12V battery to USB adapter operating issues and my work-around

Sooo… you got some villagers with nothing but a 12V battery (no real 'lectricity). Have you seriously thought about this? Why I say that is as follows. Yesterday I was out camping and brought the outernet dreamcatcher setup (after ginning up my previously shown platform and antenna mount for gorilla tripod. I used a Samsung adaptive fast charger. Here are my results:

1: Plug into cig. lighter outlet, car off: Board blinks, runs for 30 seconds, shuts off
2: Plug into cig. lighter outlet, car on: Board runs
3: Plug into cig. lighter outlet, start with car on, leave 30 seconds, shut car off - board runs.
4: Add 6’ USB extension to setup, try scenarios 1-3. Board blinks, runs for 30 seconds, shuts off.
So there is a marginal voltage condition. The Samsung adaptive fast charger is spec’ed for 2 amps. This might be marginal. Even with car on and adding a bit of overhead Voltage, that extra vew mllivolts might get droppped down again in the 6’ USB.
5: My 120V usb Samsung adaptive fast charger. Works fine, last a long time. Didn’t try with extension yet… :slight_smile:

Soooo… what 12V usb charger is KNOWN TO WORK WITH CAR OFF AND BATTERY FULLY CHARGED (I think 12.6 v is average good charge for a normal battery). OUTERNET should already loooonng ago have answered this.

I am testing this device.


The description is a little misleading in that it says lot’s of words like ‘transformer’ .‘converter’…all rather unscientific … but I’m not sure what your ‘adaptive fast charger’ really is … Is it stepping up to 120vac then going back to 5vdc for the usb?

Here are my first impressions…
1- it runs warm at 1a on the output,
2- rapid spikes/changes on the input do have a noticeable ‘blimp’ on the output
3- I think a medium sized capacitor on the output would be helpful
4- All off my tests with 15 foot usb extension cables have caused similar 30 sec run then shutdown of the Dreamcatcher

HEre’s the chargers I was using… https://www.amazon.com/Hotbin-Adaptive-Charger-Samsung-Galaxy/dp/B071DT8DLG/ref=sr_1_1?ie=UTF8&qid=1499568504&sr=8-1-spons&keywords=samsung+adaptive+fast+charger+car&psc=1

https://www.amazon.com/Samsung-Adaptive-Charging-Charger-Qualcomm/dp/B01CO9KJ6E/ref=sr_1_fkmr1_3?ie=UTF8&qid=1499568529&sr=8-3-fkmr1&keywords=samsung+adaptive+fast+charger+120v

Innnnnnteresting results. Outernet has some homework to do. It’s not for me - I am in a 1st world country. What does a dude with a battery do?

This whole 5 Volt USB standard is a huge pain in the A…

In my experience most USB to Car Cigarette lighter adapters put out 5.3 volts.

A dedicated regulated 5 volt output will be five volts exactly and will not work for most Arm processor boards.

The car cigarette adapter 5.3 volts gives you a little bit of voltage drop when you add a 6 foot USB extension cable.

USB extension cables are ALL over the place in Quality and wire thickness.

When I buy a USB extension cable I literally take, what I want to work with the USB 5 volt adapter and the ARM board to the shop. And try it all out in the shop. If it works I buy it.

A ARM board / Dreamcatcher and one or two USB dongles will probably use ! amp. In usb adapter world that is a heavy load.

i am actively looking at better “5 volt” power supplies for my Dreamcatcher and Armband Boards. (Mainly Orange Pi’s)

Hi @Seasalt , If your experience is like mine… I like the dedicated 4.0x1.7mm pin power connections. but since our dc’s having been following the trendy rpi’s that use the micro-usb… I will adapt… I wish the usb standards had been designed for better power handling, but that’s water over the dam, I think the original intent was to handle add-on peripherals (not as a primary power source)

My ‘work around’ for the DC when I want to try and use the otg usb connector… Is to power up the DC using the ‘power’ micro usb, then hook my pc to the otg. I understand that the 5v bus is ‘paralleled’ between the two micro-usb’s and could cause some backfeeding on power terminals… I hope some auctioneer occurs that keeps the DC at the highest available +5v (maybe there is blocking diodes incorporated?).

That all being said, I can’t expect 5vdc not to be affected by line-loss or cable resistant voltage drop. So I am limiting the length of the 5v cable to minimum by placing the 12v to 5v regulator next to the DC and all other power cables to the higher 12v

Electrical Noise is One thought that comes to mind and the possibility of adding a capacitor on the 12 volt side. Plus a clip on torpid.

And also a capacitor on the 5 volt side. ( I assume this will filter out some electrical noise before it gets to the DreamCatcher.

I have absolutely no idea what the formula for a good filter but I sort of believe that a capacitor and a toroid are worth doing.

If any one has any training notes on filtering 5 volt dc power supplies for radios I would be delighted to read it.

All great responses from everyone!

This ALL begs the question: What does a person in a tiny village in Africa/Asia/S.America do? It is THEY to whom this is all intended and directed.

Those answers MUST be simple and dead reliable.

If these are being shipped to them NOW, answers must be here NOW.

INdeed on my mobile setup using the single cable was what I ended up doing and after starting the motor (to boost voltages slightly), letting the board power up and then shutting the motor off, the outernet worked all day long, no problem.

I think the simple answer is that a proper 12v to 5vDC power supply (prob 2amp) is needed, and connected directly to the VCC of the device.

The problem with the USB car type adaptors is that they are often to “Smart”. The reason your Samsung one plays silly buggers is because it is probably “chipped” to only supply full current to Samsung phones - That sort of thing is really common, and bloody annoying! :frowning:

Thinking about it a “solar controller” that has a 5 ( or 6) volt output would probably work perfectly ( even is there is no solar panel charging the battery )
(edit) teh example below is prob a bad example as the "USB output current is low, but I have one here that has 6v at 2 amps output

Great idea, and, once again… HELLO OUTERNET ADMIN!! You guys have to provide the
outer-dwellers with a reasonable solution. I don’t need it. I’m fine. The folks in the boonies need it.

I think the issue with the “Outernet admin” is that there are surprisingly few people actually employed and driving the project. So it is “focus on one thing at a time”…
Am I right or am I right @syed

the community here at this time needs to work together to find solutions, and if we can come up with something, then we have all helped :slight_smile:
It is a shame that there is nothing but hardware sales to fund the project at this time too…

Your points are extremely well taken. I do think at some point the list of "to do"s to make this ready for prime time should be formalized and a forum or hey, even a once annual conference would be really really useful. As it is a very tiny group funding this I think boo boos could be fatal. So formalizing the engineering improvements (as well as the existing ad-hoc forum stuff) is essential. I’d be curious to know what the business plan and strategy is/are. It is invisible to me and must be issued from the top. Hey, I’m not just an occasional critic. I’m a FAN and an early adopter! :slight_smile:

@neil Your description is very accurate :wink:
Technical improvements developed by the community are always appreciated, but you are correct that the most important problem is the cost associated with power and bandwidth.

I use this when I go camping. I set it at about 5.3v to compensate for voltage drop. I have the chip system so I can just plug into the chg-in header. But you can get a USB extension and cut the end off so you can use your normal USB cable.

I might well try this next time 'round. Does someone have the color code/wire/whatever for the microusb cables? Thanks for the info!.

Having said that, it is still a hack, and a complete solution for the ultimate campers - i.e. villagers - will be needed.

I learned the hard to make sure that cable is at least 24awg for the two power connectors. Look for

The usb 3.0 otg ‘standard’ says up to 20v and 5amp… but I don’t believe that…

check wikipedia usb for pin-outs and color standards… not always followed… and the 5 pins and only 4 wires just add confusion. But
there are non-standard colours floating about I would be very wary of connecting them up without finding out from the manufacturer what colour they are using for what.

Colour: RED, ORANGE -> Connects to: POWER, VCC, SVCC, +5V
Colour: WHITE, YELLOW -> Connects to: P-, DATA-, SBD-
Colour: GREEN, GREY -> Connects to: P+, DATA+, SBD+
Colour: BLACK, BLUE, BROWN -> Connects to: GROUND, GRND, GND

USB devices are normally well protected as long as you are operating within voltage spec. However i would test this out on a battery bank, USB fan, etc. Devices that most likely don’t have data lines that you can accidentally fry. Under most conditions if you miswire the cable it just wont work, no harm done. Most cables will have a red and black wire or a shade of those colors, i have seen pink/grey before. You can also just buy a charge only cable.

Thanks. Caution is always the better part of valour! I think I’m getting a 2nd board anyhow. (upon which to experiment).