Author Topic: Connector for B+M charger - what is it?  (Read 394 times)

Connector for B+M charger - what is it?
« on: July 09, 2020, 12:22:25 pm »
Anyone know what the connector is on the charger for a B+M I on IQ light?  And if it is a standard one that I can buy separately?
Ie this :
   

I'm trying to make a usb charger so that I don't have to carry the plug around. I could always buy one of these and cut it up, but it seems a shame to do so.


Kim

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Re: Connector for B+M charger - what is it?
« Reply #1 on: July 09, 2020, 12:26:12 pm »
Yes, it's one of the standard ones.  No, I can't tell you which.

I used to charge mine from a generic Maplin wall-wart, of the type supplied with a dozen interchangeable ends.  Alas, the light has gone to Silicon Heaven.

Hang on, doesn't it need more than 5V?
Careful, Kim. Your sarcasm's showing...

Re: Connector for B+M charger - what is it?
« Reply #2 on: July 09, 2020, 01:01:18 pm »
This pic of one with an alternative design charger shows 6-16V, so it looks like it needs a constant current supply rather than constant voltage:

https://www.bikester.co.uk/bicycle-equipment/bike-lights/battery-run-front-lights/223917.html

Re: Connector for B+M charger - what is it?
« Reply #3 on: July 09, 2020, 01:05:51 pm »
OK, scrap that idea then!

Kim

  • Timelord
Re: Connector for B+M charger - what is it?
« Reply #4 on: July 09, 2020, 02:37:29 pm »
This pic of one with an alternative design charger shows 6-16V, so it looks like it needs a constant current supply rather than constant voltage:

https://www.bikester.co.uk/bicycle-equipment/bike-lights/battery-run-front-lights/223917.html

I was definitely using a voltage-regulated supply.  6V or 9V or something.  It's probably not that fussy.

(Either way, it's charging the cells in series, so it's best if you can put them in a charger with independent channels from time to time.  Which is a shame, because charging in situ avoids excessive stress on the battery springs and case catch, which are known weak points of the design.)
Careful, Kim. Your sarcasm's showing...

Re: Connector for B+M charger - what is it?
« Reply #5 on: July 09, 2020, 10:04:50 pm »
Actually it might still work : a wall charger can give greater than 5v via USB. I was thinking 5v was maximum for anything usb but that's not right.

I've ordered a multi plug wire of Ali express for $2. I'm on holiday shortly so it might get here for when I'm back at the start of next month!

Kim

  • Timelord
Re: Connector for B+M charger - what is it?
« Reply #6 on: July 09, 2020, 10:27:59 pm »
Actually it might still work : a wall charger can give greater than 5v via USB. I was thinking 5v was maximum for anything usb but that's not right.

Yeah higher voltages are possible given:

a) A really shit charger with poor regulation.
b) Non-compliant use of USB connectors.
c) A QC or PD compatible charger, and something to tell it to turn the voltage up.

You can also get cables with a USB A plug on one end, a boost converter lump in the middle and a DC jack plug outputting some higher voltage at the other, which are handy for things like this.
Careful, Kim. Your sarcasm's showing...

Re: Connector for B+M charger - what is it?
« Reply #7 on: July 10, 2020, 06:43:23 am »
I had thought USB was always 5v but I saw this yesterday, which gives out 20v on USB c and 12v on normal USB

  https://www.bhphotovideo.com/c/product/1536598-REG/hyper_hj_gan100_gan_100w_usb_type_c.html

It was linked from an article on best USB chargers so assumed it was ligit tech, but maybe not

But most likely the USB terminals won't be right. I actually just realised first thing this morning what you meant by the maplin charger. I used to have a box of those things, but they seem not to be a thing any more and it was a while branch of technology I had forgotten about. Need to find the box of them as I expect one in there will work!  But won't solve my problem though if I shouldn't be putting more than 5v across usb...

Kim

  • Timelord
Re: Connector for B+M charger - what is it?
« Reply #8 on: July 10, 2020, 11:29:55 am »
I had thought USB was always 5v but I saw this yesterday, which gives out 20v on USB c and 12v on normal USB

  https://www.bhphotovideo.com/c/product/1536598-REG/hyper_hj_gan100_gan_100w_usb_type_c.html

It was linked from an article on best USB chargers so assumed it was ligit tech, but maybe not

That sounds like:

c) A QC or PD compatible charger, and something to tell it to turn the voltage up.

Though it isn't clear.  It will output 5V until a compatible device asks it (via the USB data lines, using one of the above protocols) to increase its output voltage.  So it's safe for normal USB devices, but newer ones that support it can increase the voltage to get more power down a typical USB cable.

ETA: The kickstarter page confirms it.  PD on the C ports, and QC3.0 on the A ports.

Barakta has a laptop that charges at 19V or so via USB-C using such a scheme.  You can charge your phone with its power brick.  It's quite clever.

(You can do the client side of QC negotiation using little more than a microcotroller and a few resistors.  But I'd suggest an in-line boost converter would be a better way to solve this particular problem.)
Careful, Kim. Your sarcasm's showing...