7-Way battery maintainer

[gemarsh]

I was wondering if the 12-volt battery circuit in the 7-Way would backfeed charge the truck batteries. Would like to build an adapter using a 12volt sae pigtail to use a battery maintainer for extended storage of one of my truck's, during some winter months.

 

 

[64BAwagon]

Assuming that the 12v+ in the 7 way is powered while the ignition is off (not every GM truck is set up like this from the factory)  I dont see why not. 

Thats actually a really good idea. Since I dont drive my truck very often. especially if we are home during the winter, I put the trickle charger on it every couple of weeks. 

[gemarsh]

I tested with a dvm and it's live with truck off. I didn't know if they had some kind of diode on the circuit.

 

I would like to pull up tight to the wall and not have to pop the hood up to clamp to a battery, myself. I like to keep the bed accessible for storge.

[64BAwagon]

Easiest way to check for it would be to verify the battery voltage with everything off, then connect the positive line from the charger to the 12v+ on the 7 way plug. If your battery shows an increase in voltage then youre good. 

 

If that doesnt work you could always wire a 2 prong connector to the battery and then leave it inconspicuously in the corner of the grille. Put the other end of the plug on your charger and just plug it in, no need to lift the hood.  

Edited December 17, 2022 by 64BAwagon

[PhilB]

15 hours ago, 64BAwagon said:

If that doesnt work you could always wire a 2 prong connector to the battery and then leave it inconspicuously in the corner of the grille. Put the other end of the plug on your charger and just plug it in, no need to lift the hood.  

I did exactly as 64ABwagon is suggesting this past month.  I picked up a NOCO Genius5 battery charger from Chevy Accessories using my Chevy points so I only paid taxes.  It comes with the clamps.  I decided to get the NOCO battery rings so that I could wire it to the battery and not use the clamps.  I also got the NOCO wire extender so that I could run the wiring from the battery to the driver side of the grill.  Now all I have to do is stick my finger through the grill to pull out the plug and connect it to the battery charger. 

 

I thought about connecting via the 7-way plug but was not sure about the voltage backfeeding into something it shouldn't.  I also thought about connecting the charger to the cigarette lighter power port but decided not to.

[64BAwagon]

I checked today and verified that the charger connected to the rear 7 way plug on the bumper will in fact charge the battery. 

I am still debating on which one to do. I likely have all the parts I would need for the one under the hood so I may just go with that. 

[gemarsh]

Thank you for checking. I'm waiting on the pollack 7-Way. 

[Pryme]

Are you guys talking about the block heater plug or the one in the box for 5th wheel?

 

I know on my truck the 12v on the dash is live even without the key in the ignition and honestly I don’t like that because I have to remember to uplug thing’s connected to it. Don’t want to drain the battery. 
 

for maintainers I’ve always just connected the ring terminals to the battery and run the small plug either out the grill or up to the cowl near wipers. 

[gemarsh]

7-way trailer plug in the bumper or bed.

[Wxman]

On 12/18/2022 at 6:33 PM, Pryme said:

Are you guys talking about the block heater plug or the one in the box for 5th wheel?

 

I know on my truck the 12v on the dash is live even without the key in the ignition and honestly I don’t like that because I have to remember to uplug thing’s connected to it. Don’t want to drain the battery. 
 

for maintainers I’ve always just connected the ring terminals to the battery and run the small plug either out the grill or up to the cowl near wipers. 

Will this help?

12 V outlet description.pdf

[Black02Silverado]

I was looking at hooking something up to the battery like this to put a maintenance charge on it since it doesn't get used a lot.  All the short trips and such put more drain on the battery.  Advantages to living close, you save on fuel but then other things take a hit, like the battery and oil not getting up to temp. 

 

Was looking at getting the Genius 2 and just mounting it in the truck.

[64BAwagon]

I got my trailer side 7 way plug today and connected the wires and the plug to it. I am using a cheap Harbor freight trickle charger because I am only going to connect it occasionally. If I was leaving the truck unattended for a while I would use my other charger, only because I trust it more than the cheapie from HF. I used the weatherpack fittings because that what I already had on hand but any 2 prong connector would work since its going to be indoors. I now have the set of alligator clips and the 7 way plug that I can switch back and forth. Other than the $6 on Amazon for the Curt 7 way plug I had everything else on hand. Much easier than having to set the charger under the hood, now it sits on the workbench behind the truck and all I have is the cord. 

Edited January 4, 2023 by 64BAwagon

[Pryme]

1 hour ago, 64BAwagon said:

I got my trailer side 7 way plug today and connected the wires and the plug to it. I am using a cheap Harbor freight trickle charger because I am only going to connect it occasionally. If I was leaving the truck unattended for a while I was use my other charger only because I trust it more than the cheapie from HF. I used the weatherpack fittings because that what I already had on hand but any 2 prong connector would work since its going to be indoors. I now have the set of alligator clips and the 7 way plug that I can switch back and forth. Other than the $6 on Amazon for the Curt 7 way plug I had everything else on hand. Much easier than having to set the charger under the hood, now it sits on the workbench behind the truck and all I have is the cord. 

So this maintains your battery from here?

 

are you using the ultra cheap hf one or the one that’s a little bigger with the green and red lights? The 20.00 one I’ve had great luck with but the ultra cheap black little box one I had bring a power sports battery up to like 16v. Tossed that one. 

[64BAwagon]

Yes, I tested the battery after hooking it up and it was charging fine.

I am using the really cheap one from HF, so far it has worked very well. Usually around 13.4 when on and the battery ends up around 12.8 with it off so the numbers are good. I really do need to get a small NOCO for this but as long as the HF one keeps working I cant bring myself to spend the money. I only put it on for a day or so every couple of weeks. During the winter the truck mostly sits unless we are traveling. 

[Pryme]

1 hour ago, 64BAwagon said:

Yes, I tested the battery after hooking it up and it was charging fine.

I am using the really cheap one from HF, so far it has worked very well. Usually around 13.4 when on and the battery ends up around 12.8 with it off so the numbers are good. I really do need to get a small NOCO for this but as long as the HF one keeps working I cant bring myself to spend the money. I only put it on for a day or so every couple of weeks. During the winter the truck mostly sits unless we are traveling. 

That little cheap hf one worked fine for me too, until it randomly stopped maintaining and cooked my 12v power sports battery. Luckily it was only 30.00 to replace. I’d at least upgrade to the one with the red and green light so you know what the status is.