Have a gen 4 prius that doesn't get driven often enough as I now WFH and am walking distance to stores. I'd been charging the aux/12v battery (w/ optimate 2 usually, do also have a noco genius 2) w/ clamps every so often, but I no longer have covered parking and want to be able to close the hood fully while charging, so I'd like to install a quick connect. But, I'm not sure how/where exactly the o-rings go. I'm especially not sure where the negative o-ring goes. If it can't go directly on the negative battery terminal, where else on the car can it be attached to easily? W/ the clamp I'd been attaching it to metal part near the engine as shown on the official toyota video for jumping: . There is a bolt right next to that, is that the best place, or is there somewhere better? Attached some photos of best guesses of where the o-rings might go... but if anyone has pictures of their setup or can provide any guidance, that would be appreciated. Ty!
any convenient unpainted bolt is fine. tou can even attach it to the neg terminal becuse it is permanent and won't cause sparking. yes, the positive terminal is also fine.
I charge at the battery posts, and then plug the charger in. The charger cable slips in between the headlight gap, hood locks. You could add a metric nut to the stud in the last pic, I wouldn’t unscrew the existing nut.
Fourth Gen battery being under the hood makes it straightforward. Well, it can go directly there; I seem to recall some charger ads even picturing it thus. It’s when your regularly connecting/disconnecting to neg, as the last connection, there’s a small spark, and IF there’s an accumulation of hydrogen gas, it could ignite. In reality, even just lifting the hood, any hydrogen atoms will dissipate. Still, it might be more convenient to connect negative elsewhere, less malarkey cluttering up the battery posts. Any bare metal point with a direct, conductive path to the neg post will work. To verify conductivity between a potential neg connection point and the battery neg post: a multimeter set to ohms (résistance) or continuity, is needed. Set to ohms is best option though; it’ll confirm continuity AND resistance. A lower resistance path is preferable. The connection to battery positive post can also be done remotely, but that be more difficult in practice. BTW, your use of the expression “O-ring” confused me. It’s usually for circular rubber gaskets. Circular brass plate, electrical connectors are usually called “pig-tails”, god knows why. food for thought: for less “secure” parking scenarios, on-board chargers are preferable. The entire charger “brick” is installed, typically under-the-hood close to the battery, and a power cord is the only thing that extends out of the car, say through the front grill, similar to a block heater cord. a couple of advantages: 1. The charger is under the hood, secure from theft. 2. Only an AC plug is accessible outside. With the alternative, a quick connect plug, someone could put a jumper (short length of copper wire, paper clip, tin foil, water) on the plug, essentially short-out your battery. Google: Walter White wet squeegee battery short out
A very good option when only the connector is visible. Security of the device from theft and damage. connector plug by MAX2 posted Mar 31, 2025 at 7:06 PM
