Best Portable Solar and how many watts is best?

TerryV6

I was told that.  Renogy called me this morning...  My email response had been a bit sharp..  George was with me on the phone for some time with explanations.  More to follow...  Darn snow....

TerryV6

Renogy called me in the morning the other day and said that they would like to work with me on this.  I was told that the Zamp thing is something they are aware of, however, not everyone has this problem. 
!.  In other words, I was to check my plug first of all with a multi-tester.  I told them I wasn't an expert and mostly checked for continuity, and was meaning to learn more.  He asked me what kind of tester I had and looked it up.  He walked me thru the process, where the switch should be turned to and which plugs my cables should be in.  Then, I am supposed to have my battery installed, (right now its in the basement on a trickle charger), if I get a positive reading, I'm okay, if negative, its reverse polarity.  If the latter, I was to go to my solar panel, peel the controller back and switch the wires.
2.  Then, he told me to get an inline fuse of at least 15-20 amps and gave me a link for that.  Also a link for the adapter.  

https://www.renogy.com/renogy-mc4-waterproof-in-line-fuse-holder-w-fuse/

3.  I asked him about cable length and told him about advice I received on length.  He cautioned me that I shouldn't really go more than 20 feet as there would be a drop in voltage? to the battery and could result in badness for my battery.  Since I already had about 3 ft on the back of the panel, I should really buy a 10 footer, keeping me under 20.  

So, if positive test result, go to 2&3, otherwise switch the panel wires and then do 2&3.  Lastly, watch my extension length.   ( kinda looks like a simple flowchart...  I used to do a lot of those in college... if then /else, DoWhile)

My camper is in storage, I will have to run the battery out there to start this. I'm in no hurry to make these purchases till I get more feedback.  I would like to add more length..

TerryV6

Well, Christmas is winding down here but the temp outside is -10.  I don't think I'll be running out the the camper to soon.  Sitting here however, I was thinking of ordering a few things in advance.  Now, some people here have 20ft of cable but say that is not enough.  The Renogy guy said not to go over 20ft without hurting my battery.  Since the panel already has 3ft, that would be a 10 cable.  I was all set to get 30ft, now I am stymied...  

Sharon_is_SAM

Terry, the only issue regarding your battery would be undercharging.  As you extend the distance from the panels to the battery, there is a drop in voltage, so less amps delivered to the battery and it will take longer to charge fully, or may never charge fully depending on temperatures, cloud coverage and panel position.  You can alter the voltage drop by using a larger gauge extension.  We have a 100 watt panel with 30 feet of extension and using 10 gauge extensions, we limit our loss to 3% ( 3-5% loss is acceptable if you want to maximize charging.).  A 200 watt system and 30 feet of extensions requires an 8 gauge extension to limit loss to 3%.  You can use 10 gauge as well, you would have a higher voltage drop and just not maximize your charging ability.  It may well still be adequate for your needs.  See the renogy calculator attached link.  

https://www.renogy.com/calculators/#tab_solar-cable

TerryV6

Thanks a bunch Sam....  That's exactly the info I needed... 

ScottG

@TerryV6, I believe you can mitigate some of the voltage drop problem by locating the controller near the battery rather than at the panels. I don't know if that's an option for you.

Panels in full sun will put out more voltage than needed (usually ~18V). Simpler controllers step this down to a good charging voltage (usually ~14V) and effectively throw away the excess. Therefore, losing a little voltage between the panel and the controller is generally less of a problem that losing it between the controller and the battery.

Using what I had lying around I built a nearly 30' 12 gauge extension to connect my panels to my controller. While this is a little light on paper, it seems to work just fine. The longer cable definitely facilitates getting the panels in to the sun, and in my experience that is far more important than worrying about having a little too much voltage drop!

Sharon_is_SAM

I think Terry has the 200 watt suitcase with the charge controller at the panels.  Scott, I think it also helps to compensate for the voltage drop by having more wattage than you need.  We added a second 100 watt suitcase to our system. Anxious to try it out in Utah.

ScottG

Agreed, @SAM. Higher wattage will translate to more amps at a given voltage, which should increase the overall charging ability of the system. Regardless, you still need to maintain a charging voltage higher than your battery for anything to work.

I've considered a second suitcase as well, thinking it might allow some flexibility in placement when I'm not in camp all day to chase the sun. I'm looking forward to your report after Utah!

lapowers57

The other way to mitigate voltage drop is to use a heavier gauge wire.  I believe the 15 foot extension I bought from ZAMP is a higher gauge wire then the 15 feet that came with the panels.  

bikegirl

@SAM @ericnliz I'm about to buy a Renogy suitcase. Haven't decided about 100 or 200 watts. 

@ericnliz you said you went 10 days without hookups on 100 watts which is amazing. I love that you can slide it in beside the toilet. I wonder if the 200 is wider. I'm not techy or electrical DIY handy so a few of the posts are over my head on my thread and there are things I wouldn't do myself.

From what I've seen you don't want to let your battery go below 50%. I thought the controller would regulate that on these so it keeps you charged up and keeps you from overcharging? 

How long per day do you usually have to have them sitting out? Or do you wait until your down to 50% and then get them out? I guess that would depend on sunlight. 

Where did you get the MC4 to SAE adaptor? Is it plug it in and it converts it or are there other things I have to do?

Is there anything else I will need?

Also, I think it depends on the size of my battery. Or the amp hours. This is mine.

• 1500 Pulse crank amps, 1010 marine crank amps, 76 amp hours, 160 minute reserve capacity

I cannot thank you enough for your help! 

Paige 

pthomas745

I have a portable 100 watt panel, and basically the same battery you have.  My limit on how long I can stay out is more dependent on water and waste disposal then battery power.  As long as the sun comes out, I have power to use. 

Your controller "controls" how much of the panel's output is sent to the battery, but it will not "limit" your use to keep you above the magic 50 percent level.  You have to monitor your battery yourself, using the SeeLevel meter, one of the 12V plug in meters, or a voltmeter.  Some of the newer solar controllers do have LED readouts of the battery state of charge.

My panels are just usually "out" during the day.  I might have to putter around and make sure they are pointed toward the sun as it moves across the sky.  Given a nice sunny day and a few hours I can usually have a full battery, even while using the fan or lights inside the trailer. 

What you will learn is the power "drain" of each item you use in the Tab, and I've wound up thinking twice every time I plug something in or turn something on:  what is my state of charge?  how much power am I about to use?

Further up in this thread is the link to JKJenns web site that has a description of how much power the things in the Tab uses.

bikegirl

Thanks @pthomas745. Do you have a Renogy portable 100w? I was checking out JKJenns spreadsheet so I now have a general idea of what uses how much.

I have a laptop, ipad and iphone that I have to keep charged as I work on the road. Do you happen to know how much they will use when I plug them in? 

Right now I'm in full sun most of the day in desert. My concern is when I head up towards BC and I'm in shaded areas. Plus I'm nervous to leave them outside unattended as I am gone from my T@B for parts of the day. I guess that's just more stretching of my comfort level that has to happen!

pthomas745

I have a Renogy panel, but I now carry a 100 watt flexible panel instead.  It is not a "suitcase".   As far as the "safety" of the panel goes, it all depends.  I have small bike locks that I use to secure mine.  If I'm going to be away and my battery is full, I'll stow it under the trailer as out of sight as I can get it. 

Each electrical appliance has the energy usage on the appliance itself or on the wall wart. Honestly, I can barely keep the math straight in my head, even though it seems pretty simple.  I do have a Kill-a-Watt meter, and I've discovered my laptop uses less than an amp an hour while in "sleep mode" and charging.  It uses about 2-3  amps while I have it open and on.  Your "screens" will use more power the higher the brightness levels are. 

The important battery specification here is your Amp Hour Rating:  you have a 76 amp hour battery, and you can use easily 50% of those.  So, you have 38 Amp hours to play with.  Jenn's spreadsheet shows you how she works that out.  Running the fan on level 1 for one hour uses 1.25 amps.  You can use the Kitchen light on low for 5 hours and only use 1 amp.  If you use those two things, you have now used 2.25 amps of your 38 amp hours of your battery.  (Also note the top line of Jenn's spreadsheet:  the safety functions of your Tab and a few other things are always drawing power, and use 4 amps or so  a day). 

But I'll let someone else chime in on the conversions of Watts to Amps on a 12V system. 

Sharon_is_SAM

Bikegirl, considering you are working from the road, if I were you, I would definately increase my battery capacity.  Consider two 6 volt batteries for a 235 amp capacity.  That way, in case of lousy weather or shade, you have a greater chance of not depleting your battery before you can recharge.  If you do that, it is recommended that you have similar wattage of panels, so a 200 watt suitcase or two 100 watt suitcases would be in order.  The 200 watt suitcase is larger and heavy.  

What model TaB do you have?  Does it have the Zamp ready port on the tub?  If you use Zamp suitcase you do not need the adapter.  Both Amazon and Renogy sells the MC4 to SAE adapter that accommodates the Zamp outlet.  In addition, unless you alter the wires out of the port, you will need the Optimate adapter discussed in the thread several pages back.  

bikegirl

Thanks @pthomas745
Thanks @SAM
I have a 2015 T@b. It does have the Zamp ready port on the outside of the black plastic container at the front that holds the battery/propane. 

I just ordered a refurbished 200w suitcase from Renogy for $399 and the MC4 to SAE adaptor. So I still need to get an Optimate adaptor? I will go look for that in the discussion. 

The suitcase is pretty heavy so I hope I don't regret that. My thinking was that it will take less time to charge the battery or so Renogy told me. It'll take half the time a 100 watt one will. That's appealing to me since I'm out training a lot.

After all my posts and learning from all of you, I now understand the benefit of having 2 x 6 volt batteries. AMP hours are your friend! Right now I'm in the desert so pretty much have full sun all day nearly every day so I have a bit of time before replacing my battery with that if I think I need to. 

I got the 200w also because I didn't want to constantly be stressing about my usage. I know I still have to be mindful for sure. 

Thanks for your help!

bikegirl

@SAM
@pthomas745
Okay so I do definitely need the Optimate adaptor to get the correct polarity so I'll get that. 

It sounds like most people have cable extensions so seeing as I have a 200w suitcase, I can get the Windynation 30 feet MC4 wire extensions at 8 or 10 gauge to lose less than 3-5% voltage.

The controller on this suitcase is not waterproof. I may down the road get the new waterproof controller and swap it out. In Ontario, Canada there are so many pop-up thunderstorms that are unpredictable. Another question is are all the other cable and adaptor connections safe or do they have to be waterproofed somehow? 

Did you all fuse it as well? I spoke with Renogy just now and they said it's not necessary. I'm wondering what you did? If you did fuse why did you think it was necessary for you?

https://www.renogy.com/renogy-mc4-waterproof-in-line-fuse-holder-w-fuse/

I'm going to now unscrew the zamp plug and see if I can reverse the polarity myself. Renogy and a lot of you say it's easy so I'll give it a go. 

I can do this! Never in a million years did I think I'd be learning about solar let alone buying it and DIY'ing some of it. The possibilities will be endless when I have this though!  

pthomas745

I think you need to switch the polarity of the Zamp at the battery connection, OR on the wiring coming out of the solar controller itself.  I know there is a thread around here where someone switched the wiring at the battery.  Not hard to do.

Here is the famous Optimate adapter.  https://www.amazon.com/gp/product/B00AHCWGOO/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Remember, you can also go directly to your battery from the controller with a cable that has alligator clips to the battery.  Beyond simple.

Sharon_is_SAM

bikegirl:  you are of course assuming that someone else has not changed the wiring at the battery before you... and you do not need to unscrew the outlet - just position the wires at the battery, but first...Since your intention is to try it without the Optimate, the Zamp outlet is typically wired with the positive as male and the negative as female.  Trace your wires and confirm this before switching anything.  You want to end up with the negative as male and the positive as female.  Then you can plug in your MC4 to SAE adapter without problem.  

Regarding the fusing, I suspect since your controller is at the panel, you already have a fused + line, that is why Renogy is saying you do not need any further fuses.  In my case, we placed our controller at the battery and rewired everything, hence the addition of a fuse.

The MC4 connectors are durable in weather, but I would not necessarily keep them immersed.  

Sharon

danp212

Just got back from my first trip with the Renogy 100W kit. We did 6 days in Joshua Tree with great sunny weather. I was able to fully charge my battery everyday no problem, usually took a couple hours to do so. I have the Renogy 100W eclipse panel w/ 20amp MPPT commander controller. At times I was getting 6amps of current to the battery but I averaged around 5. Keep in mind this was in the high desert with direct sunlight hitting the panel. Will be interested to see how it performs in less optimal sunlight conditions. 

ScottG

pthomas745 said:

...
But I'll let someone else chime in on the conversions of Watts to Amps on a 12V system. 

Watts = Volts x Amps. So, in the case of a 12V system...

Amps = Watts/12.

This is handy to know since the power usage of many devices is given in watts. 

ScottG

bikegirl said:

...
Did you all fuse it as well? I spoke with Renogy just now and they said it's not necessary. I'm wondering what you did? If you did fuse why did you think it was necessary for you?
...

My controller is mounted in the tub. The positive line between the controller and the battery is fused, but the line between the panel and the controller (which passes through the Zamp outlet) is not.

The original configuration (with the controller at the panel) was fused the same way. I recall researching this a bit when I relocated the controller and there was no compelling reason to fuse the line between the panel and the controller.

bikegirl

Thanks everyone so much for your help. 

I unscrewed the plate to the Zamp adaptor and that was enough for this gal. All adaptors have been purchased.  

I did a blogpost on my website about it with a special thanks at the end to the people in here whose handles always seem to pop up there to my rescue as I navigate this all. 

My T@Bs name is Foxy Cleopatra. Haha.

http://www.puravidaperformance.com/blog/how-im-going-off-grid-with-foxy-cleopatra

pthomas745

Well, if I knew I was writing for attribution, I wouldn't have rambled mindlessly so much!  Nice blog!

bikegirl

Haha! Your advice was awesome and appreciated so much and thanks!

TerryV6

I was told to test, then just reverse the two wires on the controller mounted on the panel.  Cold here... Haven't done this yet.  I have bought stuff...