My favorite type of gadget remains the type that does one thing and does it well. In the case of the Griffin PowerBlock Reserve, that one thing is charging iPods and iPhones. Yes, there are countless gadgets for charging iPods and iPhones on the market, and essentially all of them do the job well.

The plus with the PowerBlock Reserve is the ability to carry a bit of extra juice along without adding a special case. This gadget comes in two parts: a wall plug charger that can completely replace the one provided with the iPod or iPhone, and a battery that fits within the charger. The charger includes the requisite USB jack for connecting an iPod or iPhone. A USB cable is not included, unlike many of Griffin’s other charging devices, although this didn’t concern me much since I treated the PowerBlock Reserve as a replacement for Apple’s power plug.

The Griffin PowerBlock accommodates the Reserve battery via a magnetic connection without the need of the dock connector, as well as a USB jack for directly charging an iPod or iPhone. The 2-prong power socket plugs fold into the PowerBlock for easier storage.

It’s a very nice touch that the battery attaches to the PowerBlock via a magnetic connection. The dock connector on the battery just rests inside of a space formed out of the PowerBlock, and the battery is charged through the same metal contacts that are magnetized to hold the battery in place.

Upon leaving for the day, I can simply retrieve the battery and drop it in a case or even my pocket. Although the iPhone’s internal battery usually lasts me all of a typical day, there are some days I can wear it down by late afternoon. Rather than carefully rationing my use and trying to figure out how soon I can plug the iPhone into a power socket, I now just reach for the PowerBlock Reserve’s battery and attach it to the bottom of the phone.

Overall, I’m very pleased with this product, but before I’m willing to hand it highest marks, there are a few areas I feel could be enhanced. For one, the dock connector on the battery just sticks out as if it were asking something to bend or break it off. A snap-on plastic cap (which, of course, would be completely optional to use) would undoubtedly add considerable life to batteries that are otherwise dropped in a pants pocket along with keys, change, or whatever else one might carry in their pockets.

Also, considering the size of the battery casing, I have the impression there’s the same, if not more, physical capacity for whatever makes a battery work as what the iPhone has. Yet, Griffin indicates the actual capacity as 500mAh (milliamp hours) which, according to Wikipedia, is just less than half the capacity crammed into my iPhone 3G. Unsurprisingly, in about 30 minutes’ time, the PowerBlock Reserve restored approximately 50% of a full charge. I’d be more impressed if the Reserve battery could provide nearly a full charge to a drained iPhone. However, for my own use, an extra half-capacity charge has proven adequate for the times I found myself running low on iPhone power.

I should point out that I only tested the PowerBlock Reserve on an iPhone 3G. The capacity of an 80 GB iPod classic is only 580mAh. Even though it’s reasonable to assume the Reserve battery will come pretty close to fully charging an 80 GB iPod classic, I see the PowerBlock Reserve as a product marketed for iPhone use. Since iPods use so much less power than iPhones, even their lower capacity batteries last many times longer. Indeed, with my infrequent use of a 5th generation iPod, I hardly charge it even once a week. Few people are ever going to find themselves suddenly realizing they need to top off their iPod battery.

Another improvement Griffin could make is a simple one: the LED capacity indicator lights only function while the Reserve battery is attached to its charger, or when it is docked to an iPhone or iPod and the button on the front is pressed. There’s no logical reason I can think of to not allow the capacity to be checked when the battery is not attached to anything.

Finally, it may be of interest to note that though I only tested the PowerBlock Reserve product, Griffin also sells the PowerJolt Reserve which is identical to the PowerBlock reserve in function and in price, except that it draws power from a car power port rather than a 2-prong wall socket. Customers can also choose the PowerDuo Reserve, which bundles both the PowerBlock and PowerJolt units with one battery which is interchangeable between both chargers and is sold for $60. Additional Reserve batteries are $20.

Suffice to say I’ll now be more confident in my day-long outdoor excursions, knowing I have extra battery life for posting photos, tweets, and Facebook updates of my activities.

Copyright © 2009 Lee Bennett. Reviewing in ATPM is open to anyone. If you’re interested, write to us at reviews@atpm.com.