Questions tagged [battery-chemistry]

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42 views

How much energy do Li-Ions/Li-Pos have below 3.2V threshold?

How much energy does a battery still have when a protection chip disconnects it? I know that such discharging kills the battery, but in some cases it would be useful. For example, in drones: when you ...
9
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2answers
376 views

Can copper-zinc be substituted for silver-zinc?

Silver-zinc batteries are in the news (the pop science news) these days because they are being researched to compete with lithium ion batteries. But the price is high because silver is expensive. So ...
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2answers
2k views

Electrical neutrality between electrodes of galvanic cell: why is it necessary for current flow?

I know that as electrons move from anode to cathode through wire in a galvanic cell, there remains in the anode +ions (Zn for example) while - ions are created in the cathode. Afterwards a salt bridge ...
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3answers
271 views

Is there such thing as a 9V NiMH battery with 600 mAh?

I want to buy some NiMH batteries for a meter, the stocked NiMH that comes with the meter is 9V 300 mAh NiMH. Looking on eBay I found several NiMH batteries which appear to be 600 mAh, here is a link ...
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1answer
3k views

Is it ok to use a 10 years old set of NiMH rechargeable AA batteries? [closed]

I've just found my 10 year old pack of rechargeable NiMH AA and AAA batteries. The AAA ones are completely blown with a dark powder all over their positive terminals. The AA ones look fine when ...
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1answer
139 views

Discharge Behavior of a Battery

I am working with a zinc air battery (emf 1.3 V). I have plugged a resistance of 100 ohm to this battery and I have recorded the voltage at the battery. When the circuit is opened, the voltage is 0. ...
57
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1answer
20k views

Duracell PowerCheck - How Does It Work?

I've been using these batteries for a long time and I've never seen such a feature. There's a band on its outer wrapping having two ends: The white circle on the left side and the another one on the ...
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2answers
283 views

Estimating Li-Ion (or any other type) battery resistance

I have a Li-Ion battery cell, with a given datasheet providing the following discharge curve: I thought to estimate its DC impedance (resistance) by, at a given capacity, making the ratio between the ...
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1answer
2k views

Battery capacity: Says 12V18Ah/20Hr - how do I interpret that?

I have two sealed lead-acid batteries in parallel that have that inscription on the sides. They power multiple 10W (Actually, 7 on the meter) PIR lights all night long, as required. That ...
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1answer
82 views

Battery voltage quickly drops when measured

I have a 9V battery that has around 9V when I first apply the probes for a multimeter. However, if I hold the probes on it for a few seconds, it starts dropping... about 0.10 V per second. And it just ...
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3answers
728 views

Why do lead-acid batteries fail after about five years of operation?

I had some time ago a failure in the batteries of my UPS. The UPS periodically performs a self-test of the battery, and it failed, causing all the computers behind the UPS to shut down. The batteries ...
3
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1answer
2k views

Do brand new rechargeable batteries have a charge?

When a standard Duracell AA battery is manufactured, it contains all the charge it will ever have (right?), and can't be recharged. But, for a rechargeable battery like a NiCd AA battery, or a ...
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2answers
398 views

Modular 18650 battery pack - using differnet chemistries?

I have been building an 18650 based battery pack for our new motor home and have run into a few snags that I cannot find answers for. Some issues have been addressed on this site but I am going to ...
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0answers
100 views

Simultaneous Cathodic Protection and 4 Wire Resistance Measurement

I am making an electrical resistance sensor for erosion rate measurement using the Arduino. Since my sensing element is a thin strip of carbon steel, I have to ensure that it is protected from ...
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1answer
116 views

3.7 V battery compatiblity?

Can I use 3.7V 400 mAH battery instead of 3.7 V, 520 mAH, 2.00 W ? How much difference it can make ? Sorry not more techical sound here... Thanks !
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1answer
846 views

What is difference between Qmax and Design Capacity of battery parameters?

I'm working with the BQ27742-g1 (Texas Instruments) Fuel Gauge. I have some confusion about battery parameters. What is Qmax and Design capacity? Are they the same or different? What is the ...
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1answer
49 views

bulid 12v switch off circuit

i have a tv that works on 12v dc and also 220v Ac. i can attach both power cables. I run it on the 12v battery almost of the time but some times the 220v electricity is back so i have to make it work ...
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1answer
1k views

Why battery charge C rating is usually lower than discharge

Why most (or all?) batteries can be discharged at an higher C rating than the charging C rating? For example I have the following battery for my quad-copter: https://hobbyking.com/en_us/turnigy-...
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2answers
293 views

Deciding on lithium battery chemistry, lithium ion (protected) or Lithium Iron Phosphate (no protection) Safety is critical

I am designing a product requiring high power and energy storage capability. I have narrowed down the selection to two (most cost effective) systems: a 3s system of protected 18650 lithium ion cells (...
3
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1answer
2k views

Is a battery's internal resistance a function of integrated current over time?

I've got a question regarding the internal resistance of a CR2032 coin cell. Here's some background info on the project I'm working on: I'm working on an electronics project in which I hope to have ...
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2answers
170 views

9V Battery gauging

I need to gauge a 9V alkaline battery to display using a MCU and a LED when the voltage drop below a certain treshold. I checked on TI website most of gas gauge are for lithium battery. We have ...
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1answer
218 views

Do high-temperature rated coin cells exist?

I'm currently working on a project that will implement a coin cell as its primary power source. My PCB will likely be exposed to high temperatures ranging from 100C upwards. Now I realize that I will ...
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2answers
667 views

Li-ion Battery Rejuvenation

What can be done to repair or restore an ageing/dead/failing Li-ion rechargeable battery? As they get older; they typically, gradually lose their capacity to hold a charge. What physical and/or ...
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3answers
3k views

Why does the voltage of vinegar batteries in series not equal the sum of the individual voltages?

I'm working on an in-class demo / hands-on for my sons primary school class, and I've made some small batteries with New Zealand 10 cent (copper coated) coins, and zinc washers, and vinegar soaked ...
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0answers
46 views

How to Recognize a Battery's Technology [duplicate]

Given a battery of unknown chemistry and unknown origin, how to I tell it's a rechargeable alkaline manganese, NiMH or NiCd battery by looking at its electrical or physical properties, eg. maybe they ...
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2answers
1k views

Slightly bloated LiPo; still save?

I am using lithium polymer batteries without much internal protection, as is common in RC planes and such (weight constraints). I have noticed that some of the older ones feel like they built up some ...
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1answer
2k views

How does charge/discharge current increase battery temperature?

I already know that charging or discharging a battery causes it to heat up, and that increase in heat is proportional to the current. But what physical process is behind this? My back-of-the-envelope ...
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1answer
933 views

Using a fruit or salt-water battery to power a motor

I´m trying to build a fruit or saltwater battery to power a motor. From my 8 cell saltwater battery connected in series, I get a reading of 5V or so and 2-3A... but it won´t fire up my 5V DC motor. ...
0
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1answer
142 views

Understanding Li-ion Battery(ICR18650-26H)

I trying to use a Li-ion Battery in my project. ICR18650-26H is suitable for my project(GPS data logger) I think. I am having hard time understanding one particular parameter in the specification ...
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2answers
700 views

Battery discharge current

What is the meaning of standard discharge current mentioned on the datasheet of lithium batteries. Does it represent the maximum current load can take or it represent the instantaneous current battery ...
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3answers
412 views

Car battery capacity in colder countries

The capacity of the battery is affected when the temperature drops, particularly Lead-acid batteries. So how in cold countries this situation is solved. In this PDF about automotive batteries at low ...
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1answer
54 views

Using other Lithium based batteries

My question pertains to different types of the Li-ion batteries currently available. http://investingnews.com/daily/resource-investing/energy-investing/lithium-investing/6-types-of-lithium-ion-...
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2answers
289 views

Why do batteries have a short lifetime despite having no moving parts?

Chemical batteries do not seem to have any moving parts, but seem to have a rather short lifetime anyway. Why is this? The only reason I can think of is electrolyte leaking, but I have never noticed a ...
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1answer
847 views

Li-Ion pulse discharge to improve output characteristics

There are many scientific studies done on pulse charging of Lithium-Ion batteries. However, I have found nearly none on pulse-discharging those. Here is probably one of the few-ones. This study ...
1
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1answer
84 views

Old 9v battery - Strange Behavior

The battery in my garage door remote finally quit. Before replacing it, I measured the voltage with a digital multimeter and was surprised to find it reading 9.70v, quite a bit higher than the ...
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3answers
9k views

Charging a battery with float voltage

Is it possible to charge a lead acid battery(12V) with float voltage(13.6V) instead of charge voltage(14.4V)?I understand it will take lot of time to charge if we charge with float voltage.
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1answer
91 views

Does the positive pole of an an electrolytic capacitor act as a cathode when discharging?

As far as I know, the anode of a polarized device is defined as the location where the oxidation occurs. For a galvanic cell, this means that it corresponds to the negative pole, while for an ...
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1answer
478 views

Equal charging of new and old battery [closed]

I am using four "12volt" batteries of 150 amp hour each, for a 24 volt solar backup system of ouyback things since four years. Now i add 4 new batteries of same capacity to increase the backup time ...
0
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2answers
947 views

How could a rechargeable battery charge itself without an external source?

While I was working on my graduation project I had to charge a rechargeable battery then discharge it and so on.I was shocked when the battery charged itself without any other external sources for ...
2
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1answer
88 views

at what temperature does it become expeditious to use a lithium battery's charge to heat itself?

battery capacity diminishes the colder the battery gets. Is there a point where it's worth using the battery's energy to warm it up, increasing capacity? If so, where's the break-even point? If not, ...
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2answers
130 views

Are there any battery chemistries that can be fabricated at home?

My question is simple. How hard it would be to fabricate a Battery of customized shape say of 30cm x 30 cm x 0.5 cm that can be fabricated by DIY without requiring any specialized/ hazardous chemicals ...
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1answer
66 views

NiMH 1.2V 1/3 AA 280 mAh is it possible the claim made for size and capacity?

I am browsing some batteries to use for a wearable project.Initially I wanted to go with Lipos but upon stumbling upon this link I am amazed at NiMH and the variety of size, shape and battery capacity....
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2answers
631 views

avoid Li-Ion batteries explosion

As a student group project, we are going to use Li-Ion batteries to test our charging and balancing circuit. These batteries at risk of explosion. How should we avoid that danger? Is there any ...
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1answer
4k views

Charging NiMH batteries with 1W solar panel, charge controller needed?

I want to know if a charge controller would still be needed despite the solar panel never outputting more than C/10 of current to the battery. This is a follow-up about my question here. The solar ...
5
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2answers
6k views

what is the Outer casing of alkaline battery made of?

what is the outer casing of a typical small 9v alkaline battery made of? Is it conductive?
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1answer
81 views

custom battery for CO2 generation

I want to design a small, cheap device that generates CO2 but I also want to capture the voltage to drive an LED. Any advice about which half-cell reaction I should use (oxalate?) or battery design. I ...
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1answer
322 views

Eneloop rechargable batteries for mouse? [closed]

I have a Apple Mighty Mouse, and I want to use rechargeable batteries, but I read somewhere on such a device I should only use Eneloop rechargeable batteries as they hold a charge when the device is ...
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2answers
238 views

How does a laptop maintain battery at full?

I know how a laptop battery becomes charged, however, I am not so sure how the power is maintained when when the battery has been charged to the maximum. I am unsure whether the laptop would switch ...
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3answers
12k views

Best kind of battery for electric motorcycle? [closed]

I want to try and build a DIY electric motorcycle, but am having issues finding the right batteries to use. I've tried searching for this online but there is surprisingly little information about the ...
1
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1answer
142 views

What is the purpose/benefit of using different electrodes in the same circuit?

I've studied various science fields in depth for years it seems, and I have never been able to get an understanding of this fundamental idea. I understand the purpose of different types of electrodes ...