The cell-battery tag has no wiki summary.
4
votes
1answer
62 views
Is it ok to power several op amps with the same pair of 9V cells?
I'm experimenting for the first time in the wonderful world of operational amplifiers. I'm processing signals in various ways - amplify, envelope detection, voltage differences, voltage-to-current, ...
8
votes
1answer
82 views
Arduino: Measure external voltage
I have a "problem" while trying to measure the external voltage from a coin cell. I have simplified my circuit, but basically I have a DS1307 real time clock powered by the Arduino 5v output, and a ...
-5
votes
0answers
51 views
Measuring voltage change between two separate circuits [closed]
Is it possible to measure a voltage produced from one circuit in another which is powered by a different cell / power source.
To give a simple example, is it possible to have a potential divider on ...
-1
votes
1answer
336 views
Charger specification of 3000mah battery
I am planning on making a USB charger for my Tablet whose battery is of 3000mah. What should be the output current and voltage required for the charger? Is there anything else other than the output ...
2
votes
2answers
122 views
AA cell for low power embedded system -Debugging help needed
I am using AA LI cells for an embedded system project.This is a low power embedded project with various modules consuming current in pulses.
Recently one of the prototype board stopped working. ...
17
votes
2answers
1k views
How is wristwatch with 10 years battery life possible?
Turns out Casio offers a handful of wristwatches with "10 year battery life". The claim is that thanks to "an advanced technology" the battery life in those watches is extended to ten years.
Now if ...
3
votes
3answers
341 views
Coin cell battery for Bluetooth?
I'm trying to determine which battery to use for my application. I'll be using a class 1 or class 2 Bluetooth (not low energy) module, which requires about ~50/60mA of RX/TX current. In addition, ...
1
vote
2answers
270 views
Consequence, effects and solutions - mobile-phone always connected to AC power
Would like to ensure that a mobile phone is always charged, without requiring manual intervention (s.a. disconnect/reconnect charger, switch on/off charger etc.). One thought is to put the phone ...
1
vote
3answers
2k views
Energy consumption when cell phone charger connected to socket but not to phone [closed]
When my cell phone is charged fully, it says 'Please remove charger from wall socket to save energy'. How am I wasting energy if the charger is connected to the socket but the phone is not connected? ...
0
votes
1answer
287 views
How I can to reduce 9V battery to 7.4V - it is for R/C model [closed]
What size of resistor I can use to reduce the 9V rechargeable battery to 7.4V output for R/C model please?
I would like to use rechargeable 9V batteries instead of 7.4V as it´s handy to go a grab one ...
0
votes
1answer
242 views
Using old notebook battery to power electric screwdriver
I have:
Dead notebook with live LiIon battery (HP HSTNN-CB50):
14.8V, 8 x 2500 mAh 18650 LiIon cells.
Rated at 73 Watt-hour.
I haven't managed to open the battery pack yet, but it's clear from the ...
1
vote
2answers
251 views
msp430 and LiFePo4 cell as supply
I want to use a LiFePo4 cell as a supply for the msp430. For this purpose TI developed the TPS61221. I'm wondering if that's really needed if I can guarantee that the cell voltage is between 2 and ...
3
votes
7answers
289 views
Effects of Pulsed vs Direct Current on Battery Depletion
I'm doing some work with a portable, cell-battery-based electronics and someone on the design team mentioned that pulsed current will more quickly deplete a battery than constant current, even if both ...
7
votes
3answers
682 views
Memory backup capacitors: why a capacitor?
Why would an engineer choose a memory backup capacitor instead of any of the types of rechargeable batteries available?
Their energy density seems far poorer, and they can't hold their charge very ...
0
votes
6answers
2k views
How to charge Laptop Li-ion Battery cells manualy?
I have received some Li-ion batteries which were originally used in Asus A2 Laptop battery original one and I would like to know if it is possible to charge each cells independently with some device ...
20
votes
3answers
1k views
Are coin cells a suitable replacement for AA batteries?
I am currently using AA batteries in my projects but would like to look at cell batteries for my next project, due to their compactness.
Apart from the physical appearance, how do cell batteries ...
