It doesn't matter as the 12V does not have a starter. The primary requirements: size - must fit in the available space or make mods to hold the battery sealed or vented - it is in the trunk, technically part of the vehicle interior where the people live Ahr - there is ~30-35 ma parasitic load when the car is turned off and this defines how long it has to hold enough charge to start the electronics Bob Wilson
my aux battery was depleted, so I took it into my local auto parts store to get it tested and charged. they asked for the specs because there were none labeled on the battery. it was a Panasonic and all in Japanese.
If you have the Panasonic in your Gen 1, it's this one, originally 48 Ah, upgraded in current stock to 51. The CCA (as if it mattered in a Prius) is under 400. The part on the label that does matter most is the part that says "when you charge battery, charging current should not be higher than 5.0A and charging time should be within 12 hours." -Chap
My dome light had been left on a couple of times and battery was down. Since it is 5yrs. old, I decided to replace it. I bought and installed one of these several months ago, deep cycle and sealed, working fine and a lot cheaper than original or Optima replacement. It fits original space, only used a wood spacer under the top hold down. http://www.ebay.com/itm/New-12V-35AH-U1-SLA-AGM-Battery-Scooter-Wheelchair-Replaces-UB12350-AGM1234T-/171418973916?pt=LH_DefaultDomain_0&hash=item27e95df6dc
I put in a group 35 AGM. the Panasonic was dying. I had to mod the tray slightly and put in a mat on the bottom to space it up higher. it fits and is sealed, so no venting. itsa 680 CCA and 50 amp hours.
