04 escalade battery drain

A 200mA current draw IS a big deal when it comes to a car sitting.  It will kill the battery quickly.  A typical rule of thumb is the at rest current draw sould be under 50mA, but ideally should be lower then 35mA.

You can typically figure out how long a brand new battery will last by the reserve capacity of the vehicle.  Divide the reserve capacity by the actual idle current draw and then divide that number by 24 to give you 'days' before the battery will be too weak to start the car.

The idle current for the Metra piece is WAY too high at rest.

What I would do, is connect a current meter to the battery (through the ground lead) and measure the current yourself (with all lights off and nothing else on).  Then, start unplugging things one at a time until the current draw is less then 50mA.  If you find a 'smoking gun' replace that part and see if the current level stays down.

I would be somewhat concerned about the alternator only charging at 13.5 volts.  Run it down to an Autozone and they will check the charging system for free.

Good luck and keep us updated.

Figure the battery is rated for 60 amp hours.. at 0.2 amps, it'll take 12 days for the battery to be dead. At 0.035 amps, it'll take 71 days.

I'll second KP about 0.035 amps being about all you want to see.. the 0.2 amps seemed high to me, but then car stereo stuff isn't what I do, so I wasn't going to say that the module was drawing too much cause I just don't know.

13.5v charging voltage when?.. At idle, with nothing on, I'd like to see 14v. As you turn on more accessories, voltage will drop (staying at idle) until the alternator can't keep up and the battery starts discharging. GM has released a TSB concerning that; extended idling and low speed driving with lots of accessories on will cause the battery to go dead.

The parts store might be able to check it.. depends on who does it. I really don't trust them much. The last alternator I had tested outputted, according to them, 140A. That it was a 90A VW alternator, and that they wired the alternator up with 14g wire, told me all I needed to know about them.

Jim

300mA at idle?  Are you waiting for the dome light and other accessories to shut off?

For the battery to be dying only hours after it was running it would have to be a much more significant draw.

Can't you simply disconnect all the things you added and let the customer drive the vehicle for a few days.  If it is something you added the problem will go away, if it isn't something you added it will stay.  I know this isn't very scientific, but it is something the customer will understand.