I’m an RC guy and have a lot of experience with LiPo’s. I run a very large and heavy hexacopter with 5S batteries and have a range of 5000MAh ones from 20C to 90C - the 20C ones will catch fire if I use them for the hexacopter (don’t ask…) but will power my big motor-glider just fine for an hour. To get high-performance maneuvering on the Hexa, I need to use 50C at a minimum. If you aren’t familiar, the ‘C’ rating is the C rating is the maximum safe continuous discharge rate of a pack. If you see 10C on your battery, it means it can be discharged at 10 times that pack’s capacity. so, a 20C 5000mAh can deliver 10A continuous, a 90C 5000mAh battery can deliver 45A continuous.
Overload them and they WILL catch on fire - which is why all the crap about shipping LiPo-equipped electronics by air.
While the Limewire might look good on paper and they might rate it as able to deliver 5A, I doubt it is 5A continuous for the full capacity of the battery.
If it was me, I would buy a few of these: http://www.hobbyking.com/hobbyking/store/_23640__ZIPPY_Flightmax_6000mah_2S2P_50C_Hardcase_Car_Lipoly_USA_Warehouse.html
They are in a hardcase and are rated for ROAR racing which has some huge surge numbers when they home shooting out of a corner and go full on the gas. 7.4V at 6000mAh and 50C means 30Amps continuous. The only thing you need to worry about is sweating and electrocuting yourself 
(I would encase in a snap-lock food-keeper box, if it was me).
They are in the US warehouse and should get to you in a couple of days. Get an appropriate charger and you can charge from a car battery, mains supply, etc.
http://www.hobbyking.com/hobbyking/store/_15164__Turnigy_MAX80W_7A_Lithium_Polymer_Battery_Charger_USA_Warehouse.html
They’re meant to have over current protection too, so no matter how much I tried to draw, if they were operating within spec they should have just cut out. Which leads me to the conclusion that one was busted to start with.
I still think they have overstated the power delivery ability. How many devices can you think of that connect by USB and draw 2.4A continuous? That’s a shedload of power through those tiny 28AWG wires. If it’s broken, crack it open and give me a pic of the lipos inside (and check for swelling… ) Seriously though, I would be careful of such a thing - Lithium fires are nothing to be cavalier about. They are nearly impossible to extinguish with a conventional fire extinguisher, although used beer can be used to control the burn.
A story related by an RC acquaintance: " few years ago I saw i lipo fire from about 5 miles away.
the cloud was atleast 500’ high and 50’ wide. more then likely it was alot bigger but hard to measure.
I was on my way to the field when i saw it. by the time i arrived it was out and no one was badly burned. I should have taken a picture of all the spent fire extinguishers by what was left of the 6s 5000.
the guys that used the extinguishers were blown away by how inafective thier attemps were at putting out the fire."
One of the local guys in the club burned his Toyota Prado to the hubs by incorrectly charging a couple of big LiPo packs… $70,000 worth of car gone.
I went with these Limefuel packs specifically to avoid toasting my nads with macho RC lipos (that, plus not having to worry about a 5V buck converter—though I know some have success with with 3.7V lipos directly.)
I hear you on the optimism of actual getting 4.2A continuous out of one though. I’ll set it to top out a little below that.
(Also, iPads will happily slurp down 2.1A for six or seven hours when charging. From the mode of failure I’m pretty sure it’s the electronics I’ve toasted and not the cells themselves; it’s almost certainly 16850s inside and there’s no swelling evident, though it is a hard case.)
Some tablets will happily (and greedily) consume upwards of 2.5A while in their quick charge rate, then drop down to a more acceptable range of 250-500mA range, then lower than 100mA for trickle.
I am by no means an expert, but perhaps the smoke is not from a broken lipo, but maybe a broken overdraw protection circuit? I would definitely air on the safe side but it could be just a manufacturing defect of this particular pack considering that they’re more than just batteries
That’s my current (ha!) theory, @Ryan_Clough . Just to be explicit, the literal smoke didn’t leak out, but sniffing the charging port rewards me with the acrid odour of fail.
If they don’t have a return/exchange policy, it’s time to bust that sucker open.
Yeah, I think I’ll have a go at returning it first.
Ask them what the ‘C’ rating of the cells they are using is, then you can work out the actual peak power delivery.