I am very new to Solar in caravans and hope someone out there can help me understand some basics; I'm not to technical.
I have a 200W Solar Panel on my Pop top roof. I also have two 110 amp batteries in the boot, 240V charger. My 4WD has a twin battery system.
The Pop top is connected to the car with an Anderson plug. (Normal towing plug also).
My question is; when moving does the 4WD alternator send charge to the caravan batteries. Also does the solar send charge to the car batteries.
If not, should this be happening.
When the caravan has 240V connected and is obviously charging the van batteries does it send charge to the car batteries if the Anderson plug is connected.
I think what I am trying to ascertain is that whatever the power source; solar, 240V or Alternator (Anderson plug connected) will there or should there be some charging to all batteries in the van and 4WD
simultaneously.
Any advice would be appreciated. I'm sick of trying to get straight answers from the Auto Elec who did the work.
I'm sorry if this does not make complete sense and I have not supplied enough information.
I'm new to it as well, my setup here: https//thegreynomads.activeboard.com/t65231112/custom-6x20-watts-solar-setup-with-mppt/
Alternators these day are smart so they don't charge all the time. They try not to charge when you need priority engine power for driving. They will charge going down hill. The engine battery probably hovers around an 80% charge.
I have wired from within the car which has very stable voltage, a Victron 10amp DC to DC charger set to about 13.8 volt output which runs at about 6 amps output. The circuit can do 15 amps.
I may buy a 24 volt DC to DC charger & feed it into the solar charger as it charges the batteries correctly. Whereas my DC to DC charger though stable output, it is not smart (charging the battery correctly as it gets fully charged).
Your solar cells are obviously connected to the solar regulator which in turn may or may not be connected to the car battery. Depending on what you want it to do, it maybe better to have it connected only to the auxiliary batteries where the charging is required when off-grid. You shouldn't need to have connected to the car battery as you shouldn't be using it to run fridges etc. Maybe have a switch so you have options.
Your 240 volt charger may or may not charge the car battery. Best to check using a multimeter, or better still, a DC clamp meter, brilliant things.
Doesn't matter how much you spend on a clamp meter it will be still cheaper than the hours you will need to pay for an electrician to get on top of your network. You really need to make a diagram of the network as is, then modify the diagram to what you want to achieve. Cheaper to do that than making numerous physical alterations. I had to buy a larger MPPT regulator even though the original one according to specs should have been large enough, not happy! At least I have a spare as a backup!
I hope your regulator is near your auxiliary batteries.
It could be that you have a well laid out system but it is nobbled by undersized wiring which seems to happen all too frequently in cutting costs, so things are not being charged as well as they could be.
Better you spend the time learning how your network works so when something fails in the outback you have a complete understanding or how it works so you can fix it. Otherwise you will be going through this whole process everytime there is problem.
Back to the questions, your setup, basically may or may not be charging things & the Anderson plug should be wired back to the source with at least 6 AWG wire & not through the car's wiring since you are charging 220 AH of batteries.
hi
gypsy
Your system will charge and discharge depending on wiring install .
Assuming u have a second battery in engine bay ??? type AH size ?? Whats the cranker batt??
The on/off between them either a solenoid or VSR??
Or are they 2 x agm in the back ??
Van batt AGM ??
connected to what VSR?
wired to ???
Car charging to van batts
Minimum of 25mmsq or 3b&s for over 200ah
Smaller cabling has lotsa volt drop causing charge time to be upto 3x longer .
There is no way to answer your question sitting in front of my computer. There is no standard way set to wire in all the parts of a caravan battery and charging system. The auto electrician may have done it so they all work together or not, he is the only one who can say. Perhaps you could ask him to draw a wiring diagram for his work and then how it works. If you do not know how it works and are not technical then you need something or someone to look at it with a meter, test what is happening and write it down. Guessing is no good ! Sorry !
Whenarewethere's answer is full of good information but could be too much information for you at this stage.
Jaahn
-- Edited by Jaahn on Friday 7th of June 2019 09:25:05 AM
There is no way to answer your question sitting in front of my computer. There is no standard way set to wire in all the parts of a caravan battery and charging system. The auto electrician may have done it so they all work together or not, he is the only one who can say. Perhaps you could ask him to draw a wiring diagram for his work and then how it works. If you do not know how it works and are not technical then you need something or someone to look at it with a meter, test what is happening and write it down. Guessing is no good ! Sorry !
Whenarewethere's answer is full of good information but could be too much information for you at this stage.
Jaahn
-- Edited by Jaahn on Friday 7th of June 2019 09:25:05 AM
Ditto to above & with specific details regarding Cable sizes, switches, cutouts, VSRs, blocking diodes, etc used
But you could also ask him these specific questions
Have you wired it so that :
[a]Heavy cables to the van battery so the alternator has a good chance of supplying a high charge current?
What size cables[ In MMsq cross-sectional area or B&S Gauge] not auto cable size based on overall diameter ??
with a cutout so the crank battery cannot be discharged when the van is connected but the engine not running?
[c] If fitted, what sort of cutout?
Does it allow the Van charger & solar panels assist in charging the crank battery or feeding a heavy load in the tow vehicle[ fridge in the vehicle] when vehicles connected & engine running?
Basically, if there is a Voltage Sensing Relay (VSR) fitted at the start battery end of the Anderson cable, it will generally open once the engine stops so the start battery will not be charged by the solar with the engine off.
When the engine is running and the VSR is closed, charge can run in either direction. If the solar is pushing the van batteries to a higher voltage than the start battery, the solar will end up powering the vehicle stuff that the alternator should be powering.
If you have a DC to DC charger fitted in the caravan then this will block the hose battery trying to charge the start battery and will allow the house batteries to fully charge using a combination of solar and the DC to DC charger.
All that has been mentioned about cable size is very important, a DC to DC charger rated at around 30 amps will run successfully from 6 B&S cable (13.5mm sq conductor) and this is the biggest cable that will fit into the lugs in a 50 amp Anderson. The charging voltage of the start battery is critical here, if the car has a smart controlled alternator that drops the charging voltage to 13v after 30 mins each time the engine is started, you will need a bigger cable than 6 B&S 13.5mm sq cable.
There is no harm in using bigger cable, but you will need to get suitable sized Anderson plugs for the bigger cable or the bigger cable will be a waste of money, time and effort.
T1 Terry
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I have read all your notes at least three times and now have some understanding of the Solar System for Caravans.
I will be asking the Auto Elec to draw me a wiring diagram of the work he completed.
Most likely I wont understand it but I'm sure if I attach the diagram to my post someone will be able to explain what I have in layman's language.
Thank You All,
Bob
When you get the wiring diagram ask him to explain it in plain and simple English and not some mumbo jumbo that assumes that you have a masters degree qualification in electrics.
I have read all your notes at least three times and now have some understanding of the Solar System for Caravans.
I will be asking the Auto Elec to draw me a wiring diagram of the work he completed.
Most likely I wont understand it but I'm sure if I attach the diagram to my post someone will be able to explain what I have in layman's language.
Thank You All,
Bob
When you get the wiring diagram ask him to explain it in plain and simple English and not some mumbo jumbo that assumes that you have a masters degree qualification in electrics.
That will be fine as long as they truly understand just what they are doing/have done. We are seeing an increasing volume of work in just setting up the charging system correctly in off grid houses and houseboats. The problem is the auto sparkie who installed it only knows how to set them up for a rental house boat. I think they have learnt it parrot fashion from someone else without actually understanding the effect of each setting.
As for the number of tow vehicle that turn up here to get a DC to DC charger installed along with the other work and I find the Anderson plug to VSR and through to the start battery is wired with 6mm auto cable makes me wonder just what they are teaching auto sparkies these days, every one of them had trusted the auto sparkie to do the job right the first time
T1 Terry
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You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
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hey Bob, lets try and get you some answers instead of posing more questions. Yes, my responses will be based on some assumptions but I believe they are fair ones to be made. Of course, if you can get it from the horses mouth, that would be best.
*The Pop top is connected to the car with an Anderson plug. (Normal towing plug also).
My question is; when moving does the 4WD alternator send charge to the caravan batteries. Also does the solar send charge to the car batteries.
If not, should this be happening.
Most likely, yes to the alternator and no to the solar.
That is the whole purpose of having an Anderson plug going to your van from your vehicle. It is possible that it is only wired up to run your 12v appliances (light, fridge etc ) on the van side whilst the car is connected in place of your battery. However it is more likely that it is indeed charging up your battery when on the go.
You want this for obvious reasons. It helps you turn up at camp with your batteries topped up .
No, your solar won't be sending anything back to your car batteries.
*When the caravan has 240V connected and is obviously charging the van batteries does it send charge to the car batteries if the Anderson plug is connected.
No, it won't be. As per above, it's likely your alternator is sharing the love with your van batteries, but this won't happen in reverse.
Anything charging your vans batteries, save the alternator, will only charge your vans batteries. Sure, it could be done like that, but I've never seen anyone do so.
* I think what I am trying to ascertain is that whatever the power source; solar, 240V or Alternator (Anderson plug connected) will there or should there be some charging to all batteries in the van and 4WD
no and no . It's not likely and as per above, neither should it be.
From the Tug back to the Van is a 1 way street from a power perspective. The car looks after its own needs for charging.
Again, ANYTHING is possible but I think my answers above would cover the majority of installs and in theory, should also apply to your situation.
Plenty of other info above for you but I think sometimes we forget when someone says, I'm not technical, they mean i'm NOT technical and jsometimes what seems basic for them is not for the poster.
So I've tried to give you straight answers to your questions with little info otherwise, to overload the brain.
If anyone thinks I'm giving you a bum steer with my replies, I'm sure they'll let you know in due course
Hi Brett The solar being able to charge the crank battery is quite common & purely depends on the type of isolator fitted. If it is a simple VSR , or ignition controlled relay, there is nothing stopping the solar also feeding back to the crank battery when the engine is running[.IF the house battery is in a high state of charge] In fact, I had just such a set up on both van & motor home with a centre zero amp meter in the circuit. Over long drives, I regularly had the situation where the alternator had shut down & solar was actually running the engine & vehicle, etc , electrics. The effect was most noticeable on driving from bright sun into the shade, when the solar would drop out & the alternator take over On many occasions, we drove for hours with no alternator output.
-- Edited by oldtrack123 on Saturday 15th of June 2019 04:26:31 PM
You're right OT , it could be but I'm just trying to give the OP the most likely scenario.
As he self professes to be 'new to solar' I put myself in his shoes and gave the answers I would want if I were asking the question.
Like I said based on some assumptions and best to get it direct from the horse.
I think sometimes we forget what it's like to be be new to the game (what ever that may be) and trying to get some basic answers to questions.
I know everyone is just trying to be helpful, but sometimes too much info, I think has the opposite help.
That set up would have been very handy for a mate a while back. He's alternator pooped itself when out back on a 4wd track.
He was with another vehicle and they just did short runs, and swapped over the charged batteries from the support vehicle into the dud one.
Painful but got them there. That said though, if I recall the story, it was at night and raining, so probably not help.
Could have added that bit in for dramatic effect on his behalf though :)
Some VSR (Voltage Sensing Relay) have a bypass wire you can connect to link the house battery to the start battery so the house battery can be used as a booster to start the engine. It will double as a link for the solar to charge the start battery.
Some DC to DC chargers have a trickle return to the start battery once the house battery reaches float voltage so this will maintain a start battery over a long period when parked up.
The down side to the VSR remaining on because the house battery is higher than the start battery or the engine is running so the solar ends up doing the alternators job, the house battery really never get fully charged. The solar is trying to get the house battery to 14.4v, but there is current constantly feeding off to the start battery so the house battery never reaches the 14.4v required to drop down into absorption mode and float mode. Driving at night, the house battery will be drained down to the alternator voltage upper limit before the alternator takes over the job of powering the headlights etc. The end result is a house battery not fully charged when you pull up for the night.
T1 Terry
__________________
You can lead a head to knowledge but you can't make it think. One day I'll know it all, but till then, I'll keep learning.
Any links to any sites or products is not an endorsement by me or do I gain any financial reward for such links
Yes have that through a 200+amp
Relay ., So no chance of choke or burning wires ., Whats acceptable for charging is not beefy enough to start motor !! Come into effect when you depend on it . When for some reason the starter / motor batteries are low on charge .,
