- iPhone battery life seems to be shortening. Using it for a whole day out leaves uncomfortably little battery
- Might have to charge other iPhones
- Along with an iPad
- Useful on holiday
- 2 USB ports
- Cheap (it was on offer)
Capacity: 3.6V, 4000 mAh = 14.4 Wh (yes, I know voltage isn't constant so this is an overestimate)
Charging time: 5 hours
Weight: 44.5g (meaasured, AC adapter, stated 45g). 146.7g (measured, battery pack, stated 145g)
- 5 hours is a bit long to charge
- AC adapter got worryingly hot at first, then cooled off. I think it charges faster when there's less power remaining, so the adapter gets hotter.
- Adapter also makes a sound during charging
- Cannot use USB ports while charging! It would have been nice for this to double as an AC-USB adapter as well. I guess they don't want to encourage people to leave this charging (the instructions say to turn off the power when full)
- The connection on the battery pack is on a circuit board. It's hidden behind the green door. I'm worried something may touch the contacts and short the battery.
- Hey, what about using USB connectors to charge? That way, the adapter can double as a USB power supply.
- Can charge iPad and iPhone at the same time! Yes, it has the intelligence to charge the iPad.
- Turns off automatically if you unplug the device. Supposed to turn off if the device is full as well (untested)
- Reminder: iPhone 4 battery capacity = 5.25 WH, iPad 2 = 25 WH, so this should be able to charge 2 iPhone 4, but can't fully charge an iPad 2
This is my hierarchy of indicator lights, from best to worst:
- Shows amount charged when charging and time left to charge. Indicates (not shuts off) when full. (MacBook)
- Shows amount charged when charging. Indicates when full. (iOS devices, Kensington battery pack)
- Shows amount charged when charging. Shuts off indicator when full.
- Shows when charging (not amount). Indicates when full. (Kindle, Oral-B toothbrush, Nikon D50 charger)
- Shows when charging. Shuts off when full.
Compared to Energizer XP4001
- Although both are 4000 mAh, the XP4001 is at 5 V while the CP-A2L is at 3.6 V. This means the XP4001 has 20 Wh, or 139% the capacity of the CP-A2L. You could also say the CP-A2L has 72% the capacity of the XP4001. I wonder if Sony reduced the voltage to increase the mAh, since that's what people compare?
- XP4001 recharge time is 4 hours
- XP4001 is 150 g
- XP4001 output up to 1.5 A
- XP4001 includes tips for a few devices and coiled cables, which should be easier to use on-the-go. The tips are useful since several devices don't come with USB charging cables.
- XP4001 is $80 at the cheapest, CP-A2L half the price at $40.
- XP4001 uses the standard adapter where the bulk is at the plug and there's a thin cable to the device. This might not last as long if the cable frays.
- Both claimed rechargeable for 500 cycles
- XP4001 has 3 year warranty, CP-A2L says it has a warranty but doesn't specify how long
- XP4001 may have more safety mechanisms. At least they both have temperature protection.
- XP4001 may come charged (CP-A2L does not)
Update 7 Jan 12I was thinking about how I use this, and I think the thing I'll look for in my next battery pack is charging speed. If you're on the go, you may only have a few minutes to charge your batteries. It would be nice to get as much power as you can.
Update 28 Jun 13
After using this for a while, I noticed it doesn't charge devices as fast as other battery packs. I suspect it can only output 0.5 A on each USB port, which is considered low. It also has the double problems of using a proprietary power supply and charging slowly (only 1 A charge current and 4.1 V). I mean, if you're going to charge slowly, at least use a USB supply so I don't have to bring an extra adapter. If you need a special adapter to do what every battery pack does, what's the point? As a result I do not recommend this battery pack.