Using DPDT switch w/ two sources and Inergy Apex

[AntiGroundhogDay]

Hello All, new 2016 RAV4 Hybrid owner here building out for full time living.

I would like to build my electrical needs around the new Inergy Apex. Please note the instructions state the MPPT controller can take 30a and 26V.

My roof rack has room for a 90w panel producing 20 some odd volts and 5+ amps and it will likely not meet my electrical needs at times, thus I'd also like to wire a Renogy 20a DC to DC charger to the 12V battery in the car.

Question: Can I use a Double Throw, Double Pole switch to feed in the output from the solar panel, and the output from the DC to DC charger and toggle from one source or the other depending on my needs?

When I am parked for awhile and it's nice and sunny, I throw the switch one way to use the solar panel, but if it's cloudy for a few days and I need to recharge via the car for a quick charge or I happen to be on the move that day, I'd throw the switch the other way.

Also: Would any of these components, including the MPPT controller inside the Inergy Apex, the solar panel, or the Renogy DC to DC charger react poorly to switching back and forth with the toggle switch?

Side Note: Ideally I'd be able to combine the Solar and DC to DC charger at all times into the the MPPT controller in the Inergy Apex, but as I understand (#newbie) MPPT charge controllers they generally want to see the same voltage from sources.  That's why you generally want to match panels.  If I'm not thinking of this correctly and there is a way forward, please chime in!

 

[jasper]

It appears, upon a short read, that an inexpensive dpdt knife blade switch could possibly work.  In the middle position, nothing is connected to the load.  The sources are kept well separated.  I have used the inexpensive orange ones a number of times for various switching applications.  Just keep tabs on maximum loads and volt/amp ratings.

https://www.ebay.com/sch/i.html?_fr...kw=knife+blade+transfer+switch&LH_TitleDesc=0

 

[AntiGroundhogDay]

It appears, upon a short read, that an inexpensive dpdt knife blade switch could possibly work.  In the middle position, nothing is connected to the load.  The sources are kept well separated.  I have used the inexpensive orange ones a number of times for various switching applications.  Just keep tabs on maximum loads and volt/amp ratings.

https://www.ebay.com/sch/i.html?_fr...kw=knife+blade+transfer+switch&LH_TitleDesc=0

That does not look ~too~ big, but decent sized:


I still would like to know if flicking this switch would break anything within the Inergy Apex.  Thanks for the tip!

 

[tx2sturgis]

I have doubts that your solution will work well, and it is overly complex...and the Apex could be damaged...so you should check with the company to verify if any of this is a problem for the components they sell.

But, the Inergy Apex already has a 12 car charger port. This will take care of charging it (somewhat) while driving, or on cloudy days.

While parked, plug in the rooftop solar panel into the solar input port, to charge the Apex while stationary.

If you really need or want a backup method to charge the car's 12v battery if it were to become discharged while boondocking, simply plug in a standard 120v powered wall plug type battery charger into the Apex, and attach the clamps to the starter battery. This will partially deplete the Apex, but then it can be recharged once the car is running, or when you have solar input.

Or, you can buy a simple $30 solar panel car dashboard battery maintainer to keep the starter battery topped-up during extended stays. That's what I do.

 

[AntiGroundhogDay]

I have doubts that your solution will work well, and it is overly complex...and the Apex could be damaged...so you should check with the company to verify if any of this is a problem for the components they sell.

But, the Inergy Apex already has a 12 car charger port. This will take care of charging it (somewhat) while driving, or on cloudy days.

While parked, plug in the rooftop solar panel into the solar input port, to charge the Apex while stationary.

If you really need or want a backup method to charge the car's 12v battery if it were to become discharged while boondocking, simply plug in a standard 120v powered wall plug type battery charger into the Apex, and attach the clamps to the starter battery. This will partially deplete the Apex, but then it can be recharged once the car is running, or when you have solar input.

Or, you can buy a simple $30 solar panel car dashboard battery maintainer to keep the starter battery topped-up during extended stays. That's what I do.

According the manual, the two female cigarette plugs on the Inergy Apex are output only.  I don't believe they would accept 12v / ~5a coming from the car's 12v battery and alternator.  But certainly I could plug in the solar panel's output into the Inergy Apex, but the end goal would be for any charging solutions to require the least amount of effort, thus my idea about the switch! 

Unfortunately I won't have a home base or place to top up the Inergy Alex with a maintainer.

 

[tx2sturgis]

Again, the Apex has two low-voltage electrical INPUTS. One is for a low-current AC or car charger (called the Apex Car Charger) and one is for a high-current input such as solar panels. The Apex Car Charger looks a lot like a laptop charger....about $60 on the Inergytek website.

Use either of those inputs for charging it. No switch needed.

(very low effort required to use whichever you need to use)

 

[AntiGroundhogDay]

Ok now we're on the same page, when you said "12 car charger port" I took that as your typical cigarette female plug. The Inergy Apex has a low voltage port (accepting their standard car charger is listed as 100 watts) and a high voltage EC8 plug accepting 30a and/or 26v.

In the end, I didn't want to have to plug and unplug stuff all the time and wear out sockets, etc., but alas this will not work after calling Renogy:

- The Renogy DC to DC charger has it's own controller inside it and will only work when directly connected to the battery. Inergy does not have a sanctioned way to do this to my understanding. Renogy stated they run into a similar problem with people who purchase their suitcase offering with built in solar controller and try to connect it to an Inergy Apex/Kodiak or Yeti that has a built in PWM/MPPT controller. Any controller wants to connect directly to a battery. So even if I was willing to manually swap input from the solar panel to the DC to DC charger, the DC to DC charger would not work since it is not directly connected to the battery.

 

[AntiGroundhogDay]

The secondary goal was to minimize the amount of time the car's engine and traction battery were being used to charge the Inergy Alex and really pump in as close to 30a as possible.  Seems the best I can do is purchase an inverter to run off the starting battery / alternator, then plug in Inergy's quick wall charger connected to the Inergy Alex 30a/26v charging port?

 

[tx2sturgis]

I left out the 'v' after the '12' and the meaning might have been unclear, but yes, that was the input port I was referring to.

Simple typo on my part, sorry for the confusion.

When I said low voltage, that means 12v or up to 26v....high voltage would be 120v. Anyway, the input ports are both low voltage, but one is low current, and one is high current. Standard electrical definition for 0-49 volts is 'low voltage', that is how I was defining it. Again, sorry for the confusion.

I had a bit of 'hands-on' with the previous model, the Kodiak, at Quartzsite, and from my time working with it, the ports and connectors seemed robust and well made....but of course YMMV....(your mileage may vary).

 

[thegoodtom1]

So, pick up a small motorcycle battery as a buffer between them. Renogy to MC battery, then MC battery to 12v DC input. Just make sure to install fuses.