HV battery maintenance suggestions

You can buy a grid charger at the Priuschat shop for $399 and it should help keep your battery from going toast......for now

 

i think there is someone in denver... ...boulder hybrids? okay, that's not denver.

 

You could give PriusChat member and frequent contributor 3prongpaul | PriusChat a private message and ask him if anyone in Denver is good.

 

We have sold close to a thousand of our charger systems over the last 24 months, over a hundred to Prius owners like yourself. Our customers report very positive results including eliminated re-calibrations, improved MPGs, increased EV mode, and more. This is a typical example of what a two-deep discharge cycling of a 140k 9 year old Prius battery:


A 19% increase in usable battery range. Re-calibrations are eliminated for months. Our products regularly add years to the life of Honda NiMH batteries that have already 'failed' with the equivalent to a triangle of death. They are already delivering the same type of results for Prius owners worldwide. The sooner that one starts using a charger to maintain their hybrid battery, the more benefit will be received by using it. Feel free to send me a note or email through the website with any questions. I am happy to help however I can

 

i disagree somewhat. gen II batteries are rock solid and a small minority have trouble before 150,000. if you're not experiencing any problems, why make a $2-3,000. investment now?

 

If you mean replace when it fails, I agree. While it is true that all traction batteries have finite lifetimes, that does not even remotely equate to all Prius eventually requiring a battery purchase. 10 year old Prius seem to be running a ~ 5% replacement rate.

Odds are in your favor that the car will enter car heaven with the original traction battery still operating.

 

I wouldn't equate the two options exactly that way. Trading up is usually the more expensive option, unless maintenance costs have put you under water with the value of the car, in which case, get rid of it asap. Otherwise, repair is usually the best option. It amounts to whether you can afford the upgrade or not.

 

For any gen2 Prius owner that has an out of warranty car and wishes to keep it for a long time, I strongly recommend Jeff's grid charger with the discharge ready harness and get the simple discharger too. You can purchase it in the Priuschat Shop. You may have to go to his website to get the simple disharger.
Store - Hybrid Automotive - Honda & Toyota Grid Chargers

If you own more than one gen2 Prius (or have friends or family with one) this is an even better deal. You can buy a separate harness for each additional car and split the cost of the charger.

 

Are there any indications of HV trouble (cooling fan running on high, fast changes in state-of-charge)?

If it's not exhibiting symptoms, I follow the "just drive it and don't worry about it" philosophy. It's easy to become somewhat paranoid about the lifespan of the components from following forums and rumors, but, as mentioned, failure rates are statistically low. The Prius continues to be among the most reliable and easiest-to-own production vehicles. Even the 1st-gens that we're wary of are probably more trouble-free than most of the other cars out there.

I'm not sure if you've seen this item, but it helps put me at ease about the Pri (see the chart near the bottom):
Honda Civic Hybrid Battery Reliability | Hybrid Batteries - Consumer Reports News

 

Prospective customers report decreased MPGs, negative re-calibrations (where the SOC display suddenly drops to two red bars and the car idles high while force charging the battery), and less frequent EV mode. These are all early signs of NiMh battery failure. If the battery is charged & re-balanced, or even better deep cycled at this point, the symptoms will go away for a significant amount of time (multiple months is typical) depending on driving conditions and user habits. When the symptoms start to return, repeat the process. Many Prius owners have become customers and used this process to 'bring back' deteriorated packs and/or prevent their packs from reaching a deteriorated condition in the first place.

 

Yes if the car is sitting for several days or more self-discharge of the HV battery cells will become an issue over the long term. The charger very slowly charges the cells above their actual maximum capacity. Full cells hold at 100% charge and give off some heat that is easily dissipated. Weaker cells continue to charge until all cells are at 100% and balanced. For even better results, performing a deep cycling of the pack 2-3 times a year will recover lost capacity and deliver better overall results than just charging alone.

The charger draws power from any normal AC outlet in your home. The current draw is 75W or less, so any socket will work, no special residential electrical hardware is required.

 

Discharging the pack to a low level to break down crystal formations and regain lost battery capacity, then charging it back to full. On our 2005 Prius with 140k miles, we increased the usable capacity of the HV battery by 19%.