Jump starter battery pack too good to be true

[Kepler]

One of my work colleagues brought in one of these for me to have a look at today.



About size of a large smart phone. Very neat package. Even has an EC5 plug output. 4 units in series and you would suposably have a 12S 48V 6ah pack stacked into the size of 4 smart phones and weighing only 800 grams. Site says up to 300A and 500 cycles

If only this was really possible. This would mean they have managed double the energy density of an RC liPo.

I am tempted to buy one just to test it and see what it can really do. I am tipping it is more like 3ah capacity at best.

http://www.arnosmater.com/index.php?route=common/home

 

[dogman dan]

Better start on the first crank. It won't do twice.

 

[Punx0r]

It claims to have an on/off switch and reverse-polarity protection and a 300A rating. So that's all got to fit in that tiny case along with a ~12V 6Ah battery.

Seems very unlikely.

 

[Ypedal]

quite the exaggerations.. 3 to 4 hour charge at 1 amp .. but 6 ah capacity

the 18ah module is cool, if it comes even close to it's claims.

Unless it's electronically regulated, it would have to be lifepo4 chem to be compatible with SLA without going way over voltage ( if left on for any length of time ) or under to the point of not turning over the starter.

 

[Hillhater]

Some serious specification discrepancies...

Dimension: 139x75x15mm
Weight: 200g
Battery Capacity: 6000mAh (22.2Wh)
Output: 5V/ 2A ; 12V

how can a 12 v , 6000mAhr pack only have 22.2Whrs ??

 

[Kepler]

So we can probably presume the battery is more like a 1850mah pack which fits in with the package size and weight.

So with a 300A peak out of what is most probably a 1.85ah pack gives it a 160C rating. Its another new record

 

[Ypedal]

a strech of imagination but if you left this hooked up to the SLA brick long enough to buffer up some energy, you " might " get a few hundred amps for a fraction of a second between the 12v sla and starter. :lol:

 

[Matt Gruber]

when my car battery gets weak, say 5+ yrs old, it only needs a boost of 25-100 amps to crank fast and start right up. I've used my 10a charger and it really cranks fast, less than a 50a boost probably.

 

[Punx0r]

Boosting a weak, but charged, battery is easy. Boosting one that has been accidentally discharged is much more demanding as you're not so much assisting, but replacing, the lead-acid starter battery. The video for this device shows no signs of life when the ignition key is turned, simulating an utterly over-discharged battery (most likely disconnected for the purposes of the video).

 

[Punx0r]

Actually, for boosting a weak, or nearly exhausted, battery it might be better to use the remaining energy in the starter battery to charge some super/ultra caps. Often the starter battery has enough energy remaining but cannot muster the discharge current required.

 

[parabellum]

(most likely disconnected for the purposes of the video).

At the end of the video, on the firs started car, one pole looks disconnected from the main battery, resting over cloth preventing contact to the battery.

 

[Matt Gruber]

also keep in mind few cars draw even 200a,
using a mini-starter my 350v8 is 125a. is was 180a using the antique full size starter.
of course guys in, say, canada need more in the winter.