Philips OneBlade USB Charger




The Philips OneBlade razor is great, but the charger that comes with it is annoying to carry when traveling, since it is relatively bulky and the prongs do not retract. Since the AC adapter on the one I have (QP2520) is rated 4.3v at 70mA, it was within the range of USB. For what it is worth, when I measure the output of the AC adapter directly, it shows 6v with no load, despite being marked 4.3v, so they are likely counting on some dropoff under load.

NOTE: Apparently there are other versions of the OneBlade that use a different voltage. I have no idea for those, so check the AC adapter that came with your OneBlade to make sure it is within 5v USB range.

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Step 1: Snip and Solder

We snipped the connector off about 6 inches from the end of the Philips AC adapter, stripped the wires, and soldered them to the stripped wires of a charge-only (2 wire) standard USB-A connector cut off of an old USB cable. Make sure to not reverse power and ground, so use a multimeter to check the polarity of the AC adapter and the stripped USB cable before you start.

You need to heat shrink the individual wires and then the entire assembly, so don't forget to put all three pieces of heat shrink on before you solder the wires together.

Step 2: Double Check the Polarity of the Assembled Cable!

Make sure the polarity is the same when you connect it to USB, before plugging it into the razor! Note that the connector only fits into the razor one way, so make sure you have the positive and negative on the correct sides. If they are reversed. it will probably destroy your razor.

Step 3: Working!

When connected, the USB power meter shows a little over 5v, at 0.08A, or about 80mA, which is similar to the rating on the AC adapter that came with it. It is drawing more than the 70mA you might expect since the USB power meter draws a bit of power as well. Note the voltage is also a bit higher than the 4.3v AC adapter rating. I've charged the rasor a couple of times with the cable, and have not noticed any ill effects, but your mileage may vary - this mod certainly voids your warranty, and is at your own risk.

If I did it again, I'd make the overall cable shorter so it would pack even more easily, but this is much better for travel than the original AC adapter!

Thanks to my 9yo son Cory, who did this project with me.

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    8 Discussions


    Question 5 weeks ago on Introduction

    Hi there, I mad this cable but the current I’m getting afterwards is off the scale on my ammeter (250+mA) any ideas why this may be?

    1 answer

    Reply 5 weeks ago

    Hm. Not sure without knowing more. Is it somehow shorted or something? Or, if it is not the same model as mine, did you check the specs on the AC adapter that came with it? 5v at 250mA is only 1.25w, so is well within what I would expect for charging even a NiMH battery.


    3 months ago

    Nice ! Exactly what I was looking for.
    Found this on ebay too :
    Any idea if its fits and has the right polarity ? I have the One Blade QP2520 but its not listed by the seller. Gonna order it anyway and test the polarity before using it.


    11 months ago

    nice! I was looking for some cable like this on ebay, couldn't find..
    I was afraid to ruin my single charger for this.. you gave me the guts :D
    Working great!
    I measured 6v on the original charger as well and on my bathroom's long cables (after usb splitter) the voltage drops down to 4.69v on the usb port, but with higher amps..

    jeffblDIY Hacks and How Tos

    Reply 1 year ago

    Thanks for the encouragement! However, we live in Quebec, Canada, so are not allowed to enter.


    1 year ago

    If you want to be save, you always can insert a Schottky-diode with just about 0.6V drop @ 80mA like the cheap MBR160 (Price about 0.3$ @ Mouser. Mouser-Number = 863-MBR160RLG) for the 4.4V.

    Added benefit: Polarity-Protection.

    Also, Normally those USB-Powermeter measure the current OUT and not Current IN. That way, the consumption of the meter is NOT in the displayed current

    2018-10-03 14-50-08.png
    1 reply

    Reply 1 year ago

    Thanks for the comments!

    1. Dropping voltage: Yes, something to drop the voltage and polarity protect would be a good idea. May add after my trip...didn't have anything on hand, and still no ill effects from charging overnight. As I mentioned, the AC adapter I received with my OneBlade is marked 4.3v, but I show it outputting 6v on my multimeter anyway.

    2. Power Meter: Oddly, if I connect the power meter to my battery pack, but do not connect anything to the outputs, it still shows something like 0.03A, which was indeed surprising. So at least for my cheap USB power meter from aliexpress, it does appear to show some current draw from the meter itself.