Seeing everyone’s discussions about their 12V batteries unexpectedly draining really has me a bit concerned. What I want to ask is: if I keep a small lithium jumper starter (around 1000A output) in car, will it be able to save me if the battery is drained?
Depends what you mean by “save me”. there’s several categories of devices associated with 12 volt automotive batteries: 1. jump starter: a portable 12 volt battery with cables and clamps, suitable for starting a car with a depleted battery. For emergency use only. 2. charger: an AC-powered device that can recharge a depleted battery. For ongoing maintenance of a battery that’s getting insufficient charging. 3. Multimeter: a device that can measure battery voltage, and also milliamperes draw, when the car is off. The latter is sometimes referred to as phantom draw; the constant load imposed on the battery. 4. load tester: a device for checking a battery’s viability.
1000 amps is an impressive number and more or less irrelevant: it's easily ten times more raw current capacity than any Prius needs to go READY, and also it doesn't tell you for how long the pack can supply the current. That (how much current at 12 volts for how long) is, in short, the total amount of energy the pack stores, which is the more interesting number. Sometimes it's harder to find on the box though. I have a small one that stores about 39 watthours (Wh) and fits in the glove box (with plenty of room left for other stuff). It's generally adequate for readying a Prius and even jumping other people's cars too. There's one thing to be aware of, just for those really extreme cases where the car's 12-volt battery is really severely discharged. Prius 12-volt batteries have tended to store around 500 to 600 Wh, so if the battery's super empty a thing can happen where you connect the little jump pack and all its 39 Wh just disappear into the car's empty battery in less time than it takes you to reach in and try to push the button. Then you're out of luck, looking at the jump pack showing zero bars and thinking "wasn't this fully charged when I brought it out?" In those severe cases I've jumped gen 1 and gen 3 cars by unplugging the car battery first, jumping the car at the jump point, then plugging the car battery back in once the car is READY and can recharge it the way God intended. But I've never looked at the connections in a gen 5 to see how easy that would be.
FYI In the winter, you should probably carry that jump pack inside with you. If the car gets too cold, along with the jump pack in the glove box - it may not work. You should be good the other three seasons, leaving it in the glove box.
This dude talks fast so you have to pay close attention and take notes if you want to remember any of it. He got a good team that requests uptodate videos to make and some even support his purchases that he compares for us. This is his newest jump pack video, got to youtube to watch is excellent older jump pack video(s) that compare other brands. enjoy if you can keep up.
I had the endurance for about six minutes of it. He had to talk fast because he's mostly just reading the claims from the different products' boxes, and those boxes make a lot of claims. Six minutes is also enough to learn that the multiple-thousands-of-amps claims printed on those boxes have pretty much no correlation with how fast those jump packs crank that engine. And those huge claimed numbers are all dozens of times larger than needed to ready a Prius, where the pack isn't cranking the engine anyway. It takes nowhere near twenty minutes of auctioneer-speed jabbering to choose a nice jump pack that will do just fine for a Prius. I would pay most attention to the watthours of stored energy, the size and convenience ... and the brand, also, because this will be a lithium incendiary device you carry in your car. Recognized brands that have offices for legal service have a bit more incentive not to cut safety corners than the random-string-generator "brand names" of most of the products seen in that vid. The one in my glove box at the moment uses lithium iron phosphate cells instead of lithium polymer, just to be a bit less incendiary. Such a pack will be a little larger than a Li-poly one of the same capacity, but I'll make that trade for the peace of mind. Shopping for LiFePO4 packs can be a bit of a challenge, though, because the type of cell is rarely a detail the product listings go into.
Some of um pump up tires, beach balls, air mattresses, etc.. , others recharge smaller electronics. Only question left for many of them is longevity. But like most everything else subjective, mostly depends on how, and what they are used for. Since the only way to find out what kind of cells are in them is to open um up.
