Since there is an AC outlet in back, and presuming it is powered by the 300V battery, can you use that outlet with a battery charger set to a load level lower than the outlet capability to charge a dead 12V battery including its own?

You know ... lifting yourself up with your bootstraps.

Just curious,
Nick

 

The rear AC outlet is powered by the 12V system. It is 150 Watts. The vehicle needs to be running for that outlet to work.

 

Thanks for the reply. Bummer it wouldn't work. Oh well ....

 

However, I have heard and I can attest to, if the 12V system is weak or on the verge of failure, putting the car in the off position will "recharge" the 12V system via the high voltage hybrid system.

I have no idea why or how but when my 12V battery was failing, if the tahoe failed to start, waiting a few minutes somehow "recharged" the 12V system enough to get the tahoe started. I would normally say just dumb luck but it seemed somehow to be "recharging". I tested this several times before finally replacing the 12v battery.

 

I noticed my battery to have a 13V charge on the DIC and like you said after turning off the vehicle for a few minutes to hours, the DIC will show a charge of 14-15V. Since it doesn't have an alternator, it cannot be the charging state that indicates the higher voltage.

 

The 12V charging system has a State Of Charge SOC algorythm to maintain the 12V lead acid vehicle battery. The algorythm is pretty much common in GM vehicles hybrid and non-hybrid. It is designed to recharge the 12V battery after a discharge. It is designed to boost voltage for the benefit of headlights, HVAC, and windshield wipers.

So DIC voltage will be higher with lighting, HVAC, and or wiper loads. DIC voltage will be higher immediately after most start ups.

The programmed voltage regulation is designed for fuel economy. In a fuel economy mode 12V system voltages drop to a lower maintenence voltage. I had a chance to drive a 2015 non-hybrid. I was surprised to see 12.2V on the DIC information center. But this vehicle boosted to 14 and back several times on my hour drive.

Voltage regulation is no longer a single target setting. It is variable. A vehicle 12V system is mostly resistance. There are inductors and capacitors but the ohmic value dominating is resistance.

Therefore POWER is still Voltage squared divided by Resistance. To run a 12V system at 14 or 15 volts after the 12V battery is healthy only wastes power. That power comes from the wall outlet or gasoline in many of our new technology vehicles.

The DIC voltage on the 2 Mode is what the 12V system SOC algorythm commands the Accessory Power Module APM to put out.

Likewise an new alternator system has SOC control to adjust the alternator output.

A 12V battery that is going bad will have high DIC voltages ALL the time and a weak or dead 12V battery the next start attempt. Just as a alternator system would have a hard working alternator to attempt to charge the bad battery.

 

I am having problems with my 2009 cadillac escalade hybrid.... There are no check ingine lights on, but have seen the" check engine ", "service hybrid system " lights have come on for a few minutes and turned itself off since I bought the s.u.v 7 mos ago. Every time the light came on I experienced a lunge, and stall between modes at low speeds. ..seems almost like maybe the 12v battery may be weak even though autozone tested it and told me it was good....I also am experiencing a loud electronic clicking sound coming from the throttle body every time I shut the car off...almost as if the throttle body is recalibrating itself. .I hooked up my scan tool and found 3 codes...two codes being the same exact code..(2).POAC4 AND (1) POBBD code....these codes were only in the history. ..again no check engine light is on .....plus electic running boards even went up slowly yesterday. ...I have noticed this cold weather and rain are causing more frequent stalls and lunges and even seems to hesitate in reverse after a cold start...I hope it's not time to change the 300v battery. ...please help me somebody! !!! I tried jump starting someone 3 mos back and have noticed all these symptoms come and go ever since...would that of caused it to throw them codes? I wrote them down and deleTed them all...haven't seen them since but still have the throttle body loud clicking, slow running boards and lunges..again please help!

 

There is a throttle body bulletin. The P0BBD needs looking into and could be a HV battery.

 

How many miles in your escalade hybrid?

 

Just hit 130k. ...craziest thing happened today although it probably has nothing to do with the problems I'm experiencing. ...I was feeling around the back side of the engine (making sure I didn't have a frayed wire in my harness ) and felt a rather large peice of paper....I pulled hard till it came out. ...someone at cadillac factory left a 4 page printout stuck in the engine! Looks like it's gotten very hot in the past....looks and smells a little smoky. ..it looks like it has part #'s to all the vehicles components. ..everything from the bose system to the 2-mode transmission. ..who knows...!