4.35v Li-Ion Charger Option (YiboYuan External Cell Phone Battery Charger - various models available)

Well today I received my two new YiboYuan chargers I ordered on Ebay (see post#26 above). Came from a US Warehouse, not extremely fast, but not terribly slow either (faster than Tmart!). I did in fact receive YiboYuan chargers, HOWEVER I received two model AC-11's and not AC-10 (it was only the photos in the Ebay listing that showed AC-10, it wasn't stated anywhere in the listing). I don't think this is a big deal though since I can't spot any difference between an AC-10 and an AC-11. Both are 4.35v @ 600mA charge rate with a USB output as well.

In any case, here are some pics:

The internals don't look as sophisticated as the first charger. My first question is, where is the AC -> DC circuitry (i.e. the 4 way bridge rectifier circuit)? So how does this one look? Does it look safe?

-Garry

No response?

-Garry

Cheap equipment sometimes only uses one diode not a bridge rectifier.

It does not look safe for 230VAC.

Thanks HKJ. Well I won't ever use it on 230V AC. So you think it's safe for 120V AC use? And what is controlling the charge termination? I don't see an IC like I would expect.

-Garry

I cannot say it is safe, but if the blue part beside D3 has some safety approvals it might be (I expect it is placed between mains and low volt side).

It looks like the charge is controlled my Q3 and Q4 and I doubt it is very precise and I also doubt there is any charge termination.

If you had provided a photo of the other side of the circuit board also, it would have been easier to see.

Would you use these chargers or recommend them for the general population? Really, thats the question isn’t it? :slight_smile:

No, I believe they look to much like the cheap usb power supplies:

But due to the 110 VAC, the safety requirements in US is considerable less and it might pass.

So it seems the first chargers I received from T-Mart would be better suited to use than this second set. I would definitely charge up to 4.2v on another charger first due to the slow 350mA charge rate on that first charger. Ugh - thought I had a good solution going.

-Garry

Tmart one, post 19

Could you take a picture of the markings on the blue capacitor (marked “CY1” on the pcb) and a picture of the other side of the pcb?

Ok, but you will have to wait as I don't have it with me right now.

-Garry

CY1 bridges the high voltage & low voltage sides. Needs to be a quality cap with a proper rating. HKJ asked about its markings earlier in the thread.

OK, here are photos of the first charger (350mA from Tmart):

Backside of board:

And a closeup of that cap.:

As you can see, it reads "102/1KV". So how is that? Any additional concerns?

(I'm going to see if I can replace that first pic with one in better focus (I'm only using my phone) - be right back. EDIT - Done.)

Thanks,
-Garry

Yes, it is not a safety capacitor.

On the mains there will sometimes be spikes with very high voltage. One of these spikes can punch through the isolation inside the capacitor.

A safety capacitor is guaranteed to fail open, i.e. there will not be a direct path from the mains to the usb and charger wires.

A non-safety capacitor can fail shorted or open, it is undefined. If it fails in shorted condition you got mains on the usb and charger wires.

I see. So this charger is still "not recommended". (So does this mean it's "CE" on the label on the back of the case is bogus?) I would ask what capacitor I could replace it with to make it safe, but I don't think this 350mA charger is worth the effort - the 600mA might have been. Any photos of what a proper labeled capacitor would look like or how it would be labeled?

I think I'm just going to bite the bullet and buy an Xtar SP1 from RMM. I just feel that price is a little high for a single bay charger and the price on the dual bay is crazy high! At the same time, I'm tired of throwing my money away trying out these cheap Chinese chargers! At least I will be charging 4.35v cells safer and more properly.

Anybody want to buy 5 cheap Chinese 4.35v chargers?

Thanks,
Garry

I think I found what you mean by "safety capacitor". Something with markings like this:

-Garry

A prober safety capacitor usual looks like this:

Y means it is designed for usage between mains and low voltage and then all the marks from different authorities.

When the capacitor is wrong, there might also be other problems, i.e. the transformer might not have enough isolation.

Ah, I think we posted at the same time. Thanks HKJ!

Now I'm curious what is in the other charger, and I didn't bring it with me to work this morning!

-Garry

It looks like the circuit board has space for a prober safety capacitor.

It is not all equipment that has a capacitor between mains and low volt side, but leaving the capacitor out can give problems with EMC (I.e. noise or jamming of radio equipment).

Well, opened up the other (second) charger and it has identically marked caps

-Garry

Might it be reasonably safe to use on the line with my computer's UPS with surge protection and line conditioners?