New car with 10 miles and low battery indicated. It didn't have the expected low end grunt. Could the car have been in a battery saving mode?
By low battery, you mean 2 bars or less on the screen? You just have to prod the accelerator more. Yes it's a bit noisy (esp. since it doesn't have much sound insulation in the firewall) and it's a bit more strained with a low battery. However, don't try it just yet, the car is still new. Just keep in mind that it's ok if the engine revs up because that's the way the CVT works.
The Prius does not grunt at the low end. That's just not how it works. If you floor it from a stop, the engine will rev because it's driving MG1 (motor-generator 1) to generate electricity which then drives MG2 to drive the wheels. You might have less oomph than normal if you see zero bars or only one on the battery icon. But 5 minutes of normal driving will get the battery charged back up again and give you the normal amount of power. The Prius is not a muscle car, however, and will not accelerate as fast as a car with a much bigger engine. There is no "battery saving mode," but if the battery is low, the car will not try to draw energy from it, and it will have less power. This condition (as noted above) will last only a few minutes, as the car will re-charge the battery rather quickly.
Brings up a good point, though (but not about giving grief to people posting after test drives). We should be advising people to make certain they understand the SOC at the beginning of a test drive. If the car is brand new, it may have a low SOC. I recall with my car that I was always seeing purple bars for the first couple of weeks. A test drive is not going to tell you much about the real performance of the car if the SOC is low.
We took delivery yesterday and after a few miles I'm happy to report it has more oomph than that short test drive. Thank goodness!