As regular readers may recall, I’m fond of acquiring gear from the “Warehouse” (now renamed as “Resale”) area of Amazon’s website, particularly when it’s temporary-promotion marked down even lower than the normal discounted-vs-new prices. The acquisitions don’t always pan out, but the success rate is sufficient (as are the discounts) to keep me coming back for more.
Today’s product showcase was a mixed-results outcome, which I’ve decided to tear down to maximize my ROI (assuaging my curiosity in the process). Last October, I picked up EBL’s 8-bay charger with eight included NiMH batteries (four AA and four AAA), $24.99 new, for $17.22 (post-20%-off promo discount) in claimed “mint” condition:
The price tag was the primary temptation; that said, the added inclusion of two USB-A power ports was a nice feature set bonus that I hadn’t encountered with other multi-bay chargers. And Amazon also claimed that this Warehouse-sourced device was the second-generation EBL model that supported per-bay charging flexibility.
Not exactly (or even remotely) as-advertised
When it arrived, however, while the device itself was in solid cosmetic condition, its packaging, as-usual accompanied by a 0.75″ (19.1 mm) diameter U.S. penny in the following photos for size comparison purposes, definitely wasn’t “mint”:
and the contents (including the quick start guide, which I’ve scanned for your educational convenience) were also quite jumbled:
(I belatedly realized, by the way, that I’d forgotten one piece of paper, the also-scanned user manual, in the previous box-contents overview photo) 
Not to mention the fact that the charger ended up being the first-generation model, not the second-gen successor, thereby requiring that both bays of each two-bay pair be populated (also with the same battery technology—Ni-MH or Ni-Cd—and size/capacity) to successfully kick off the charging process. When I grumbled, Amazon offered $4.49 in partial-refund compensation, which I begrudgingly accepted, rationalizing that the eight included batteries were still fine and the charger seemed to function fine for what it truly was. Only later did I realize that the charger was actually extremely finicky, rejecting batteries that other chargers accepted complaint-free:
Turning lemons into lemonade
And like I said before, I’d always been curious to look inside one of these things. So, I decided to pull it out of active service and sacrifice it to the teardown knife instead. Here’s our patient:
Note how both sides’ contact arrangements support both AA and AAA battery sizes:
Onward. Top:
Bottom:
Left and right sides:
And back, also including a label closeup:
Before continuing, here are both ends of the AC cord that powers the charger:
When at first you don’t succeed, muscle your way in
And now it’s time to dive inside. No visible (or even initially invisible) screws to speak of:
So, I resorted to “elbow grease”. The device didn’t give up its internal secrets easily (an understandable reality, given that its target customers are largely-tech-unsavvy consumers, and it has high-voltage AC running around inside it), but it eventually succumbed to my colorful language-augmented efforts:
Mission (finally) accomplished:
Some side (left, then right, at least when the device is upright…remember that right now it’s upside-down) shots of newly exposed circuit glimpses before proceeding:
Close only counts in horseshoes and…
And now let’s get that PCB outta there. At first glance, I saw only three screws holding it in place:
Uhhhh…nope, not yet:
Oh wait, there’s another one, albeit when removed, still delivering no dissection luck:
A bit more blue-streak phrasing…one more peek at the PCB, this time with readers…and…
That’s five minutes of my life I’m never gonna get back:
Upside: the PCB topside’s now exposed to view, too. Note, first off, the four multicolor LEDs (one per pair of charging bays) running along the left edge:
Binary deficiency
I was admittedly surprised, albeit not so much in retrospect, at just how “analog” everything was. I’d expect a higher percentage of “digital” circuitry were I to take apart my much more expensive La Crosse Technology BC-9009 AlphaPower charger (I’m not going to, to be clear):
Specifically, among other things, I was initially expecting to see a dedicated USB controller IC, which I regularly find in other USB-inclusive devices…until I realized that these USB-A ports had no data-related functions, only power-associated ones, and not even PD-enhanced. Duh on me:
Flipping the PCB back over once again revealed the unsurprising presence of a hefty ground plane and other thick traces. The upper right quadrant (upper left when not upside-down):
handles AC to DC conversion (along with the transformer and other stuff already seen on the other side); the two dominant ICs there are labeled (left to right):
CRE6536
2126KD
(seemingly an AC-DC power management IC from China-based CRE Semiconductor)
and:
ABS210
(which appears to be a single-phase bridge rectifier diode)
while the upper left area, routing the generated DC to the USB ports on the PCB’s other side (among other things), is landscape-dominated by an even larger SS54 diode.
Further down is more circuitry, including a long, skinny IC PCB-marked as U2 but whose topside markings are illegible (if they even ever existed in the first place):
I’ll close out with some side-view shots. Top:
Right:
Bottom:
And left:
And I’ll wrap up with a teaser photo of another, smaller, but no less finicky battery charger that I’ve also taken apart, but, due to this piece as-is ending up longer-than-expected (what else is new?), I have decided to instead save for another dedicated teardown writeup for another day:
With that, I’ll turn it over to you, dear readers, for your thoughts in the comments!
—Brian Dipert is the Editor-in-Chief of the Edge AI and Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.
Related Content
- Resurrecting a 6-amp battery charger
- Tricky 12V Battery Charger Circuit
- Simplifying multichemistry-battery chargers
- 12V Battery Charger Circuit using SCR
The post Tearing apart a multi-battery charger appeared first on EDN.
