[For those who have not read the first part, here it is.]

Thanks to a few words and pictures, and a reasonable seller, the issue of the counterfeit charger in terms of faulty goods and financial compensation was sorted. Thank god I did not have to post it back – as that would have costed a dollar more than the total purchase price. However, the seller was adamant that the charger was an “other region” charger – hence the use of figure-eight connector. I wasn’t so sure.

Given that it wasn’t functional, no self-respecting engineer wouldn’t resist a peek inside. If you break it, no big loss, right? So I peeled off the label to find just two philips head screws (most big brands won’t use regular screws – electrical safety issue). Undoing them, the two halves parted without much force to reveal …

My lord, this is almost definitely a fake right away. Firstly – note the use of only positive and negative leads to the battery – no big name manufacturer would risk not hooking up at least a third wire for the internal thermistor and possibly more for the internal battery smarts. Secondly, not a single IC is in sight – this is a fully discrete SMPS (except for a TL431A linear regulator U1)! Hardly anyone reputable builds these monstrosities because they tend to have poor regulation. I can’t see any interference mitigation whatsoever – no big primary caps, no isolation transformers, no inductors and only two puny rubbish-branded Jwco (?) branded capacitors. Lots of goopy potting adhesive in ways which don’t inspire confidence, and no fuses on the primary, but those 1N4004s will probably blow much quicker.

And a quick look at the underside shows that there are no ICs hiding here either. God, those Chinese manufacturers can build an SMPS so simply (although not great) – I don’t think I could match them on this kind of simplicity!

A couple of last notes – it almost looks like this charger was designed to charge small camera/phone batteries in a compact charger, and the same PCB was “wired up” to another case which can accommodate a different sort of battery (hence the large “empty” space at the bottom half of the PCB – which might have been where the original battery it was designed for would have been). After all, if you run the standard CC-CV charging mode of Li-Ion and you know your battery voltage, you almost don’t need the other smarts in the battery to blind charge and signal completion when the current tapers off in the CV region of charging.

So, how can we conclude it is a fake? Well, the only way to know is to compare it to a genuine charger. Do NOT try this at home!

I took apart my genuine Nikon charger just for this experiment – you need to be really careful, or you might end up sacrificing it too. Anyway – this was a bit more tough to dismantle – after removing two Torx T8 screws (thank god for my toolkit!), I still had to de-clip the side latches to get it open. At least I didn’t peel off any labels or break any warranty seals! What a difference!

It’s a mixed bag as soon as I look at it. There’s some really confidence inspiring things – for example – the fuse on the primary as soon as we get in, an inductor, an isolation transformer, a fully wrapped transformer,  a really large (possibly Schottky for efficiency and speed) rectification diode, a few more caps, an optoisolator and a Matsushita (Panasonic) MIP2F4 Switching Regulator Controller, and all pins marked on the battery. +, – are self explanatory, T is probably thermistor/temperature, OL maybe overload/current, and ALM might be alarm. Woo – I now know the pinouts of the battery – the battery itself is known to communicate with the camera and “authenticate” itself as real/fake to stop counterfiets working.

But there is already some depressing things – the use of four regular 1N4004’s rather than a bridge rectifier is always code for “we skimped on price” – as is the CapXon branded capacitors – famed from the bad capacitor plague. Under high-heat and high-current situations, these would vent and fail … Aside from that, the wiper-arrangement for connection to the rotating bi-pin head was rather flimsy and touchy from the looks of it too.

Lets turn it over for some more examination …

Wow, what a stark contrast. There is a lot of surface mount resistors and capacitors – and several transistors. There is also (most importantly) what appears to be a smart charger IC as well. You can see another two CapXon caps in the corner as well.

So, was the one I got from eBay a fake? It’s almost proved beyond doubt from these photos of the internals that it lacks the sophistication expected from a major-brand charger and lacks a lot of the intelligence required to safely charge batteries under all conditions (high temperature, overheat, low temperature, over-discharge). The fake, if properly made, may function correctly just fine – until one day you meet a bad battery – then who knows what might happen. It could even be a smoke/fire hazard.