I've been driving my Prius for a month now and I notice something about my battery. It never seems to be fully charged. The highest charged I got is still two bar short. Is this a problem or is this something normal?
That's normal,i wouldn't worry at all,it's very rare for all bars to be coloured unless you're braking or using the "B" function quite a lot,then you'll fill the bars quickly.
The Computers save room for regeneration from braking. If they routinely filled the battery, all your braking energy would be wasted. If you go down a incline with more than a 600 foot drop, the HV battery will fill up and the car will have to waste energy to keep from speeding up. B mode allows you to begin wasting at the top of the hill, so it is a more controlled decent. http://www.techno-fandom.org/~hobbit/cars/b-mode.html
perhaps it depends on where you drive and what kind of driving you do, but io routinely see battery full and quite often, battery nearly empty. of course, most of the time it's somewhere in the middle.
The battery will last longest if the state of charge stays in th 40-80% range. It doesn't like to be full charged.
This is from Wiki Toyota Prius - Wikipedia, the free encyclopedia Battery life cycle As the Prius reached ten years of being available in the U.S. market, in February 2011 Consumer Reports decided to look at the lifetime of the Prius battery and the cost to replace it. The magazine tested a 2002 Toyota Prius with nearly 208,000 miles and compared the results to the nearly identical 2001 Prius with 2,000 miles tested by Consumer Reports 10 years ago . The comparison showed little difference in performance when we tested fuel economy and acceleration. Overall fuel economy of the 2001 model was 40.6 miles per US gallon (5.79 L/100 km; 48.8 mpg-imp) while the 2002 Prius with high mileage delivered 40.4 miles per US gallon (5.82 L/100 km; 48.5 mpg-imp). The magazine concluded that the effectiveness of the battery have not degraded over the long run.[48] The cost of replacing the battery varies between $2,200 and $2,600 from a Toyota dealer, but low-use units from salvage yards are available for around $500.[48]
Keep in mind even with all bars lit you are still at 80% charge. The HSD has to keep headroom to dump regen braking energy. It also is not a good thing to fully charge a NiMH battery. Some cells will charge to full before all the others. They will then be over-charged while the rest continue to charge and could loose electrolyte in that process. This would be a "bad thing" (tm). This is the main reason all bars lit is actually 80% charge. Another thing that happens with NiMH batteries is that when they reach 80% charge further charging becomes inefficient and they convert a lot of the charge current to heat. Heat is the enemy. So the HSD tries to avoid that. A major newbe's mistake is to try to outguess the HSD. Just let it do its' thing. It will remain healthier and will provide you with the longest service. Said another way, relax and watch the blinking lights.
