Our GenIII 12 volt battery died yesterday

This was the orignal battery the gen III prius came with that died. it lasted 7 years (and 53000 miles).
It went high internal resistance. It could power headlights (full brightness) showing 12.6 volts at lead pencil terminals.
When trying to ready the car without headlights the initial spike of current would open circuit the battery internally providing only 3 or 4 volts.

After letting it sit the internal open within the battery would close making it look ok.
This action resembling a bad battery (external) connection was not the case. As i imbedded by voltmeter probes directly into the lead battery terminals. proved the bad connection was internal to the battery

Calling Oreilly's they had a direct replace for 179.00 with 3 year warranty. I have one of these in my genII still working fine after 3 years. My genII oreilly battery has a 4 year warranty but has no carrying handle (I don't know how I will remove it when it fails).

So I call around. Autozone has a duralast with carring handle for 181.00 (direct replacement) So I decided on the duralast.
Finding a store with one in stock was difficult. Out of 15 stores 6 locations showed 1 duralast (In computer system) as in stock. However only 1 store actually had one.

Prior to the battery failure I could hear regen braking whine getting louder (month to month) through stereo speakers (when radio is off). Speakers are always on for announceators (seat belt, revers beep, warnings etc)
This whine was also present in my genII speakers prior to its two battery (12 volt ) failures.

With the new duralast battery installed I hear no regen braking generator whine any more (gen III prius).
This was also the case with two new 12 volt batteries I replaced in my gen II no whine.

HOWEVER the regen whine came back (very slightly) within the first 1000 miles both times after replacing my genII batteries.

The moral of the story. Do you think I'm smart enough to replace my genII battery now? NOPE.

My (genII) regen whine is not quite as loud as our GenIII was the day before yesterday.

So I will wait till i'm stranded somewhere!