Hello to everyone....i am experimenting a simple portable distance meter with arduino micro (that uses ultrasonic module HC SR04, and some simple buzzer and vibrator motor). Finished the "thinking" and prototyping part, i am in trouble with the external power for that project...what i can use ?
- I want a external power that is independent from my AC source (because i have to carry it with me also in isolated places, without possibility to use AC power);
- I want an esternal power source that can give me abouth 1 day (12hours about) without change and charge battery, when i come home i can recharge it;
- I want an esternal power source that can be lightweight and not too big because i have to carry it with me;
Now, i have found Li-Po batteries....my project's consumption is about 80mA, so i need for 1day-use a battery of about 960mAh, 1000mAh so.
To consider exceptional use of more than 12hours, i choosed 2000mAh battery.
Now the problem.
The battery i found (2000mAh 7.4V 35C) can give me all i want, but i have some doubts...:
- Can i use a simple DC/DC step down converter to use this lipo directly injecting 5V power in arduino ? I have this DC-DC converter, and i want to bypass arduino voltage regulator for his heat dissipation...
- I found on internet that lipo batteries are very delicates and not loves scratches or shock...i have to close battery pack in a plastic box to avoid this?
- I will not use this project every day...if one day i use this only for about 1hour and later i use it after for example 2 days, lipo battery can be damage from not using?
- I read that lipo batteries must be NOT discharged on less than 30% (something like this) of total charge....when i use the battery in my project how i can check percentual? there is a self-protection against too battery discharge?
the battery i found is this: http://www.ebay.it/itm/181460656935?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
Can anyone help me? Please...