Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [discharge]

The process of removing energy from a store, such as a capacitor or battery. Stores may be parasitic, resulting in rapid spontaneous accidental discharge, as in a static shock.

Discharging is the opposite of charging. An energy store is discharged when energy is removed from it. Discharging can be partial or complete, purposeful or accidental.

442 questions
44
votes
4 answers

At what voltage is a NiMH battery empty?

I have a battery pack of NiMH batteries. It is ten cells with 1.2V, 4000mAh each, put together in series. So rated voltage is 12V. After charging, i.e. when the charging device says that it is finished, I measure 14.3V. When I now discharge, at…
Till B
  • 541
  • 1
  • 4
  • 5
28
votes
6 answers

How to Calculate the time of Charging and Discharging of battery?

How do I calculate the approximated time for the Charging and Discharging of the battery? Is there any equation available for the purpose? If yes, then please provide me.
Farid-ur-Rahman
  • 1,011
  • 6
  • 22
  • 34
27
votes
4 answers

How do I calculate how fast a capacitor will discharge?

Say I have a 1F capacitor that is charged up to 5V. Then say I connect the cap to a circuit that draws 10 mA of current when operating between 3 and 5 V. What equation would I use to calculate the voltage across the capacitor, with respect to time,…
PICyourBrain
  • 3,695
  • 10
  • 41
  • 55
25
votes
4 answers

How can I quickly and safely discharge a charged capacitor (small and low voltage; <= 42V)?

I am learning how to use capacitors (ceramic and electrolytic from 1pf - 1000uf) and am trying out various experiments using a breadboard. I am constantly adding/removing things to my layout to see what happens... but waiting for a capacitor to…
glenneroo
  • 439
  • 2
  • 6
  • 13
20
votes
11 answers

How to safely discharge oneself

At work I have the problem that I seem to collect a lot of static charge as soon as I leave my desk and return. I am not quite sure why this happens. Strangely enough the effect is stronger the briefer I am away. Since I work with electronics being…
Karsten
  • 419
  • 5
  • 13
15
votes
5 answers

Is it safe to discharge Li-Ion to 0V?

first of all: I know that a completely discharged battery is damaged permanently. I know it experiences irreversible chemical changes. I know it might blow up if you try to charge it. But that's not at all relevant to my question: Is it safe to…
xsrf
  • 461
  • 1
  • 3
  • 7
14
votes
6 answers

Understanding voltage and current

While reading "Electronics for dummies" went through the following block and I realised that I have some uncleared concepts about electricity: Electrostatic discharge involves very high voltages at extremely low currents. Combing your hair on a…
Firdous
  • 307
  • 1
  • 6
13
votes
3 answers

How much do lithium polymer batteries expand in volume?

I'm designing a device with a small lithium polymer battery (4x12x30 mm, 120 mA-h). Looks like this: I've heard that there is a rule of thumb that the space left for the battery in a case should be around 10% larger (I suppose primarily in…
Alex I
  • 3,341
  • 2
  • 36
  • 59
13
votes
3 answers

What is a safe max. discharge rate for a 12V lead acid battery?

I've got a 12V 2.4Ah lead acid battery which I plan to connect a water pump to. I've looked at various pumps, but the one I'm most interested in draws 2.2A. I'm not so interested in how long the pump can run, as it only will need to run for about 5…
sbrattla
  • 636
  • 2
  • 10
  • 19
10
votes
2 answers

Properly charging and discharging Lithium cells during battery testing?

I'm working on some software that automates charging and discharging battery cells to generate discharge curves. I have a few concerns about properly charging and discharging of lithium-ion / lithium-polymer cells: Concerns: I understand when…
Rob
  • 291
  • 1
  • 11
10
votes
5 answers

How does corona ring help against corona discharge?

Corona discharge is flow of current from the electrode to the outer air. Corona discharge happens (among other) in high-voltage power lines. One way to reduce corona discharge in this case is using so-called corona rings - that's just a ring made of…
sharptooth
  • 12,374
  • 26
  • 83
  • 144
10
votes
2 answers

What is 1C charge/discharge rate in battery instruction manual?

Instruction manuals and discussions mention battery charge and discharge rates in terms of "1C", "2C" and so on, without giving an indication of what "C" is. I presume it is not a Coulomb. What is readily available for most batteries or battery…
user40966
  • 111
  • 1
  • 1
  • 4
9
votes
1 answer

Constant power discharge of a non-ideal capacitor

My employer sells boost converters to hold up motor drives during power loss. These boost converters are fed from capacitor banks. In order to size these banks correctly, we need to take their voltage, capacitance, and ESR into account, to ensure…
Stephen Collings
  • 17,373
  • 17
  • 92
  • 180
9
votes
5 answers

Why do most battery protection circuits have 2.5V discharge cap?

I was looking for a battery charge- discharge circuit from ebay, and most if not all, state to have overdischarge protection voltage at ~2,5V. Isn't this way too low? By my knowledge Lithium batteries (LiPos in this case) can only be brought to…
Elmore
  • 225
  • 3
  • 7
9
votes
5 answers

Battery balancing circuit

I am facing the following problem. I need to power my device (RC airplane) with 2 separate battery packs 12 V each in order to extend the capacity. Connecting them in series will not work, as the power stage is not prepared for that. When I connect…
Łukasz Przeniosło
  • 1,619
  • 1
  • 19
  • 37
1
2 3
…
29 30