Stock battery:
Panasonic 80D26L-MF
530 A CC
Group size 26F

260L x 170W x 200H

Lead acid flooded with individual caps to refill the water

Terminals are reversed compared to US batteries. 26 is a common battery size. 26f is not common with the positive pole is reversed.

Since a group 26f battery is not really available locally, most people go with a 27f battery. With a 27f, the CCAs are more than enough, and the capacity is better (This means the radio can be on longer without the car running). And besides that, a group 26 battery is tiny!

Group 27F
273L x 173W x 229H
Little taller than the stock Panasonic

Group 34R
260L x 173W x 200H


When my battery stops reliably starting my vehicle, I will be getting a batteries plus X2 group 27F deep cycle:
SLI27FAGMDP X2Power Premium AGM 930CCA
This is a rebranded northstar battery that is available locally (Denver)

On my 3rd gen 4runner, I had a optima yellow top, and it lasted 10+ years until I sold the rig. Too bad optima batteries are not made in the US anymore.


Battery testing
I have learned that in 50 degree weather, when my battery is testing at 250CCA, it will not start. Here are my test results using a cheap (but worth it) conductive tester from amazon (Topdon ab101)

Not starting the vehicle at 50 degrees
250CCA
12.15 volts
12.34 resistance

Barely starting the vehicle at 45 degrees
275CCA
12.23 volts
10.86 resistance

Normal starting the vehicle at 55 degrees
370CCA
12.37 volts
8.1 resistance

For reference, a new AGM group 34 700CCA test
842CCA
12.7 volts
3.56 (AGM batteries have a very low internal resistance)


Advanced auto parts battery chart:
Advance Auto Parts - Down for Maintenance