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It is a shame that manufacturers don't take a little more time when they build RV's.  The quality of workmanship is really lacking.

I'm a long ways from adding solar just yet but ran across these panels and wondered if anyone knew anything about them.. good or bad?
 

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Kathy & Bill said:
It is a shame that manufacturers don't take a little more time when they build RV's.  The quality of workmanship is really lacking.

I'm a long ways from adding solar just yet but ran across these panels and wondered if anyone knew anything about them.. good or bad?
Click to expand...

good well made panel, just low on efficiency therefore heavy for the wattage vs other makers

one benefit for diy from this supplier is the free postage vs other suppliers that charge an arm and a leg for shipping



 
Kathy & Bill said:
I hadn't thought about that.  That would work good for running my C-Pap at night.  I already have a 300 watt inverter that I used for that, then the bigger one could be turned off for the night.  If everything is under the bed, it would be an easy install.  Great idea... Thanks!
Click to expand...
About the CPAP:
--  Turn off the humidifier heater or heated hose and you will most likely find the CPAP pulls less than 1amp of 12V power.  The heater jumps the current to 4-7amps of 12V.
--  Check the actual voltage the CPAP actually uses.  Most (or many) use 12V or 24V.  There is a transformer in the 120V power cord to lower the voltage.  If 12V, just tap into the 12V light fixture at the head of the bed with a 12V outlet.  If 24V, you can buy a 12V to 24V converter which may be more efficient than an inverter.
--  If you find you can sleep w/o the humidifier heater, you can just wire a 100watt inverter into the light fixture and use that for the CPAP. 
 
No matter where you install the inverter/charger, solar controller and batteries, you MUST have ventilation for removing the heat from the components.

Additionally inverters and solar controllers usually need space below and/or above for air circulation. This makes it difficult to mound under the bed.

Most mfg allow you to download the install and operations manual for the devices you are thinking of buying to see where you can mount them.
 
A few more thoughts for the OP.

Lithium batteries are MUCH lighter than lead acid. For example; My 10,000 Wh lithium bank weighs 230 lbs and measures 22? X 19?x 10?. I would need fourteen 6V batteries to achieve the same usable capacity. That would weigh approximately 1000 pounds and consume a lot of space. I realize you are not looking at that large of a bank so you'll have to do your own comparison.

Having lived with lithium for nearly two years, I love them.  That said, there is no doubt that they are not for everyone. In general, I'd say they are an unnecessary expense for weekenders, occasional users, and full hookup type campers. 

PSW inverter is always better (but not necessarily 'required'). Many/Most components will run on MSW but it is certainly not ideal.  Choose your inverters carefully, especially if putting one under your bed. IMO, many of them are terribly noisy (the cooling fans). The fans will always(??) come on when the inverter is working hard so no avoiding that.

 
AStravelers said:
No matter where you install the inverter/charger, solar controller and batteries, you MUST have ventilation for removing the heat from the components.

Additionally inverters and solar controllers usually need space below and/or above for air circulation. This makes it difficult to mound under the bed.

Most mfg allow you to download the install and operations manual for the devices you are thinking of buying to see where you can mount them.
Click to expand...

I've been thinking about ventilation and contemplating several ideas.  My compartment under the bed is probably 3'x4' by 20" deep, should be no problem with air circulation.  Downloading the install manuals is a good idea, I thank you for your thoughts.
 
AStravelers said:
About the CPAP:
--  Turn off the humidifier heater or heated hose and you will most likely find the CPAP pulls less than 1amp of 12V power.  The heater jumps the current to 4-7amps of 12V.
--  Check the actual voltage the CPAP actually uses.  Most (or many) use 12V or 24V.  There is a transformer in the 120V power cord to lower the voltage.  If 12V, just tap into the 12V light fixture at the head of the bed with a 12V outlet.  If 24V, you can buy a 12V to 24V converter which may be more efficient than an inverter.
--  If you find you can sleep w/o the humidifier heater, you can just wire a 100watt inverter into the light fixture and use that for the CPAP.
Click to expand...

I have a small portable CPAP I use for camping, no humidifier or heated hose.  The machine I use is 120V with no transformer in the power cord, it's basically a computer power cord.  This machine works fine for a week or so, but when we snowbird or fulltime it in a few years I will want humidification.
 
JDOnTheGo said:
A few more thoughts for the OP.

Lithium batteries are MUCH lighter than lead acid. For example; My 10,000 Wh lithium bank weighs 230 lbs and measures 22? X 19?x 10?. I would need fourteen 6V batteries to achieve the same usable capacity. That would weigh approximately 1000 pounds and consume a lot of space. I realize you are not looking at that large of a bank so you'll have to do your own comparison.

Having lived with lithium for nearly two years, I love them.  That said, there is no doubt that they are not for everyone. In general, I'd say they are an unnecessary expense for weekenders, occasional users, and full hookup type campers. 

PSW inverter is always better (but not necessarily 'required'). Many/Most components will run on MSW but it is certainly not ideal.  Choose your inverters carefully, especially if putting one under your bed. IMO, many of them are terribly noisy (the cooling fans). The fans will always(??) come on when the inverter is working hard so no avoiding that.
Click to expand...

The only place I have for lead acid batteries is on the tongue and I wouldn't be able to get enough AH's for what I want to do.  I guess I could put AGM's under the bed but then you have the weight which I'd like to stay away from.  Lithium seems like the answer for my install.

We enjoy the quite of campgrounds without hookups.  The Allegheny National Forest is close by and we take advantage of that many times during the summer months.  In a few years we hope to follow the weather and take advantage of BLM's out west when we retire.

I will be purchasing a PSW inverter, a little more money maybe but as you said "PSW inverter is always better".  I have thought about the noise factor under the bed and have a concern about that.  It should be at idle (or off) at night, or very low draw if I'm using it for my CPAP.
 
Up to this point I have been exploring a 12 volt system only.  I have seen 24 volt systems but they seem to be on big AH battery banks.  I really don't see myself going any bigger than 400 AH's but still need to do my power assessment.  If 400 AH's is my max, is there any reason to investigate a 24 volt system?

Seeings how I put the camper to bed in a friends barn for the winter, I will have to wait the 5 long months of Western NY winter before I can do a assessment or anything else for that matter.
 
Kathy & Bill said:
If 400 AH's is my max, is there any reason to investigate a 24 volt system?
Click to expand...

Given what has been said here, I would say no. 

I have a 24VDC bank and am very happy with it but, as you you've noted, it is supporting reasonably large loads AND high charge rates.
 
I agree, I don't think it's necessary. The overwhelming majority of RVers do just fine with 12 volt battery banks of all sizes. Would a higher voltage battery bank be more efficient...? Probably, but at what cost? Once you change the operating voltage, you need to change some components. Only you can decide if making those changes would be worth the additional expense.

Kev
 
Kevin Means said:
I agree, I don't think it's necessary. The overwhelming majority of RVers do just fine with 12 volt battery banks of all sizes. Would a higher voltage battery bank be more efficient...? Probably, but at what cost? Once you change the operating voltage, you need to change some components. Only you can decide if making those changes would be worth the additional expense.

Kev
Click to expand...

Yes.... I think it would be prudent of me to stay with a 12 volt system.  Keeping it simple has its pluses also.  Maybe our next camper when/if we fulltime will be bigger and I can think about it at that time.
 
solarman said:
good well made panel, just low on efficiency therefore heavy for the wattage vs other makers

one benefit for diy from this supplier is the free postage vs other suppliers that charge an arm and a leg for shipping
Click to expand...

How does the efficiency calculate?  It doesn't mean that these panels only put out 17.3% of the 200 watts does it?
 
A solar panel's efficiency rating refers to the portion of visible light energy (sunlight) the panel can convert to electricity via photovoltaics. A 200 watt panel, for example, will produce 200 watts under ideal conditions - when measured at the panel itself. Unfortunately, we rarely have ideal conditions. Things like, the sun's angle, clouds, shading, temperature, wire run distance and installation errors will all reduce the amount of volts/amps that ultimately make it to the batteries.

Kev
 
Kathy & Bill said:
How does the efficiency calculate?  It doesn't mean that these panels only put out 17.3% of the 200 watts does it?
Click to expand...

The supplier quotes efficiency of 17%, that's on the low end, better panels have a figure of 20 to 22%.. so for an identical surface area, the lower efficiency panel
produces less power.. it's not really a deal killer, one merely increases the panel size or number to compensate
IF you have the room.. if you are tight on room then the higher efficiency panel are desirable.

efficiency is a measure of light to wattage output, for panels of the same physical size then higher efficiency = more watts



 
I can't tell you how Great it is to have a forum such as this.  The wealth of knowledge, ideas and opinions on here makes it easier figuring out projects/repairs/upgrades.  I can't thank everyone enough for the help and ideas.  If one didn't have resources like this forum, they most certainly would be spending their hard earned money on trial and error methods of figuring stuff out.

I saw post someplace (maybe from solarman) about wiring batteries in parallel so they are balanced.  I have attached a picture of a diagram showing 4 batteries wired so they are balanced for draw and charging.  This looks correct to me but want to make sure.  Also should all wires between the batteries be the same length regardless of the distance between the terminals?  I thought I read that they should be.

Again.... I thank everyone kindly....
 

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Just to expand on the efficiency discussion; the average insolation is on the close order of one kiloWatt per square yard. That means that, under average conditions, a 17% efficiency panel measuring 36- by 36- inches would produce about 170 Watts of electricity or about 14 Amperes at 12 Volts.

The above will be reduced by the efficiency of the charge control circuit.

Ernie
 
Kathy & Bill said:
I can't tell you how Great it is to have a forum such as this.  The wealth of knowledge, ideas and opinions on here makes it easier figuring out projects/repairs/upgrades.  I can't thank everyone enough for the help and ideas.  If one didn't have resources like this forum, they most certainly would be spending their hard earned money on trial and error methods of figuring stuff out.

I saw post someplace (maybe from solarman) about wiring batteries in parallel so they are balanced.  I have attached a picture of a diagram showing 4 batteries wired so they are balanced for draw and charging.  This looks correct to me but want to make sure.  Also should all wires between the batteries be the same length regardless of the distance between the terminals?  I thought I read that they should be.

Again.... I thank everyone kindly....
Click to expand...


here is an example of a power distribution system.

ideally all batteries should have a fuse on the positive side. this prevents shorts between batteries from destroying each other.
each fuse can be sized to the 90 degree temp spec of the cable + 50%. if you have a max current draw of say 200 Amps
then for 4 batteries as shown, the cable size on each battery can be 1/4 of that so for 50 A per leg we could use 8 AWG and a 75 Amp fuse
to balance the currents somewhat, make sure all cables from the battery to the collection point are the same length.
the collection point could be a small bussbar or have all cable lugs connected to one point on the distribution bussbar..
this will give you an idea.. just scale the cable and fuses for your requirements.

a little academic, but you get the idea.. for a quick and dirty method, choose the cable and fuse for half load.
so for 200 A you could use 4 AWG and a 100 A fuse.. 4 awg cable is less than $1 per foot.


for fuses, these are a good choice https://www.bluesea.com/products/5191/MRBF_Terminal_Fuse_Block_-_30_to_300A
 

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Kathy & Bill said:

It is a shame that manufacturers don't take a little more time when they build RV's.  The quality of workmanship is really lacking.

I'm a long ways from adding solar just yet but ran across these panels and wondered if anyone knew anything about them.. good or bad?
Click to expand...

Something else that you might want to consider are residential style panels. They are typically 72-cell, and therefore in the 40 Volt range. One does not necessarily have to put those in series to work effectively with an mppt controller. This also means that you can use an odd number of panels with no problem. They are all wired parallel.

When we installed our system 2 years ago, they made two kinds of residential solar panels. One uses a 5 in Ingot to produce the cells, and the other uses the more common 6 in ingot. Panels made from 6 in ingots are about a meter wide, which is often too much for an RV roof. The ones made from the 5 in ingots are closer to 32 " wide, which worked very well on our 30 foot travel trailer. I was able to add a strip of panels on each side of the trailer, and not have a huge issue with shading. I found that the cost of the individual panels themselves was a relatively small amount of the total install cost. Therefore, if one has the space, one can add a couple more panels for a small percentage of the total system cost. That way, even if one or two are occasionally shaded, you still get good efficiency in direct sunlight, and much higher efficiency in cloudy or rainy weather when shading is a much smaller issue.

Residential style panels are more than robust enough to mount on the roof of a travel trailer, as our experience has shown. Their price per watt is often very good, and their overall efficiency is often very high. One benefits from the fact that there are far more residential panels developed, and manufactured, than lower voltage RV type panels.

Just a thought.

Be sure to bounce that off the experts here before you make a decision one way or the other.

http://www.rvforum.net/SMF_forum/index.php/topic,106669.0.html


 
A little curious  ::)  if one has a 24 volt system with.. lets say a 300 AH battery bank, is that kind of like having a 600 AH battery bank on a 12 volt system?
 
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