7
votes
How is it possible that "fiddling around with" batteries can apparently give them more power?
It is common for both the button contacts on the ends of a battery and the springy metal fingers that make contact with those buttons to get a thin film of oxide forming on them. It does not take much ...
- 15.1k
6
votes
Why is electrical energy most commonly stored in metal acid batteries?
Using hydrogen efficiently is difficult. If you burn it, you're typically back to IC engine efficiencies, i.e. catastrophically low. If you use it in a fuel cell, that usually involves rare metal ...
- 1,630
6
votes
Why aren't gravity batteries everywhere?
So, this battery costs US$70, weighs 406 grams, and holds around 200,000 Joules of energy.
To get the same energy from that weight as a "gravity battery" you'd have to pick it up over 49 kilometers ...
- 2,692
5
votes
Why lead was chosen as the metal for lead-acid batteries?
each electrochemical reaction involving a lead atom in a lead-acid cell releases two electrons into the external circuit, which means it has a relatively good extractable power-to battery mass ratio. ...
- 15.1k
5
votes
Why aren't gravity batteries everywhere?
Consider 1 kWh = 1000 W * 3600 seconds = 3,600,000 J.
1 kg lifted 1 m = ~10J.
Let's use 1 metric tonne. 1000Kg. So we get 10,000 J per meter of elevation.
3,600,000 / 10,000 = 360 meters. Around ...
4
votes
Accepted
Looking for a device that breaks the circuit if the voltage gets too low
The simple answer is that you can get off the shelf modules which does exactly what you want.
They are often called 'split charge modules' and are designed for installations like boats and motor-...
- 15.2k
4
votes
Do commercial fuel cells actually exist or it is just hype?
Fuel cells have hit the start of commercial success in Japan, where sales so far have been at least 120,000. Given they only became viable commercial products very recently, that's pretty good uptake.
...
- 3,771
4
votes
Specific energy vs Specific power in batteries
Batteries can't deliver unlimited current. Internal resistance, and limitations of the chemical reaction within the battery make that it can only deliver so much current. And the more current is drawn,...
- 1,194
4
votes
What is the best practice for ensuring the best possible connection between a battery cable and a battery terminal
We really need more info on the batteries and type of connection.
Will the connection be permanent? In that case soldering or welding are the best choices. If you're connecting to wire, you'll need ...
- 1,991
4
votes
Can lithium ion batteries solve the world's energy storage problem?
I would like to answer this question slightly differently.
The challenge with rechargeable batteries (Lithium Ion), each charge discharge cycle causes internal resistance of the battery to increase. ...
- 7,135
3
votes
Accepted
What is the capacity of a WWII Submarine battery in kWh?
Collecting bits from sites,
fleetsubmarines
World War II American fleet submarines had two batteries, each
composed of 126 cells. By comparison, a 12-volt car battery contains
only 6 cells, ...
- 4,249
3
votes
Accepted
Why lead was chosen as the metal for lead-acid batteries?
Lead acid batteries has been around a long time and is easy to manufacture. They are rechargeable, recyclable, and reasonably safe. AGM or Absorbent Glass Mat lead acid has the added benefit of being ...
- 8,226
3
votes
Why is electrical energy most commonly stored in metal acid batteries?
Cost per watt-hour of storage. Other means are either more expensive to manufacture, more expensive to maintain, or have shorter total lifetime increasing the amortization costs. The one viable ...
- 6,115
3
votes
Why is electrical energy most commonly stored in metal acid batteries?
One of the reasons why hydrogen isn't more widely used is that is extremely explosive requires great care when bein handled. It also needs to be stored away from naked flames or sparks.
The hydrogen ...
- 9,712
3
votes
Why do rechargeable Lithium Ion & Lithium Polymer batteries explode or catch fire?
Here is a good resource that has very detailed information about Li-Ion hazards:
Lithium-Ion Batteries Hazard and Use Assessment
(Lithium-Ion Batteries Hazard and Use Assessment. Celina Mikolajczak, ...
- 1,943
3
votes
Why aren't gravity batteries everywhere?
Are there some shortcomings that I am missing here?
Yes there are a couple of things you have missed.
Firstly I will deviate slightly from your question but I believe this is relevant.
The need for ...
- 318
3
votes
Why Sony headset's charging station doesn't charge other NiMH batteries rather than which came with it?
Looking at photos of the battery used in your headphones, I believe they use one of two ways to do this:
1- The cells are parallel in orientation, leading me to believe they are electrically parallel. ...
- 151
3
votes
Why Sony headset's charging station doesn't charge other NiMH batteries rather than which came with it?
Based on the information shared and available there mostly three more possibilities.
There is a make break switch that is triggered based on the battery packaging. Review the original battery package ...
- 7,135
3
votes
Why do modern diesel electric submarines predominantly use lead acid batteries?
Lead-acid batteries are reliable, robust, easily recharged, and exhibit almost zero fire risk. Mass on a submarine is pretty much irrelevant.
- 4,249
3
votes
Why do modern diesel electric submarines predominantly use lead acid batteries?
A) Specific energy isn’t so important for submarine batteries since ballast is needed
Counter: This doesn’t account for space, which is vitally important, and lead acid batteries have relatively poor ...
- 2,477
3
votes
Accepted
How much force needs to be applied on a battery cell to maintain contact?
Here are some examples from Lee Spring that could be useful. All the AA size springs listed have 1.75 lb nominal load.
Source: https://www.leespring.com/battery-springs
- 1,551
3
votes
Why do I not get zapped when I hold my fingers on each end of an AA battery, like 3R12 ones?
with dry fingers, your skin represents a high resistance to the flow of electricity and so very little of it flows along your skin. In addition, there are no nerve endings right at the surface of the ...
- 15.1k
2
votes
Why do rechargeable Lithium Ion & Lithium Polymer batteries explode or catch fire?
The chemical inside the battery begins to heat up, which causes the degradation of the separator. The battery can reach a temperature of more than 1000 degree F. At this point flammable electrolytes ...
2
votes
Accepted
How much of a battery needs to be replaced for it to be a fresh battery?
One plate is lead, one plate is lead dioxide. Hand-waving a big: sulfuric acid dissociates in water, making a lot of hydrogen sulfate ions. The lead plate reacts with the hydrogen sulfate to make lead ...
- 3,565
2
votes
How much of a battery needs to be replaced for it to be a fresh battery?
In theory yes (although what you would actually need to change isn't the electrolyte as such and may very well not be a fluid depending on the battery type), however you are effectively changing most ...
- 15.2k
2
votes
Torque and Speed of a DC Motor with Pulleys and Wheels
Maximum speed is affected by air drag, rolling resistance and power of the motor.
The force pushing the skate is simple to calculate:
$$ f_a = k_m{ P \over v }$$
Where $P$ is the power output of ...
- 131
2
votes
What tools to use for a solar powered backup?
It sounds like what you are after is increased energy security. You want a backup which would have a very low load factor - it wouldn't get much use each year. You want fast response, times of high ...
- 3,771
2
votes
Battery Swapping in Electric Cars
Advantages:
Minimal turnover time
Simple, standardized connection
Disadvantages:
Varying "remaining life" in batteries
Overhead of disposing of spent batteries
Needs standardization (or better, ...
2
votes
Questions regarding CR-P2 battery specification
The mAh is a unit for measure of energy dished out by 1 ampere flowing continuously for 1 hour. It's a measure of the capacity and strength of battery over time. So 100 J of energy should count when ...
- 201
2
votes
How would I measure this battery circuit with a multimeter?
If you trying to measure voltage, connect the black connector probe (Terminal) to COM. Move the rotatory switch 20 DCV. The dot should point to 20 DCV. Then place the black exposed probe to negative ...
- 7,135
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