12 volt DC charger/adapter for 18650 flashlight wiith dc charging port

[usrnam]

What sort of charge circuit is used with the less expensive flashlights that come with a DC charging port?

I have a DC (auto/cig) charger/adapter that came with a flashlight with a charging port, output measures ~12.97 volts. Whereas the AC/DC adapter's output measures ~4.2 volts same as the labled rating (output = 4.2 volts @ 500 mA.)

There appears to be something wrong with the DC adapter. After dismantling the DC adapter there is a small pcb comprised of 2 resisters and 1 LED. One resister is for the Pos+ and the other for is connected to the LED. When used with the flashlight for charging the DC adapter become hot to the touch and the LED doesn't change color to indicate state of charge i.e. on, charging & full charge.

The AC/DC adapter charges the 18650 to full capacity, with led color changes indicating the state of charge.

The DC charger other than turning on and become hot, doesn't appear to be doing anything at all, perhaps damaging the battery?

?????

I'm thinking of building my own 12 volt DC adapter such as e.g.

1. (12 Volts) ---> (12vdc to 5 vdc stepdown) ---> (TP4056) ---> (3.5 mm dc plug).

or

2. (12 Volts) ---> (12 volt cig. to USB 5 volt adapter) ---> (TP4056) ---> (3.5 mm dc plug)

Update: I made a charging cable similar to the second one (#2). Still in the process of testing, it seems to be working ok. Connected to a USB adapter, the red led is ON indicating charging mode.

 

[Acika011]

Could you post a pic of that pcb? Voltage drop can't be achieved with just one resistor. They probably forgot a few diodes...

 

[usrnam]

Could you post a pic of that pcb? Voltage drop can't be achieved with just one resistor. They probably forgot a few diodes...

 

[usrnam]

Here's a couple pics of the one made from a TP4056 board with micro usb connector. I fogot to take pics before heat shrinking.

USB Cig adapter >> standard USB == (usb cord) == micro usb |=| micro usb TP4056 == (cord)== 3.5mm plug |=| Flashlight

"In addition to its smaller size, the micro USB is more durable than the mini USB connector. A micro USB features a stainless-steel shell to allow for over 10,000 insertion cycles, as well as a latching mechanism that provides higher extraction forces without sacrificing the USB's ease-of-use for synching and charging your portable devices."

Works as expected, Output approx. ~4.2 volts, Red LED while charging, Full Charge Blue LED.

 

[d123]

"In addition to its smaller size, the micro USB is more durable than the mini USB connector.

Im not sure where that statement comes from but in my experience that's far from true. As someone who has been involved in phone repairs running a Repair Service Centre for many years I can only remember a handful of miniUSB failures, compared to hundreds or thousands of microUSB failures. That's one of the reasons why USB-C is about to replace microUSB as USB-C is a complete redesign of the easy to break microUSB design.

 

[hiuintahs]

I'm thinking of building my own 12 volt DC adapter such as e.g.

1. (12 Volts) ---> (12vdc to 5 vdc stepdown) ---> (TP4056) ---> (3.5 mm dc plug).

or

2. (12 Volts) ---> (12 volt cig. to USB 5 volt adapter) ---> (TP4056) ---> (3.5 mm dc plug)

Update: I made a charging cable similar to the second one (#2). Still in the process of testing, it seems to be working ok. Connected to a USB adapter, the red led is ON indicating charging mode.

That original charger looks to just have a burnt power resistor between 12v and battery with another resistor forming a voltage divider (in parallel with the battery) so as to not exceed a certain voltage which of course will vary somewhat with whatever the 12v power actually is..........YUK. Talk about cheap :shrug:. Is it really a battery charger?

I ended up making a couple of chargers but I used Linear Technologies LTC4053 which is more robust than the TP4056. That was my USB charger. For 12v direct, I use a switching power supply to charge the battery via summing both battery current and battery voltage to regulate a constant current / constant voltage output to the battery........very efficient.

http://www.candlepowerforums.com/vb...n-battery-charger-gt-suggestions-needed/page2
(Just post #43)

 

[usrnam]

Im not sure where that statement comes from but in my experience that's far from true. As someone who has been involved in phone repairs running a Repair Service Centre for many years I can only remember a handful of miniUSB failures, compared to hundreds or thousands of microUSB failures. That's one of the reasons why USB-C is about to replace microUSB as USB-C is a complete redesign of the easy to break microUSB design.

Yes, it appears the article I was referring to is out of date. I was mainly comparing Mini to Micro USB. I'm not yet familiar with USB-C devices, which implements USB 3.0.

http://www.wisegeek.com/what-is-micro-usb.htm#didyouknowout
http://topics.wisegeek.com/topics.htm?micro-usb#

However, I don't believe most TP4056 boards yet come with a USB-C port.

There are USB hybrids, similar to USB-C where there is no top or bottom, plug can be inserted in either direction.

Appears similar to USB-C with sharper angular left & right sides, <====>

 

[usrnam]

That original charger looks to just have a burnt power resistor between 12v and battery with another resistor forming a voltage divider (in parallel with the battery) so as to not exceed a certain voltage which of course will vary somewhat with whatever the 12v power actually is..........YUK. Talk about cheap :shrug:.

I ended up making a couple of chargers but I used Linear Technologies LTC4053 which is more robust than the TP4056. That was my USB charger. For 12v direct, I use a switching power supply to charge the battery via summing both battery current and battery voltage to regulate a constant current / constant voltage output to the battery........very efficient.

http://www.candlepowerforums.com/vb...n-battery-charger-gt-suggestions-needed/page2
(Just post #43)

Are there LTC4053 boards available that can be impletmented into a project, silmilar to a TP4056?

 

[Acika011]

That PCB's main purpose is to light up that red LED otherwise it would have more components. Don't trash it. Use it as signal lamp for ON/OFF 12V circuit.:lolsign:

 

[hiuintahs]

Are there LTC4053 boards available that can be impletmented into a project, silmilar to a TP4056?

Not that I am aware of. Send me a PM if you are interested in a bare board as I've got a few extras.........if you are willing to solder your own chip on. The LTC4053 isn't as cheap as the TP4056 and so this may not be an option for you plus the pin spacing is narrow and may be hard for someone that hasn't worked with this small of surface mount to be able to solder it. I'm using a microcontroller to control the LTC4053, but if you wanted to adapt your own fixed control that wouldn't be hard. If you have any electronic background and with a schematic you'd be able to figure it out easy.

Edit:
I just thought of something else. I have a couple of extra XTAR MP1S charger boards that I took out when creating my charger. If you want to pay for shipping I'd just send you one. If you go back to my link above you will see a picture of my board next to one of these. They must be very similar to the TP4056. I couldn't make out what chips they were using.

 

[usrnam]

Not that I am aware of. Send me a PM if you are interested in a bare board as I've got a few extras.........if you are willing to solder your own chip on. The LTC4053 isn't as cheap as the TP4056 and so this may not be an option for you plus the pin spacing is narrow and may be hard for someone that hasn't worked with this small of surface mount to be able to solder it. I'm using a microcontroller to control the LTC4053, but if you wanted to adapt your own fixed control that wouldn't be hard. If you have any electronic background and with a schematic you'd be able to figure it out easy.

Edit:
I just thought of something else. I have a couple of extra XTAR MP1S charger boards that I took out when creating my charger. If you want to pay for shipping I'd just send you one. If you go back to my link above you will see a picture of my board next to one of these. They must be very similar to the TP4056. I couldn't make out what chips they were using.

At this point I'm having space and workspace limitations. The TP4056 has been able to fit into a mod or upgrade.

I installed a TP4056 into a 60 LED umbrella lantern that is essentially comprised of a 18650 battery holder, 3.5mm input jack and pcb with switch that controls the 60 LEDs. Space inside the lantern's case is limited. I purchased two of these lanterns and was thinking of creating a different type of mod for the second one.

I have a couple of 12 volt 5 watt solar panels I was thinking of incorporating into battery charging and mobile energy/power applications. Full sunlight 10 watts provides around ~.8 amps enough for battery charging. The solar panel wattage needs to be increased to match higher demands and limited sunlight. For solar applications it's often more feesable to draw power from a solar storage battery vs directly from solar panels.

To use a XTAR MP1S charger or similar charging board I would probably need a case of some sort. Possibly could be installed into a cable, however the width and length may become an issue for installation.

I found a couple LTC4053 demonstration boards. Their dimensions are significantly larger, requiring more mounting and installation space.

http://www.digikey.com/catalog/en/partgroup/ltc4053-demonstration-boards/49666
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One item I'm still working on is some sort of reverse output polarity protection. If a person happens to insert a battery in the wrong direction the TP4056 shorts out, destroying itself in order to protect the battery and circuit.

I found a reverse protection module, uncertain what effect it has on battery charging, current draw, etc.

http://www.ebay.ca/itm/4A-Auto-DC-t...336941?hash=item19f77cd9ad:g:RB8AAOSwkNZUcb9F

----

There is a TP4056 3 Amp version I don't have a datasheet for.

http://www.icstation.com/tp4056-hig...ery-charging-board-charger-module-p-6834.html

and a LTC4056 that looks interesting, however the demo boards often are going for over hundred dollars each. Creating your own board design involves alot more time and work.

http://www.digikey.com/catalog/en/partgroup/ltc4056-demonstration-board/49667

 

[adnj]

Micro USB was planned to be more durable because all of the sprung contact elements were in the cable and not in the device.

Im not sure where that statement comes from but in my experience that's far from true. As someone who has been involved in phone repairs running a Repair Service Centre for many years I can only remember a handful of miniUSB failures, compared to hundreds or thousands of microUSB failures. That's one of the reasons why USB-C is about to replace microUSB as USB-C is a complete redesign of the easy to break microUSB design.

 

[d123]

Micro USB was planned to be more durable because all of the sprung contact elements were in the cable and not in the device.

Unfortunately they forgot to factor in human nature that tends to want to push the plug into the port upside down using as much force as they possibly can until they push the port off the pcb .

 

[snakebite]

looks like a cheap and dangerous way to drop voltage for the typical cheap charger those lights have.its the cheapest and worst way to do this.and unnecessary with the proliferation of cheap 5v phone chargers.
i wouldnt trust the rest of the light without inspection...