Batteries are often used to power embedded devices, and create some design challenges like minimizing the power consumption, protecting from overcharge and full discharge, etc.
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1answer
57 views
Two 6v batteries in series charged by two separate solar panels
I have two solar panels - first 30 watt 2 amps second 40 watts 2.3 amps, and two 6v deep cycle batteries in series on my RV. My question is: can I simply use two separate charge controllers (max 7 ...
1
vote
1answer
42 views
XBEE S2 RPSMA not working with batteries
I have a couple of XBEE S2 with RPSMA antenna
I'm using the xbee explorer(with arduino) and XBIB development board with X-CTU on a PC.
if I drive the arduino from the USB,,, it works... not really ...
1
vote
1answer
45 views
How to calculate battery capacity required for home applications?
The issue I'm facing is calculating current draw from different household items. Like, if a fan is rated at 75 Watts, its current draw would be A = W/V so A = 75/220 and A = .34 amperes.
That doesn't ...
0
votes
2answers
84 views
Battery powering an unknown DC motor
I know nothing about motors. I have DC motor (sealed in a casing) that uses 6v/12v 1a (mains switching power supply) with 2.1x5.5mm DC connector. It has variable speed controller, reversible ...
0
votes
2answers
35 views
Cell phone battery with solar shield, arduino [closed]
I was looking for your opinion on this product: http://www.seeedstudio.com/wiki/Solar_Charger_Shield_v2.0b
Do you think I could use a cell phone battery (3.7v 1000mA) with this? I have a standard ...
5
votes
1answer
115 views
Boosting a Lithium Coin Cell
I made a board recently and just started checking it out yesterday. I used a typical lithium coin cell and a boost converter (Microchip MCP1640). With a battery plugged in I get no voltage out of the ...
1
vote
1answer
45 views
Building a small D cell battery charger?
I am looking to buy/build my own D cell Nimh battery charger with the following requirements:
-dual prong AC wall input
-charges Nimh D Cell
-is safe
-contained within 1" x 1.7" x 2.2" enclosure
As ...
0
votes
1answer
55 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?
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0answers
49 views
adjustable battery indicator
I've got a simple circuit powered by one 18650 LIon battery.
Now i want to light up a LED when the battery voltage drops under a specified value (e.g. 3,4V)
I know it would be easy with a ...
2
votes
1answer
66 views
Can a linear regulator in shutdown mode have the output in parallel with a switching regulator
I am trying to design an efficient battery powered circuit using a 3.3V microcontroller (NXP LPC1343). One of the requirements is that the microcontroller periodically read a value from an ADC and ...
-4
votes
0answers
49 views
How many D cell batteries would you need to replace a 6V 4.5Ah battery used in a WAL? [duplicate]
How many D cell 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 battery to compare ...
0
votes
1answer
64 views
Battery charger for AA batteries
I am looking for a battery charger for AA batteries, without taking out the batteries from the board.
The board which is powered by AA batteries is : ...
5
votes
2answers
201 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% ...
1
vote
1answer
73 views
Can leaving rechargeable batteries in the unplugged charger for a few weeks cause batteries to lose their charge?
Is it okay to leave rechargeable batteries in charger even if it's not plugged in?
-3
votes
0answers
39 views
How long does my battery last? [closed]
The only information I'm given is that each battery has a useful energy of 100000 Wh (500 Wh/kg), my discharge rate is 10C, and has to power an electric motor that should output 1000 kW. I'm having ...
0
votes
0answers
66 views
Soft latch switch seems incompatible with boost voltage regulator
I am using a lithium ion battery to power a circuit board at 5V. I am using the LM2623 boost voltage regulator, which works fine when the battery is hooked up to the circuit board. I would like to add ...
0
votes
0answers
46 views
Desulfation and High Capacity Charge Frequencies for Lead Acid
I realize this is a total shot in the dark but it doesn't hurt to ask. Most of the experimentation that has been done in this area is highly guarded by individuals hoping to pull a ton of loot from ...
2
votes
3answers
243 views
How do I calculate battery life allowing for duty cycle?
I have a battery rated at 2610mAh.
The device it's powering transmits to the network for 35ms during this time it uses 1.95mA of power. the rest of the time the device draws 0mA. I want to workout how ...
0
votes
0answers
42 views
In “primitive” electrolyte batteries, how far apart should the anode and cathode be?
I'm trying to make potato batteries using zinc and copper, and I'm wondering how far apart they should be for maximum efficiency (minimum resistance, maximum voltage). Should they be as close as ...
1
vote
1answer
67 views
Does connecting batteries in parallel increase the current?
I was watching this video about potato batteries: http://www.youtube.com/watch?v=FITxr6bJmd8
He ends up connecting them in 3 pairs (parallel) of two (in series). This way, by connecting them in ...
0
votes
0answers
44 views
What is a good Solar panel for a 12 volt 10 amp hour lead-acid battery
I want to be able to charge a 10 amp-hour lead-acid battery with a solar panel for when I am away from a power source (camping etc.) I don't want the battery to take longer than a daylights time to ...
4
votes
1answer
96 views
New alkaline batteries with 10-year shelf life—what's changed?
I'm finding that some new alkaline batteries, such as the new Duracell Duralock and Energizer Power Seal batteries, have a shelf life of 10 years. Most other alkaline batteries have a shelf life of 7 ...
1
vote
2answers
49 views
Connecting two transformers of equal rating to recharge a battery
I have two transformers having capacity 6-0-6(volt) & 0.5amp each.
However, my battery requires 6v & 1amp. How can I connect two transformers to get my battery charged?
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votes
2answers
60 views
Choosing leds for batteries power
Can I use 3V (2*AA or 2*C batteries in series) as power for 10/20 leds connected in parallel?
LED specs:
Diameter: 3mm / 0.1"
Emitting color: Red/Green/Blue/White/Yellow
Material: GaP
Forward ...
0
votes
1answer
25 views
mobility scooter battery charger
I have a mobility scooter that I put a Raspberry Pi and Arduino on to make a robot. I left all the original electronics in place so I didn't have to buy a motor controller.
I was able to charge the ...
2
votes
0answers
75 views
Are “wider” battery packs less at risk for polarity reversal?
If make a 5V battery pack as a series of four 1.2V NiMH batteries, there is some risk of polarity reversal when the pack is discharged too much. I doubt this risk is reduced by plugging such packs in ...
0
votes
1answer
85 views
How to power a remote control car using solar power
My daughter is trying to power a remote control car that currently uses 4 AA batteries as power. She is trying to convert it to solar. What does she need to do so?
3
votes
1answer
108 views
How to detect low battery of a lead-acid battery?
I've heard that discharging a lead-acid battery to 0% is bad and wears it out. I have a 10Ah 12v lead-acid battery, is there a circuit to tell me when the battery is low?
4
votes
2answers
107 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)?
2
votes
2answers
124 views
Why do batteries in series add up voltage?
This question will probably sound easy to most of you, but to me, it is still a kind of magic :)
Taking in account all I know until know, I guess a battery has two sides:
one that "emits" electrons ...
-2
votes
0answers
43 views
Battery Leaked In Motorcycle Alarm Remote [closed]
I left my remote controls (both of them) in a locker for about a month... I think it must have gotten really warm in there because in both of the remotes the batteries had leaked. Anyway, I put a new ...
6
votes
3answers
275 views
NiMh or LiPo batteries for unattended charging/usage
I'm in the planning stage of a summer project: A WiFi controlled robot for remotely monitoring a shore home. The robot will consist of a 4-wheel platform (4 motors, 1 A stall current each, 7 V), ...
2
votes
2answers
129 views
Getting 5VDC from 6V (4S 1.5V AA alkaline batteries)
For my current project, I need 5VDC rail to power an ATtiny85, an RF module, and an Ultra-sonic range sensor, all of which require 5V. 5V ensure that the ATtiny85 can be operated without crystal at ...
-2
votes
0answers
65 views
Lithium Batteries: LiFePO4 vs LiPo vs LiCoO2 vs LiMnNiCo vs LiMnO2 [closed]
What are the differences between these battery chemistries?
LiFePO4 (aka Lion?) vs LiPo vs LiCoO2 vs LiMnNiCo vs LiMnO2
2
votes
2answers
113 views
Energy-efficient LED driver circuit
I want to light a normal LED for as long as possible on two AA or AAA batteries. It does not have to blink or so, just stay on. The LED doesn't have to light at the max, as long as it's visible from ...
1
vote
1answer
66 views
How to power a 12v outdoor project with microprocessor?
Forgive me if this is a really basic question, but I'm still at the "consideration" stage of a basic LED project, thinking about lighting up one of those flexible LED strips from a microcontroller ...
-3
votes
1answer
84 views
How do I measure ripple current in a battery charger? [closed]
Minimizing ripple voltage is major factor to avoid failure of equipment such as digital axle counters. (Eldyne)
How do I measure ripple voltage in a battery charger with a 230 VAC input and a 24 VDC ...
2
votes
3answers
124 views
Rechargeable battery type recommendations for a 1-2 amp bicycle LED circuit
We are building a blinkey-blink circuit for a bicycle and not sure what battery to use.
The circuit will need to run on about 5V, since is is powered by ATmega chip which must run at 20mhz.
When all ...
0
votes
1answer
62 views
Help finding Buck/Boost Regulator IC
I have been trying to find a suitable Buck/Boost IC with certain features, but having gone through multiple Manufacturer's product tables, I can't find one that meets my needs. I think this is more ...
1
vote
2answers
134 views
Problems when sharing a battery between motors and radio in an RC car
Background
I am building an RC Car that I am trying to modify to control from an Android phone.
When I connect the remote control module as well as the car circuitry (servo & motor) to separate ...
1
vote
1answer
102 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
77 views
Current draw in a battery contactor
In a battery continuous contactor used as a master switch, what limits the current draw through the coil once the contact is shut?
1
vote
1answer
51 views
Lithium Ion charging problems - power outages
Does any one know if general charge circuits for lithium ion batteries suffer from this problem:
-Flat Battery put on to charge.
-A power outage of long duration occurs (say 8 hours).
-When power ...
5
votes
1answer
91 views
How to tell if a battery pack is draining while in water
We currently have an issue where we think maybe water is getting into our battery packs and possibly draining them. We'd like to setup a battery pack into a similar state an put it into water. But ...
1
vote
3answers
183 views
Convert 9v of battery into 5v at 3.5watt
I want to run Raspberry Pi using a general non-rechargeable 9v battery.
Raspberry Pi needs 3.5W and 5V input.
Questions:
Which LDO should i use ?
For what amount of time general 9V battery is able ...
-3
votes
1answer
77 views
Treadmill ups backup [closed]
I need to connect a treadmill to a ups backup battery. The only information on the treadmill is:
Input voltage: AC 110V/60HZ
Input power: 2.5 HP
What kind of battery should I get?
Thanks!
2
votes
2answers
80 views
Communication between embdedded system and Mobile phone
I am software developer and new to the embedded systems.
I need to use a wireless communication method to send/receive data from embedded system and a mobile smart phone (Android - iPhone).
My target ...
0
votes
1answer
83 views
power loss calculation
I was reading StevenVH's response to the post How long will it take... and he brought up something I was completely unfamiliar with; the power loss associated with the large volt difference between ...
-3
votes
1answer
79 views
calculating the battery amperes to connect with UPS?
I have 500 watt UPS, which outputs 220v and 50Hz. The calculation says that I need 500/12v = 41.67 Ampere and 12v battery to use with this UPS. But mostly people around me suggested 120A/h battery. ...
2
votes
2answers
95 views
Constructing a simple emergency light kit
This is my first adventure in the electronics world and, as I'm a CS student, you can expect a lot of associations that maybe aren't that right.
The main feature of my circuit is:
If there isn't ...
