20,000mAh USB external battery for $29


1 Like

And it has a flashlight built in.

1 Like

It’d be interesting to know if the real capacity of these batteries matches the claimed capacity - a lot of these chinese-made battery packs test out to hold a fraction of what they claim.

I have a Juno Jumper battery pack. It is rated at 6000 mAh, and I have used it to fully charge my two phones. It’s the size of my Moto X; it and my phone fit in my pocket.
Its unusual feature is it has a port where you can attach supplied jumper cables, and I have jump started my car several times on one charge!
This is a really handy little toy, and I keep one in each of my three cars.

The battery pack in the article is rated much higher and should be great if your phone battery is low.
Then you could call AAA if you’re stuck!

1 Like

I have not bothered to deep test my Chinese made USB battery pod but when used with my bicycle dynamo-E-werk USB power converter and outlets in coffee shops it is a great way to keep my phone and other USB standardized rechargeables toped off when camped out cycle touring.

You can do better than that though.
This one is twenty bucks for 50,000mah
It seems to do the job. No flashlight though.

I wonder about the actual capacity. It is often overstated.

A good ballpark is to take a look at known-good state-of-the-art battery cell, and calculate watts per cubic centimeter (volume-density of power). Then compare with the same value of the product offered. (Assuming there is no dead space for padding nor charger nor other electronics inside.) If the numbers roughly match, the claim is somewhat plausible. If the volume-density is claimed higher on the product than on the known reference, the product lies.

1 Like

Or is alien technology.

1 Like

I’ve only just bought that one, and haven’t yet done a full stress test. The previous generic 50,000mah battery I had (one of the common black curved models) was about the same size and all I needed to keep me going through a 6 day trip to a music festival.

WIth smartphones and the ability to burn battery quickly I am surprised that more people are dnot getting a phone capable of installing a bulged battery cover and doubling up. N900 users are still discussing tips and tricks using a Mugen bulged battery cover and a double up modded battery to get up to a week out of that device.

1 Like

I keep thinking about how redundant it is to state life as so many thousand milli-amp-hours. Why not just 20Ah? Is it purely because it’s only recently become possible to carry more than fractional amp-hours around in a pocket, or is it just because 20,000 is a bigger number?

1 Like

The second one. That’s standard advertizing procedure. You always state numbers as big or as small as possible.


Thats what i’ve been doing for years. the XL mugen batteries are ace. currently have a 4600mah one for my galaxy S3 instead of the default piddly 2100mah one.

Never have understood the obsession with excessively thin phones that cannot even handle a days light usage…


Depends on the phone - and Samsung has caved in to the “let’s make it 0.5 mm thinner” crowd with the S6. No more replaceable battery and no more MicroSD slot. Not that I’d buy a flagship phone in the first place (they’re too expensive), but the S6’s omissions would be a guaranteed deal-killer for me.

1 Like

Seems like Frauenfelder is short on money. Another affiliated link…

Bugger. I used to use HTC devices pretty much exclusively, only swapped to Samsung because of the non-upgradable batteries HTC started using :confused:

Hope we don’t end up in a position where no manufacturer has that option available anymore…

Then it will be the world of 3d printing the modded cases and just hacking it in without asking the vendors.

We don’t have to ask the manufacturers for merciful hand-downs. We can make and take the features we want. We are the Engineers.


If only it had a 510 connector.

Build it in. :stuck_out_tongue: :smiley:
There are quite some DIY instructions for these connectors Out There.

LG has been back and forth on that; the G2 went with the non-replaceable battery and no card slot, while the G3 brought them back.