What am I missing? That linked Amazon booster appears not to share much - brand, nor appearance - in common with the booster depicted here. Is the browser on my iPad stuck in some kind of cache hell, preventing me from seeing a truly comparable Amazon-listed product?
@RedOak I think they’re relying somewhat liberally on the “for similar” statement. Both boosters offer 12,000 mAh, and are capable of jumping a car. But yeah, the Amazon one also has a flashlight. And a second USB port. And a display, and a couple other I/O ports.
@RedOak the only place I found this specific jumpstarter is on the manufacturer’s website, where it’s listed at $99.99, so this is an even better deal… for something of unknown quality. I get the feeling a car battery might fry this thing on the first use, but it could charge your phone a bunch of times. I do like that it has a car charger so you can charge it with your car and then use it to jump start your car. Or use it to jump start the car and then use the car to recharge the jumpstarter. Either way, it’s basically free energy. This could be the key to my perpetual motion device.
@Bumplepimp Do you really want to know, or just want to beat your chest and fling poop?
Lead acid batteries have a specific power of 180w/kg, modern lithium polymer have nearly 500w/kg. So 2.5x as many CCA, energy density is also 2-3x as high so full car battery made of Lithium Polymer cells would be half the size.
But most importantly, the car battery is made to run the electronics (including the headlights) for a short while when the car is not powered. The Jump Battery is not intended to do that at all, merely have enough energy to start the car a few times.
@Bumplepimp@hodr Most batteries are optimized for energy density, however the manufacturer can trade off energy density for power density.
Conceptually, it is very simple. They put in electrodes with much more surface area. To make space for the additional electrode material, they put in less of the goo that actually stores energy.
The copper and aluminum electrodes in LiPo and LiIon batteries are excellent conductors of both heat and electricity. Increasing the amount of electrode material, also improves thermal and electrical characteristics. For extreme power densities, not only will the electrodes have a larger surface area, they will also be thicker.
I am more familiar with Lithium Ion batteries. Several years ago, Panasonic’s highest power density battery had one third of the energy density of their regular battery, but it could pump out a hell of a lot more current.
There is also a simple way to increase power and energy density at the same time. Instead of rating the battery for a thousand cycles, rate it for 50 cycles or less. This also involves redefining 0% and 100% charge. On a new battery, it is possible to use a different charging curve with a higher voltage for 100%.
An unfortunately common technique for really impressive specs is to put whatever the marketing director wants on the label. ie. Lie.
@Bumplepimp For what it’s worth, I bought a lesser spec’d no-name one from China (I believe it said 300CCA w/ 3000mah) with the intent of starting my quad with it since the battery died years ago and I don’t use it enough to justify buying another battery and have it die on the battery tender.
It worked good for that purpose, but I also had opportunity to use it on a 1.6L Escape and it had no issue starting the engine (and I completely disconnected the car battery).
@Pufferfishy a lot of vehicles now have power plugs in trunks or in the back storage space of the hatch so you could just have this charge whenever you’re driving. And lithium batteries don’t have the sort of slow discharge that alkaline batteries do. You can come back to one weeks later and still be above 90%.
I have the blue one, bought it a month or so ago. Finally had an opportunity to try it the other night.
The specs say “up to a 3.0 liter engine”, well I tried a 3.9 liter engine, and it was not enough.
Considering that is the smallest engine in my stable, i guess i have a really nice phone battery…sigh.
@swechsler I only know the plane answer - currently the TSA site is saying that power banks are fine in carryons but NOT allowed in checked bags. However under batteries it says it’s limited to 100 watt hours which is 20,000 mAh at 5 volts so this as 12,000 mAH @ 5v should be good to go online. (I’ve flown with one this big before without an issue but TSA is notoriously fickle by location and agent so not going to base anything on one experience )
I bought this more for lawn mowers. It sucks when the mower battery is dead and I have to go get my extension cord, set up my battery charger and try to jump it that way. My cars are all 4 cylinders so I hope it will work for them as well. I just wonder how long it takes to recharge. Does anybody know?