It's my understanding that the big battery starts the Clarity, but the 12 v is big enough to jump start another car, heck one person connected an inverter to the Clarity 12 v battery and powered some of his appliances during one of the big storm that hit the east coast. Technically the 12 v battery in the clarity doesn't do anything other than close contacts to "wake up" the car computers. The big battery powers all accessories via the DC-DC converter which converts 300+v to 12v. Honda missed a big opportunity to save weight by not eliminating the 12v battery, or at least replace it with a motorcycle battery. If you're really concerned about hurting your Clarity but want to help out a fellow motorist simply disconnect one of the terminals to isolate the battery from the car and give a jumpstart. Again, that is just my understanding of the Clarity system so if you read it on the internet that you can't do that then it must be true......it's on the internet.
Last edited by Claire Greene; 12-29-2018 at 02:53 AM.