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Questions tagged [batteries]

An electric battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy

2
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2answers
121 views

Reserve Capacity Testing On Lead-Acid Car Battery

All car batteries have Reserve Capacity ratings instead of Ah ratings for deep-cycle batteries. Using this data to test the health of the car battery a good way to estimate life left? Let say I have ...
0
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1answer
41 views

will dc converter discharge battary?

I am using a mini-360 dc-dc converter with arduino pro mini, so will mini-360 discharge battery without any load? Is it correct to use power switch as on image?
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0answers
21 views

how to make rechargeable 2s2p 7.2v configuration with tp4056?

I am using NCR18650 li-ion batteries I need to make 2S2P configuration get higher capacity and 7.4V the same pack I need to charge with TP4056 modules. also, I am using B0505S voltage isolator as ...
0
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2answers
47 views

What determines if a battery is charging or discharging in a circuit?

I have a basic understanding of DC circuits from high school and university physics courses, but those courses only covered circuits that discharge batteries. I'm trying to build an rudimentary ...
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0answers
29 views

Using a laptop battery with a buck converter with current limiting

I am building a smartphone-powered laptop similar to this. The case is an old HP Pavilion DV4000 that I got. I would like to use its battery for this project, because laptop batteries already have ...
2
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0answers
28 views

Advice for a Solar Charger and Battery Project

I am a high school robotics teacher (no formal engineering training) and I am taking a group of students to Kenya this summer to work with high school students there. The organization we are ...
1
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1answer
59 views

What is the minimum charging current for NCR18650 li ion battery?

I need a rechargeable battery pack for my project, I need to know what is the minimum charging current for NCR18650 li-ion battery? In the datasheet, it says max charge current is 2A. what is the ...
1
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3answers
234 views

Is it OK to reduce the charging current for a Li-ion 18650 battery?

I am using NCR18650 batteries with the tp4056 charging module. When I connect the charger at 2.8 V (fully discharged), the tp4056 IC is getting hot at a 1 A charge current. Is it OK to ...
2
votes
1answer
27 views

Safe to add large external batteries to APC SMT2200RM2u?

I recently got a very good deal on a refurb APC SMT2200RM2U battery backup. The unit seems to be in perfect working order, however the seller either gave me really cheap or old batteries. The ...
0
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1answer
82 views

Battery voltage increase after load

I have a GEL battery 225Ah. After fully charging it, it holds a 13.1 - 13.0 volts after 24 hours. I tried to put it on load (20 watts light) for 2 hours and voltage droped to 12.5 volts. I know that ...
1
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3answers
70 views

powering an old 9V multimeter with a 6x AA battery pack

I have an old Nimex NI2100 multimeter that is working fine with 9V batteries. Btw i'd like to power it with 6x AA batteries instead so i've bought a battery holder and wired like this: I've checked ...
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0answers
80 views

is it OK to use battery while charging? [duplicate]

I am using the tp4056 module with protection to charge NCR18650 li-ion battery. is it OK to connect to the load to the battery while it is charging? I am using a booster to boost 3.7V to 9V(load ...
0
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1answer
47 views

Can I charge this li-ion battery with this solar panel setup? [closed]

Since a couple years I've been messing around with a raspi and some motors. Building random stuff with dc-motors and such. I now want to power a self driving boat-robot with some solar power. For this ...
2
votes
1answer
30 views

Battery choice: Effect of “pulse current” and “continuous current (maximum)” rating differences

I am trying to understand the consequences (if any) of substituting a CR2450 battery for the specified CR2340 lithium battery in a small device. The device is constantly "on" and transmitting a ...
1
vote
1answer
46 views

Measure battery pack cell voltages with analog multiplexer and instrumentational amplifier

I'd like to measure the voltages of individual lithium based cells (LiPo, LiIon, LiFePO4) in a battery pack (up to 4 cells in series), using an ADC. I was thinking about the following approach, using ...
0
votes
1answer
34 views

What happens to the backup time when batteries are connected in series?

I have a backup power system consisting of a charger, a battery and an inverter. The inverter powers my load (a few mains appliances). Currently I am using a 12V 200 Ah battery which gives me a backup ...
0
votes
1answer
29 views

240v dc connected to 24v dc battery bank

1.I connected my 3 phase ac pma generator/hydro turbine to a 600vdc rectifier. As I opened the water nozzles the generator produced from 38vDC to 213vDC.How do I connect to my 24vDC battery bank ...
3
votes
1answer
42 views

Voltage drop on batteries when connected to ups/inverter

I have recently installed a solar system and trying to understand the voltages of batteries when they are being charged and when they are providing power to load. Here is what I observed: I have 2 ...
1
vote
1answer
23 views

Electron transfer and thermal efficiency in series vs single battery?

If you have 10 batteries in series all generating 5W, does every battery in the series have the same temperature as a single battery drawing 5W? I have trouble visualizing how the electrons travel ...
1
vote
1answer
54 views

Reverse Current leak Battery+Diode in parallel

on my design, I am using two coin batteries in parallel and each battery has a Schottky diode in series to block the reverse current, in theory, it will avoid the higher potential battery "charge" the ...
1
vote
0answers
33 views

Sense resistors in system-side Li-Ion charger/gauge circuit

I'm working on designing a charger and fuel gauge circuit for a premade 3S3P Li-Ion battery pack. The battery pack has basic protection circuits onborad (over/undervoltage and a PTC) and only the pack ...
0
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2answers
58 views

Drop 0.7V using a diode for use of a lithium battery with a 3V mouse?

I plan to use a rechargeable lithium 3.7V battery in my wireless mouse, which takes 2 AAAs. As I understand it, I could theoretically drop 0.7V using a diode in series with the mouse, but would it be ...
1
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1answer
44 views

Measure capacity of Lithium by Coulomb counter method while charging

I'm learning to design a module to measure capacity (percent left) of ebike Lithium battery. Lithium cell ' specifications are 48V-13Ah, it's built from cell pin 18650- 2600mAh. I choose the Coulomb ...
0
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0answers
17 views

LiIon battery discharging

I have a question regarding LiIon battery discharging. Lets say I have a battery which is connected to a dc bus via a battery charger which has a bypass contactor in parallel. The charger is ...
7
votes
3answers
2k views

If a lithium cell is said to have a capacity of 20 Ah, does that mean all 20 Ah can be used?

Toshiba's SCiB 20 Ah Lithium titanate cell is said to have a nominal capacity of 20 Ah. The cutoff voltages are 1.5 V and 2.7 V. Does this mean that all 20 Ah of charge exist between those two cutoff ...
0
votes
1answer
89 views

Where do I place the on/off switch in a multi voltage circuit?

I've got a simple Arduino setup where I need to supply a 3.3V Arduino with adequate power - and at the same time provide higher voltage to a sensor which needs 5V. The Arduino is powered by bypassing ...
1
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2answers
107 views

How to measure the battery voltage while charging

I am designing a battery charger with 48 volt 10 amp output. I am controlling the buck converter pwm using PIC controller. During charging the battery's current and voltage have to be constantly ...
0
votes
0answers
27 views

Backup battery convert 3.6v nicad to 3.7v li-ion non-rechargeable

Have a slot machine MPU backup battery 3.6v nicad. Would like to replace w/ 3.7v li-ion and NOT have the battery charge. Was thinking I might be able to insert a diode in line with the battery to ...
0
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0answers
29 views

charger design for 48V 20Ah lead acid battery

I have to complete project of battery charger for 48 V 20 Ah Lead acid battery having 5 A max charging current. I have designed boost pfc using UC3854 and buck converter . Output of buck converter is ...
1
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0answers
26 views

Battery Powered System and Input Capacitance

I have a battery powered system in which the battery is connected to a buck/boost converter to derive 3.3V from two or three AA batteries. The regulator I'm using is a TI TPS63050, and it has a power ...
1
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0answers
51 views

How to disconnect 3.7V battery when USB is connected (boost)

I am developing a circuit which enables me to charge a lithium battery and boost the output voltage up to 5V for a microcontroller. My boost converter is the MT3608, and the charging circuit is the ...
1
vote
1answer
106 views

--Electric Bike— How to measure left percent of battery?

I intend to make a module to measure battery of the electric bike instead of using the bike's indicator. Measured battery (VRLA) is 48V, 12Ah. As I know, the specifications of an battery are voltage(...
2
votes
1answer
98 views

Actual lifetime of 18650 cells

For a project, we are currently looking at how long we could use battery cells, such as the LG 18650MJ1 at maximum discharge and maximum charge in 25°C ambient temperatures. Basically, in this case, ...
0
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0answers
30 views

Continuous Current Rating in Lithium Battery Cells

What is the implication of running at/near/above the max continuous current rating for a cell? Is it only an indicator of cell heating (I2R losses), and if I maintain cell temperature through cooling, ...
2
votes
2answers
63 views

What is the difference between these two battery setups in parallel?

I have a couple of batteries with original main feeds connected to them. I want to add another battery in parallel, without touching the main feeds. Setup 1 in the image below shows the current setup,...
-1
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1answer
64 views

9v battery made from 3 18650 cells not working properly [closed]

I am trying to make my own 9 volt battery from 18650 cells. I have 3 cells (Samsung INR18650 35-E) in series and have a voltage divider (7k and 15k resistor) at the end. When I measure the voltage I ...
3
votes
0answers
55 views

Power use question for a trail camera

I am trying to calculate how long that a trail camera can be deployed before the batteries run out. The trail camera in question is a Reconyx HyperFire 2. Here is a useful review of the trail camera ...
0
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2answers
60 views

Brightness when using 3.7v battery for powering 6 LEDs rated at 5v in a series

I am using 6 LEDs in a series (APA102C spec) these specifically powered by some atmega chip, and am having trouble finding a sufficiently small battery that will allow me to run the LEDs at maximum ...
0
votes
1answer
47 views

Can I use a MPPT Solar Controller to charge my auxillary 12V AGM Battery from the car battery/alternator?

I have a RedArc solenoid and a Victron 75/15 Smart Solar Controller. Can I use the combination of these two units to charge an 12V AGM Deep Cycle auxiliary battery from the car battery/alternator ...
0
votes
1answer
56 views

Connect multiple 3.7 V Lithium-ion Polymer Battery in parallel [duplicate]

If I connect 2 1000mAh battery in parallel would I get 2000mAh over 3.7V? https://www.aliexpress.com/item/1000mAh-3-7-V-Lithium-ion-Polymer-Battery-102050-For-MP3-MP4-MP5-GPS-KTV-Household/...
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0answers
33 views

Powering refrigerator using solar inverter

I have got a 3 kVA (2400 watt) solar hybrid inverter (pure sine wave) which is connected to a 1280 watt PV array and 2 x 12 volt 150 Ah batteries. It is supposed to switch to utility mode if the ...
0
votes
0answers
59 views

How can I connect many brushless motors to a big battery pack instead of using a separate small pack for each motor?

Usually brushless motors comes with indications on how many batteries you can connect to them, it is common to to see 2x3 battery packs where each battery provides 3.6 Volts or so to power a single ...
0
votes
1answer
38 views

Battery Protection IC in Series

I want to make a project to protect each individual cells of 16 series battery pack. I have read some data sheets of battery protection IC's such as BQ29209DRBR,S-8261,AP9281 etc. None of them clearly ...
0
votes
0answers
11 views

Cannot set battery profile on LC709203FQH-01TWG

I'm using a LC709203FQH-01TWG Battery fuel gauge. I can read the data provided by the IC, like temperature, voltage, RSOC (Relative state of charge), etc. I can also modify the temperature value, but ...
0
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5answers
149 views

Can a 9 volt battery through your bloodstream kill you? [closed]

I usually try to do some research before asking questions on this site, but everything I've found has been contradictory. If I were to direct the positive and negative ends of a 9 volt battery ...
2
votes
2answers
94 views

Switch to battery when voltage supply drops certain threshold

I have made this circuit but can't quit make it work. Vext is my main supply from a car (9 - 14V) Vbat is 8 AA batteries (10 - 13V) Vout supplies power to a SMPS As it is now, supply "fades" between ...
3
votes
2answers
159 views

Why do alkaline batteries seem to leak (corrode) more frequently when installed in a device?

I know that dead batteries can leak and the alkaline ones are specially corrosive. Alkaline batteries self discharge even when not installed in any device. I've already opened a four battery pack ...
0
votes
0answers
57 views

Voltage for SAFE dismantling of a lithium ion battery?

I was wondering at what voltage i can SAFELY dismantle a lithium ion battery? Does it really have to be at 0.0 V to avoid short circuiting? I have tried connecting a load to discharge it but after a ...
-1
votes
1answer
48 views

Does battery wear depend more on EMF voltage (capacity) or terminal voltage? (charging full slowly vs. charging fast)

Let's say there are two identical Lithium-Ion batteries. (is it any different for Ni-MH batteries?) One gets charged at 0.1C until the EMF voltage (which is capacity-dependent) reaches 4.3V. The ...
1
vote
2answers
57 views

Possibilities for 24v Solar charging of 12v batteries in series and parallel with different Ah capacities

I have two 12 volt 200Ah lead acid batteries and two 12 volt 150 Ah lead-acid batteries. I have a 24 volt 50 Amp charge controller connected to a 150 watt PV panel (overkill for now, but ready for ...