View Full Version : Battery choice
05-06-2006, 02:37 PM
I am building a rocket payload that consists of an eeprom, RTC, two ADC's, and an accelrometer. Because of the weight I need to find a small light weight battery.
I don't know alot about the power supply end of things so bear with me. If I add up the supply currents I have 13 mA. I have the power connected to Vin to internally regulate the voltage to 5V.
I have already built a prototype using a 9V battery but this weighs almost 2oz.
Does anyone have a suggestion on a sutable light weight battery?
05-06-2006, 08:56 PM
LiPo (lithium polymer). They are a bit expensive, but very light. They come in various capacities and in multiples of 3.7v.
05-06-2006, 09:18 PM
I believe there's an "N" cell. And you can stack 'coin' cells.
05-07-2006, 08:33 AM
Here is the schematic.
The two ports are PC screw terminals so I can add with ease. In the future I will probably use a MAX186 instead of the 187.
And if I understand SPI correctly I should be able to connect the SCK of each IC to 1 pin and the SI SO pins of each IC to 1 pin. I just need to connect each IC's CS to seperate pins. Right?
Post Edited (Mike15) : 5/7/2006 12:05:03 PM GMT
05-07-2006, 12:20 PM
Selecting the proper IC via CS is generally fine, as is using common CLK and DATA lines.
05-07-2006, 02:09 PM
·· Perhaps I am missing something in your schematic, but you mentioned an RTC, but you don't seem to have one listed in that schematic.· You also have a crystal connected to the Digital Thermostat in the schematic.
Parallax Tech Support
05-07-2006, 07:55 PM
The DS1602 is a RTC from Dallas Semiconductor.
05-08-2006, 02:29 AM
Sorry, I re-checked your schematic and last night my eyes transposed the 02 to 20...I thought you had the DS1620.
Parallax Tech Support
05-09-2006, 06:57 AM
I found a 12V 23A N cell that seems to work fine. Thanks for the help. In the next couple of days I'll post the whole project.
05-09-2006, 08:40 AM
Just a friendly reminder. If/when you post your completed project, please do so in the "Projects" Section of this forum, as that's where folks will go to look for it. Thanks!
Post Edited (Bruce Bates) : 5/9/2006 12:50:23 AM GMT