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A lot of Chinese tablets (and probably some others as well) use a barrel connector instead of microUSB to charge. They all seem to use the standard size of 2.5 mm OD (outside diameter) and 0.8 mm ID (inside diameter).

I just bought a used Chinese tablet (a Pipo P1 to be exact) whose previous owner says the battery no longer charges when plugged in. After reading this and this, and finding out how much noise is output by cheap Chinese chargers, I’m looking to buy a charger with some actual quality behind it so I don’t destroy the tablet even more (I’m somewhat confident the issue of the battery not charging anymore was caused by the power adapter it came with… in fact, I already experienced something similar myself when I used a cheap Chinese power adapter to charge a laptop for a few months).

Here are some pictures of the port on the tablet as well as the power adapter it came with showing its specs:

A cropped image showing the label on the power adapter that came with the tablet: Power Supply’s Label http://f.cl.ly/items/3o1D1U2q293Y1x3Z3f2y/power%20supply%20label.png

The contents of the label transcribed:

型号:KZ0902500C

输入:100-240V〜50/60Hz

   0.5AMAX

输出:9V ⎓ 2500mA

where 型号 = Model, 输入 = Input, and 输出 = Output

(The character between '9V' and '2500mA' is U+2393 DIRECT CURRENT SYMBOL FORM TWO. If you can’t see it, it means you don’t have a font installed containing a glyph for that codepoint. If that’s the case, I recommend installing a font like Everson Mono, STIXGeneral, or Symbola, which does contain a glyph for it).

An image showing the DC 9V port on the tablet: DC 9V Port on Tablet http://f.cl.ly/items/3S3H032k1A1X3Y3L1n3B/DC%209V%20port.png

And here’s an image showing the entire power adapter (might not want to click on that link though… it’s an uncropped 20 MB picture of the power adapter that came with the tablet that I only bothered uploading since you can also see the barrel connector).

At first, I thought I could just use one of the genuine Apple 12 W USB Power Adapters that I already own, by buying a 2.5 mm OD / 0.8 mm ID barrel connector to USB connector cable like this one. But then I realized there might be a few issues with going that route. The first issue would be that I would have no idea what AWG the cable would be (buyers of that product have said that the cable they received didn’t have the same AWG as the one shown in the picture). In addition to that, the specs of the Apple 12 W USB Power Adapter I have will pose a problem with using it to charge the tablet:

Input: 100-240 V〜 0.5 A 50-60 Hz

Output: 5.2 V ⎓ 2.4 A

Specifically, the output voltage of the Apple 12 W USB Power Adapter is only 5.2 V, while the voltage the tablet requires is 9 V. From what I’ve read, supplying an incorrect voltage is a very bad idea. The current supplied by the Apple adapter is also less than the current supplied by the adapter that came with the tablet (2.4 A vs. 2.5 A). Of course, the tablet might not actually draw an entire 2.5 A, but since I don’t know how much it draws for sure, it’s probably better to be safe than sorry.

This leaves me with two options:

  1. I can buy a 2.5 mm OD / 0.8 mm ID barrel connector to USB connector cable like the one I linked to (despite not specifying the AWG of the cable, it seems like others have gotten it to charge their tablets fine, so it may be good enough), which would then make my question: are there any reputable (non-'no name' brands) that sell a USB power adapter that supplies an output voltage of 9 V (DC) and an output current of 2.5 A?

or

  1. Buy a power adapter that already has a 2.5 mm OD / 0.8 mm ID barrel connector on the other end, which would then make my question: are there any reputable (non-'no name' brands) that sell a power adapter that has a 2.5 mm OD / 0.8 mm ID barrel connector on the other end of the cord and supplies an output voltage of 9 V (DC) and an output current of 2.5 A?

Regarding option #1, I’ve searched around quite a bit, but the closest I could find were these USB power adapters from Anker: the A2130111, A2010111, and A2132121, but they only provide an output voltage of 9 V with an output current of 2 A.

Regarding option #2, I’ve searched extensively on that front as well, but have still come up short. Places like Farnell and Digi-Key don’t seem to have anything matching those requirements. The best I was able to find was S-9V0-2A5-U30 from Condor Electronics. It seems perfect; they even let you configure the type of barrel connector for them to put on it! That’s where the issue lies though, as the closest thing they have to one with an OD of 2.5 mm and an ID of 0.8 mm are their two EIAJ-1 barrel connectors (one with OD of 2.35 and ID of 0.7 and the other with OD of 2.45±0.05 and ID of 0.7), which might be good enough size-wise, except that the rated voltage and current of an EIAJ-01 connector is too low (0–3.15 V and 2 A). Of course, that’s also ignoring that the only reason Condor Electronics even lets you customize the barrel connector on the adapter at all is because you have to buy 100 pcs. at a time…

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