Hacker News Reader

Comment by mcny | Hacker News Reader

My number one concern is how do I avoid the spicy pillow problem... If I could have phones run off of USB without a battery, I would love to do that.

View on HN

The worst part of the spicy pillow problem is that even if you remove the battery cell and solder a power supply to the BMS, Android will eventually decide "I must be out of battery by now" and shut itself down. You have to root the device to override this and it is supremely annoying.

Of course if the thing could just run directly off wall power like you suggested, this wouldn't be a problem.

I'm told that most phones have power usage spikes that exceed the power delivered by the charger, and they use the internal battery as a capacitor to soak up those spikes.

To a certain degree, that might be true. However, small batteries like they are found in phones have relatively high internal resistance (voltage drops as current draw increases). They can't deliver huge currents like capacitors. A beefy enough power supply should be able to handle power spikes even without a battery installed.

My small army of old android devices are plugged into a USB 'charging station' (multiple USB charging ports off a single plastic device) which in plugged into a smart switch. The smart switch turns on for a couple of hours overnight, to keep the phones charged at least minimally.

Most of the devices also have a custom ROM and are rooted, and using the ACCA app I restrict charging to a maximum of 80% battery capacity.

I had a Samsung Note 5 (released in 2015) that only went spicy maybe 6 months ago. I have a Samsung S9 and a Nokia 6.1 that are both still going strong with fairly recent versions of LineageOS. Both are 2018 phones, so around 6.5 years old (old for phones, but shouldn't be 'electronically' old).

> Most of the devices also have a custom ROM and are rooted, and using the ACCA app I restrict charging to a maximum of 80% battery capacity.

I used this method too but then LineageOS merged the functionality in a few years ago and it works perfect.

I have a Nokia 6.1 as well but my oldest continuous use device is a Oneplus 8T used to provide hotspot to a location 24/7/365.

https://www.instructables.com/Power-an-Android-Phone-Without...

You can also buy dummy batteries for certain models online.

For simple live streaming, the standard setup is a mid-range/DSLR camera, a dummy battery, and an HDMI capture card. (I have a Sony ZV-1 and Camlink 4K.)

My concern too. I go check on it about once a week. I definitely need to find something safer.

Don't run it empty or get it super hot. Gas generation and cell degradation really seems to skyrocket if cells drop below 3V, so don't run them flat. Doesn't seem to ever happen on devices kept on around the clock and powered so long as they aren't in crazy hot conditions.

I have tried this with devices that remained on all the time. The display or camera being on all the time also seems to cause spicy pillows?

Spicy pillows are basically caused by 1 of 2 things:

1. Heat

2. Being fully charged all the time

Recording video consumes a considerable amount of power, leading to heat. The display less so, unless you're operating at maximum brightness all the time.

#2 is what killed my Pixel 3 after only about 2 years. Once I started working from home, I had a bad habit of letting my phone sit on the charger all day and after about 3 months of WFH the pillow got spicy.

For a phone that's going to be repurposed as a server, I wonder if it'd be worthwhile to open the case and attach a heat sink to the battery.

Some phones now have an option to limit charging to 80%. That should eliminate the problem entirely.

If your phone won't do that, you can use a smart power switch. Some mentioned to simply have it on a timer, but if you wanted to get fancier, you could use IFTTT to toggle it on/off based on battery percentage. I'd likely make it turn on at 40% battery and off at 60%.

Put it in a fireproof box and if it dies it dies.

My 2002 TiBook's original battery is buried in sand, in a bucket. It should probably get recycled.

The easiest way is with a programmable plug, it does not have to be smart, just set it up to charge the phone for 1 or 2 hours at the cheapest, or available by solar, the rest of the day the phone will use battery as usual. Is the battery cooked? Then set it to be half an hour every 4 hours or so.

Reply on news.ycombinator.com