Hi all. I recently purchase the mini2440 with 3.5 lcd but I want to know if someone already attached a 6v4ah battery for portable purposes. I'm thinking to wire the battery without any diodes, just the battery but I don't know if adding 1v more can burn my mini2440. I appreciate your commentaries. I wish to run the mini at my car 24/7 with a 6v battery, totally separated from my 12v car battery since 6v 4ah are cheaper.
NO.. Don't apply more than 5V to the board or you will fry it. The 5V is used by the system and anything above 5V will most likely kill them. The 5V input is used to power the USB so you would also fry any USB device plugged in. You will need a regulator but also bear in mind that a rechargable battery will reduce the voltage output as it discharges so you may not get a long life out of the battery as you might expect. Why not look at using a 3.7V battery with a suitable charger circuit from the likes of Microchip or Texas. These are what are called power path IC's and will route the charging voltage (max 5V) to the output and charge the battery at the same time. When the charger is removed, power comes from the battery. You then use a buck/boost switching voltage regulator to power the board. This will generate 5V from the lower 2.5 to 4.2V of the battery. Dave...