Battery will only charge

Enough...you're wearing me out w/dupe threads.

 

Did the traction battery state of charge meter show just one, purple bar? Commonly, while climbing a long hill, the traction battery will reach minimum charge (~40%), at which point it will not supply the electric drive for the remainder of the climb and you will be limited to only the output of the gasoline engine, which is pretty limited.

How many miles are on the car? If the traction battery is not holding charge as well as it used to, it may be degrading. On level freeways, the traction battery should rarely be at minimum charge.

On the freeway, energy flow is often less predictable than in the city. The electric drive is generally used less on the highway than in the city, but it still should be available for moments of increased power demand.

 

This is completely normal. The Prius is designed to use the hybrid mode more in the city at speeds below 42mph. Above that, you'll only use the electric assist when the battery gets near 70-80% to burn off extra charge and maintain it at 6 bars.

 

Ok, that means your prius/battery is working perfectly, only your expectations are off.

When freeway driving it's very common to see the green arrows showing charging of the battery most of the time. Once the SOC (state of charge) reaches 6 blue bars however, then this charging current drops to a very low level, but is still charging. Remember that the power for the entire 12V system (all the ECUs and displays etc) comes from the traction battery via the DC-DC converter. So, on average, it has to be charged slightly from the engine just to maintain its SOC.

Sometimes I drive for ages with it mostly showing the green arrows charging the battery. Other times it tends to flip about an change directs fairly often. I think that if you're seeing mostly green arrows then you're probably driving very steadily on fairly level terrain.

Anyway, the bottom line to take away from this is that just because it seems to be mostly charging, that doesn't mean you'll necessarily see the charge level increasing on the display. When it's at 6 blue bars it's basically just "treading water".

 

I think most curious types would find the use of one of the various monitoring devices/software instructive.Those directional arrows on the MFD are misleading, as they can jump back and forth quite frequently making one think that there important things being done in the energy realm, but the actual currents being controlled at such times are just a few amps, i.e. nothing much. I think there could have been some sort of magnitude information incorporated in the display (thickness of lines, brightness, color), but perhaps they thought it was geeky enough as is.