Please Help! Renogy solar panel wiring

ericnliz · May 2016

Just as I thought I had all my questions about this answered, I received my Renogy 110 amp solar panels the other day, opened up the case, and to my dismay, the cable is only 10ft long for the clamps to the battery. I have the plug for the zamp connection, and my question is this: How do I adapt this for a 20ft cable to my panels? I do have the controller box with my panels, and was told by Renogy tech that I would need a 10amp in line fuse for this application. My knowledge of solar panels, you could fit in a thimble, and still have room, so please be as descriptive as possible. Any and all help in this matter would be GREATLY appreciated. Pictures would be a BIG plus!

jkjenn · May 2016

You will need to:

Either 1) Remove and replace the cable from the controller to the clamps with one that goes from the controller to a 2 pin SAE connector (like the Zamp port uses) or 2) Cut the ends off of the existing cable before the clamps and splice on a piece that has the 2 pin SAE connector.

You can buy the 2 pin SAE cable from either amazon or eBay, easily. It will likely have a 2 pin connector on each end and you will have to cut off one end, just be sure it is the right end you cut off.

source3 · May 2016

Post pics of what you need to connect. I am not familiar with your setup. I created a 20ft extension for my Zamp. Like Jen stated you will need a 2 way flat molded connector. Make sure you match wire connector gauge with what you already have.

Zamp controller. Hand is holding one end of connector Inline fuse is also visible.

20 ft of extension I wrapped the wire in automotive wire loom to reduce the chance for critters to chew wires.

Hand is holding the two ends of the molded connector on the 20 ft extension. One end plugs into the Zamp controller wire the other plugs into the Zamp plug on the trailer battery side that came with the T@b

ScottG · May 2016

The Renogy 100W suitcase comes with 14AWG wire throughout. I think there is some limitation on how far you can extend the cable without significant voltage loss, but I don't know what the guidelines are. Renogy might be able to advise you.

Let us know what you figure out--I may want to do the same thing in the future.

Nomad · May 2016

Saw one that was 14/16 and thought that was weird. My Zamp is 10/12.

Verna · May 2016

You can get the "Zamp" plugs for your extension cord from Walmart in the trolling motor section, and they are 10 gauge wiring. It will say "MinKota" on the package. I did forget to see how much they were--sorry, I was more concerned with the size of wiring.

This is purely what I did, and you don't have to do the same. I purchased 10 gauge marine wire with a red and a black wire inside the white sheath from a boat supply business. It is not cheap. It is very flexible, and I've come to like that. 25' of this 10 gauge wiring creates no noticable loss of power.

ScottG · May 2016

Upon further consideration, I like the idea of just replacing the whole cable rather than trying to adapt or extend the existing equipment. This would allow for any needed upgrade of the wire size for the full length. Since the Renogy controller uses basic screw terminals, a special connector wouldn't even be needed on that end.

I particularly like Verna's marine cable idea for its ease of use, and that it should coil nicely inside the suitcase for storage--I will likely go that route once I get a chance to use and become a little more familiar with my system. (However, I suspect source3's equally effective approach is more economical!)

Ratkity · May 2016

I didn't bring the Renogy solar suitcase with extension cables on this trip (I use a different controller - nothing wrong with the one they sell, it was just circumstances that I already had one). When I get home, I'll look at the wiring gauges since they were from Renogy. I only have 25' if I recall. I have 2x 25' independent cables for 2 MC4 connectors from panels. Those mate to my MC4 hook-ups on the controller. No cord mods made. I'm gonna check out the marine cables V mentioned for future use when I get home.

Edited: Oh.. ScottG said the suitcase wiring was 14g. BTW, they make an in-line MC4 fuse for the positive side that is very weather resistant.

ericnliz · May 2016

Thanks to everyone on your comments,and help so far. Right now, the wife [Liz] has me working on bed slats for our comfort! [I have to say more mine than hers!]
I will pursue this matter of the solar dilemma next week, more diligently, please keep comments, and help coming! you guys ROCK!

jcfaber1 · May 2016

The thing to consider is voltage drop. Voltage drop needs to be minimized. What length of cable do you want? In addition it would be helpful to know the amps and voltage output of the panel then I can calculate the wire gauge options.
John

ScottG · May 2016

Thanks John--that would be very helpful. Note that the suitcase in question has the charge controller mounted on the panels. If it makes any difference, we (ericnliz and I) are talking about the cable that runs from the controller to the battery (as opposed to the panels to the controller).

The panels are 100W total. If I'm interpreting everything correctly, the max boost voltage from the controller is 14.8V (though it can be set as high as 17V). The included controller has a 10A maximum, though normal operation maxes at 6-7A.

The 10A controller terminals are rated for a maximum wire size of 12AWG. However, I have confirmed that 10AWG will fit easily.

If someone with more experience using these panels wants to add to or correct what I have said, please chime in!

jcfaber1 · May 2016

7 amps with 17 volts with a 25 ft cable requires 10 gauge wire will yield a 2.2% voltage drop. I would stay in the 2 to 3% or less range. If you want another scenario just let me know.

ScottG · May 2016

Thanks again, John. That sounds right in line with Verna's marine cable set-up.

Forgive me if this is a really dumb question--I know how to run wires, but this 12V solar trickery is new to me...

Is the voltage drop a greater or lesser concern at lower outputs? For example, in float mode on a less bright day, I might be looking at 13.8V with 4A.

jcfaber1 · May 2016

You can get 10 gauge landscape wire at home depot. You should be good to 30 ft. Beyond that you should go to 8 guage. The issue surrounding voltage drop is the loss in effective charging capacity. If the PV is putting out 17 volts, with 10% drop only15.3 volts is going to the battery. Only the voltage from the PV above the battery voltage is going into the battery. If a full battery is 13.2 V then you only have 15.3-13.2=2.1 volts to charge with. This is why you need to protect against voltage drop. I would put the controller at the battery and the cable between the CC and the PV.

ScottG · May 2016

Good explanation. I think I'm starting to wrap my head around it, and why people advocate having the controller closer to the battery. I may relocate the controller at some point, but for now I like having the suitcase self-contained, as I do not expect to need it on every trip.

As a side note for anyone following this, I was told by Renogy that relocating the built-in suitcase controller would void the warranty. The reasoning for this is not clear, as the controller is only taped to the panels, and all the wiring could be extended and upgraded without actually dismantling or damaging anything. The controller and panels are no different than what you would get if you purchased everything separately.

Ratkity · May 2016

That's odd, ScottG. I have the same Renogy suitcase without the controller (has the place to put it, but I didn't need it). I have no idea why moving it would void anything, but I guess it's up to them to decide what their business model is - meh.

I like jkjenn's energy chart on her archive (it's posted here on the forum.. but "solar" gives you a lot of hits). I think knowing your energy usage is most important overall after you get the wiring gauge size and distance thing cleared up. I imploded a few brain cells with too much physics and math about controller positions.

For me, focusing on what I'm using and what the boondocking limiting factors seemed more important in the long run (is it energy? Gray or black tank space? Fresh water? - food never seems to be an issue lol). I lost less brain cells when I shifted my focus to these types of issues. BTW, for Harvey, it's space. He's a bed hog, a pillow hoarder and loves the glamping side of T@B-life. Bears... geesh. Who knew they liked to decorate so much and absolutely adore the pretty T@B lights in the TearDrop Shop?

ScottG · May 2016

Yeah, when and if I decide to relocate the controller I'm not going to worry too much about the warranty issue. Either way, I figure I'll spend a season determining how I use the suitcase before making any modifications.

I'm well familiar with jkjenn's famous energy use chart. I put it to good use when planning my solar suitcase purchase and group 27 battery upgrade. Good stuff!

jcfaber1 · May 2016

I suspect the voiding the warranty clause is to protect themselves if you reverse polarity while in bright sunlight and it fried something. The comment on understanding your current demand is very important. I would also suggest a good meter that runs through a shunt such as Bogart Engineering 2030-RV. They really help understand the charge of your batteries.
John

Ratkity · May 2016

If I never did anything else with solar, I'd still install a permanent, accurate battery meter, I'd set up the shunt as described and either get the Bogart Trimetric meter or the Victron setup. Both awesome and accurate. I covet jkjenn's Victron because she did an fabulous professionally looking install and it seems to have more information features that come with it. Like I said, both are great for the inner-scientist data collector.

jkjenn · May 2016

Ratkity said:

If I never did anything else with solar, I'd still install a permanent, accurate battery meter, I'd set up the shunt as described and either get the Bogart Trimetric meter or the Victron setup. Both awesome and accurate. I covet jkjenn's Victron because she did an fabulous professionally looking install and it seems to have more information features that come with it. Like I said, both are great for the inner-scientist data collector.

The Bluetooth dongle rocks, too! Can check the battery from my dining room. It is also used to install firmware upgrades.

ScottG · May 2016

jcfaber1 said:

I suspect the voiding the warranty clause is to protect themselves if you reverse polarity while in bright sunlight and it fried something. The comment on understanding your current demand is very important. I would also suggest a good meter that runs through a shunt such as Bogart Engineering 2030-RV. They really help understand the charge of your batteries.
John

The warranty comment came from Renogy tech support via email. I'm not sure if it's explicitly written somewhere, or if it applies to all the components or just the controller. It didn't make much sense to me either, since the exact same pieces-parts can all be purchased separately (with their own warranties), and nothing is permanently hard wired. I went with the suitcase w/controller because that was far cheaper than buying the panals, controller, and cables individually.

So, maybe moving the controller voids the warranty, maybe not. Like Ratkity said, "meh." :-)

ericnliz · May 2016

Hi again!
Do I need to purchase the reverse polarity two prong plug to adapt to the Zamp port on the trailer?

source3 · May 2016

You are not reversing polarity. Reversing polarity is a bad thing. Take a look at the third photograph in my post on May 12th. The left connector, the one with the black and red wires showing, plugs into the zamp connector on the trailer. You will need this type of connector to plug into the trailer.

ericnliz · May 2016

source3,
You have the Zamp unit, I have a Renogy unit, Zamp reverses polarity into the trailer plug as I understand it. I have already ordered the cables with MP4 connectors to adapt to my Renogy setup. I already have the two prong plug to plug into the trailer which you show in the third photo. Please correct me if my thinking is wrong, thanks!

ericnliz · May 2016

http://tab-rv.vanillaforums.com/discussion/comment/19501/#Comment_19501 Please lookat this post, I think it might explain it better than I did! Thanks again

source3 · May 2016

Ok, I get it. I never gave the zamp wiring a second thought as it seamed logical to me that the exposed male plug from the controller (below photo, left plug) is negative to avoid a short circuit in case it came into contact with metal (http://littleguy.vanillaforums.com/discussion/3568/battery-tender-zamp-solar-port-information)

For sake of discussion, the right plug is what the zamp connector on the trailer would look like

All you need to do is splice the connector to match polarity. To not confuse polarity you can use heat shrink tubing to match whichever wire color is needed. I place the shrink tubing near the connector end.

ericnliz · May 2016

Thanks for your clarification on the polarity. I already ordered the extension reverse polarity plug from Amazon. I can just simply follow my wires down from the controller, put the plug on [like the one pictured at the right of your photo] with disconnect connectors, plug into the reverse polarity plug & go! I'll let you know how it works when I receive the extension wires [comes with the MP4 connectors like I need] and get the rest connected. Thanks again for your help, and the photos!

source3 · May 2016

Glad it helped.

FYI: I just looked at the trailer box wiring. Between the zamp connector and the battery, Little Guy spliced the wires to add a ring connector for the battery terminal.

male (positive) zamp connector -->red wire --> [splice] -->red wire --> positive battery terminal
female (negative) zamp connector -->black wire --> [splice] --> white wire --> negative battery terminal

ScottG · May 2016

Regardless of how you approach it, the bottom line is that you need to make sure the positive and negative terminals of the controller are attached to their respective counterparts on the battery. Trace all wires and connections visually, or check for continuity with a multimeter. Configurations change and wires get swapped, making it too easy to miswire something that you haven't checked yourself.

For my modification, I spliced the connector shown on the right (black negative wire connected to the bare pin) to the end of my Renogy cable. This allowed me to directly match the polarity of the existing Zamp connector on the front tub without any further modifications or adapters. However, don't take my word for it--if in doubt, ring it out!

ericnliz · May 2016

I just want to give a BIG "shout out" to ALL of you that commented and helped in this post! My set up is complete, works great, and Liz and I are ready to go Tuesday for seven days! I checked EVERYTHING prior to starting the project, including pulling the battery top off, and taking out the Zamp port to verify, that it was in fact reverse polarity. Scott, I went to Amazon, and found a reverse polarity plug such as you gave the picture for. Thanks again for your help! Also ordered the MC4 connector wires in 15' length, and the "in line" fuse as well [10amp]. Shout out to Ratkity for the advise for the MC4wires! Source3, even though we had different manufacture panels, your photos were a great help as well. I also went with wire wrap for the cables, as it makes it easier to pack & unpack! Now if the sun stays out, I'll be in great shape. Keep the shiny side up, hope you all either had, or are having a great weekend, and once again, THANKS!!!!

Ratkity · May 2016

Well done!!

I'm already a wee sunburnt from Rolling Thunder activities this weekend in the DC metro area - need stronger sunscreen! Been a great time so far. Rubber side down on the bike.

Have a great trip starting Tuesday! I'm going for a small weekend camping jaunt with my crazy TJ friends to Susquehanna SP next weekend.

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Please Help! Renogy solar panel wiring

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