Chargie Phone Battery Saver

I got a Chargie device for my phone. I’m sorry but I can’t recommend it.

The promise is “Chargie is an app+hardware phone charge limiting solution that makes your battery last for much longer than if you had charged it regularly to 100% all night, every night.” It limits charging by unplugging the USB cord when your phone is charged enough.

Here’s the review I emailed to the developer and posted on Google Play. I’m sad that after a month, there’s been no response. 

Two Stars out of Five: I got my Chargie April 2, 2020 for my Pixel 2. This review is on Jun 3. It’s a good idea, the app is well written and the device works (with a few tiny glitches) but I’m concerned that it won’t save my battery. Now instead of staying at 100% in the overnight, my battery goes between 80 and 85% charge several times per night. If it’s the act of discharging that is bad for a battery, then Chargie won’t solve the battery-wear problem. :-( I want it to work but I uninstalled it. Maybe it would help if it automatically turned on Battery Saving mode while on the Chargie device.


  1. Tyler says:

    Your battery is discharging energy constantly, (even if you were to remove the battery it would still slowly lose charge) but charging your phone in the 60-90% range is more efficient then a full charge to 100%, (the lower you set the maximum charge the better within the 60-90% range, anything below 60% and the scale starts to tip back towards inefficiency) so it makes sense for the charge to fluctuate if the app’s trying to keep your battery close to 80%.

  2. Lee says:

    Tyler, I assume that batteries lose capacity by being used (ie. turning chemical reactions into electric potential and back again). So then the best way to maintain the capacity of a battery is to hold it at one particular voltage. If I could plug my battery directly in to a 3.6 volt DC power supply, that would do the trick; my phone would draw electrons from the power supply and not the battery. But the battery in my phone is “hidden” behind the power system. When I used the Chargie, my battery bounced between 60 and 70% charge several times in an evening. That’s not good. It is conceivable that less wear on a battery happens between 70% and 60% than between 90% and 80% but NO wear happens between 100% and 100% when I plug it in at night. I’d be happy to be wrong about this, heck, I bought 2 Chargies hoping it would help, but, absent some good research, it seems like it won’t help the problem. :-(

  3. Chris says:

    Lee, I understand where you’re coming from but in my opinion you are mistaken. I have used Dell’s Battery Command Center for years and set it up to maintain a charge between 55 and 85 percent. The result is that my battery capacity decreases very slowly. I have done the same thing with Battery Charge Limit (on a routed Android phone) and my wife time some application that bros at her when her phone gets up to 80 percent. Her phone is three years old and mine is two, and they both have almost all of their original capacity. It’s been a night and day difference for us. In fact, my wife’s battery is still rated at over 90 percent. Then I unrooted my phone and just started charging to 100 like everyone else and my battery’s capacity fell like a brick. It’s about 2/3 what it was before. That’ why I’m here, going to find a good solution that doesn’t require root.

    TL;DR – don’t jump to conclusions based on what you _think_ will happen. It seems odd that you would but this product, observe it doing exactly what it says it will do, and then declare that it’s no good on hypothetical grounds. I can tell you that this works using software, or by just being disciplined about it like my wife. Try it. If I’m wrong, you will just have one in a long line of phones you own over time with a battery that degraded just like all the others did, as I swear that bouncing between two percentages has not hurt my laptop or phone batteries.

    Wow, that’s a long TL;DR, sorry. But I love telling people how well this works with software. I’m just trying to find out if chargie will do it as well. And it might surprise you to know that your review tells me that chargie does exactly what I want: it cycles my phone battery between two percentages. Thanks. :)

  4. Lee says:

    Chris, thanks for the comment. Since you’ve now tried both methods (Battery Charge Limit with rooting and Chargie) you might want to answer this question for yourself and the world: How many charge cycles does your phone experience using the two different methods?

    With Chargie, I was seeing about 5 cycles per night going from 80% to 85% and back again. So the battery got 25% of a cycle. when you use Battery Charge Limit, does the charge hold at exactly one percentage of charge? That might give a good idea as to whether Chargie would work. But the best way to test out whether Chargie saves batteries is to run it for a few years. I just didn’t have a patience to do it. And it don’t have a “control” for the experiment so my multi-year-long study wouldn’t be terribly valid. Good luck to you and have fun!

  5. Sergiy Markutsya says:

    To better understand the charging process in smartphones (laptops work the same way) we need to accept the following facts:
    1. Smartphone always drains energy (unless you remove a battery from it), so it is constantly discharging.
    2. When you connect your smartphone to a power source, power from the outlet goes to the battery and charges it. Smartphone uses energy from the battery. There is no way smartphone can bypass the battery to get a power directly from the outlet.

    Based on statements 1 and 2 we may draw the following conclusions: 1. The level of charge you set up for a battery doesn’t prevent or limit discharging/charging cycles that happen in your smartphone. 2. By lowering the level of charge to 80% we are significantly reducing physical and chemical stress within a battery during discharging/charging cycles. Thus, significantly increasing the “life” of a battery.

  6. Lee says:

    I’m sorry but I disagree with your “facts”. Though neither of us know exactly how our phones are wired, which is unfortunate.

    I can’t speak to the phone in my pocket because I don’t have a schematic for it. But in general, if a device and its battery are held at a certain voltage by a power supply and the device draws some power, that power will come from the thing that is at the highest voltage, namely the power supply. I assume that phones have internal circuitry that try to hold the battery at 3.7 volts (max charge for a lithium-ion battery). If you could tell that circuitry to hold the battery at a lower voltage, you’d be rockin’. I hear there are Android apps that require rooting that actually have this function. But Chargie doesn’t have access to that subsystem. I’ve owned laptops and phones that had the ability to stay at a lower state of charge than full.

    I’d love to be wrong about Chargie’s core failing but your argument doesn’t sound convincing to me.

  7. Henry says:

    I see a different problem entirely than what has been discussed. You reported that while using Chargie, you saw your battery bounce from 80% to 85% and back 5 times during the night. That indicates that while idle for around 8 hours, your phone consumed 25% of its capacity. Android has supported a deep sleep mode for years now, and that should put you in the 1-2% range for overnight discharge.

    On one hand, it sounds like Chargie is doing what it is supposed to be doing. It is charging the phone to 85% then turning off. But what is causing it to repeatedly drop from 85% to 80%? That’s the important question. I’ve ordered three of the devices just now. One for Android Auto, one for nighttime charging, and one for a phone I keep plugged in 100% of the time to use as a server of sorts. I’ll keep an eye on it and make sure that the phone isn’t quickly draining when using Chargie.

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