USB batteries

[Andrew1972]

USB port rechargeable batteries are quite cheap and work quite well due to massive competition and large uptake.

The output is 5V/1A or 2.1A. They work wonderfully at charging. However how would they work at powering items normally using batteries like AA,AAA, or C,D etc?

Things like camping or emergency lighting it seems far more economical to use these instead of normal battery packs or standard batteries.

 

[Rand]

if it takes AA or AAA just get NI-MH rechargables very cheap.. very safe.

LI-ION type batteries can explode I certainly wouldnt want to leave one in my car all summer with the in car temps exceeding 150F.

 

[NateDN10]

These things are typically single-cell Li-Ion batteries combined with a charging circuit and a boost circuit to go from 3.7V at the battery to 5.0V at the output.

I'm not familiar with how much they cost, but per Watt-hr, they can't be cheaper to produce than conventional batteries.

 

[SwampSurvivor]

I have one. It's nice to carry when I will be walking around NYC all day, or out in the woods where I may not be in my vehicle (taking videos kills the battery).

They are also nice to have in emergency situations. I used mine when I was off roading all day and killed the alternator, and subsequently battery, in the Jeep and had to make a few calls to AAA to get a ride home.

 

[wrcsixeight]

I have a 4$ single cell 18650 USB power source. It maxes out at 0.88amps, but will do 0.98 amps very briefly.

It has been extremely useful, and I have well over a dozen 18650 cells harvested from a laptop battery. These cells likely only had 2100mAH new and are likely only 1600 to 1750mah currently.

I have some panasonic ncr18650 cells at 3400mah that obviously run longer and are my first choice if I do not want to carry extra cells.

I have some protected cells which are a smidge longer than 65mm and a smidge wider than 18mm, and these can just barely be shoehorned into the device.

The 4$ device can also charge the cells from a USB source, and it stops charging at 4.18 volts, where these cells should not be charged above 4.2v.

I bought 3 of these and have given 2 away with some extra cells to friends who have found them useful, and some other friends have borrowed the one I have left, then ordered the same thing.

I do not trust the multicell models, as one might decide to put one depleted cell and one charged cell into them, and this is a big No no with lithium unless the device has built in protections.

Harvesting laptop 18650 cells is also possibly dangerous. Usually it is just one of the 6 or 9 cells which has failed, and the other 5 or 8 still have usable capacity left, and these, if shorted while being disassembled can do unpleasant things.

One should also have a means of determining which cells should not be recharged.

So if does not have a voltmeter or the will to use it, then do not eye your old laptop batteries with interest for the usable power they might still contain.

http://www.candlepowerforums.com/vb/show...8650-Extraction

 

[901Memphis]

Check out this link for reviews on batteries chargers and usb boxes if you want to find one that suits your needs, this guy's awesome.

http://lygte-info.dk/