We have way too many powerbanks.
I was going through my junk drawer today when I noticed the pile of powerbanks. You know, stuff that your family and relatives give you after they upgrade to the latest and greatest powerbanks with bigger capacities. Stuff that you receive from free giveaways. Stuff that you receive from promotions. So on and so forth. Our family had amassed quite the collection: primarily Xiaomi powerbanks (they make some pretty good powerbanks), no-name ones that we got from promotions and giveaways, and a couple of powerbanks that we bought from street vendors that still somewhat worked.
Most of the powerbanks worked, but I noticed a certain pink powerbank held less charge than it did before. When I measured the capacity with a USB tester, I noticed that it only charged about 4,000 mAh from 0%. The power bank itself was rated for 8,000 mAh. That was 50% of capacity gone!
I decided to try and fix it. Opening up the plastic shell with a pry tool, I saw that the connections were just wires soldered onto the powerbank circuitry. I thought I had a good shot, as it wasn’t a powerbank where the tabs were spot-welded to the battery and the board - something that would be impossible for me to fix.
Oh, how wrong I was.
Lesson 1 - some things are just not worth your time
How much do powerbanks retail for? Ten bucks? Twenty bucks? To figure this out, I went to Danawa (a site like Amazon but for Koreans) and listed all the powerbanks there.
Seeing as the powerbank I was replacing was only 8,000 mAh, I searched for powerbanks with a similar capacity. The Xiaomi 5th gen powerbank is currently selling for 13,820 won, which is about $10 or so. And it has a capacity of 10,000 mAh!
Next, I searched up a replacement 8,000 lithium battery on Taobao (since I’m still currently in China) and bought one for 25 kuai, or about $3. OK, that’s pretty cheap, but consider this: I had to wait three days for it to ship, and I had to get soldering equipment that is worth well over what it would’ve cost me had I just bought a new powerbank, and I had to invest my time into soldering the thing. All in all, that completely cancels out the $7 difference multiple times and then some!
There’s also the question of safety, as all powerbanks sold in Korea must pass the KC standard in order to be sold. Therefore, you can be reasonably assured that the damn thing won’t just blow up in your bag one day and give you 3rd-degree burns, or wallop off your leg if you prefer to keep it with your phone in your short pocket. Do you trust that random seller on Taobao to keep you safe? Do you consider $7 to be too expensive when it could just as well easily be a $9,000 bill for skin graft surgery? Didn’t think so.
But just for science, say we decided to repair that powerbank…
Lesson 2 - BMS
All lithium battery-powered devices have something called a BMS, or Battery Management System. It may be called a “Protection Circuit” or something similar on the powerbank’s specification page. These things handle stuff like overcharge protection, temperature protection (for when the battery gets too hot), low voltage protection (when you use the powerbank too much, past its depletion point) and so on.
Now, I made the mistake of buying a battery with a BMS included, when the previous battery didn’t (which means that the BMS is included with the powerbank circuitry and not with the battery itself). Now, this wouldn’t be a terribly bad thing, except for the fact that there are now two BMSes working against each other. So I saw weird symptoms where the powerbank wouldn’t charge fully (hovering at the 95% mark but never quite reaching 100%) or it wouldn’t let me use the full capacity of the battery (because the cutoff voltage didn’t match).
But that’s not the worst part. Because the BMS in the powerbank circuit is calibrated for the old battery, when I replaced the old battery with a new one it still thought the old battery is installed. Therefore, it would treat the new battery the same way it did the degraded one, which means the entire procedure was useless! The new battery still had the limit of 4,000 mAh that the old circuitry artifically imposed.
You could theoretically reset the gauge in the powerbank circuitry, but at that point, again, is it really worth your time?
Lesson 3 - Reduce, reuse, recycle
But, less e-waste is better! You say. Right to repair and all that!
Yes, sure. And let me make this clear: this article is not about discouraging you from repairing your own things. If you want to take the adventure, then by all means don’t let me stop you. But I’m warning you that some repairs may be more than they are worth.
People seem to forget that the mantra “Reduce, reuse, recycle” has the word “reduce” first. If you really want to help lessen the impacts of e-waste, then stop purchasing new shiny things. I keep telling this to my family: if your current tech works, then please don’t buy a new one until it breaks in such a way that repairs are not economically feasible. (Of course, not that they would listen…) If you spend less and if you use up your products before buying a new one then you can definitely help the environment more.
So yes, repair is important. But it is just as important as to figure out when something is just not worth repairing. If a new product costs you the same amount as it does to repair the old one and potentially get a dangerous outcome, then the choice becomes extremely obvious.
Now excuse me, for I have a fire hazard disguised as a Taobao battery on my desk that I need to get rid of.