Does anyone have an idea how we can check the Charge of the Hybrid Battery? I have had my Tahoe Hybrid about 3 weeks and do a lot of driving. When I keep the ECO meter in the center of the green I am averaging 29MPG. I have also noticed that if I do not watch my braking the ECO meter will go out of the green to the left, I am possibly lossing some regenerative charging power here.

 

I don't think the hybrid battery charge status is available for us to see (not sure why .... anyone at GM listening out there?????). The only voltage I've been able to find is the 12V battery status on the DIC. Welcome to the club by the way. Keep checking this board as it's the best place for info on our trucks out there. Believe it or not I've actually gone through and read every post and the info is very helpful.

 

I have noticed on my DIC that the battery voltage sometimes reads 15 volts? If the electric motors start the engine is the 12 volt battery only for the accesories?

 

The 12V electrical system is actually a 14V +2V/-4V electrical system, with the ability to withstand momentary applications of 60VDC (load dump).
Thus the new-era electrical components designed to reduce weight by using less current (and, therefore, thinner wires) are called 42V systems. They are 14V x 3 = 42V.

So, seeing 15V is not uncommon. You could even see 16V occasionally. Although the regulators are good enough now that this should not happen.

 

I think there are voltage peaks at some times, and the voltage may vary slightly
Toyota Prius

 

Just like normal charging systems you can see charging system voltage pretty close to 16 volts but this indicates that the 12 volt battery is low on charge. You should see the charging system voltage lower to about 13.9 once the battery is fully charged. At 13.9 the battery charge is maintained and the alternator, (or DC to DC convertor) is providing the battery with the extra amps to run the accessories.

 

Should a resting state of 11.7V be considered "normal"?

 

Per the OP's original question ... should anyone else find this old thread ... Use torque and the custom PID's for the hybrid battery.