Ok, stupid newbie question....

[shawnb2]

Do the Gen III's have an alternator? The reason I ask is for aftermarket stereo equipment and whether or not it charges the car battery like any other car or does it regenerate from braking as well like the hybrid battery does. Any info and help would be greatly appreciated. I know the engine doesn't have any accessory belts so wasn't sure if it had one as a direct drive unit or something along those lines.

[fuzzy1]

There is no 12V alternator. Normal accessory electricity is generated from MG1 and/or MG2, put into the HV battery and electric system, then stepped down to 12V for the low voltage battery and electric system.

[JimboPalmer]

Not as such, no. MG1 most often serves to charge the High Voltage Battery, although MG2 may do so as well during 'braking'. The HV Battery recharges the 12v battery, which runs the accessories. As I understand it, you can never run down the 12v while the car is in 'Ready', it gets recharged by the HV battery, which starts the ICE when it gets low. The 12v battery is smaller than usual, as it never runs a starter.

MG1 - The smaller Motor/Generator, It starts the ICE, and most often charges the HV battery

MG2 - The larger Motor/Generator, It directly powers the wheels, and when deaccelerating, charges the HV battery

ICE - Internal Combustion Engine, Ultimately, all energy in the Prius comes from here.

[Fuzzy beat me while I was deciding how much detail to use]

[shawnb2]

I guess I'm going to have to take a reading at the car battery while someone is driving and check the voltage at the battery. I don't think this is my problem with the aftermarket stereo equipment but it would make me feel better to know for sure. Thanks to you both.

[donee]

Hi Shawnb2,

The Prius does not have an alternator. It has a switching power supply similar to what is in any desktop PC that outputs 12 V (instead of 3 or 5 volts in the PC). In the Desktop PC there is a rectifier that provides 170 to 300 volts DC to the switching power supply from the wall outlet AC. In the Prius there is just a 201 volt battery supplying the DC for the switching power supply.

In the Gen II the rating was 1100 watts. But that includes all the 12 v stuff that is in the car too, including the lights. What is available for add on stuff is less. Park the car, and put it in READY mode with the lights off , and you can maximise the available current for add-on stuff. Adding a much larger 12 V battery can help buffer large current demands from the add-on equipment.

Some people (electrical engineers with high power experience and capability read safety equipment and knowledge to use it properly) tap the 201 volt battery directly with their own switching power supply. Much more power is available this way. Any such work has to be done perfectly the first time. There is no room for error, as the Battery has about 30 HP of output. Imagine what a car tire landing on you being spun with 30 hp, and that is what 30 hp of electricty will do, but even faster as it will penetrate throughout the body instantly.

[lenjack]

"Ok, stupid newbie question.... "

Newbie yes, stupid no.

[shawnb2]

Thank you all guys. Helped a ton. My stereo has had no problems in the power department. It has worked out just great. Thanks again for all of your help and explaining the workings of our cars to me and everyone else who didn't know for that matter.

[KK6PD]

There are no "Stupid Questions", only unasked ones, so that would be stupid not to ask it!

Yours is actualy a smart question!
The one limitation a Prius has is how much current that can be delivered to large high power aftermarket sound systems some folks install. Not enough available volts/amps, will certainly make a great system sound like crap!!!