Do I have a Zamp port?

Captenaj

I, like many others on the forum, am trying to increase the amount of time I can camp in my 2021 320 Boondock without being plugged into shore power. One option is getting an external solar panel to supplement the factory installed panels. Some people have mentioned a Zamp port that an external solar panel can plug into. Is this something I have to get installed or do I have one already? I have looked high and low but I'm really not sure what I'm looking for. Thanks.

Sharon_is_SAM

If you had one it would be on the driver side of the front tub close to the battery.  I believe the solar ports are no longer standard with the 2021 models.  Easy enough to add one.  If you get a Renogy panel/suitcase, get a standard SAE port and you can use it for a battery charger as well.  

jimrj

It should be on the driver’s side of your tub. Here’s a photo of mine. 

WayneW

Our 2021 320S Boondock did not come with a solar port. I added one to the tub, similar to the pic above. I use it for solar and for a battery charger. 

pthomas745

And, until you figure it out, you can be instantly connected (well, almost) with a simple pair of battery clamps from the solar controller to the battery. No drilling necessary. Well, you will have to cut off the plug on this set and trim the wires a little.  https://www.amazon.com/gp/product/B00JOY6U7U/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Captenaj

Fantastic, thank you! Our Boondock did not come with the Zamp port but it sounds like I can just purchase a solar suitcase (like the Renogy 100 Watt Eclipse Monocrystalline Charge 20A Voyager Waterproof Controller Solar Suitcase, 100W-Waterproof which was recommended in another post) and clamp it on to the battery posts. Have I got that right? Will that be enough to allow me to charge my battery fully during the day so I can keep the refrigerator running all night? I have the green Interstate that came with the Tab.

Novice question but do I need the 20A? The 12A (still 100W) is half the price. I'm sure there's a reason it's half the price though.

Thank you for the help! We are going on a trip at the end of August and there are no electric sites available. I just want to be able to run the refrigerator and charge our phones.

Sharon_is_SAM

@Captenaj - I am not sure what the frig Amp draw is for the Isotherm.  You need to know the Ahr of your battery to see if you have enough capacity.  Usually, if you intend to Boondock, you need to have a backup plan if you have limited sun.  That usually means a larger battery.  The extra solar panel will allow you to move a panel to capture more light, but you need 20-30 feet of 10 gauge extensions.  The 12A controller will work for the 100 watts.

ScottG

Is the 20A also waterproof? Are they different types of controllers (PWM vs MPPT)? That may further explain the price difference.

My older Renogy 100W suitcase came with a (non-waterproof) 10A controller. As Sharon said, that is more than sufficient for a 100W panel. At maximum panel output (100W at ~18V) a PWM controller will only draw/provide about 6A.

CharlieRN

I bought the Renogy RNG-KIT-STCS100D-VOY20 solar suitcase in April through "The Renogy Store" on eBay. The kit includes a hinged 100 Watt monocrystalline panel and 20A MPPT type waterproof charge controller, along with adjustable stands, 15' of cable (MC4 to alligator clips w/fuse) and a padded suitcase to carry everything. The claimed max panel output is the same as @ScottG cited for his older unit. The MPPT controller has some limitations but it is waterproof and seems to be robust. We've only boondocked once but the combination of the stock solar system and the Renogy easily kept our puny 80 Ah battery charged. I need to caveat that however, since we were pretty frugal with our power usage.

It looks like the price has increased quite dramatically, nearly doubling from the $221 it was back in April. That increase has erased most of the price advantage that the Renogy enjoyed over its competition, but even at $350 or so, it seems like it offers reasonable value.

pthomas745

My separate controllers all sit inside the propane tub within easy reach of the battery.  No need for waterproofing (I pack them away for travel.)  It is always better to have the controller close to the battery.  You can debate endlessly about PWM/MPPT/MONO/POLY LMNOQ......but having the controller close to the battery for that short wire run is (normally) considered a good thing. 

Tabaz

Be careful with polarity.  You can buy on of these "reverse polarity pigtails" (yellow arrow) if needed.  My Zamp has a different polarity than the ARB fridge and Battery Tender, hence the two SAE outlets.  That pigtail allows me to use the Battery Tender in the Zamp outlet (bought the pigtail before adding the ARB outlet).

CharlieRN

pthomas745 said:

. . . 

You can debate endlessly about PWM/MPPT/MONO/POLY LMNOQ......but having the controller close to the battery for that short wire run is (normally) considered a good thing. 

Since I'm a relative babe in the woods when it comes to solar, how much of a difference does having the controller at the battery end of the wire run from the solar panel rather than having it at the panel itself make?

I thought that voltage output at the panel was about 18v, while that from the charger is in the range of 13-16v, depending on where you are in the charge cycle. So in one case, you have 18v on a long run from the panel to the charger and only a few feet from the charger to the battery. In the other case, it's a very short run from the panel to the charger and then 13 to 16 volts from there on a similar long run to the battery. Is the difference in voltage significant enough to translate to a larger loss for the latter setup?

pthomas745

I'll let someone else answer all about "voltage drop."  You can fall down the rabbit hole so fast your head will spin.  Our systems are very small, charging small batteries.  The difference in any of these technologies are (to me, a non engineer) are a tiny factor in the length of time it takes to get my battery back to charge when the sun comes up.  I can tell no difference in my PWM and MPPT controllers, the older polycrystalline vs monocrystalline, the 40 foot extension cable vs the 30 foot extension cable. 

pthomas745

And here is a better thread that describes the placement of the solar controller much much better than I can. And, you can admire ScottG's solar lunchbox.

https://tab-rv.vanillacommunity.com/discussion/11361/mounting-location-for-solar-charge-controller

ScottG

@CharlieRN, I can't give you hard numbers on voltage drop in each situation, or how significant an effect it has. I just figured that since PWM controllers (like I have) "waste" voltage above what the can feed to the battery, loosing a little upstream of the controller is better than losing a little downstream.

What I can tell you is that my panels--even connected to the controller with 40' of comparatively puny 12g wires--work just fine to recharge my battery. That is, of course, assuming I can put them in the sun. All that armchair theory about optimizing every volt and amp is mostly for naught if ol' sol isn't feeling cooperative!  ;-)

Captenaj

I have been told (by another member) that my battery is 81AmpHr. The sticker in the refrigerator says maximum amperes is 6A. I am sure I read the website incorrectly when I said one of the units had a 12A controller. Each Renogy solar suitcase controller is 12V and 20A, and both have waterproof, PWM controllers. The difference between the prices seem to be an older panel technology on the less expensive one. The Renogy 100w Microcrystalline Eclipse is $350 and the Microcrystalline is $220. The less expensive one is 6 lbs heavier and 6" larger in one dimension.

We almost always have hookup when we are camping but for our upcoming trip all the electric sites were taken. I was thinking of getting a 100 AHr LiFePO4 battery but at $900 I am probably not going to be able to do that yet. We will conserve energy to the best of our ability on this trip and see how it goes. Hopefully the price of lithium batteries will come down in the next few years and I will be able to get one by the time my current lead acid battery dies. 

For those who are interested, I saw Renogy is having a 15% off sale July 20-21 (2021).