Got myself the Sanyo Eneloop Mobile Booster KBC-L2S  after my previous Sanyo Eneloop Mobile Booster KBC-E1S  could not give me enough juice for my iPhone because it is using only 2x AA batteries which only gives you.
The recommended retail price (RRP) for the KBC-L2S is S$69.90, but I got it for S$57 from ebay and paid additional S$2 for delivery. The seller name is Desmond Han (tecpoint2139) . His service is excellent and efficient, I ordered at 10pm on Friday, 9th January 2010 and it was delivered to me at 1pm on Saturday, 10th January 2010! That is less than 24 hours and furthermore it is on a weekend! In the Eneloop paper bag, there are several goodies as well like the Eneloop 2010 calendar and the Eneloop Product Catalogue.
If you are skeptical about ebay, you can get it from onlineshop.com.sg  for S$59.90 and it includes free delivery. The reason I prefer ebay to onlineshop.com.sg is because I can use PayPal and not because it is cheaper.
The iPhone 2G has a battery capacity of 1,400 mAh, the iPhone 3G has 1,150 mAh and the iPhone 3GS has 1,219 mAh.
It is stated that each AA battery has 2,000 mAh so if I am using 2x AA battery, I should have 4,000 mAh? But unfortunately it is not true as it can charge my iPhone 3GS to only 71% which makes it 866 mAh, so I presume there is some maths formula which I have left out or because it is using AA battery.
The KBC-L2S has a capacity of 5,000 mAh and uses lithium-ion battery which technically should be able to charge my iPhone battery at least 4 times on a single charge. I did read up on HWZ Forums  and apparently what is stated is true and I can charge up to 4 times on a single charge. In additional, the KBC-L2S comes with an AC charger which speeds things up because charging a 5,000 mAh lithium-ion battery is going to take a very long time using USB.
DC In (Left View)
DC Out (Right View)