Running Frendly-ARM mini2440 128MB with battery

Hello,

I need to run mini2440 on the go, so do you believe
I can use 4x 1.25 2500 mAh NiMH rechargable batteries
in series even to get 30 working minutes?

I mean connection directly in the power jack.

Would that work or it might cause problems?

Thanks in advance

One issue is what is the max voltage of fully-charged cells?

4*1.55 to 4*1.6 = 6.4Volts

I think the LCD runs off the raw "5Volt input".  You need to check what
it's max voltage rating is . . . and anything else that runs off this line!
 

Another issue is what voltage will the unit stop working at.  The cells can
go down to 4 * 1.0Volts = 4 Volts, but the FriendlyArm may not.

I use 2 packs of 6 * 1500mAh cells that I can switch in parallel or in
series (max 18V), driving a 5Volt 2 amp "switcher".  I need to be able to
change the configuration of the cells because I have to charge from a
13Volt source.

I'd suggest 6 * cells and run a 2Amp 5v LDO.  Another improvement, to
reduce current consumption is to change the linear regulators to little
switchers.  Backlight control would be nice as well.

Have fun!

Using 4 x NiMH rechargeable batteries will work.  When I tried it, I used 4
x 2000mAh batteries and plugged them into the regulated 5V input.  They ran
the Mini2440 for more than 4 hours (with light usage).  I also had a
multimeter to measure the voltage of the batteries while being used, and
the Mini2440 continued to work even when their total voltage dropped below
5V.

At 5.0Volts each cell is at 1.125Volts.  This is close to the minimum
voltage I would allow the cells to drop to.  You are probably not going to
get much extra running time trying to go down to 1.0Volts per cell.

OK with that.

4 fully charged cells can get to 6.4volts.  Can the LCD driver handle that
and anything else the is run off the raw 5Volts? The maximum voltage rating
for the NL2432HC22-22B is 6.0Volts.  

Therefore, I would not run the FriendlyArm off 4 * NiCd or NiMH cells that
have been fully charged.

Good luck!

Android_04 can you tell me what batteries do you use?

Hi,

you can use an DC/DC Converter between batteries an mini. This makes you
very independ from battery type/voltage and gives your mimi an very good
5.0 V. Look i.e.
http://www.produktinfo.conrad.com/datenblaetter/150000-174999/154994-da-...

Hi,

I am looking into getting a mini2440 in the near future, and I would like
to try and set up a laptop like battery monitoring system for it so I will
be able to have more portablity with it, if anyone can point me in the
right direction on where to find the required hardware to set this up if it
is even possible.

Thank you

skip2816  would u plz resend the pdf cos it is crashed.

i got this
http://www.libelium.com/tienda/catalog/product_info.php?cPath=21&pro...

and am still exploring how to connect it to the mini2440

hi,

your link points to a battery charger, not a dc-dc converter.

I use this one for my micro with 7' display by 12 V input:
http://www.gadgetpool.de/bestellen/catalog/product_info.php/cPath/21/pro...

It's works nice.

skip

Are there any commercial battery ready for the use with mini2440? I mean
something dose not require welder...

@marco

The dc-dc converter skip2816 mentioned does not require any soldering or
even welding. It comes fully assembled and ready to use.

Hi,
i am using 6V 4AH 
http://shop.vendio.com/valuebuybatteries/item/937937901/
its available commonly.
I am using 9v adapter. regulation with 7808, 10 ohm 2 watt resistor,1000 uf
25 volt capacitor,4007 1amp diode .this is for charging of battery.
Then the output of battry i connect to another 7805 regulator its output
very regulate. and mini runs and runs i checked for 4 hour and no problem
at all.
Please do it if u have any electronics idea,,
Aware,,,,, DC always polarity conscious. So please be sure the right
polarity, means -ive and +ive,, so be care full.
Always use heat sink with regulators...
Regards.
Arif

Dear,
can you provide also a schema for describing how to connect batteries and
circuit required (DC DC) to mini2440?
Thanks

I'm also interested in thaa kind of solution 
to have the FA autonomous but with little batteries (AA for ex)

Thx