Is Hybrid Battery the Culprit to my Poor MPGs?

How long has it taken to put in the 400 miles?

Also, how frequently is your Prius taken out for a drive and for how long?

Could be other reasons for the poor mpg's, but check the obvious stuff first.

Getting the egr circuit cleaned is a big step though .

Good luck and keep us posted.

 

How fast does the battery cycle full to empty?

Did you pull the 12 volt lead when doing the above work?

Tire pressures and how old are the tires?

Any other recent maintenance?

Chasing mpg's can be difficult as there are a lot of variables.

I also invested in the Hybrid Automotive equipment for our old 2010 to maintain the HV battery and it worked well for the over 2 years that I had it paired to our Prius.

It definitely helped the mpg's while ensuring other factors were accounted for.

Good luck and keep us posted .

 

If you sit in traffic, or in a drive thru line, how fast does the battery drain and the engine kick on?

When I was in traffic is when I noticed battery degradation which prompted the investment in the Prolong equipment.

But battery degradation can explain mpg loss.

I'd eliminate the low hanging fruit and plan for what solution you want when the hv battery does fail.

 

Have you cleaned the battery fan and associated ductwork?

Honestly it does sound like the hybrid battery is tiring, but you might squeeze it a little longer.

Consider a used genuine battery out of a wreck. car-part.com can lead you to parts recyclers.

 

40% on the Dr. Prius test is pretty low, so you are near the brink. For comparison, I have a 2010 Prius with just under 100,000 miles that gets 65 to 70% on the Dr Prius test. My driving is less consistent than yours, so I don't see why mine is doing better. I also get worse mileage than I used to but not as bad as yours, about 42 mpg average. It is mysterious why some batteries do worse than others.
Your daily use should be good for your battery.

Since none of your blocks have actually failed, a Hybrid Automotive prolong system might buy you some time, but I don't know if it is worth investing that much in your weak battery.

 

Here is the thread I started for my specific situation on the topic:

2010 Prius II HV Battery Reconditioning

More light reading .

But if I recall correctly, I was at 44-46 mpg prior to the Prolong equipment use. Hope that helps.

 

You'd be surprised. If the battery temperature isn't in the range the computer likes, it will silently limit the battery's participation in your propulsion, and the general result is more fuel burned.

Personally I see less risk & hassle in the junkyard battery vs. the work of a repacker like greenbean.

 

Green Bean IS a used battery......
The Prolong system is about $650..... A lot less than a USED greenie beenie battery...

 

Once every six months I would do a top end balance, then every thanksgiving, I would do a 2 cycle reconditioning.

That isn't that frequent in my book, and was scheduled.

Had I kept the 2010, I think it would have been fine with the same battery and the equipment. If I would notice any issues with it, I'd have the right equipment available to address it.

 

How long do you hope to keep the vehicle and how many miles will you put on it? That makes a difference in weighing the options which all have trade offs.