Lenmar Battery has recently come out with a cover for the iPhone 3G and iPhone 3Gs. The cover itself is a fairly standard hardened rubber sort of affair, with a couple of notable exceptions. For one it has a battery built into the case, which can be charged from an external USB source, it also addresses the lack of a flash on the iPhone.

The case has a super bright LED mounted into the back of it which is turned off and on with a small button on the back, the same button is used to switch the phone from using its internal battery to making use of the external one provided in the pack. While the LED isn’t anywhere near as good as the flash you’d find on an actual camera it does provide a passable amount of illumination for close up photos.

The battery pack itself is a 1300mAh Lithium Polymer battery which according to the documentation will provide you with an additional:

• 4 hours of 3G activity
• 4.5 more hours of Wi-Fi
• 17 hours of additional audio
• 5 hours of video
• Up to 240 hours of standby

The unit sets itself apart from the others in the category by being a fully enclosed case unit in two parts, once snapped into place on the phone it has a nice seamless look and adds very little (2 oz) heft to the iPhone, though it does bulk it up a little.

The battery case charges through a USB (micro) port and also has a handy three stage charge indicator light on the back of the case.

Americans use around 2 Billion disposable batteries a year, one of those numbers that’s big enough for most of us to have no actual concept of it, but it’s a lot.  If you find yourself being a larger than normal part of this statistic the obvious solution would be to use a rechargeable battery.

Generally speaking a rechargeable battery will save you money over the long run, you can recharge most of them up to 1000 times before you have to replace them.  The cost-saving benefits of this are clear when you compare it to disposable batteries.  Though disposables can often have a higher mAh rating they just get tossed out when you’re done with them.

Good in theory but horridly inconvenient

One of the major disadvantages of the rechargeable batteries has been that they don’t come ready to use.  Typically you would need to fully charge your batteries before you used them so you wouldn’t be able to just go to a store and pick some up and carry on.  Often we just don’t have the time or forethought to have some spare charged batteries lying around.

Another issue with rechargeables is that they never really stay charged. After a year or so they’d be generally useless to you and need to be recharged, now however there is a new type of battery that has a much lower self discharge characteristic than previously.

Your standard NiMH rechargeable is below 60% capacity after about 2-3 months and essentially dead after a year.  The Graph above shows the discharge rate for the eneloop battery vs one of Sanyo’s other Nickel Metal rechargeables.

Ready to go rechargeables

Hybrid NiMh cells offer the best of both worlds, you can use them out of the pack but you also get to do the environmentally friendly thing and re-use them.  If polar bears had the capacity to vocalize their appreciation they no doubt would.

Three of the more popular types of these batteries are the Rayovac Hybrid, Ultralast Hybrio and the Sanyo Eneloop series.  Each has essentially the same characteristics, with Eneloop being the forerunner and probably the best marketed.

The hybrids are marketed as being a viable replacement for digital camera batteries, for instance the energizer ultimate lithium (a disposable) makes claims to somewhere around 640 photos worth of battery life.  The Rayovac Hybrid battery states that it will do 400 photos.  Your general use alkaline would struggle to do more than 100.

Also there are the cost savings to be considered. For 8 of the Rayovac Hybrids and a charger you’d pay $23.95.  Four Energizer photo lithium batteries would be around $17.95, and you can only use them for those 630 photos before throwing them away.

The bottom line being that while no rechargeable can hold the power of their high end disposable counterparts, the pre charged rechargeables at the least make going the greener route a more convenient prospect.