My apologies, Here is the link to the relay's I'm using.
Thanks; what I said in #35 applies to your relay including the numbers for current & voltage.
I got it. It's going to be useful in two other projects where I made the same mistakes, but now I know how to correct them. Thanks again for all your help.
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And are you really Harold Hill?
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Me? No, I'm Glenn. I don't know who that is. Is that name somewhere on my profile?
"The Music Man" is Harold Hill. Broadway musical.
Lol, being a drummer you would think I would know that, but I didn't.
One other thing you might want to consider. When the charger decides it's time to charge the battery, it will start drawing an additional 1A from the buck converter - on top of whatever the load current is at that point. Since there apparently will be very little battery usage, you probably don't need to charge at that rate.
The charging current is set by the value of a resistor from pin 2 of the TP4056 to ground. Most modules come with a 1.2K resistor there, which sets the charge current to 1A. There's a table in the datasheet showing the value needed for lower currents. The module will have a surface mount part, but you can probably replace it with a regular resistor.
You could reduce the current to 500mA, or even 250mA should be enough.
I have a whole slew of surface mount resistors. Where do I find the datasheet to determine the resistor value?
You Google TP4056 datasheet.
Hello Sir,
I'm back 
So I had to redesign my schematic a bit. Everything works except the battery. It charges but it won't power the entire unit even for 10 milliseconds. When I switch to battery, the Arduino and the GPS module have power (low power) but nothing else. I apologize in advance for my messy schematic, but I still don't know the basics and since it's an existing project I didn't want to fool around with it too much. Would you be so kind as to take a look and see where I went wrong? Pretty please with whatever you fancy on top? 
Thanks in advance.
Glenn
Tell me again what the output voltages are of the buck converter and the boost converter. They should be around 7+V if you're powering through Vin, with the buck being higher than the boost.
Well, nothing happens on backup battery power because the battery isn't connected to the input of the boost converter.
The output of the charger, which is also Bat+, connects to the input of the boost converter. The output of the boost converter goes through the diode to the connection point with the other diode. And then the other side of the switch goes to Vin. See my changes in orange.
I had them both set to 7.2 volts. 12 volts coming in from an adapter down to 7.2 volts, and a 3.7 volt battery boosted to 7.2 volts. Thanks for pointing that out.
In a two-diode circuit like this, the one with the higher voltage always powers the circuit. So if the boost converter has a higher voltage than the buck converter, the battery would be powering the circuit even if 12V is present, which is not what you want. So you want the 12V side to be a bit higher voltage than the battery side. Then the battery will take over only is there's no 12V.
Got it and it worked. Thanks again for your help.