Dead Battery while parked.

[krbjmpr]

Same 2012 Yukon, haven't gotten around to changing shocks yet...

Needed to make a grocery run, and found battery was near dead. Gauges and such, incl headlights, came on but were dim.

Battery has tested good as recent as 2 weeks ago, no issues there. Last time I drove was over a week. I know I do have a lot of parasitic loads: dash tablet, dash cam, USB charge block, blah blah. Nor have I gotten around to solar panel on top.

Thinking about plugging a maintainer to the truck via 7way trailer connector. Pretty sure this model has a charge relay enabled by ignition / ecu. Can anybody confirm? Does ecu only turn on this relay when it detects a trailer, or all the time when engine running?

If it is present, was going to remove relay and replace with jumper, so 7way is hot all the time. That would be most expedient. I am thinking about putting a diode inline in the trailer charge so that it would block power to rear. Diode would be shorted by another ignition controlled relay effectively bypassing it so current can flow to/from trailer connector. If Diode Relay is off, current only ablento flow from trailer connector.

I anticipate the truck doing a lot of sitting in the driveway.

Thoughts?

 

[Mean_Green]

I use an on-board charger like this:



Mine is inside the garage, so an extension cord is no issue.

 

[Geotrash]

Same 2012 Yukon, haven't gotten around to changing shocks yet...

Needed to make a grocery run, and found battery was near dead. Gauges and such, incl headlights, came on but were dim.

Battery has tested good as recent as 2 weeks ago, no issues there. Last time I drove was over a week. I know I do have a lot of parasitic loads: dash tablet, dash cam, USB charge block, blah blah. Nor have I gotten around to solar panel on top.

Thinking about plugging a maintainer to the truck via 7way trailer connector. Pretty sure this model has a charge relay enabled by ignition / ecu. Can anybody confirm? Does ecu only turn on this relay when it detects a trailer, or all the time when engine running?

If it is present, was going to remove relay and replace with jumper, so 7way is hot all the time. That would be most expedient. I am thinking about putting a diode inline in the trailer charge so that it would block power to rear. Diode would be shorted by another ignition controlled relay effectively bypassing it so current can flow to/from trailer connector. If Diode Relay is off, current only ablento flow from trailer connector.

I anticipate the truck doing a lot of sitting in the driveway.

Thoughts?

Mine will both eventually drain their battery if left sitting for 2-3 weeks. The 2012 sits in the garage for weeks at a time because it's our dedicated towing rig, so I keep a maintainer on the battery. We drive the 2007 at least weekly so no issues.

 

[Coolman1987us]

I use an on-board charger like this:

View attachment 398829

Mine is inside the garage, so an extension cord is no issue.

I had the exact same model. Problem with that cheap design, when the 120v power is disconnected the battery its attached to back feeds and powers the charger leaving the leds on. Not a big deal if its overnight but 2 or 3 days at -20f and your battery is toast. Schumacher isn't as good as they once were.

 

[Fless]

Thinking about plugging a maintainer to the truck via 7way trailer connector. Pretty sure this model has a charge relay enabled by ignition / ecu. Can anybody confirm? Does ecu only turn on this relay when it detects a trailer, or all the time when engine running?

If it is present, was going to remove relay and replace with jumper, so 7way is hot all the time. That would be most expedient. I am thinking about putting a diode inline in the trailer charge so that it would block power to rear. Diode would be shorted by another ignition controlled relay effectively bypassing it so current can flow to/from trailer connector. If Diode Relay is off, current only ablento flow from trailer connector.

I anticipate the truck doing a lot of sitting in the driveway.

Thoughts?

I think the AUX on the 7-pin trailer connector is hot all the time. No relay. Easy enough to check with a volt meter or test light at the connector.

 

[swathdiver]

Same 2012 Yukon, haven't gotten around to changing shocks yet...

Needed to make a grocery run, and found battery was near dead. Gauges and such, incl headlights, came on but were dim.

Battery has tested good as recent as 2 weeks ago, no issues there. Last time I drove was over a week. I know I do have a lot of parasitic loads: dash tablet, dash cam, USB charge block, blah blah. Nor have I gotten around to solar panel on top.

Thinking about plugging a maintainer to the truck via 7way trailer connector. Pretty sure this model has a charge relay enabled by ignition / ecu. Can anybody confirm? Does ecu only turn on this relay when it detects a trailer, or all the time when engine running?

If it is present, was going to remove relay and replace with jumper, so 7way is hot all the time. That would be most expedient. I am thinking about putting a diode inline in the trailer charge so that it would block power to rear. Diode would be shorted by another ignition controlled relay effectively bypassing it so current can flow to/from trailer connector. If Diode Relay is off, current only ablento flow from trailer connector.

I anticipate the truck doing a lot of sitting in the driveway.

Thoughts?

The "hotel" wire is not connected from the factory. It's wrapped up under the brake booster and goes to the right stud on the fuse block, secured with an M6 nut.

Many short runs and leaving all that stuff plugged in for a week or more at a time does not allow the battery to be fully charged. A simpler solution is to put a battery tender on it. Ring terminals on the battery nuts with a quick disconnect is how I do it with a Battery Minder 1510.

Your idea sounds cool though.

Last night Joe made a post about the same thing that many of us responded to.