Solar The Solar Panel Thread
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Good point there @Drover and an important one too as GEL do not like too high a charge current, max 20A I think. The AGMs can handle up to 30A or more. Need to see specs on side of battery though. Yes, I missed that one!!
Yes Mike @mikerezny , but one of the batteries would have to be very low or have a short circuit. Unlikely with the two van batteries connected in parallel as they would draw down equally in use. I doubt the Power hub would be allowed to get that low either. If AGMs, they can handle 30 plus amps in charging, but GELS can only handle approx 20A. I agree in theory, but in practice unlikely to happen in "normal" circumstances. A very heavy sparking would be visible when connection was made to van batteries if Power hub battery was down that much. I do believe that the existing wiring in the van would be more than adequate to handle that sort of current. The weakest link would be the wiring from Power Hub to van. But if in doubt, your advice is credible if batteries have been neglected (for weeks or months??) and their state of charge condition is unknown or untested. A suitable fuze in line to/from Power Hub as suggested would also protect the battery.
In the "old" days, people got away with a lot because 12V systems were relatively small an simple. Nowadays, 12v systems are getting quite large and more care needs to be taken, similar to practices used in power industries. For example, a car cranking battery is well able to supply over 700A at somewhere around 10V, more power than an arc welder. I have seen a large shifting spanner completely destroyed when it was accidentally placed across the 48V busbars in a telephone exchange I used to work in. We had procedures for handling batteries.
This is not theory, it is good working practice. If connecting two batteries in parallel with heavy duty leads, there exists the real possibility that a large current will flow at the moment of connection, it can cause a spark not dissimilar to welding., it can get very hot, and once it is connected, it can draw enough current to buckle the plates in a battery. The better the batteries, the lower the internal resistance and the greater the possibility of a mishap.
My practice, in such cases, is to assume that this might happen, not that it will probably be ok. I would connect both batteries with one of the heavy leads (+ve or -ve, it doesn't really matter) then connect ONE end of the other lead to one battery. Now there is only one connection left to make. I would have a small lead of thin wire with alligator clips at each end. I would then connect that between the unconnected end of the lead and the battery terminal. This limits the current that will flow between the batteries until they are equalised. I would use a clamp meter to measure this current and when it has reduced sufficiently (less than say 10A for the battery sizes we currently have in vans), you can then safely connect the properly.
When one has been working in this area for over 50 years, one picks up a lot of safe working practices that become second nature. Eventually one doesn't even need to think about them. This is one of them. It isn't that hard to do and, one day, it might just prevent a fire, burning your finger off, damaging a battery, or even having it explode. Each of these batteries store a kilowatt or more, just because it is not 240V does not mean it cannot not dangerous.
Yes, I am sure the cowboys will say that this is all overkill and they have never had to worry about any of this rubbish. A bit like some who are towing caravans that don't want to be concerned about all that technical rubbish about proper towing weights and procedures until the van goes belly up.
Apologies for the rant, but if, one day, it helps just one person then it will be well worth the effort.
cheers
Mike
This is not theory, it is good working practice. If connecting two batteries in parallel with heavy duty leads, there exists the real possibility that a large current will flow at the moment of connection, it can cause a spark not dissimilar to welding., it can get very hot, and once it is connected, it can draw enough current to buckle the plates in a battery. The better the batteries, the lower the internal resistance and the greater the possibility of a mishap.
My practice, in such cases, is to assume that this might happen, not that it will probably be ok. I would connect both batteries with one of the heavy leads (+ve or -ve, it doesn't really matter) then connect ONE end of the other lead to one battery. Now there is only one connection left to make. I would have a small lead of thin wire with alligator clips at each end. I would then connect that between the unconnected end of the lead and the battery terminal. This limits the current that will flow between the batteries until they are equalised. I would use a clamp meter to measure this current and when it has reduced sufficiently (less than say 10A for the battery sizes we currently have in vans), you can then safely connect the properly.
When one has been working in this area for over 50 years, one picks up a lot of safe working practices that become second nature. Eventually one doesn't even need to think about them. This is one of them. It isn't that hard to do and, one day, it might just prevent a fire, burning your finger off, damaging a battery, or even having it explode. Each of these batteries store a kilowatt or more, just because it is not 240V does not mean it cannot not dangerous.
Yes, I am sure the cowboys will say that this is all overkill and they have never had to worry about any of this rubbish. A bit like some who are towing caravans that don't want to be concerned about all that technical rubbish about proper towing weights and procedures until the van goes belly up.
Apologies for the rant, but if, one day, it helps just one person then it will be well worth the effort.
cheers
Mike
The thing with this connecting the extra panel and battery pack to a van set up, while it sounds good on the bench actually doing it with a battery not quite the same as the house batteries which would be connected with equal length cables hopefully and wired to the van controller to best advantage, so to add this other battery which would more than likely require direct connections to terminals not thru the box, I don't think it would provide much added benefit including the extra panel, I doubt very much it would be worth the effort required.....
Hi there @Drover , your comments are not encouraging for poor @Clewsy , but it is his choice to try it out for himself. It may not seem to be too much trouble for him as it may have been for you. Lots of things on this forum appear difficult or not worth the effort for some, and I am sure people may have said the same about some of the things I have tried. Yet without trying, NO improvements can be achieved. I say let @Clewsy give it a go for his own satisfaction (or disappointment) and he can let us all know how he went. That is what this forum is all about!
Hey , not bagging anyone just from a real world view I don't think its worth it .......... Just my views on applying the idea out in the field with all the bits that go with that sort of thing compared to looking at it from a bench perspective...................and in the end " Just my view" to be liked or not.......... I think it was a very good question to ask and @Clewsy always has good input and ideas...........
Hi @mikerezny , all you said is absolutely correct and in the power industry , workers have to be protected from their own incompetence, as common sense is non existent without any knowledge. In fact, NOBODY should be working on ANY electrics unless they have some basic knowledge and a bit of experience. The more complex, the greater the knowledge and experience required. After all we have @Crusty181 connecting his solar system up by himself and hopefully he has attained sufficient and correct information from members on this forum!!
Your method of checking with a thin wire across the last connection in paralleling two batteries or two banks of paralleled batteries would result in the thin wire burning out immediately if one of the batteries or banks had an INTERNAL SHORT or a very large difference in voltage potential. That is where your safety/safety message is extremely valid. As for working over any battery or battery systems, most of us know or should know what will happen if you place a metal tool or drop the same thing across the battery terminals. I remember @Drover and another member telling us how they nearly burnt their finger off and bashed their head on the vehicle bonnet trying to get away , all because their ring shorted out battery potential to earth or some other incident. Absolutely correct in your warning that just because you are only dealing with 12 or 24 volts that you do not need to pay careful attention to what you are doing. And when you mentioned your experience with a 48 volt busbar, you are not only talking about higher voltage (which is bad enough) but ALL that current that is available and looking for a place to deliver all that potential. So point well taken.
If you did not know how to connect batteries, it is highly unlikely that you have any understanding of electrics, let alone own and be able to use a multi meter or clamp meter. I am not trying to denigrate your comments in any way, but one has to be practical in these things. A typical example would be a person (with NO knowledge trying to connect up a flat battery to a fully charged hi power AGM of considerable capacity (say 1200CCA) in an effort to "jump start" their car. I think that would be a disaster waiting to happen and the most likely issue would be a wrong connection to the batteries or shorting out the fully charged battery on the body of the car. However, if you KNOW what you are doing, it is quite safe and the risks are limited by YOUR knowledge and experience. I witnessed a 12mm thick screw driver placed across such a battery which could deliver over 4000A for 5 seconds on a dead short. The screw driver glowed red hot within a second and continued to burn until it was removed. And the battery was UNDAMAGED!!!! So I still stand by my post about connecting batteries within small systems (but what is small?) but still acknowledging the potential for large current flowing, however unlikely in @Clewsy case. His fused line as suggested would protect his battery and himself. BUT NOT NECESSARILY TRUE IN OTHER CASES.
Sorry Mike about "my rant" but had to put my side of the story as I do not consider myself "a cowboy" by any stretch of the imagination.
and when electronic ignition came in as standard folks were still oblivious to the fact and probably still are that it will blow you into the next decade or the idiots that play with their CRD fuel lines, that can kill you quick smart as well, many hidden dangers around in the world of vehicles which most have no idea..................Jump starting batteries has always worried me, a miss fire in a gun is far safer to handle I reckon.
All so true @Drover . Interesting that you see less risk in fire arms than jump starting a car with a flat battery. You are obviously well aware of the dangers when using/handling fire arms, yet are not the least bit concerned. No doubt good training and extensive knowledge of how to use it, and the inherit dangers if NOT used correctly. It is a different story with your electrical know how on jump starting cars with flat battery when you do it, but you are smart enough to be aware of this and take extra precautions and be extra careful too. Hence your lack of confidence, but not your ability to do it!! But as you implied, technology is changing all the time and familiarity can lead to errors when changes are made. You are not on your own on this I can tell you. Cheers.
Hi team,
Just want to be sure that these posts are actually in response to my questions, me being @Joves, not @Clewsy?! If not, it’ll make for a pretty funny/disastrous scenario... me taking your advice, meant for a completely unrelated topic, and burning myself to cinders!!
Seriously though, I do really appreciate everyone’s input and believe that it is all valid. If I thought I knew as much as you guys do, I wouldn’t ask the question in the first place.
@Boots in Action, I’m actually really keen to pursue your idea of two separate Anderson’s... one effectively being a solar input and the other being an output/connection to add the auxiliary battery in parallel with the house batteries. I reckon, in theory, its an ingenious idea. I think it is important to note that I am not looking for a solution that gets me the absolute best theoretical outcome possible, drawing the absolute most ah out of each battery and taking in every last watt of solar. I’m looking for an option for the occasional boost to power capability, for the odd occasion that I’m freecamping and feeling as though the current house setup might fall slightly short. If there is a way that I can get an extra day or so out of the venture by utilising the equipment I already have, then that is absolutely fine by me. I don’t really care if its not wired up in the most efficient way possible (note “efficient”, I do want it to be safe). If it buys me more powered time, then goal achieved. Your solution seems to fit that bill very nicely and, for that, I thank you.
@Drover, throughout my limited time on this forum, you’ve been a great help (I’m @Joves btw, not @Clewsy.. haha) and have always seemed to be a great voice of reason. Your input to this question has made a lot of sense and is also massively appreciated. I’ll always appreciate someone giving it to me straight and telling me “in my opinion, it’s not worth it!” My current setup may prove this to be true, which I will get into further in a bit. The main reason I’ve gone down the path of purchasing the aux battery is to power the secondary drinks fridge. The reason I’ve purchased the 300 watt solar panel is to power the aux battery. It then struck me that and extra 105ah of battery and 300 watt of portable solar seems a bit of a luxury for a plain old drinks fridge, so I wondered if there might be a way that I could ALSO utilise them both to supplement the main van’s power supply when freecamping and running only on 12 volt. The aux battery being used separately wont power my van lights or TV etc. if not connected to the actual van. This is what i’m Hoping to achieve. It seems as though there is a way, albeit perhaps not the most efficient way, which sounds great to me. I do completely take on board that the reward may not be worth the effort though. I’d have imagined that having an Anderson plug fitted to connect to a portable 300 watt solar panel, for when the van is parked in the shade and the roof panels are all but useless, would be a no-brainer though, wouldn’t it?!
@mikerezny, you clearly know your stuff, so I appreciate you coming in with advice also. It sounded more to me like you were providing advice on how to go about doing it safely, not that it was a terrible idea altogether?
Anyhow, now back onto the important parts of the topic, the practical application of what is either a genius or imbecile idea. It looks as though it might not be practical after all. Not due to the possibilities of it all, but due to my current setup. Taking a closer look at my power setup today, it appears that Jayco have installed Gel batteries, rather than AGM, as specified at the time of purchase. This is actually pretty frustrating, as it seems that this will knock the plan on the plan on the head before it has even gotten off the ground (my auxiliary battery is an AGM). I purchased the AGM auxiliary battery of similar capacity for this very reason, but stupidly did not check to make sure that Jayco had installed AGM batteries in the van, as purchased. This, i assume, makes my van batteries and auxiliary battery non-compatible for connecting in parallel, so that pretty well rules out the second Anderson connection for the time being. As for the first, to add portable solar supply to the existing roof panels, this may not be viable either. I took a good look at the setup and specs for what has been installed and I have the BMPro3 J35c. This is only rated to 28amps/450 total watts of solar input. Plus, it seems too good a system to be ripping out of a new van and replacing with an MPPT controller for this type of “once in awhile” venture.
So, it appears I have an auxiliary battery that is non-compatible to link in parallel with my van batteries (due to Jayco supplying me with different type batteries than i actually purchased) and a controller that isn’t up to the task of an additional 300 watt portable solar panel.
I guess now my main real question is if the rating of the BMPro3 should stop me from occasionally adding the extra 30 watt solar panel at all, or should I just not expect to get the full benefit from it? I thought the whole point of the controller was purely to limit the flow into the batteries. Would having a theoretical 620 watts of solar panels (even though we all know they’re unlikely to be putting out the amount of power/wattage they state even under perfect conditions at the same time) connected to a controller rated for 450 watts, actually pose a real issue? If so, I think there is still a real case for being able to add the portable panel when the rooftop panels are parked up under full shade. Am I right in assuming that, when parked in full shade, the rooftop panels will likely be putting out a low enough wattage that the 300 watt portable panel could comfortably be used to supplement?
Again, thanks to ALL for your replies.
Joves
Just want to be sure that these posts are actually in response to my questions, me being @Joves, not @Clewsy?! If not, it’ll make for a pretty funny/disastrous scenario... me taking your advice, meant for a completely unrelated topic, and burning myself to cinders!!
Seriously though, I do really appreciate everyone’s input and believe that it is all valid. If I thought I knew as much as you guys do, I wouldn’t ask the question in the first place.
@Boots in Action, I’m actually really keen to pursue your idea of two separate Anderson’s... one effectively being a solar input and the other being an output/connection to add the auxiliary battery in parallel with the house batteries. I reckon, in theory, its an ingenious idea. I think it is important to note that I am not looking for a solution that gets me the absolute best theoretical outcome possible, drawing the absolute most ah out of each battery and taking in every last watt of solar. I’m looking for an option for the occasional boost to power capability, for the odd occasion that I’m freecamping and feeling as though the current house setup might fall slightly short. If there is a way that I can get an extra day or so out of the venture by utilising the equipment I already have, then that is absolutely fine by me. I don’t really care if its not wired up in the most efficient way possible (note “efficient”, I do want it to be safe). If it buys me more powered time, then goal achieved. Your solution seems to fit that bill very nicely and, for that, I thank you.
@Drover, throughout my limited time on this forum, you’ve been a great help (I’m @Joves btw, not @Clewsy.. haha) and have always seemed to be a great voice of reason. Your input to this question has made a lot of sense and is also massively appreciated. I’ll always appreciate someone giving it to me straight and telling me “in my opinion, it’s not worth it!” My current setup may prove this to be true, which I will get into further in a bit. The main reason I’ve gone down the path of purchasing the aux battery is to power the secondary drinks fridge. The reason I’ve purchased the 300 watt solar panel is to power the aux battery. It then struck me that and extra 105ah of battery and 300 watt of portable solar seems a bit of a luxury for a plain old drinks fridge, so I wondered if there might be a way that I could ALSO utilise them both to supplement the main van’s power supply when freecamping and running only on 12 volt. The aux battery being used separately wont power my van lights or TV etc. if not connected to the actual van. This is what i’m Hoping to achieve. It seems as though there is a way, albeit perhaps not the most efficient way, which sounds great to me. I do completely take on board that the reward may not be worth the effort though. I’d have imagined that having an Anderson plug fitted to connect to a portable 300 watt solar panel, for when the van is parked in the shade and the roof panels are all but useless, would be a no-brainer though, wouldn’t it?!
@mikerezny, you clearly know your stuff, so I appreciate you coming in with advice also. It sounded more to me like you were providing advice on how to go about doing it safely, not that it was a terrible idea altogether?
Anyhow, now back onto the important parts of the topic, the practical application of what is either a genius or imbecile idea. It looks as though it might not be practical after all. Not due to the possibilities of it all, but due to my current setup. Taking a closer look at my power setup today, it appears that Jayco have installed Gel batteries, rather than AGM, as specified at the time of purchase. This is actually pretty frustrating, as it seems that this will knock the plan on the plan on the head before it has even gotten off the ground (my auxiliary battery is an AGM). I purchased the AGM auxiliary battery of similar capacity for this very reason, but stupidly did not check to make sure that Jayco had installed AGM batteries in the van, as purchased. This, i assume, makes my van batteries and auxiliary battery non-compatible for connecting in parallel, so that pretty well rules out the second Anderson connection for the time being. As for the first, to add portable solar supply to the existing roof panels, this may not be viable either. I took a good look at the setup and specs for what has been installed and I have the BMPro3 J35c. This is only rated to 28amps/450 total watts of solar input. Plus, it seems too good a system to be ripping out of a new van and replacing with an MPPT controller for this type of “once in awhile” venture.
So, it appears I have an auxiliary battery that is non-compatible to link in parallel with my van batteries (due to Jayco supplying me with different type batteries than i actually purchased) and a controller that isn’t up to the task of an additional 300 watt portable solar panel.
I guess now my main real question is if the rating of the BMPro3 should stop me from occasionally adding the extra 30 watt solar panel at all, or should I just not expect to get the full benefit from it? I thought the whole point of the controller was purely to limit the flow into the batteries. Would having a theoretical 620 watts of solar panels (even though we all know they’re unlikely to be putting out the amount of power/wattage they state even under perfect conditions at the same time) connected to a controller rated for 450 watts, actually pose a real issue? If so, I think there is still a real case for being able to add the portable panel when the rooftop panels are parked up under full shade. Am I right in assuming that, when parked in full shade, the rooftop panels will likely be putting out a low enough wattage that the 300 watt portable panel could comfortably be used to supplement?
Again, thanks to ALL for your replies.
Joves
Hi @Joves i think the comments are for you & not me.
Sounds like you have your answer
I'm with @mikerezny on this one. A couple of reasons, don't parrallel batteries if
1. different types of batteries gel, agm etc
2. Different size Ah's
3. Different ages (their internal impedance / resistance increases overtime)
4. Different lengths of cable or length between batteries (different resistance)
5. If you don't fuse them in the type of setup you were suggesting
Your projecta power hub doesn't have a charger in it for the solar i'm guessing?
I'd stick with keeping them seperate, i'd be surprised if you ran out of power for your power hub. And unless you use the coffee machine a lot you should be okay in the van too. Have you done a bit of free camping for extended periods already to know you need more power?
The kickass are good panels, at least the portable glass ones i have are. Haven't used or tested their thin ones.
In regards to solar, i'd personally use a seperate charger for each type of panel. the fixed and portable will have different Voltage and Current curves, you'll be most like loosing some efficiency in one lot of panels. Yes you won't be loosing heaps so not a huge deal. If you did I'd fuse the panels, not that there is any fault current from panels, in case something else goes wrong.
I'm just cautious and tend to lean on side of safety. You can't see electricity until the smoke escapes, and then it's to late.
I echo seeing spanners evaporate and people being treated for 3rd degree burns and hearing their stories of treatment in burns units, lost for words......
Batteries also can explode if not ventilated properly when they get overcharge and vent Hydrogen which is an explosive gas.
Sounds like you have your answer
I'm with @mikerezny on this one. A couple of reasons, don't parrallel batteries if
1. different types of batteries gel, agm etc
2. Different size Ah's
3. Different ages (their internal impedance / resistance increases overtime)
4. Different lengths of cable or length between batteries (different resistance)
5. If you don't fuse them in the type of setup you were suggesting
Your projecta power hub doesn't have a charger in it for the solar i'm guessing?
I'd stick with keeping them seperate, i'd be surprised if you ran out of power for your power hub. And unless you use the coffee machine a lot you should be okay in the van too. Have you done a bit of free camping for extended periods already to know you need more power?
The kickass are good panels, at least the portable glass ones i have are. Haven't used or tested their thin ones.
In regards to solar, i'd personally use a seperate charger for each type of panel. the fixed and portable will have different Voltage and Current curves, you'll be most like loosing some efficiency in one lot of panels. Yes you won't be loosing heaps so not a huge deal. If you did I'd fuse the panels, not that there is any fault current from panels, in case something else goes wrong.
I'm just cautious and tend to lean on side of safety. You can't see electricity until the smoke escapes, and then it's to late.
I echo seeing spanners evaporate and people being treated for 3rd degree burns and hearing their stories of treatment in burns units, lost for words......
Batteries also can explode if not ventilated properly when they get overcharge and vent Hydrogen which is an explosive gas.
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I think I have probably jumped started a few hundred batteries and having seen batteries explode by just turning key I treat them with respect just like Dets and bang things.
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I was just following the line by Booties, the posts get that big on here one gets lost......both you and Clewsy put forward great questions and follow ups.
If roof top panels have a bit of shade they'll be most likely doing next to nothing energy wise.
You could use your regulator output of the portable panels during these periods, i'd fuse that cable also.
Most likely you'll get 80% at best of panels ratings. 620W x 80% = call it 500W to round off. Could be around 35 - 40 amps altogether going into batteries which could be too much also.
You could use your regulator output of the portable panels during these periods, i'd fuse that cable also.
Most likely you'll get 80% at best of panels ratings. 620W x 80% = call it 500W to round off. Could be around 35 - 40 amps altogether going into batteries which could be too much also.
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Thanks @Clewsy. So, if I’m clearly parked up in the shade, it’s be pretty safe to setup the portable solar panel in full sun, even with my current setup, you think? Would never hold you to anything, if anything ever went wrong, just looking for some practical advice.
Hi,
it was certainly not my intention to label you as a cowboy. Sorry if it came across that way.
cheers
Mike