Batteries drop to 11.9v overnight. How to find and fix the phantom power drain?

[SkwurlyFab]

I've been having a lot of trouble with a phantom power draw on my 04 Chevy 2500HD. I've got two XS Power D3400 batteries under the hood wired in parallel with a Mechman E-series 250a alternator powering them. My system consists of a Kenwood DNX-8120 HU feeding an Orion HCCA-D5000 sub amp, and a JL 300/4 amp for my mids. All 1/0 wiring with big 3 done.

I also have a Directed Smart Start alarm installed with the cell phone connection service, but it isn't activated right now (not sure if that makes a difference).

I will charge my batteries all day up to 13.1 volts, and by the next morning my volt meter is reading at 11.9v. Well below the 12.6v minimum charge. I'm quick to charge them back up, but I'm worried about damage over time and obviously this is a huge pain in the *** since I'm always worried my truck is gong to die.

I have no idea how to locate what is drawing all the power out of the batteries as the truck is parked. I have a multi meter I can use to test the system, but how do I figure out what component is actually draining the power?

At one point I noticed that my sub amp was staying on, since the red logo was lit up even when the truck was off. This seems to have gone away and I have been keeping an eye on it, but that is concerning.

I also noticed that my dome light stays faintly lit when the truck is off, locked, with alarm activated. I replaced the bulb with an LED so I don't think it can drain enough power to take two XS batts down to 11.9v, but if that is staying on, maybe something else in the system is too.

Any and all help would be appreciated! I searched through the forums for answers but couldn't find anything definitive so I had to post up.

 

[Jeffdachef]

I've been having a lot of trouble with a phantom power draw on my 04 Chevy 2500HD. I've got two XS Power D3400 batteries under the hood wired in parallel with a Mechman E-series 250a alternator powering them. My system consists of a Kenwood DNX-8120 HU feeding an Orion HCCA-D5000 sub amp, and a JL 300/4 amp for my mids. All 1/0 wiring with big 3 done.
I also have a Directed Smart Start alarm installed with the cell phone connection service, but it isn't activated right now (not sure if that makes a difference).

I will charge my batteries all day up to 13.1 volts, and by the next morning my volt meter is reading at 11.9v. Well below the 12.6v minimum charge. I'm quick to charge them back up, but I'm worried about damage over time and obviously this is a huge pain in the *** since I'm always worried my truck is gong to die.

I have no idea how to locate what is drawing all the power out of the batteries as the truck is parked. I have a multi meter I can use to test the system, but how do I figure out what component is actually draining the power?

At one point I noticed that my sub amp was staying on, since the red logo was lit up even when the truck was off. This seems to have gone away and I have been keeping an eye on it, but that is concerning.

I also noticed that my dome light stays faintly lit when the truck is off, locked, with alarm activated. I replaced the bulb with an LED so I don't think it can drain enough power to take two XS batts down to 11.9v, but if that is staying on, maybe something else in the system is too.

Any and all help would be appreciated! I searched through the forums for answers but couldn't find anything definitive so I had to post up.

 

[Massive spl]

Yea your dome light shouldn't stay on all night. That will drain your power

 

[wew lad]

get a dc clamp and see where the power is going

 

[SkwurlyFab]

This is a great video, thank you for the link. Only thing is I need to figure out how to perform these tests on my truck with two batteries. His demonstration only used 1 battery. Google seems to have some answers on that which I'm reading up on now.

I can already tell it's going to be a huge ***** to find the drain since I have so much aftermarket equipment wired into my truck. I've got the Amp power steps, full audio system, cell phone connected alarm, a train horn setup, extra 12v plugs, LED replacement bulbs, trailer brake controller, etc.

 

[Jeffdachef]

This is a great video, thank you for the link. Only thing is I need to figure out how to perform these tests on my truck with two batteries. His demonstration only used 1 battery. Google seems to have some answers on that which I'm reading up on now.
I can already tell it's going to be a huge ***** to find the drain since I have so much aftermarket equipment wired into my truck. I've got the Amp power steps, full audio system, cell phone connected alarm, a train horn setup, extra 12v plugs, LED replacement bulbs, trailer brake controller, etc.

i'd get a nice accurate lil clamp meter that can detect slightest bits of current and test each power wire in the car with the car off. However that dome light, very likely issue that needs to be addressed firsthand.

 

[SkwurlyFab]

Do you have a clamp meter you could recommend that doesn't cost an arm and a leg?

 

[wew lad]

Do you have a clamp meter you could recommend that doesn't cost an arm and a leg?

you wont find a DC clamp that is accurate for less than about $60-80

 

[SkwurlyFab]

Under $100 isn't bad then. What model do you use?

 

[wew lad]

Under $100 isn't bad then. What model do you use?

im borrowing a friends fluke meter, fluke is said to be some of the best and i intend on buying one eventually. i just have a cheap $15 ac clamp meter, dont usually need a dc clamp

 

[Jeffdachef]

Under $100 isn't bad then. What model do you use?

klein tools is trusted too

 

clamp meter

 

[wew lad]

klein tools is trusted too  

clamp meter

thats ac current only

 

[Jeffdachef]

thats ac current only

whoops lol

 

[wew lad]

you're in luck OP, i spent some time and found a good option for you: Robot Check

be aware its limited to 100a dc

 

[SkwurlyFab]

wow thank you! that should definitely work. I hope I can figure it out on my own so I don't have to pay my audio shop $70/hr to trace the power draw. I've never used a clamp meter before but I'm sure it can't be too hard to figure out.