I returned from a 2 week vacation last Monday, needed to go to the store but the car would not start. A lot of error lights came on and I recognized the dead battery problem because I had seen it a few times before. The problem this time was I could not turn the car off no matter what I tried. I tried to connect my battery charger to the car but it acted like the battery was a dead short the circuit breaker on the charger would keep cycling. I took my wifes car to the store and when I returned, my car had shut off. I measured the voltage on my battery at 4.5 volts. I connected my charger to the battery and after a few hours the battery was up to 12 volts and the car would start. Today I took the car to my Honda dealer for a battery check which was good. My main question though is how large LI battery do I need to carry in my trunk for an emergency start where I don't have to wait more than a few minutes for the battery voltage to get high enough to start the car. Any one with experience with that?
I’m pretty sure that most 12 volt jump boxes would work. The 12 volt battery is only used to boot the various computers that actually control the car. It does not run a starter like most ICE only cars. If I were going to buy just one, I’d get a larger amperage unit so I could use it for other applications as well. Sent from my iPhone using Inside EVs
I'd also get one that has "boost" option. This allows you to jump a completely dead battery. Without the "boost" option, the jump pack will not work on a dead (or nearly dead) battery.
One other comment RE the lithium ion boosters. I have one, but you have to take it inside the house periodically and charge it (if it normally lives somewhere in the car/ i.e. trunk). I have not had any occasion to use it (touch wood) but hopefully I'll have enough charge in that thing when I do. I just mean the human element to this type of solution is you have to remember to keep the jump-pack charged. And just like my conventional car I used to have I do carry jumper cables. i.e. I can ask for help, or give help the old fashioned way.
I used a NOCO GB40 on one occasion. It allowed the car to power up immediately. Any device with a similar capacity should perform as well. It can be charged from the 12V accessory outlet (cigarette lighter plug) or a USB outlet. Fully charged it should hold the charge for at least 6 months.
Holding a charge for more than 6 months has been my experience with a DBPOWER 1600A Li starter pack. I've used it multiple times to start 5.7L V8s with no problem, even after it sat for 8 months since its last recharge. I suspect that recharging it once a year (maybe with the annual oil change) would be fine for "powering up" a Clarity. I still have the original 2018 battery in my car, so one of my DBPowers is now kept in its trunk. I'm curious to see how long the Clarity's battery lasts.
