Battery Myth Busted

except that the battery isn't under the hood. just bustin' ya stevie.

 

I do a fair amount of PC and copier repair. The copiers store Codes so I get both the client's opinion of what is wrong and the copier's opinion.

For the Prius, truly wonderful folks post their Codes, (often after prompting) which gives us the car's opinion of what went wrong.

Getting it right in so few posts without Codes is pretty darn good!

 

Of course I can't prove that driving after running out of gas shortened the life of my hybrid battery but I think it probably did. Here is my theory. As we know in normal driving the hybrid system never lets the battery get below a certain level before the ICE starts charging it again. Normally for me this is about halfway on the battery meter. The only time that I see the SOC lower than that is when I am doing something other than normal driving. For example one time when after I did some extensive stealth driving in a parking lot and got the hybrid battery down to about one bar.

Another time I was parked for quite awhile with the air conditioner running. The ICE would start up for a few minutes then shut off so I didn't think much about it as I figured it was taking care of itself. But when I was ready to leave I was surprised to find that the hybrid battery level was down to about two bars, which means that the ICE was only keeping it minimally charged.

My guess is that letting the hybrid battery get this low is not good for the life of the battery, even though the hybrid system will allow it in those situations. And driving after running out of gas lets you go even deeper into the SOC than you normally ever would. My theory is that you might get away with this type of non-standard drain on the hybrid battery, but you also might not. These batteries are being asked to do a lot over their 100,000+ mile lifespan and pushing them beyond their normal level of drain is probably not a good idea for battery life.

 

If I drive my normal car until the low oil light comes on and then drive it several more miles, and then later I do this again and have to replace the engine, would you blame the car?

 

You had me at shift-thingie.