Anyone tried using cell phone charger as battery?

Any miscellaneous pieces and parts that don't fit in the above forums.
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a_shorething
Posts: 289
Joined: Sep 10th, 2013, 5:26 pm
Location: New Jersey Shore

Anyone tried using cell phone charger as battery?

Post by a_shorething »

I was just doing some shopping and saw some REALLY slim and light battery power options that might work for ROV operation.

They're cheap as dirt for what they appear to offer.

Here's one that is listed as 10,000 mAh!!! (output is 5m at 2Amp) It's got two standard USB outputs and it's listed under $30. I've seen others from 1200mAh up to 13,500 mAh ranging from $25-$75. For me these look like great options for lightweight low draw power.

http://www.walmart.com/ip/INSTEN-Dark-G ... 5/41509576

I've heard that you should keep the controller/video feed and thruster power lines separate so that the there is no interference from the electric motors and I'm thinking this kind of thing would be PERFECT for powering the controller board and small devices that don't have much draw.

Anyone tried this?
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ROVER3D
Posts: 128
Joined: Nov 9th, 2012, 7:45 pm
Location: Wuppertal, Germany

Re: Anyone tried using cell phone charger as battery?

Post by ROVER3D »

Nice Idea, but won't work.

For powering motors and control separate you had to connect the GND (only PWM won't work because PWM need ratio to GND).

You have to be very carefull with separate power. It might be possible other connections will take these connection(to GND) for devices.
On X³-Control there is no connection to ESC 5V(BEC)output or GND. Only PWM is connected. Think about what would happen if you disconnect(switch of) the GND connection of ESC = full current will run over the X³-Control GND connection. Not a good choice...

Else people ask me why i don't use the BEC of ESC to power up the X³-Control?
If you connect every 5V(BEC) output... up to 8 ESC... and one ESC willl burn and fail you will burn all the other (happend on ROVERII caused running unsealed Brushless Motor in saltwater!!!). It causes full voltage = 14,8V on BEC line... and 5(!) ESC burned.
I did not connect only one (first) ESC to power up the control... cause you cannot switch of this ESC and if it failed... you will loose full control. (and might be 14,8V on all 5V devices and sensors on I2C Bus = a lot of smoke)
Think carefully about the circuits.
You probably do not want even have the expensive GOPRO on BEC in case ESC goes up in smoke ...

The 5V-1Ah power of X³-Control is short circuit and reverse polarity protected. I use the same for each gopro separate.

Back to your cell phone charger. I'm sure that can not keep up with the price and the performance of the Turnigy Li-Poly from HobbyKing.
rossrov
Posts: 383
Joined: Feb 28th, 2013, 5:01 pm
Location: Australia

Re: Anyone tried using cell phone charger as battery?

Post by rossrov »

If it is only the grounds that are connected, (I'm assuming that a_shorething was thinking common ground) then a good amount of interference potential is gone. Still have to be careful with ground-loops and pickup between wires. One could isolate totally (remove ground connection) by using optocouplers :) for the motor PWM, light controls and any other higher-current devices.

I have a similar charger pack and have used it as a bench supply for Arduinos etc. The label on the underside states 3.7V/50,000mAh :shock: , output 5V 1A/2A (max, and has two sockets), input 5V 1A(max). If the 50Ah and input spec is correct, then this would take a long time to recharge :( .

There would be a number of cases for and against separate batteries in ROV world. :)
a_shorething
Posts: 289
Joined: Sep 10th, 2013, 5:26 pm
Location: New Jersey Shore

Re: Anyone tried using cell phone charger as battery?

Post by a_shorething »

Rover,

I'm not following you and maybe you can help me.

I thought the whole point of using ESCs or dual H bridges was to isolate the power going from the batteries to the motors from the 'signal' circuit or PWM coming from the controller board.

If one were to have the controller board (x3, arduino, whatever) powered by one source like one of these USB rechargers and another higher output battery for the 'load' side of the ESC or dual H-bridge relay, I thought that would essentially isolate the two circuits, wouldn't it?
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