Lithium polymer and lithium ion batteries — like all rechargeable batteries — have a limited lifespan determined by the number of charge/discharge cycles. Leaving your phone plugged in all the time increases the strain on the battery, reducing its useful lifespan and wasting energy. The ProCharge goes in-line with your charge cable, and automatically delays and monitors charging of your device. This way, you still wake up with a fully charged phone, but you’ve reduced the strain on the battery and saved some energy by not powering the phone at idle all night!
There are software solutions available for both major phone OSes, but they cannot actually stop the phone from charging — they merely remind you to unplug the phone when it hits a certain charge percentage. This can also protect the battery, but you end up without a fully charged phone, and if you fall asleep before the notification goes off, it’s useless. Having a hardware solution like this is much more reliable, and doesn’t require user intervention, which means you’re more likely to actually see results!
This graph shows the potential energy savings. By delaying the charge cycle, you are saving energy, which adds up to about 90 days per year that you aren’t charging your phone!
Because smartphone manufacturers are aware of the limited lifespan of lithium batteries, they have attempted to mitigate these issues in software. The phone can detect if the voltage starts dropping quickly when current increases — the sign of a weak or nearing end-of-life battery — and it responds by lowering the clock speed of the CPU. This leads to the device acting sluggish and often causes stability issues. However, if the phone continued to run at full speed, it would quickly drop the battery below its cutoff voltage and the phone would just shut off. Apple was vilified in the media a while ago for slowing down their older phones, but I suspect it was just this mechanism in action. They were trying to preserve what little battery health the phones still had left!
Check out the product page and learn more about how the ProCharge works. It wouldn’t surprise me to learn that the ProCharge could add months to the lifespan of a smartphone battery!