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
I have been trying to run the mini2440 from a 12 volt battery with a step-down voltage regulator that is used in the automotive industry: DC DC 12V 24V Step down to 5V 3A Car Voltage PSU Converter Regulator Module. It works fine for a while, but after I shutdown and try to restart, he voltage regulator get damaged. I have also used a car 5volt 1.4 Amp USB converter with similar results. Any idea what I am doing wrong?
For the first case do you mean the 5V 3A Car Voltage PSU Converter Regulator Module fails? That seems a bit unusual. In the early days there use to be a problem with the output voltage staying up when the input voltage dropped to zero and the regulator chip would blow up. I think all modern voltage regulator chip either have protection or tolerate this condition. By shutdown, do mean turn the power switch off on the mini2440 or doing shutdown from the command line? I would monitor the supply to with a DSO (oscilloscope) to try and catch the fault condition. This is going to get expensive!
Yes the regulator module fails. I now used 3 regulators and one car USB. The regulator I used for this is similar to one mentioned in this page but for 3A. http://www.newegg.com/Product/Product.aspx?Item=9SIA3H61F95315&cm_re... For shutdown I turn the power switch of on the mini2440. Do you think that I should add anything else other than the regulator to this setup? Thanks for your help
This sound unusual, all right. Maybe, try running the mini2440 on a new regulator, then shut it down. Remove the mini2440 and check to see if the regulator is faulty. As the units seem to cope with starting the mini2440 up the first time, it seems odd that it couldn't start it the 2nd time. The mini2440 doesn't have any big caps so an input surge current does not seem likely. Have you tried another mini2440? Maybe, the unit you are testing with has a fault.