wires on the roof. Van is under carport at the moment which catches a little afternoon sun onto panels and according to input display in the boot ( around 14.8v-15.2). thanks Craig
Craig, with that kind of voltage they will be in parallel. In parallel the voltage stays the same and the current doubles, in series the current stays the same and voltage doubles.
Hi Craig
+1 Mamil has summed it up exactly
If you had a PWM regulator then there is no benefit in using series, actually a waste of the new panel really. Series is only used for MPPT which can take the extra voltage and convert it to extra current
Jaahn
iana said
08:43 AM Jul 23, 2020
And just working on the above, I understood, that a battery required a higher voltage to get the final charge into the battery, i.e. finishing off the charge. On a cloudy day, the voltage of the panels is lower, and with a PWN regulator, the regulator is unable to get the batteries "finished off". With the MPPT regulator and the panels wired in series, the regulator can easily supply the 14.2v required and the batteries are then fully charged 100%. (if you have enough solar/time).
Peter_n_Margaret said
09:24 AM Jul 23, 2020
iana wrote:
And just working on the above, I understood, that a battery required a higher voltage to get the final charge into the battery, i.e. finishing off the charge. On a cloudy day, the voltage of the panels is lower, and with a PWN regulator, the regulator is unable to get the batteries "finished off". With the MPPT regulator and the panels wired in series, the regulator can easily supply the 14.2v required and the batteries are then fully charged 100%. (if you have enough solar/time).
No. Any pretty much regulator can provide enough voltage to "top up" the batteries. The MPV (maximum power voltage) of most 12V panels is around 18V and the light needs to be quite low before that drops to under 14.2V. A good regulator will tell you what the current panel voltage being offered is.
But 14.2V is quite low and charging at 14.2V will be slow as the battery approaches that voltage. Depending on the batteries, most regulators would be set to a higher voltage than 14.2V for most of the charge in order that the charge rate is higher.
Cheers,
Peter
Peter_n_Margaret said
10:45 AM Jul 23, 2020
I might have mislead a little in my previous post.
The MPPT regulator will "finish off" a little quicker because it will offer some extra amps, not because of any voltage differences which as Iana's suggestion.
Those extra amps come from converting the "excess" panel voltage to the charge voltage. The PWM controller simply switches off (and on) to control the last bit of charge.
Changing the charge voltage from 14.2V to something higher will increase the charge rate too, provided it does not become excessive enough to start drying out the battery electrolyte. In this regard it is important to follow the battery manufacturer's recommendations carefully. I would also recommend the charger have temperature compensation.
Not all batteries are equal in this regard. The internal resistance of the battery has a significant effect on charge rate relative to voltage offered. This is one of the benefits of Lithium - they have lower internal resistance. And different brands of AGMs will have slightly different performance too.
I would conclude though that Iana is simply short of solar. It is nice to be able to get to full charge much earlier in the day without worrying about the last hour or 2 of daylight.
Cheers,
Peter
Jaahn said
11:34 AM Jul 23, 2020
Peter_n_Margaret wrote:
No. Any pretty much regulator can provide enough voltage to "top up" the batteries. The MPV (maximum power voltage) of most 12V panels is around 18V and the light needs to be quite low before that drops to under 14.2V. A good regulator will tell you what the current panel voltage being offered is.
But 14.2V is quite low and charging at 14.2V will be slow as the battery approaches that voltage. Depending on the batteries, most regulators would be set to a higher voltage than 14.2V for most of the charge in order that the charge rate is higher.
I might have mislead a little in my previous post. The MPPT regulator will "finish off" a little quicker because it will offer some extra amps, not because of any voltage differences which as Iana's suggestion. Those extra amps come from converting the "excess" panel voltage to the charge voltage. The PWM controller simply switches off (and on) to control the last bit of charge. Changing the charge voltage from 14.2V to something higher will increase the charge rate too, provided it does not become excessive enough to start drying out the battery electrolyte. In this regard it is important to follow the battery manufacturer's recommendations carefully. I would also recommend the charger have temperature compensation.
Not all batteries are equal in this regard. The internal resistance of the battery has a significant effect on charge rate relative to voltage offered. This is one of the benefits of Lithium - they have lower internal resistance. And different brands of AGMs will have slightly different performance too.
I would conclude though that Iana is simply short of solar. It is nice to be able to get to full charge much earlier in the day without worrying about the last hour or 2 of daylight. Cheers, Peter
Hi
Good posts by Peter IMHO. Possibly Iana solar has shading problems with low winter sun as part of the shortage of solar. Tony resolved his with 53% more portable directional panels.
I would make two points, firstly to get the correct charging voltages go to the battery supplier or manufacturer. There are lots of different voltages shown on the web so the manufacturer is the expert. I am with Peter and think 14.2 is low. I can point out that +0.2V makes a big difference here and +0.4V is even bigger.
Secondly you must have a multi stage charging setup in whatever charger or regulator for efficient battery management. The minimum is three stage with BULK, ABSORBTION, FLOAT. And temperature compensation probe too if possible and necessary if the regulator is not beside the batteries. Having a proper lower float voltage eliminates the drying out problem completely.
Jaahn
swamp said
11:42 AM Jul 23, 2020
Hi
Considering OP has wired in series the potential amperage lost from shade is very high . Change the wiring to parallel will restrict any losses to a single panel and not try to shut system down completely . Try this first .
Also fit a set of 200 watt portable panel .
ALL PANELS NEED THE OUTPUT VARIFIED IE so many panels donot produce as much as they claim eg 250 is 160 watt ,,350watt only 200watt
With flat batteries greater than 30% discharged how much amperage is the OP getting ,,needs to be measured .
Running 6--8mmsq cable is more than enough in parallel roof mounted . Why because the cable runs are not that long
Series wiring has little benefit in a small van etc
Whenarewethere said
01:08 PM Jul 23, 2020
For those who are not sure always calculate total length + & -
Batteries are not big enuf. 2*160 minimum. So either add 2*120 to your setup or get 2*200 new
Aus-Kiwi said
08:28 PM Jul 23, 2020
If the solar cannot charge existing batteries adding more battery wont help . Its like have two bank accounts . Wiring in parallel running wire off EACH panel . Doubles the wire size . So it will still carry the load . If it does now ? You need more solar . I keep fridge FULL even with water bottles . If battery is low ? I turn off fridge overnight till morning . As an emergency!! Then if for some reason ot cloudy conditions ? I start the generator. It is way more environmentally friendly than a 6.5 GM V8 rattling away to charge from cold . 40 /50 amp smart charger fixs battery issues in about 20 -30 minutes . Boil the jug ? All depends what type van or motorhome you have? The anxiety of getting flat batteries free camping !!
iana said
10:42 PM Jul 23, 2020
The system is set up for lithium batteries, and installing them would have helped solve two problems, weight and charge acceptance, but created a third, I would be broke! Maybe on Saturday we will win Tatts lotto. I think another panel, portable and slopped to get a better energy pick-up will be the way to go. I don't know when I will be doing our next stint of "off the grid" camping, but when it does, I shall take note of the shadows.
The charger has settings for sealed batteries, and vented batteries, the voltages are 14.2, and 14.6. Perhaps I should look at changing the settings, The batteries are AGM's.
Peter_n_Margaret said
11:03 PM Jul 23, 2020
I agree that more batteries are not the answer.
14.6V bulk charge rate is not high for typical AGMs.
Shade is a problem. More solar will help.
What is the controller?
Cheers,
Peter
Whenarewethere said
11:24 PM Jul 23, 2020
What are the loads on your system & can anything be done to make things more efficient.
iana said
06:55 AM Jul 24, 2020
Whenarewethere, things could be made more efficient, however its not always practical or possible, I can for instance take off the panel that maybe subject to a bit of shade (I need to climb on the roof as see first), and use it as a portable. But that would be a nuisance, as I would have to reinstall it every time we moved. I don't think we do enough "Off the grid" camping to warrant any major mods such as being able to angle the roof panels, but that would help.
The regulator is a GSL MPPT60-1
Thanks Ian.
-- Edited by iana on Friday 24th of July 2020 07:08:29 AM
-- Edited by iana on Friday 24th of July 2020 09:19:16 AM
Whenarewethere, things could be made more efficient, however its not always practical or possible, I can for instance take off the panel that maybe subject to a bit of shade (I need to climb on the roof as see first), and use it as a portable. But that would be a nuisance, as I would have to reinstall it every time we moved. I don't think we do enough "Off the grid" camping to warrant any major mods such as being able to angle the roof panels, but that would help.
That regulator would be good. As I always say what does the battery manufacturer say for voltages, look on the side it is often shown there, but I would use the 14.5 setting and see what that does. Note a complete power down to change that.
What is your panels setup ? two 225W panels in series or four panels. The big panels do suffer more from shading if these is any. I would be inclined to rewire in parallel to avoid shading problems if you think there are likely. The gains Vs losses are better if the current is low anyway. The series savings apply more to big roof top arrays on a house. IMHO
450 Watts of solar flat mounted, 2 x 120 AH batteries, and the system wired in series to an MPPT controller. Sun lower on the horizon, days beautiful and sunny, and a compressor fridge helping its self to the battery power, plus charging all of our gadget's. So still not enough capacity in either panels or batteries to stop the inevitable spiral down of battery charge. Now back on the grid, and the restrictions have gone. Probably need to invest in a portable panel, so I can angle it to catch the morning sun energy, but that's weight, can't win.
Hi mate. I had the same problem. Only 200w flat on the roof. I had just installed a fridge in my Hilux with a battery charged from the car. I added an Anderson plug to that set up plus one on the side of my caravan connected to the van charger. I then purchased a 160w folding panel (without the controller) to boost the charge on both, at different times of course. The Hilux battery normally just needs a top up with the morning sun. Obviously pointed east before I go to bed. I made a three metre wire rope to secure the panel to the a bar. Not had a problem since and even an overcast day gives you a dribble of power. Oh yes also I al total 12v now including van fridge but I Di have gas bbq and diesel heater. Hope this helps. Col
Are the panels clean, is the wiring heavy enough & do you get a tiny shadow anywhere on a single panel.
What max charge rate do you see in full sun?
Cheers,
Peter
I think that a portable 200 watt panel would help, so I can position it to follow the sun.
Having panels in parallel will mean that only the panel with shade will stop producing.
Cheers,
Peter
I was up in the flinders a few weeks ago.... 20 amps was common.... maybe high 20's occasionally is all I got out of my 800w.... and mostly only for the few hours when the sun was up a bit..... say 10:30 to 2pm ish..... long shadows this time of year etc.
Have a look at the bottom of this page for my notes on shadows.
https://thegreynomads.activeboard.com/t65231112/custom-6x20-watts-solar-setup-with-mppt/?sort=oldestFirst&page=3
I don't have bypass or blocking diodes. There are 2 panels in series & 3 sets of them. A very small shadow will bring that set in series to its knees, so 1/3 of my 120 watts gone. A tiny shadow on each of 2 sets, 2/3 of 120 watts gone.
What was interesting on my setup was a shadow of each of the 3 sets, is I still had about 1/3 of the 120 watts.
If you can't move the panels you really have to think very carefully how you park so any vehicle self shadowing is minimised, as well as trees!
Hi
Let me say clearly that if you want to go free camping for a while you need to put in as much power every day as you use. You cannot go long on the batteries alone. So if they are getting lower each day you do not have enough charging. Perhaps the posters here already know that but others reading here may need this spelling out.
Soooo how to do that ! There are suggestion made here, all standard things for solar. MORE solar, check the solar has no shading, that it is working as well as it should, get portable panels to chase the sun better, cut back on usage, LED lights, etc. In winter down south the sun is lower and the days shorter so care will be needed to select your sites.
Then what alternative charging do you have. The first should be your engine alternator, the best charger you have. Dumb alternators will supply a high constant voltage at a high rate, so rig that up with good wiring and perhaps that is all you need. Smart alternators will need a dc-dc charger that is bigger than most people buy, to cut the run time to a reasonable short time. EG if 20 Amps it will take 6 hrs to put in 120Ahr. At 40 amps it will take 3 hrs to do that. Basic maths.
A generator is the other means of charging. But if you have a 240V AC generator then you also need a big DC charger to get the power in to the battery in a reasonable time. So do the maths there too just like above. A small charger that charges over night is not big enough. I have a 12Vdc generator/charger that does 50Amps. I must admit that I never take it but it is an expensive but lighter option(aussie made too)
Jaahn
PS http://www.christieengineering.com.au/products/12-volt-55-amp/
-- Edited by Jaahn on Wednesday 22nd of July 2020 10:35:47 AM
I have only got 300 watts of solar on the roof, I had more or less the same problem as you
I purchased a lightweight (3½ Kg), 160 watt portable solar panel
It came with a built in 10 amp solar controller/charger
I fitted two Anderson type plugs, a grey one from the solar controller, and a red one direct from the fold up panel
From the grey Anderson type plug, I can go direct to any battery
From the red Anderson type plug, I go to the input of my DC/DC charger
I have seen 6½ amps going into my DC/DC charger
It is very handy, for early morning, and late afternoon solar harvesting, plus overcast days
When I connect it, I usually leave it, (day and night), until I leave that camp
FWIW.... for winter down south ..... I go for 4x Solar watts to battery AH (ie some would say 200w of solar for 100ah of battery.... I go 400w of solar to 100ah.... I use about 100ah a day..... so went with 200ah battery to 800w on flat van roof). Off course.... I only generally see my battery at 70% discharge as some of the 100ah consumed is straight from solar during the day.... so always have 2 or 3 days of really bad weather winter reserve.
In summer.... can tolerate some shade because of solar over provisioning for summer conditions. I went with 6 panels.... 3 parallel strings of 2 panels in series.... so some series benefit (higher voltage, smaller cable, slightly longer mppt on time), with some parallel shading mitigation.
I also didn't want to manually handle panels.... just want to relax. Haven't used a 240v charger in 18 months.... so probally could have saved $260.
-- Edited by Noelpolar on Wednesday 22nd of July 2020 11:52:33 AM
thanks Craig
Craig, with that kind of voltage they will be in parallel. In parallel the voltage stays the same and the current doubles, in series the current stays the same and voltage doubles.
Have a look at the link in my post a bit above. You probably will be bored to tears with data.
I have 2 & also had tested 3 panels in series. The MPPT controller will adjust the voltage output to what the battery needs. 2 panels in series is about 33 - 35 volts out of the panels. About 9amps from the MPPT into the batteries.
Hi Craig
+1 Mamil has summed it up exactly
If you had a PWM regulator then there is no benefit in using series, actually a waste of the new panel really. Series is only used for MPPT which can take the extra voltage and convert it to extra current
Jaahn
No. Any pretty much regulator can provide enough voltage to "top up" the batteries. The MPV (maximum power voltage) of most 12V panels is around 18V and the light needs to be quite low before that drops to under 14.2V. A good regulator will tell you what the current panel voltage being offered is.
But 14.2V is quite low and charging at 14.2V will be slow as the battery approaches that voltage. Depending on the batteries, most regulators would be set to a higher voltage than 14.2V for most of the charge in order that the charge rate is higher.
Cheers,
Peter
The MPPT regulator will "finish off" a little quicker because it will offer some extra amps, not because of any voltage differences which as Iana's suggestion.
Those extra amps come from converting the "excess" panel voltage to the charge voltage. The PWM controller simply switches off (and on) to control the last bit of charge.
Changing the charge voltage from 14.2V to something higher will increase the charge rate too, provided it does not become excessive enough to start drying out the battery electrolyte. In this regard it is important to follow the battery manufacturer's recommendations carefully. I would also recommend the charger have temperature compensation.
Not all batteries are equal in this regard. The internal resistance of the battery has a significant effect on charge rate relative to voltage offered. This is one of the benefits of Lithium - they have lower internal resistance. And different brands of AGMs will have slightly different performance too.
I would conclude though that Iana is simply short of solar. It is nice to be able to get to full charge much earlier in the day without worrying about the last hour or 2 of daylight.
Cheers,
Peter
Hi
Good posts by Peter IMHO. Possibly Iana solar has shading problems with low winter sun as part of the shortage of solar. Tony resolved his with 53% more portable directional panels.
I would make two points, firstly to get the correct charging voltages go to the battery supplier or manufacturer. There are lots of different voltages shown on the web so the manufacturer is the expert. I am with Peter and think 14.2 is low. I can point out that +0.2V makes a big difference here and +0.4V is even bigger.
Secondly you must have a multi stage charging setup in whatever charger or regulator for efficient battery management. The minimum is three stage with BULK, ABSORBTION, FLOAT. And temperature compensation probe too if possible and necessary if the regulator is not beside the batteries. Having a proper lower float voltage eliminates the drying out problem completely.
Jaahn
Considering OP has wired in series the potential amperage lost from shade is very high . Change the wiring to parallel will restrict any losses to a single panel and not try to shut system down completely . Try this first .
Also fit a set of 200 watt portable panel .
ALL PANELS NEED THE OUTPUT VARIFIED IE so many panels donot produce as much as they claim eg 250 is 160 watt ,,350watt only 200watt
With flat batteries greater than 30% discharged how much amperage is the OP getting ,,needs to be measured .
Running 6--8mmsq cable is more than enough in parallel roof mounted . Why because the cable runs are not that long
Series wiring has little benefit in a small van etc
For those who are not sure always calculate total length + & -
The charger has settings for sealed batteries, and vented batteries, the voltages are 14.2, and 14.6. Perhaps I should look at changing the settings, The batteries are AGM's.
14.6V bulk charge rate is not high for typical AGMs.
Shade is a problem. More solar will help.
What is the controller?
Cheers,
Peter
What are the loads on your system & can anything be done to make things more efficient.
Whenarewethere, things could be made more efficient, however its not always practical or possible, I can for instance take off the panel that maybe subject to a bit of shade (I need to climb on the roof as see first), and use it as a portable. But that would be a nuisance, as I would have to reinstall it every time we moved. I don't think we do enough "Off the grid" camping to warrant any major mods such as being able to angle the roof panels, but that would help.
The regulator is a GSL MPPT60-1
Thanks Ian.
-- Edited by iana on Friday 24th of July 2020 07:08:29 AM
-- Edited by iana on Friday 24th of July 2020 09:19:16 AM
-------------------------------------------------------------------------------------------------------------
Hi Ian
That regulator would be good. As I always say what does the battery manufacturer say for voltages, look on the side it is often shown there, but I would use the 14.5 setting and see what that does. Note a complete power down to change that.
What is your panels setup ? two 225W panels in series or four panels. The big panels do suffer more from shading if these is any. I would be inclined to rewire in parallel to avoid shading problems if you think there are likely. The gains Vs losses are better if the current is low anyway. The series savings apply more to big roof top arrays on a house. IMHO
Jaahn