Zamp Solar Connections - Explained

Michigan_Mike

This information has been discussed many times here on the forum and in an effort to preserve and reference it (in the future) I wanted to provide additional information and clarification on Zamp Solar's panel connections and when using a battery tender. This is basically an extract of the information I previously had posted up over on the Little Guy forum back in 2016.

Zamp wires their solar panels in an effort to make them safe to use and in an effort to avoid accidents since the panels do convert sunlight into energy and it is possible for a user to put themselves in series with a solar panel and receive an electrical shock should they become part of the circuit when hooking up and using a solar panel.  This is true whether it is a Zamp solar panel or any solar panel you may be using since they are able to generate energy when in sunlight or for that matter, any ambient light they come into contact with. 




The photo below shows the stock Zamp Solar Port wiring harness that comes on all of the trailer units and is located either on the battery box, sides of some trailers and on the tub of the T@B and T@G trailer units.  This piece wires directly to the trailer battery and as you can see in the photo the positive (+) side (red wire) of this harness is the bare contact terminal, negative (-) side (black wire) is the female part of the solar port.  




The photo below shows the style of connector that would come off the end of the newer Zamp solar panels.  In this photo the positive (+) connector (red wire) is the female style end.  Zamp wires their solar panels in this manner to protect users from accidental shock accidents.  The bare end of the connector shown is the negative (-) terminal (black wire) and this is where some of the confusion comes into play when people discuss the "Battery Tender" brand of trickle charger, as their terminals are wired directly opposite of the Zamp wiring scheme shown below.  


Note:  The gist of  Zamp's safety intent here is that should you deploy "any" solar panel and have wires connected to it in full sunlight it is producing electrical power.   If the above wiring is connected to a Zamp solar panel the risk of being injured is reduced here because the "positive end of the cable" coming from the panel has an insulated plastic coating over the energized (+) cable end.  By wiring their panels in this manner it greatly reduces the potential of accidental contact should you have the cable ends in your hand. 

Battery Tender brand trickle charger wiring explained

In the photo below you can see that the Battery Tender units are wired opposite the Zamp solar connections and unless these terminals are wired in reverse you will not be able to charge up your trailer battery if you plug a Battery Tender into the Zamp Solar Port on your trailer.  In other words you would need to do the following with the battery tender trickle charger unit:

1.  Cut the charge wire coming off the back of the Battery Tender unit, reverse the wires and splice them back together.  

2.  Use the clip on style connectors shown just to the right of the tender unit and attach them to your trailer battery when charging the trailer battery.  

Unless you follow the above steps the Battery Tender unit will not charge your trailer battery if the tender is plugged into a Zamp Solar Port and this issue has confused many trailer owners as a result of the way Zamp wires their solar panel wiring harnesses.  



The bottom line here is that Zamp Solar does not wire their solar ports for use with the Battery Tender brand trickle charge units, but only wires them for Zamp Solar equipment and apparatus.  Therein lies the difference and hopefully the above information will help people understand the reasoning behind Zamp Solar's wiring set-ups and provide them with enough knowledge to use a Battery Tender in charging a trailer battery when it has a Zamp Solar connector wired into the trailer and hooked to the battery.  

ChrisandAlexis

@Michigan_Mike, your bottom picture needs a correction I believe. The picture of the clamps to the battery shows both leads to be Negative Terminal. Thanks.

pthomas745

Thanks, @Michigan_Mike, for posting this again.  I looked all over for it the other day and I was afraid the internet had forgotten it!

Michigan_Mike

ChrisandAlexis said:

@Michigan_Mike, your bottom picture needs a correction I believe. The picture of the clamps to the battery shows both leads to be Negative Terminal. Thanks.

Fixed!  Thank you!

FishDoctor

@Michigan_Mike -- Thank you for providing another very useful and informative guide!

lkc001

@Michigan_Mike I found this information somewhere also.  Apparently the following two adapters will work to connect for example, a Renogy portable solar kit to the Zamp input already factory installed.  

Tecmate Optimate Cable O-27, Adapter, Polarity, SAE

 https://www.amazon.com/dp/B00AHCWGOO/?coliid=I35J3WTUBIMUOK&colid=10JTC9Y710WAC&psc=1&ref_=lv_ov_lig_dp_it

and this 

Renogy MC4 to SAE Adaptor 12 AWG Panel MC-4 Type Connector 

https://www.amazon.com/dp/B01N1TALFY/?coliid=I2ZK1E27IGFFQA&colid=10JTC9Y710WAC&psc=1&ref_=lv_ov_lig_dp_it

is this correct?

pthomas745

The SAE (or Zamp) connector is the step that goes from the solar controller to the connector on the trailer. In the thread the other day, I pointed out I just wired the cable so the positive out from the controller went to the "plastic" section of the cable and the negative out goes to the big metal part. 

If you don't want to do that, then wire the metal part to the positive, and the plastic part to the negative, and then plug the cable into the Optimate adapter, and the correct polarity is provided for you when you plug it into the trailer.

The Renogy MC4 to SAE adaptor would be for adapting an SAE cable to the outputs from the solar panel or solar panel wiring.  I suppose you could have a cable from the controller that terminates in MC4 and would need an SAE adaptor to get to the plug on trailer, but I don't think the linked cable adapts the polarity.  (See the first comment in the Amazon review.)  You would have to use the Optimate cable to do that for you.

mgreen2

The Renogy adapter does “reverse polarity” as people are calling it to match the Zamp. I use it to plug my Renogy solar suitcase into the factory installed Zamp port.

The Zamp port has the wiring so the hot side of the plug into it is covered. This helps prevent a short if you touch it to metal of the camper. If you just reverse the wires of the Zamp port at the battery it will work with a standard SAE plug but the hot side will be exposed. For peace of mind and to reduce risk of blowing a fuse or short the battery at a campground I’d recommend using the adapter 

https://www.renogy.com/mc4-to-sae-adapter-12-awg-cable/

rfuss928

Michigan_Mike said:

ChrisandAlexis said:

@Michigan_Mike, your bottom picture needs a correction I believe. The picture of the clamps to the battery shows both leads to be Negative Terminal. Thanks.

Fixed!  Thank you!

I think the "clamps" connector is now labeled reverse. 

First, it would not mate with correct polarity to the Tender connector pictured.  They need to be a complementary pair. 

Second, the exposed terminal of the "clamps" connector as labeled would be the batteries positive and a high risk of bumping ground somewhere on the vehicle until connected.  A much lower risk with the Tender connector because it is not grounded to anything.

( Also, I just checked my "clamps" connector.)

lkc001

So do I need both of the adapters that I linked to above?

pthomas745

@lkc001 Do you already have a panel and solar controller?