all. Haven't been here for a while b/c 2004 w/198k miles has been running fine. I cleaned out the hybrid battery fan last week after seeing some YT videos. Drove around until the battery was charged 3/4 and didn't see a difference in fuel mileage (I don't remember the last time I saw it fully charged). Parked it for the long weekend and this morning the display had only one pink bar. Drove it around until about 3/4 charged. Parked in the driveway about 4 hours ago, and now the battery has only 3 bars. Fuses all look OK. No red triangle. Any ideas what is causing this? TIA
Everything is normal... NiMH batteries self discharge when sitting unused so multiple days or weeks on an older pack becomes problematic because cells will self discharge at different rates and that can lead to red triangle and system shut down. Using a high voltage trickle charger is the solution. Maxx volts and Hybrid Automotive sell them. There some on Amazon too that are general purpose high voltage low amp chargers too. You can also build your own: Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat Once you have a charger you can periodically charge and balance the pack, especially after it's been sitting for a long time. Also you can extend your pack's lifespan by doing reconditioning too. In general the instruction on hybrid automotive website are the best for telling you how to do everything and how it works, but their equipment is buggy and way too expensive: FAQ - Hybrid Automotive
The 21-year-old battery with 200k miles will likely needs to be cycled every 12 months or even sooner. During the first reconditioning, it is necessary to discharge the battery below 84 volts, since the battery pack most likely already has cells in the modules that are worse than the rest.
OP never indicated that it was the original battery... Only that the battery was working near normally.
If you don't have a few thousand dollars for a new battery, but you have a couple hundred dollars for a charger and a discharger, and you're a DIY kind of person, then why not restore the capacity periodically over the next few years?
No it was not... You made the assumption that car still has it's original pack when OP didn't indicate vehicle pack history at all. Almost everyone who hasn't bought brand new has not look at the serial numbers of their 28 pack modules to determine date of manufacture and if it has a history of being rebuilt or not. An essential step in evaluating a pack's lifespan.
Not sure your issue here. OP made statements and asked questions. I made no assumptions outside of the facts given and responded based only on the information provided. Relax.
