that is a bummer. i have an interstate in the porsche. it lives a horrible existence. i do all the things that kills a battery. the main thing being..long down time in between drives. i have taken it down to flat dead..maybe five times. (Stupid dome light!)

if i remember i put it on a 2 amp trickle. i rarely remember. if i do..i forget to take it off. hope my charger is smarter than me, and is working.

last time, i had it in my truck to go byebye. i found out Costco doenst sell the one i need..so i went back home. what to do? i risked it. i put the charger on, and pushed the knob to "START". i just let it go for 10 minutes. i then switched it to trickle. it took a charge!!! that was 4 months ago. it is still kicking. i bet that battery is 10 years old. i've owned the car for that long, and it came with that battery.

i wont buy another one, simply because they are expensive. but at least my battery is a rock star.

I have had nothing but fantastic luck with Interstate batteries. Like Vash, I have killed two, one of them 8+ times while chasing a headlight wiring short in my old Nissan, the other at least 3 times when trying to get my old Jeep going. The battery that went into the Jeep was the oem Interstate that came with my dad's Scion when he bought it new, so it was already pretty old when it went into the Jeep. I love Interstate batteries!

My dad has an old AC Delco battery in his Barracuda that is driven perhaps 2-3 times during the summer. It never gets charged during the summer (I do throw the trickle charger on it during the winter a few times), and has been in the car since I was a baby... That makes the battery close to 20 years old...

I have been using Interstate since my college days. they were damn good batteries. I couldn't kill em'. We bought from them when ever we needed a battery for our cars, trucks or equip. About 3 years ago I switched over to Optima in my diesel truck and my land Cruiser because that they don't spill. Sometimes the truck doesn't get driven for over a month and it starts on the first crank. This is a good size Cummins. No issues with them except for the one that went on to the 930. Like you, it doesn't get driven much. it sits without a charger, my fault really. the yellow top in there now has been great.

I have heard from various people that Interstate isn't what it use to be ( like your old one) and they go bad quickly. Well, I found that out. A mechanic who works for a small city's police dept. down here told me that they use Optima batteries in all their police cars and they hold up fine to abuse. Batteries are swapped out on schedule, so he gets the hand me downs in his own vehicles and get at least another 5 years out of them.

According to this website, Interstate batteries could be manufactured by 1 of 15 battery companies, most likely one closest to your retail store:

Lead-Acid Battery Manufacturers and Brand Names List

Sherwood

I can't help but think the fact that the warranty coverage changed as of May 1, 2012 may be indicative of the change in quality.

Heck, who knows. This was the batteryhttps://www.interstatebatteries.com/cs_eStore/Content.aspx?dsNav=Arpp~12,A~Part+Number,N~21-2147384879-4294493163-4294492820-2147384903,Nr~AND(P_unique_id%3aMTP-24F%7cToyota_Sienna%7c2006_Standard+Battery_V6%2f3 .3L)

Lets try that link again. Its the black one to the left
https://www.interstatebatteries.com/cs_eStore/Content.aspx?dsNav=Arpp~12,A~Part+Number,N~21-2147384879-4294493163-4294492820-2147384906