My Romoss 10400mAh is working well http://www.amazon.com/10400mah-Exter.../dp/B00CF8N2LY the best so far was charging my Droid 4 twice, the Nexus 7 once and still be able give a helpful boost to phones of two friends on one charge. Really nice.

I'm a big fan of the Anker Astro E5 15000mAh Portable Charger. It'll fully charge my iPhone 5S three or four times before it gives out and my iPad mini with Retina display once. Seems to have the advertised capacity and haven't had any problems with it, though the allegations that many of the Amazon reviews are fake/paid for are a bit unsettling.

I've used the Mophie products before, and they've worked fine, but they've always struck me as somewhat overpriced.

I love the Jackery batteries...
 

I think that the Jackery batteries are quite nice - I've got the large 10,400 mAh model and now looking to include the smaller (and less capacity) 3200 mAh model.

Haven't had a problem with it yet and it continues to hold a good charge.

George

Grabbed a Cygnett Sport Powerbank 4400mah for $25, thought it was a decent deal. Fits in the same pocket plugged in as my iPhone 5S and will do 2.5 full charges. Built in flashlight is a nice feature too and it'll charge off a laptop USB port.

https://www.jbhifionline.com.au/rkt/...81/4481212.jpg

Good to know. I wanted to branch out and try some different brands. I have the anker mini 3000 mah and it doesn't come close to advertised capacity.

Sucks to hear that, Anker has typically been a good battery pack - I recently bought the same Anker Astro 2nd Gen 12,000 mAh pack but haven't had a chance to test it yet.

FWIW, it's on Amazon Lightning Deal for $37 right now, pretty good price: amazon.com/dp/B00CEZBKTO

5200mAh Portable External Battery Pack with Embedded Cable
 

Bought two chargers, one for my girlfriend and one for myself. My girlfriend likes her pink bean a lot. Princess color and the bean shape make it a great gift for girls! My bean is black and packs enough power for daily use. Can charge my iPhone 2 times. Great gadget when travelling.

Specifications:

Capacity: 5200 mAh
Input: 5V / 1.5A
Output 1: 5V / 1.2A
Output 2: 5V / 1A
Battery Charge Time: ~6-8 h via USB ports on PC, ~3-4 h via most AC adapters

Use JIX77YJ9 to get down from $29.99 to $19.99 (you can use the code for any colours)
Link:http://www.amazon.com/gp/product/B00F44T8RS/

The Burnaby Costco is selling this twin-pack for $20; one battery does about 1.5 full charges on my iPhone 4s.

I think I have a bit of OCD. I've bought several batteries over the last couple years because I just haven't found the perfect one yet.

My favorite small one that I keep in my headphone case is the EasyAcc U-Bright 3000mAh. It's not round like most lipstick batteries so will not roll away on it's own and has a pretty bright .5w LED. It also came with a hand strap and neck strap. I probably use it more as a rechargeable flashlight than as a battery though. $17 http://www.amazon.com/EasyAcc®-Flash.../dp/B00GAVCNZI

I have also this Lumpsing 5 USB port 1100mAh brick. It was cheap, but works pretty well. I like that I can stand it on it's end and attach USB lights and fans. I've never needed 5 USB ports at once though and I would prefer a flatter design.
http://www.amazon.com/Lumsing-11000m.../dp/B00B9BUZW2

Last year I bought a New Trent Travelpak 7,000 mAh because I liked the idea of having a built in plug. They had it for $29 on black friday. Overall I think it's heavy and the LED indicator is annoying since you can't turn it off. It blocks the entire outlet, but saves you from needing to carry a separate USB charger. We will usually bring it on short domestic flights like between our home in ATL and office in NYC. http://www.amazon.com/New-Trent-Trav.../dp/B00BFOU3FW

Lately I've been tempted with a solar powered one which we can clip to a backpack or leave out in the sun to charge up. I like the idea that I could suction cup mount it to the window in the car and always have it handy in case I need a charge. This probably would never happen because I also have car chargers in all of our cars. I haven't bought this one yet, but keep looking at it. The price hasn't changed much this year according to the camelcamelcamel. $45.99
http://www.amazon.com/Poweradd-trade.../dp/B00FXWGRHU

3500mAh,the battery is 10400mAh

the battery is 310000?! so powerful...

I had the Mophie Juice Pack Air for my iPhone 4 back in 2012, but it only lasted a month past its guarantee. Back then many issues where reported with its connections, I'm interested in learning if there's been an improvement to Mophie's battery case quality. The new space packs that include extra storage seem very intriguing!
Currently still using Mophie, I discovered their USB-batteries are made from sturdier stuff than the plastic case that broke when one accidentally dropped ones phone.. The 6000mAh Powerstation Duo is enough for both my iPhone and iPad to last 12+ hours more. Unfortunately it doesn't charge my Blackberry Curve, certainly shouldn't have expected anything else from RIM, but when I bought my Mophie Powerstation duo in 2013 it was with the intention of juicing up all 3 devices. Its size and weight is perfectly portable, it fits in the pencil case I use to carry all my chargers and adaptors. 1 1/2 years frequent use now and no problems.

Romoss 10400mah External Battery Pack this is what I use and for $17 it's a steal.

Jackery's at Amazon on Sale
 

Jackery's are on sale at Amazon - $40 for the 12000 mAh, 30 for the 5600 mAh.

Have a 5600, but just ordered at 12000 for my upcoming trip across the pond with my parents... (2 iPads, 1 Kindle, 1 Nexus + iPhones all around...)

Jim

I've been using a PowerGen power bank for the past two years - it was 8,400mAH. Went to check the charge level today but it's dead even after a full charge. So in the market for a new one - not that impressed with the last one as it wasn't heavily used at all.

Edit: just picked up the EasyAcc U-Bright 3000mAh off amazon. Just the single charge is needed here.