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7

One of the problems that plagued older rechargeable batteries (e.g. Nickel Cadmium ($\text{NiCad}$) and Nickel Metal Hydride ($\text{NiMH}$)) was the memory effect. The memory effect occurs when a rechargeable battery is not fully discharged. It then "forgets" that it has a greater capacity than it thinks it has, and so in the future it discharges less. A ...


6

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 catalysts, which are expensive and can be vulnerable to poisoning through contamination. By expensive, I mean platinum expensive, or even more exotic metals like ...


6

The part of the movie transcript you're talking about (taken from here) is where Fred Halse says: Batt B, no volts, amps are okay. Batt C, s***. No volts, only two amps. They may die before the main chutes open. To make sense of it, I think we need to ground ourselves with the real Apollo 13 and basic electronics. A battery can have zero volts across ...


6

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 into the air. There are applications where picking stuff up and powering things as it falls is useful -- the gravity-powered lighting for 3rd-world countries is ...


5

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. in addition, the charge/discharge process retains reversibility over a relatively large number of cycles, giving the cell a long usable lifetime. the materials ...


4

First of all it is highly unlikely that the one would find public information of major OEM cell phone manufactures battery charging methodology back by technical source and citations as this would be a breach of confidentiality. Having read your post and references I can safely assume that you have some understanding of rechargeable batteries and related ...


4

I am not familiar enough with your tests and your data to draw any conclusions from it. Perhaps if you infer your own conclusions citing specific parts of your data I would be able to follow better and see if your conclusions are sound. I am not sure if the data you are seeing is significant or just noise in the testing process. I am also not an EE so EEs ...


4

The slower you charge a Lithium battery the better. They are not keen on very fast charge/discharge fluctuations. One reason is that faster charging also results in higher temperatures which stresses a battery and therefore reduces battery life. Another reason is that lithium plating might occur, where the transport rate of the Li-ions exceed the rate at ...


4

I don't believe periodic charging would damage a smartphone, however it likely wouldn't charge it much either. A typical phone charger today outputs 1 Ampere of current at 5 Volts, and takes perhaps 2-4 hours to charge a phone. At 0.1 Ampere or a tenth of this current, it would take ten times as long to charge the phone. It would actually be longer since the ...


4

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-homes which have batteries charged off an engine alternator but prevent the starter battery form being fully discharged. This is one example http://www....


4

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, the bigger the voltage drop will be because of above mentioned reasons. Specific power (W/kg) and capacity, specific charge or specific energy(Wh/kg or J/kg) ...


4

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 a thousand feet. Ok. Getting a 15 cm diameter well dug and cased is on the order of \$20/foot. So \$20,000 buys you a 1000 foot deep hole. Use whatever ...


4

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 good strain relief. Any repetitive motion at the solder joint / weld will cause failure eventually. In a vehicle the battery may have a tendency to jostle around....


4

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. This causes the usable life of the battery to decrease. Therefore if the rise internal resistance over time is decreased or fully resolved then the Lithium Ion ...


3

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 alternative currently is pumped storage power plant, but it doesn't scale nearly as neatly for smaller amounts - it needs to be huge to be economically viable. ...


3

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 atom is the smallest atom and as a H2 molecule it is still extremely small. Being so small, hydrogen molecules can pass through the walls of their containers ...


3

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. They're generally being used there as domestic CHP systems. There are still open questions about their long-term reliability. So yes, they've grown beyond ...


3

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, et al. July 2011. Fire Protection Research Foundation) I will summarize it below: What is the chemical composition of Lithium Ion and Lithium Polymer battery?...


3

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, each producing about 2.25 volts when fully charged, with a maximum power output of about 45-50 amps. Each cell in a submarine battery produces from 1.06 volts ...


3

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. The IC could be matching them somehow, or perhaps the voltage is slightly different, as the eneloops are low discharge cells. the second, more likely scenario: ...


3

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 as well as the housing compartment for specific mechanical features associated with a trigger. Below are some battery packs that are similar to original. The ...


3

Lead-acid batteries are reliable, robust, easily recharged, and exhibit almost zero fire risk. Mass on a submarine is pretty much irrelevant.


3

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 energy density. From Appendix: Calculations for a full 70-day mission on one battery charge: A generic 3000-tonne diesel electric submarine showing ...


2

My input current is 300 milliamps and I am not sure if that will be enough to charge my phone's battery.* It will probably charge acceptably. This varies with product but in most cases modern cellphones and other products which use 1 or 2 cell LiIon (Lithium Ion) batteries will charge from sources that supply less than maximum rated charge current. Rather ...


2

1st suggestion would be to find a sturdier cover for the battery. However, it sounds like it might just be badly positioned. Can you move it, rotate it, flip it (if it's an AGM type that will work at any angle) to put the terminals away from harm? Failing that, can you put some solid plastic or other insulator over the top of it, snugly, so it can't be ...


2

Tilt the battery at a slight angle away from the seat so that the seat doesn't touch the terminals. You should be able to get away with small tilt angles without having the battery leak (assuming lead-acid), at least during use. You may want to remove the battery in between uses though.


2

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 can ignite or even explode when exposed to oxygen.


2

IBM/Lenovo ThinkPad line is basically the only manufacturer/brand of mobility devices that includes circuitry and software that allows one to vastly prolong battery life of laptops used as stationary workstations by making sure to never charge the battery prior to it being discharged to below 96%, and having options to start charging only when the battery ...


2

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 power, and a decent amount of storage. But it sounds like you don't need absolute continuity of power - it's ok if power goes out for a few seconds. Almost all ...


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