How We Test iPhone Battery Packs

One of the weaknesses of the iPhone 3GS is its battery life. Many applications, such as golf GPS software, can be tremendous battery hogs. Sure, you can mitigate it somewhat by turning off WiFi, Bluetooth and even the data connection, or shortening the amount of time before the iPhone “auto-locks” and goes to sleep, but those of us who are fundamentally lazy can’t be troubled to do all of that! We want to solve the problem by throwing money at it! Enter the iPhone battery extender. We tested the iPhone battery packs with both a “real world” usage test and a “recharge” test.

Usage Test

We tested the devices in the field with the Golfshot GPS application. As any iPhone owner knows, the iPhone will “auto-lock” (Apple’s term for “go to sleep”) any time it hasn’t been used in awhile. The downside for golfers is that this will disable the GPS antenna, so when you “wake up” the iPhone, you have to wait for it to reacquire the satellites before it provides an accurate yardage to the hole. The Golfshot GPS application has a feature enabling you to disable the auto-lock function and keep the iPhone active all of the time. No more cursing at the screen while it says “acquiring satellite”! Ah, but we found that in this power-sucking mode, the standard iPhone battery struggles to make it through 12 holes. And thus was born a need for an iPhone battery extender.

To simulate what we think a typical golfer would do, we put the iPhone battery packs on a fully charged iPhone and launched the Golfshot app about 15-20 minutes prior to the beginning of the round (about the time you would be walking toward the first tee). The battery extenders are designed such that power is first drained from the battery extender (as it continually charges the iPhone) – the iPhone battery doesn’t drain until the battery extender is spent. The question was, “Would we have enough juice remaining on the iPhone after playing 18 holes that we could still call our wives/girlfriends and lie through our teeth about how slow the round was going and thus buy ourselves enough time to head into the bar for a few drinks?”

Our reviews report on what percentage of the iPhone battery was left at the end of a typical round (we tested each battery pack on multiple rounds). There obviously is some variability on how long it took us to play 18 holes, but all rounds were between 4-5 hours, and our primary goal in this test was just to provide feedback on the general usability of the devices in the real world.

Recharge Test

We also tested how well the iPhone battery packs performed when used as the source of power for recharging the iPhone. We drained the iPhone battery entirely until the red bar of death appears and the phone shuts itself down (if you’ve seen the red bar of death, we can only hope it wasn’t when you were stuck by the side of the road trying to call roadside assistance).

We then plugged the iPhone into the battery pack to see if the battery extender would completely recharge the iPhone. When recharging, we keep the iPhone settings the same as they are for our usual day-to-day operation (WiFi off, Bluetooth on, regularly pulling down email). If a complete recharge was accomplished, we would unplug the iPhone, run its battery down again, and replug it into the battery pack.

Our reviews report back on how many times a battery pack could recharge an iPhone before the battery pack was spent, and the typical amount of time required to recharge the iPhone.