Solar panels on the roof

[izakjbrt]

Ok, so since I sold the rooftop, I have some space open on the roof rack....lots of space. So I've decided to place the ol solar panels on the roof. This is my plan for the river trip, since I'm not a handy man, it's gonna take some time. And from the last trip I've learned the the DC2DC does not really do that well, charging wise with the stop go stop go of the river trip.

So my question to the guys who take their solar panels on the roof, how do you protect the panels or am I just paranoid ? Lots of low hanging branches and so on. Don't think I'll drives with them on the roof down the highway . But in the river, what do you do to protect them or are they tough enough? It's normal solar panels , not flexible.

Thinking of putting them in front as the back is already taken by water tanks

And what brackets do you suggest?

[BaasWiets]

Hallo ek het n 200w op my roofrack en hardloop national luna se 25amp dc/dc met mppt controler as die son leke sterk is kan hy so 10.1amp im my 2 deepcycle's instoot takke maak hom niks nie en hael ook nie hulle is nogals sterk. Myne is al vir 4 jaar op my dak noggeen probleme nie al kak is dit vat omtrent 3kwart van jou roofrack se spasie op en n 100watt paneel help fokkol nie jy mors net jou geld en tyd yskaste trek leke baie krag. Het n flexible stel panele wat ek saam opkoppel as ek staan en dit saam die 200w stamp n stel battery lekker.

[Peter Connan]

Izak, in true internet fashion I am not going to answer any of your questions, just add concerns to your existing woes... For this I apologise in advance.

Firstly, I have never had charging issues on a river trip. Even the slower systems I had before the DC/DC I have now never struggled to cope. And since I am usually one of the first guys on the road, I probably spend less time with my engine running than you do too.
So I suspect you may have a problem either with your charging system or your battery is getting old or maybe with the power usage?

Secondly I doubt solar panels will do much to help unless I am wrong about how these systems are integrated. It is my understanding that while the engine is running, the DC/DC will create a much higher charge than the solar and thus the system will disconnect the panels and charge only from the DC/DC/alternator. Thus the only time the solar panels will help is when you are standing waiting for other guys to complete obstacles, or during brunch/lunch breaks. And during these last, I think we all like to park in the shade... Lastly having the panels flat on the roof puts them at a fairly disadvantageous angle, reducing their efficiency. And if you have to cover it to protect it, that will further introduce irritation and reduce charging time.

Assuming your battery is fine:
I don't know what DC/DC charger you have now, but if you have a small one (8-12Amps) it might be a lot easier just to change to a larger (20-25Amp) version. Alternatively maybe consider reducing your power consumption? Just enforcing some "fridge discipline" can go a very long way in this regard. IE packing it in such a way that you can quickly get hold of the stuff you need, and making sure the family communicates so that the fridge is opened once and everyone gets a new cold drink instead of each person getting their own.
Just a note, I don't do much of that and yet I have no problems on the river trip.

[izakjbrt]

Izak, in true internet fashion I am not going to answer any of your questions, just add concerns to your existing woes... For this I apologise in advance.

Firstly, I have never had charging issues on a river trip. Even the slower systems I had before the DC/DC I have now never struggled to cope. And since I am usually one of the first guys on the road, I probably spend less time with my engine running than you do too.
So I suspect you may have a problem either with your charging system or your battery is getting old or maybe with the power usage?

Secondly I doubt solar panels will do much to help unless I am wrong about how these systems are integrated. It is my understanding that while the engine is running, the DC/DC will create a much higher charge than the solar and thus the system will disconnect the panels and charge only from the DC/DC/alternator. Thus the only time the solar panels will help is when you are standing waiting for other guys to complete obstacles, or during brunch/lunch breaks. And during these last, I think we all like to park in the shade... Lastly having the panels flat on the roof puts them at a fairly disadvantageous angle, reducing their efficiency. And if you have to cover it to protect it, that will further introduce irritation and reduce charging time.

Assuming your battery is fine:
I don't know what DC/DC charger you have now, but if you have a small one (8-12Amps) it might be a lot easier just to change to a larger (20-25Amp) version. Alternatively maybe consider reducing your power consumption? Just enforcing some "fridge discipline" can go a very long way in this regard. IE packing it in such a way that you can quickly get hold of the stuff you need, and making sure the family communicates so that the fridge is opened once and everyone gets a new cold drink instead of each person getting their own.
Just a note, I don't do much of that and yet I have no problems on the river trip.

Hi Peter

It may very well be the battery. Last year I noticed that especially with excessive heat that the DC2DC was not as effective (running the victory DC2DC). Luckily my solar is on a separate controller (also victron) , so I can switch off the DC2DC if need be. I think the solar would just be a backup to make sure the beer stays cold. Fridge discipline < two teenage daughters. But I hear what you saying. Im definitely going to do some camping before the river trip to see if its the battery

[Peter Connan]

Fridge discipline < two teenage daughters.

Been there, got the T-shirt. One solution: make the fridge difficult to access.

Seems like Victron have DC-DC chargers of 10, 20 and 30A. I don't think the amount of solar you can fit on a roof rack will beat any of them, so I definitely wouldn't un-plug the DC-DC to use the solar once the engine is running.
But none of these things will "fix" a bad battery. Get it load-tested or use it as you mention.

[izakjbrt]

Me and batteries we hate each other. Mecer lithium battery just caved yesterday after only 4 months......The nearest mercer service centre is 2 hours away . So yes Im pretty sure its my deep cycle then, cause I have no luck with batteries

[Peter Connan]

Ja, I know the feeling.

[izakjbrt]

Ja, I know the feeling.

Im just gonna load the small generator in the back, problem solved! no freakin stupid batteries.....ok, we will die! But the beer will be cold

[offroadbiker]

Ja, I know the feeling.

Im just gonna load the small generator in the back, problem solved! no freakin stupid batteries.....ok, we will die! But the beer will be cold

Generator on the river trip - you will get banned from the camp

I have also never had problems with enough power on the river trip and always run 2 fridges in the back as well as the little one between the seats in front.

Have done it with and without solar.

C-tek DC/DC now replaced by Natuanal Luna DC/DC (Lithium battery)

Currently have 2 solar panels on top of my rooftop tent so they go every where, take a little beating but seem to hold up just fine.

Not the best angle as Peter says but at the stops and go's they take over from the DC/DC so it just helps. Secondly I tend to be in camp early and then park in such a way that I lift the rooftop roof with the panels facing the sun and by day's end I have a full battery for the night.

See you in the river!!

[izakjbrt]

Ja, I know the feeling.

Im just gonna load the small generator in the back, problem solved! no freakin stupid batteries.....ok, we will die! But the beer will be cold

Generator on the river trip - you will get banned from the camp

I have also never had problems with enough power on the river trip and always run 2 fridges in the back as well as the little one between the seats in front.

Have done it with and without solar.

C-tek DC/DC now replaced by Natuanal Luna DC/DC (Lithium battery)

Currently have 2 solar panels on top of my rooftop tent so they go every where, take a little beating but seem to hold up just fine.

Not the best angle as Peter says but at the stops and go's they take over from the DC/DC so it just helps. Secondly I tend to be in camp early and then park in such a way that I lift the rooftop roof with the panels facing the sun and by day's end I have a full battery for the night.

See you in the river!!

Yeah Im gonna test the battery setup a bit with a camp somewhere in feb march. I know the victron DC2DC has an overheating problem, so Im going to check it with Camp in normal weather. It also might be the engine on detection that is not set 100% perhaps, and it's not picking it up every time. But I'll play around and also keep the solar handy, brad Harris plug next to the side of the roof rack, if I camp early (which never ever happens), I can just take them off and place them on the ground