Please specify the battery type in your question. Include chemistry (e.g. lead-acid), voltage, number of cells and how they are connected (series or parallel), capacity (in A·h or W·h).
6
votes
1answer
3k views
Some advice on charging circuit used in simple UPS
I have looked around for some way of having a 5 volt power supply that acts like a UPS.
Basically want to use a micro usb connector for +5 have a battery and li-ion or other charging circuit that ...
11
votes
2answers
425 views
How fast can a Li-Ion battery be charged?
So far I've seen many Li-Ion battery chargers that do the full charge in about 1,5 hours or more. There're also NiMH battery chargers that claim they charge a NiMH battery in 15 minutes and then the ...
4
votes
1answer
669 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 ...
24
votes
4answers
14k views
Why are there 3 pins on some batteries?
Lots of new batteries (for mobile devices, MP3 players, etc) have connectors with 3 pins.
I would like to know what is the purpose of this and how should I use these three pins?
They are usually ...
2
votes
4answers
4k views
How do I determine the maximum current for charging a li-ion battery?
I have a cell phone that has a 1500 mAh 3.7 V battery. It comes with a 700 mA charger but I've sucessfully used a 1 A charger with no problems. I'm now trying to make my own multi-device charging ...
2
votes
3answers
981 views
Circuit for recharging Li-ion Polymer Battery
I have a Li-ion Polymer Battery (Apple 616-0550), 3.7V 3.44Wh (~930mAh) salvaged from an iPod Touch 4th.
What do I need to know in order to build a recharging circuit for this type of battery?
...
5
votes
3answers
1k views
Measure Lithium ion battery voltage (thus remaining capacity)
What I am working with: I am running my self-made Arduino board (in the sense that I use the Arduino bootloader and code editor) at 3.3V, and powered from a Lithium ion battery, which is USB-charged ...
5
votes
1answer
355 views
Charging two lead-acid batteries connected in series, separately (with two solar panels)
I have two lead-acid batteries connected in series to produce 24V. They are powering an audio amplifier.
I'd like to be able to charge them while they are powering the amplifier, with solar panels.
...
3
votes
1answer
582 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 ...
1
vote
1answer
203 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 ...
4
votes
2answers
3k views
How to measure capacity of a Lithium-ion battery
I bought a Lithium-ion battery for a camera (much cheaper than the brand replacement but non unreasonably cheap compared to AAA Li-Ion batteries with similar charge). I however have doubts that it has ...
4
votes
4answers
963 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 ...
6
votes
1answer
434 views
LiPo vs. NiMH for kid's toy
I've been researching here and on google regarding potential battery technologies for a toy that I want to make for my kids. I was hoping to get others' perspectives on this, keeping in mind that ...
4
votes
2answers
1k views
How to charge Polymer Lithium Ion Battery that comes with the Lilypad Development Board
There is a Lithium Polymer Ion Battery that comes with the Lilypad Development Board from Sparfun. Does anyone know if the battery charges if we plug in the battery to the Lilypad Arduino and connect ...
4
votes
2answers
2k views
Induction charging for diy projects?
I have in the back of my brain a project involving wearable "transponders". These would be worn around the neck like a lanyard or a piece of jewlery. For simplicity, they should be able to charge by ...
2
votes
2answers
4k views
Voltage input for charging NiMH Batteries
I have 12 AAA NiMH batteries(1000mAH and 1.2V per battery) and I want to know what is the optimum voltage for charging them. I am using a simple Constant Current charger(LM317 and 68 Ohm Resistor(R in ...
5
votes
2answers
195 views
Limit the current being absorbed by a battery
I have a generator that supplies a constant DC 10A current to a NiMH battery pack with 240 cells in series (nominal voltage of DC 288V). This current is too high for any cell once it has reached 100% ...
4
votes
2answers
106 views
How can charge be determined?
How can software determine the amount of power or charge left in a battery (like an iPhone battery or a laptop battery)?
4
votes
4answers
2k views
How is fully charging a Li-Ion battery in 35 minutes possible?
I happen to own a power drill/driver that runs on a Li-Ion battery and ships with a charger that charges it fully in 35 minutes and claims to charge it to 70% in 15 minutes.
According to answers to ...
3
votes
1answer
508 views
Charging batteries connected in series as isolated groups
I put an electric motor into my 30' sailboat to propel it. I'm also using 8x12V Deep Cycle Marine Batteries to create 48V system (4 in series twice, connected in parallel) I have a 24V Wind Generator, ...
3
votes
2answers
633 views
Charging affects battery life?
I wish to understand how a battery charger may best be designed in order to maximise the life of Lithium Ion batteries. I have specified Lithium Ion batteries as they are what is used in most laptops ...
2
votes
1answer
406 views
Li-Poly battery charger with protection - Schematic review
I need to build a Li-poly battery charger.
The intended schematic of the circuit is as follows:
J1 is connected to the battery.
PMOS connects and disconnects the load to and from the battery
IC ...
1
vote
2answers
116 views
Mosfets as a switch for batteries in series
I am contemplating a way to build a new battery pack for a project that I am working on. However I think that I have run into a problem, but I am not sure.
I have a battery pack with about 27 ...
1
vote
1answer
418 views
LiPo series charging
I have a 3 cell lipo connected in series and I want to charge them without removing them from circuit.
I only have single cell chargers so I can only charge one at a time or charge them in parallel ...
1
vote
1answer
131 views
Safe operating area for different types of battery chemistry?
I'm trying to find the safe operating area for various types of batteries; in particular I need minimum and maximum termination voltages, although information on temperature / power / current is also ...
6
votes
2answers
1k views
Can I charge a 12v sealed lead acid with an old wall-wart (not made for charging)?
Will it hurt the battery? If I left it overnight would I run the risk of "exploding" the battery?
I have a 7Ah SLA battery that I need to charge, but I don't have a charger and I don't want rake out ...
5
votes
3answers
3k views
Powering laptop from 12V sources without inverter
This question has two parts:
1) How inefficient is it to boost 12V to 120V and then back to 12V as in using a traditional car power inverter to power a laptop (i.e. the 12V car battery power is ...
4
votes
1answer
352 views
Parallel charger circuits
I'm constructing a power supply based on solar cells backed by batteries. The solar cells deliver between 0 and 4 A, depending on the time of day, while the charger I plan on using, the LT3652, has a ...
3
votes
1answer
395 views
Lead Acid Battery Charger Design Factors
In any lead acid battery charger how does the per ampere rate of the battery being charged factor into the design. I think. You have to worry about the current voltage, and the current current being ...
2
votes
2answers
118 views
How fast may I trickle charge a full LSD NiMH battery?
I've bought two packages of low-self-discharge nickel-metal hydride AA batteries, each made by a different well-known battery manufacturer.
Sadly, the datasheets aren't very detailed:
• One ...
2
votes
2answers
193 views
Are there any dangers to consider when replacing a permanent AA NiMH battery?
The battery in my electric razor has failed to charge for several years. It does not turn on unless I leave it plugged in for 20 minutes and it turns off immediately if I unplug it. To save some ...
2
votes
0answers
151 views
What is the usage of 3rd lead in mobile batteries [duplicate]
Possible Duplicate:
Why we have 3 pins on some batteries?
I'm trying to build (DIY) open charger for mobile battery. I would like to know what is the usage the middle one?
Is there ...
2
votes
1answer
200 views
Is there a mathematical relationship between the battery AH rating, and that of the transformer in the charger
I'm possessed of an inverter battery (12v 150AH rating) that has been out of service for a few months now. The reason it was out of service is the inbuilt charger provided with the inverter was not ...
2
votes
3answers
195 views
Charging marine battery while powering equipment
I've got a quite delicate setup with a PC and some other minor equipment such as a microcontroller connected to a large 100Ah sealed (AGM) 12v lead acid battery.
I need to be able to run my equipment ...
1
vote
1answer
75 views
Spec'ing an always-on alarm/tracker for a car battery
What is the specification of a standard car battery (e.g. of a 2008 Jetta)?
Say, I want to connect an always-on alarm or a tracker to the electrical system of the car.
Is it likely to deplete the ...
1
vote
4answers
957 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 ...
1
vote
3answers
485 views
How can I charge my beard trimmer's Li Ion battery from USB?
I have just bought a beard trimmer with a built-in Li ion battery. The charger that comes with it says its output is "4.2V, 600mA".
I know Li ion batteries will misbehave (!) if fed the 5V from USB. ...
0
votes
1answer
210 views
Can I recharge 12V batteries individually while why are attached in series? [duplicate]
Possible Duplicate:
Charging two lead-acid batteries connected in series, separately (with two solar panels)
I have 12V Solar Panels and 12V batteries. But my laptop needs 17V to recharge. ...
0
votes
1answer
368 views
Battery Voltage While Charging
I'm experimenting with a linear-mode fast-charge circuit for NiMH batteries. I was surprised to find that the voltage measured across the battery terminals while fast-charging is higher than the ...
-4
votes
3answers
103 views
How many D cell batteries would you need to replace a 6V 4.5Ah battery? [closed]
How many D cell, 8000 mAh -1.5 V batteries would you need to replace a 6V 4.5Ah battery?
I'm trying to make a power comparison and not physically make the replacement. Would you suggest a different ...
