Battery and battery operated devices' charging methods and problems encountered relevant to charging.
0
votes
1answer
56 views
Charging 12V/4A battery
Can I charge a 12V/4Ah sealed rechargeable battery with a 13.5V/500mA charger? If so, how much time would I need to charge it to 100%? If not, how can I charge the battery?
0
votes
3answers
119 views
Three-prong / USB power outlets in wooden desk [closed]
I am trying to mount a strip of three-prong outlets and a strip of USB charging outlets on an old wooden desk. I can handle the carpentry aspect, but I am struggling with the electrical aspect.
I ...
2
votes
2answers
87 views
What is the capacitor charging time when charged with a pnp current mirror circuit?
I want to use a 555 in monostable mode to make a ramp signal generator. The capacitor would be charged using a current mirror circuit.
Given a input voltage, what would be the charging time of ...
-1
votes
2answers
107 views
Multiple 2A USB Mains powered chargers [closed]
I'd like to know why there are no mains-powered chargers that can charge multiple usb devices at, say, 2A and 1A?
I'm after something that can charge 2 tablets that ask for 2A and 2 phones on 1A, so ...
1
vote
1answer
104 views
Can a phone battery be used to power Arduino or Motors
I was wondering whether it would be possible to use a rechargeable battery from an ordinary cell phone to power some electronics such as a motor shield for Arduino?
Can that be done and if yes then ...
1
vote
1answer
78 views
Disposable Camera Charging Circuit - Will it transfer a maximum amount of energy?
This may sound naive but I would like to build a toy coil gun. I have seen designs where a charging circuit from a disposable camera is used to charge a capacitor. What if I wanted to use more battery ...
5
votes
3answers
301 views
Calculate charge time of a capacitor through a current limiting power supply?
Is there a formula or a way to calculate Charge time of a capacitor given that it is charged by a current limiting power supply. This would lengthen the charge time but is there a way to calculate ...
3
votes
1answer
79 views
Is there a way to plot the current to charge a capacitor given that there is a max current in the circuit given by the power supply?
I'm trying to determine the maximum current of a circuit while charging a capacitor but since the power supply has a maximum current of 20mA that is going to extend my charge time longer than the RC ...
2
votes
1answer
286 views
directly charge a laptop battery / using laptop battery for projects
I've seen a couple similar questions, but nothing exact. I'd like to know how I can charge a laptop battery directly, meaning without the laptop. This would be a battery still intact, in good ...
-1
votes
1answer
113 views
How many lower volt charges are in a 12V/8A dry cell
On a long rafting trip I will be charging a cell phone (charger output = 5.1V/1A) and a head lamp (charger output = 4.2V/1A) using a 12V/8A dry cell battery as the power source. The cell phone will ...
2
votes
1answer
106 views
Restoring old SR-50 Calculator, odd Charger Voltage
I have an old Texas Instruments pocket calculator, for fun decided to get it working again. It is strictly a NiCd powered calculator, no alkaline recommended.
The charger is the 9130, says output 6 ...
1
vote
2answers
155 views
Why using short traces with the MCP73831 LiPo charger?
I'd like to use an MCP73831 to charge my lipoly battery. In section 6.2 I see they recommend short wires to the battery.
I bought my battery with wires, 20 gauge and approximately 30cm long. The ...
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votes
1answer
46 views
I need a charging solution [closed]
I work at a school, and we need to charge 15 Nexus 7 tablets through one unit. I've looked at Leba Notecart trolleys, etc., but I'm not sure what is best. We don't need to sync them to a computer; it ...
1
vote
1answer
211 views
charging battery while under load
my question applies to NiCd/NiMh battery types.
Can I simultaneously charge & discharge the battery? Might it cause any harm to it?
I presume there will be opposite movements of the charged ...
1
vote
0answers
91 views
what is the best way to charge a capacitor bank from an SLA battery
I need to charge a capacitor bank of 25 2.5v 55 farrad capacitors from a 2v 200Ah gel cell SLA battery, and modify the discharge time so that it discharges at 150Ah. I was wondering what the most ...
2
votes
3answers
307 views
'Stiffening' capacitor/s for DIY flash battery pack?
I'm planning to build a DIY battery pack for one of my camera flashes that involves basically wiring a bigger external battery to the battery leads in the flash. Admittedly I don't know much about ...
3
votes
1answer
729 views
3.3V Power Failover Supply with USB Li-Ion Charger
I am currently designing a "3.3V@500mA Power Failover Supply with Integrated USB Li-Ion Charger" for a uC project. I want the circuit to draw power straight from USB power when available & switch ...
2
votes
2answers
484 views
3.7 Volt external battery to charge a another 3.7 Volt Phone Battery?
I would like to know if a 3.7 V external Battery would be able to charge a phone battery of the same voltage. From my understanding, the batteries would charge each other until the charge in both the ...
4
votes
2answers
931 views
Charging capacitor bank with current limiting circuit
I would like to charge a capacitor bank with a 4.8 volt supply that I have. With the help received in response to this question, I now have a a useful current limiting circuit (shown below), that ...
3
votes
3answers
148 views
Capacitor charge circuit - 0V drop switch?
I have a capacitor charging from a supply voltage by a resistor and diode (resistor to limit current and diode to prevent energy flowing backwards when supply voltage drops).
The voltage drop on the ...
4
votes
2answers
647 views
Making a lithium polymer circuit
I want to create a circuit that will power my Raspberry Pi using Lithium Polymer. My knowledge of LiPo is rather low and I believe they can get dangerous if used incorrectly so I turn here.
THe ...
1
vote
4answers
969 views
DIY NiCad charger
I have this Ryobi 12V NiCad cordless drill that was sitting in a drawer for the past 6 years or so due to dead batteries (2 of them). At least that's what I tought at the time but looking at it more ...
0
votes
1answer
151 views
MCP73834 disintegrates after a couple of hours
For my first attempt at Li-Po charging I chose the MCP73834-FCI/UN for availability, it has an output current of 1A. I set it up the example circuit in the datasheet and used an 6Ah battery to test ...
1
vote
1answer
330 views
Is this switching power controller compromise wise?
TL;DR: Looking for all kinds of advice :-) Especially related to pushing "backwards" power into a MC34063 based step-up switching controller at times.
I'm building a device with an AVR ...
3
votes
3answers
973 views
How practical would a car booster using supercapacitors be?
Currently car boosters (a portable unit charged of an outlet and then connected to the car electrical system to start a car when the car battery is dead) typically use batteries - lead-acid, Li-Ion or ...
3
votes
1answer
1k views
Can I recharge batteries with a normal AC to DC transformer? [duplicate]
Possible Duplicate:
Charging 3 AAs in series
My batteries charger is not working, but I have an AC to DC transformer that can output different voltages.
If I connect two 1.5v ...
2
votes
1answer
451 views
Battery charging questions Parallel charging and battery balancing of LiPos
I'm having a long discussion on an RC board regarding LiPo parallel charging.
The basic crux is that my understanding of how charging works is something like this:
Charger Line voltage of x(8.4v in ...
2
votes
3answers
6k views
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.
3
votes
3answers
1k views
Is it safe to run and charge a deep cycle battery in an enclosed space like a bedroom?
I'd like to experiment with running a small server (5.5 watts) / 85AH deep cycle battery / charged via 30 watt solar panel from my bedroom.
I generally keep the window open, but want to make sure ...
4
votes
1answer
679 views
Dirt cheap NiCad charger
So sharptooth has a question up for creating cheap charger units that uses battery packs to charge a phone:
Is designing and producing a dirt cheap charger really that hard?
My question is the other ...
2
votes
3answers
210 views
Is designing and producing a dirt cheap charger really that hard?
Recently one blog service (all text is in Russian) published a curious post. The author proposes to add mobile phone charging capability to each 4-pieces pack of AA alkaline batteries.
The idea is ...
5
votes
2answers
599 views
How do snap-on induction charging systems not interfere with device functioning
There's a variety of snap-on wireless charging solutions on the market. For example, this one includes a charging mat and a plastic case that is put onto iPhone.
I suppose the winding is in the ...
0
votes
1answer
242 views
Using old notebook battery to power electric screwdriver
I have:
Dead notebook with live LiIon battery (HP HSTNN-CB50):
14.8V, 8 x 2500 mAh 18650 LiIon cells.
Rated at 73 Watt-hour.
I haven't managed to open the battery pack yet, but it's clear from the ...
0
votes
0answers
286 views
Can anyone recommend aUSB charging circuit that gives 600mA charge rate for a mobile device?
I need to build a 5V 600mA USB charge circuit for a device I want to build for my hobby project. Does anyone have a simple circuit design I can use to do this?
It will be charging a Lithium cell with ...
1
vote
3answers
129 views
Capacitors, fluid models, and pumps
In the circuit below what additions are needed so that charge will move from Ch to Ca, given that the charge on Ca can be higher that Ch?
In this system (see image below, it's a thought experiment ...
1
vote
2answers
490 views
How and when can solar charge controllers be stacked together?
I run a small busniness selling solar charge controllers.
Often I have a problem with not having controllers rated high enough amp-wise.
I know that charge controllers can be stacked.
But can all be ...
4
votes
4answers
975 views
Algorithm for charging LI-PO batteries?
What is the algorithm used in charging lipo batteries?
From watching my charger, I see that the amperage is close to the maximum specified (i.e. what I keyed in) at the beginning and gets smaller as ...
2
votes
3answers
192 views
Can an alternator cause components to run at a higher-than-rated voltage?
Given that the voltage regulator on my motorbike is set to 14.3 volts (so that it charges the 12 volt battery effectively) and given that the alternator is what provides power for the electrical ...
4
votes
3answers
822 views
What happens if you charge a laptop using it's USB power?
To play a joke on this question, we came up with the following image on the Super User Chat.
Of course this will not work, but now my question is:
What happens if you charge a laptop using it's ...
1
vote
7answers
367 views
What do you call it when you add energy to an inductor?
When you add energy to a capacitor, you say that you are "charging it".
This is kind of a misnomer, since the total amount of charge in the capacitor is the same, but whatever.
(Actually, using ...
3
votes
1answer
586 views
What component of my phone charger produces chirps and how does it do that?
My Nokia cell phone is charged with a very lightweight compact charger similar to this AC-15 (can't find the one I actually use).
While the battery is close to empty the charger works silently - just ...
6
votes
4answers
4k views
Is it possible to fire a spark plug from batteries
I wanted to create a remote fired trigger for a spud gun so I can trigger it remotely.
Ideally I'd like to use a spark plug to fire because it should work well for gas mixtures but the trigger is ...
4
votes
2answers
163 views
Capacitor Monitoring
How would you monitor a bank of capacitor to tell if they are fully charged. I would like to display the precent of they're current charged state using an LED bar graph.
0
votes
6answers
2k views
How to charge Laptop Li-ion Battery cells manualy?
I have received some Li-ion batteries which were originally used in Asus A2 Laptop battery original one and I would like to know if it is possible to charge each cells independently with some device ...
7
votes
3answers
5k views
How can a car battery be charged by dynamo (or is it an alternator?) at the same time it is being used by the car components?
note and question
* Is it an alternator or dynamo?
I am not an electrical engineer and neither have any core knowledge but, this is a simple procedure of car ...
6
votes
3answers
2k views
How do I charge a commercial lithium battery with solar cells?
I have a digital camera (Panasonic DMC-FT1) and will be going multi-day hiking with it soon. I'm looking to build a solar charger for it using something like this and strap it to my pack. Does anyone ...
8
votes
4answers
812 views
What are the basics of making a rechargeable battery pack?
We have a device that runs off of a AC adapter, or a pack of 8 AA batteries. Since in normal use we use both, it would seem to make sense to have the battery pack recharge while using the AC adapter - ...
5
votes
2answers
1k views
iPod Car Charger w/ Audio Out
I'm pretty new to this and am working it out as I go.
I have been working on a circuit design that would allow me to charge my iPhone/iPod classic 120gb from my Car.
I am going to use power from the ...
7
votes
5answers
985 views
RC circuit understandings
I am trying to understand the principles of a RC charging / discharging circuit however I'm at loss regarding certain aspects of its operation.
I have a square wave generator giving 0v to 5V levels ...
8
votes
6answers
3k views
Inductive Charging
I've build a small three wheel robot with an Arduino Mega to drive the thing.
I'm looking to keep this bot mobile as much as I can without needing to interact with it for charging etc.
For the moment ...
