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Power from battery pack

Posted: Wed Nov 20, 2013 9:53 am
by GianfrancoPa
Hi at all!

I find this battery pack on RS:

https://it.rs-online.com/web/p/caricaba ... m=775-7504

In your opinion, can I power the raspberry from this battery pack and link this battery pack always to my 220V?

In this way I can prevent power loss...

Thanks!!!

Re: Power from battery pack

Posted: Thu Nov 21, 2013 4:45 am
by hunternet93
It should work, you could also look in to getting a UPS.

Re: Power from battery pack

Posted: Mon Dec 23, 2013 9:56 am
by linux18
That battery pack on RS is an affordable UPS solution.
I will try that.

But my concern is the maximum output current and charging current :?: :?:
Do you have any idea?

Re: Power from battery pack

Posted: Mon Dec 23, 2013 10:56 am
by rurwin
The input is rated at 800mA, the output at 1000mA. Charging will be less than 100% efficient, so you're looking at a long-term output rate of under 800mA.

A naked RaspPi model B pulls around 400mA most of the time, so it should be OK. You won't want to be using any power-hungry USB devices though.

I don't know what the long-term implications running it at maximum power all the time might have.

Re: Power from battery pack

Posted: Mon Dec 23, 2013 12:46 pm
by GianfrancoPa
I tried model B + Raspberry camera with no success

Re: Power from battery pack

Posted: Mon Dec 23, 2013 5:04 pm
by Tage
the datasheet for this product does not have much content. it is a quite useless document.
from the physical dimensions I would guess that it contains an 18650 cell (3.7V), so the 2200mAh capacity number is probably for the cell and not for the 5V output.

you could try to load the output and measure the voltage to see how much current the battery can supply.

start with 10ohm (500mA) and increase the load until the voltage drops below 4.8V at the end of the USB cable that will plug into the Pi power port. you could use three 33ohm 1/4W resistors and increase the number of resistors to increase the current.
the battery electronics must contain a 3.7V to 5V power converter, and that converter has a current limit. you need to find out the current limit so you know how much current you can actually draw.

it would not surprise me if the maximum load current is much lower during charging. or it could be the other way, that it is only with a fully charged battery and the charger plugged in that you can draw 1A, briefly. and as the battery is being discharged the available load current is much less. "up to 1A" does not really promise anything.

Re: Power from battery pack

Posted: Tue Dec 24, 2013 7:35 pm
by mikronauts
FYI,

I used a Patriot Fuel+ 5200 mAh pack to power a Rev.2 Pi + WiFi + robot controller wit great success (see SPRITE, Servo Jan.2014). The servos were powered off a different 4xAA battery pack.

The Pi ran for >3h with WiFi in this configuration.

Re: Tried a Nokia DC-16 as backup today

Posted: Fri Dec 27, 2013 12:46 pm
by Nastanir
I tried to use a Nokia DC-16 (2200 mAh) as a back up today for my rasPi. It worked as a power source even with a wifi dongle. But the moment the charging end of DC-16 is connected to power supply, it automatically disconnected the power to the pi. Bottom line is that simultaneous charging and powering the pi with Nokia DC-16 is not possible.

Re: Power from battery pack

Posted: Sat Dec 28, 2013 9:05 am
by johndough
Hi

There is a difference between running the charger device and a ups type solution.

The Charger pack is just that, with a charge/recharge cycle limit. If there is no pass-through you will quickly use up all of the cycles.

The power supply needs to run the Pi and accessories first, then have the capacity to charge batteries.
1200 milliamps, 1000 for the Pi and 200 to charge / float the battery pack.

The UPS option is expensive, but will give the required continuity.