Actual Experience with Hybrid Automotive System?

then again, the remac's are nothing to write home about either.

 

it's definitely a conundrum. charger that may or may not work, remac that will get you more years, as long as your willing to possibly keep swapping them out, or new, which is 10 years of battery at a higher cost.

 

Call me a tightwad, but I'm all about not spending any more than I have to. If a reman is done right, it should last a long time. As long as a new one, probably not. A reman along with the occasional balance sounds perfect to me. Especially when all you do is plug it up for a while and let it do all the work.
Using the grid charger/discharger is not too hard. Keep in mind the fact that the high DC voltage can be very hazzardous to your health. If you feel confident about working with it safely and you have the time and the mechanical aptitude to do it, you can refurbish it yourself. You do have to change out any weak or failed modules. I like using my grid charger a lot more than using the RC chargers. I put a battery in a car with over 200,000 miles on it in Memphis last week that I used it on, and it seemed to do very well. Time will tell.
If you don't want to DIY, you can have a reman installed, but most likely will void the warranty if you have the grid charger cord installed.

 

This doesn't answer the question, but raises another one. Has anyone else noticed a drop in fuel economy with a failing traction battery? I did not. Before I replaced my car's traction battery (about the same age as the OP's), I noticed very fast charge/discharge cycles, but practically no effect on fuel economy. Most of my driving was on highway.

Based on that experience, I might look elsewhere to explain the drop in mpg, but it sure sounds like you covered the most common causes. Have you changed gasoline to higher ethanol content? Done an engine compression test? Check the brakes? Might want to double-check the health of that new 12V. Good luck.

 

How long have you been getting that type of mileage? What were you getting before the mileage reduction? I'm assuming you've owned the car for a few seasons and have seen a winter already. The Prius gets notoriously poor (by its standards) mileage in cold weather.

A few things to check before you assume it's the battery (you can throw some of these out the window if you know it's not the issue, I'm just guessing because I don't know the service history):

Tire pressure
12v battery condition (I know this was just replaced, but that doesn't mean it's functioning properly)
Oil level (or really, it might not be a bad idea to check all fluid levels)
Parking brake
Spark plugs
Air Filter
MAF
Throttle Body

Another note. Gasoline is usually given an additive in warmer months to slow its evaporation. Once the average temperatures reach a certain threshold, the additive is removed. I believe we're past that point now, where the additive is no longer added. I've never noticed a HUGE difference from hot to cold, but I also live in a pretty temperate climate.

 

If you have no DTC's, your battery is still functioning properly and that is likely not the cause of your low mileage. There could be a myriad of other reasons why your mpgs have dropped. Sparkplugs, brakes, tires, the list goes on. I would try everything else b4 I replaced the battery.

 

you can go for a drive, then feel the wheels. if a brake is dragging it will be warmer than the others.

can you give us more details on service history and when the mileage started to deteriorate?

 

Yes, the brakes may be dragging or the rotors warped. Also there are wheel bearings, and a myriad of other issues. If you already replaced the plugs that's likely not the problem.

As for the charger rejuvenating the pack, it will do that. I just hate to see you spend $400 on something you may not need. If there are no warning lights, the charger will not fix your mpg problems and neither will a new battery.