All Questions
43
questions
0
votes
2
answers
39
views
Boost converter two different voltages (9v/12v) from 3.7v battery, attach both to battery, or daisy chain off 9v
I'm sure this has been answered plenty before but I cant seem to get the search terms. I'm wanting to use a 3.7v battery to power a small 9v device and a 12v device at the same time using a boost ...
0
votes
1
answer
95
views
What is the "best" way to make a diy 7v rechargeable battery?
I have a device (the wii "sensor" bar, basically an IR LED array) that the literature says takes 7v. I can't find any battery offerings that come in 7v, but many that are 3.7v, so I am stuck ...
- 141
0
votes
1
answer
47
views
Battery consideration and topology choice
I have a system with a battery. I do not know what will be the battery at the moment. And so I can select the voltage battery in function of my system. I need to regulate a voltage (15 V) thanks to a ...
- 2,478
0
votes
3
answers
97
views
Does DC-DC 24V-12V waste less power than AC-DC 220V-12V?
I am modifying an existing UPS to allow for a longer backup time. I plan on adding a cooling fan along with an external current controlled power supply to charge the larger batteries. There are some ...
2
votes
2
answers
701
views
How much charging ripple voltage is allowed while charging a LiFePO4 battery?
We are designing a buck controller to charge a LiFePO4 battery (4 series 9 parallel cells, each of 3.2 V).
Hence, we would like to charge the battery pack with 13.90 V but the buck output has got a ...
- 29
1
vote
3
answers
113
views
Unable to start and run 12 V DC pump, only jolts
I have a 12V 19 watt DC water pump (800LPH), A 12 V DC step down converter, and two Dewalt batteries.
One at 18 V 5 Ah, other 18-54 V 9 Ah.
I've connected pump to step down to battery correctly, but ...
- 23
0
votes
0
answers
58
views
Using 2 LiPo Batteries via 2 Buck Converters for External Notebook Power Supply - will it work?
I have an old ThinkPad X220T notebook of which the internal battery is broken (and removed).
To get my notebook working on the go again I want to build an external portable power supply with 2 LiPo ...
1
vote
2
answers
738
views
12 V, 18 Ah battery for a solar panel
I have a 100 W solar panel. I bought a 12 V, 18 Ah battery with a 30 A PWM solar controller. How can I get this to charge right? The current will be too much for the battery. How can I cut down the ...
2
votes
2
answers
6k
views
Powering 24 V and 12 V device simultaneously from two 12 V batteries
I have two devices which need to be battery-powered (remote area, no grid power available). One device requires 24 V, the other requires 12 V. Both are very low amperage (~50 mA).
Can I use my two 12 ...
- 121
0
votes
2
answers
652
views
Why does the voltage of a 18650 battery drop when connected to an LM2596 module?
I am trying to get a 5V output out of a 2S 18650 cells (getting a 7.5V from them.)
I am trying to use a LM2596 module, but as soon as the battery is connected to the LM2596, the input reading goes ...
- 1
-2
votes
1
answer
139
views
Does a voltage limit in a battery increase amperage over all? [closed]
I have an 18 V battery with a 4 Ah battery. If I limit the voltage output to 9 V with a buck converter or voltage regulator, how would limiting the voltage affect the amount of current output?
- 1
0
votes
1
answer
538
views
Choosing TVS diode
We have a a project where there a system powered by 13s Li battery - 54.6V max voltage of pack. The buck regulator we're choosing for this has an absolute max of 76V. For this we're considering two ...
- 597
-3
votes
1
answer
274
views
Paralleling of battery chargers [duplicate]
Can we parallel the bbattery chargers suppose buck controllers.Two buck controllers taking power supply from the same power bus. The output of each controller will charge the batteries connected at ...
2
votes
1
answer
610
views
Why is LM2596 buck converter output current low when used as a mobile charger? [closed]
I have a LM2596 buck converter which is capable of providing 3 A and my input source, which is a transformer, is capable of providing 5 A.
When I use the buck converter to charge my Android phone ...
- 131
0
votes
1
answer
45
views
High Current Buck Converter with wide input voltage [closed]
I'm currently building a powerbank with PD outputs that are capable of outputting 5 amps at 20 volts, but my battery pack is 33.6V (8S Li-ion). I've managed to find a possible buck converter IC (...
- 3
0
votes
1
answer
1k
views
Using an old eBike battery to power an electric trolling motor
I have a couple of old 36v eBike batteries lying around. I also have a Minn Kota Endura C2 30 electric trolling motor for my small boat which needs a battery. My previous experience with a large lead ...
1
vote
1
answer
57
views
What is the best way to tap 12v from a 6x6v battery array for intermittent loads?
Greetings beloved comrades,
I recently acquired a 36v golf cart that has 6 6v batteries in series. The existing 12v accessories, mainly lights, are powered by a separate series connection to 2 of the ...
- 115
-3
votes
2
answers
82
views
Buck converter or regulator [duplicate]
I have a battery supply consisting of 3 AA batteries of each 1.5V.
I need an operating voltage of 3.3V.
Which choice of buck converter or regulator would be better?
My application requires 100mA of ...
- 49
0
votes
1
answer
185
views
Charging a Li-ion battery with a Buck Convertor & ATmega8 [closed]
I'm trying to charge a 7.4 V Li-Ion battery following the CC/CV protocol and have a few questions.
I want to use an SMPS from my old laptop that can provide 20 V/3.25 A and feed that to a buck ...
1
vote
3
answers
292
views
Battery emulator based on an array of buck converters for BMS testing
Problem: How to quickly and cheaply test if a given BMS (Brand: Daly / Tiny BMS / etc) or battery-powered system behaves as intended for various cell voltage combinations without waiting for actual ...
0
votes
3
answers
1k
views
Buck converter source current draw
I'm doing some calculations for a system that is going to use a few buck converters. I need to make sure that the battery will be able to feed enough current but I'm not 100% certain how power on the ...
- 930
1
vote
2
answers
875
views
Using LM2596 step-down with Li-po
I'm doing a project with an ESP32 (3.3 V), a DHT11(3-5 V), a soil sensor (3.3-5 V, the cheapest Chinese), NRF24L01 (2.6-3.6 V).
I'm using LiFePO4 right now (3.32 V), but when the battery voltage drops ...
0
votes
3
answers
2k
views
Can I use a current control buck converter to charge a battery?
As shown below, could I use a microcontroller to charge the Li-ion battery? I'm unsure if I'll run into issues with the voltages on the ADC. I've done this exact setup before with a generic load, I'm ...
0
votes
0
answers
180
views
Current and voltage increasing with duty cycle from buck- converter
I am designing a 2s Li-ion battery charger using a buck converter from a 10W (18V, 0.55A) solar panel. So I understand that the duty cycle controls the ratio of the input power vs output power and ...
- 33
1
vote
1
answer
126
views
Power supply question in regards to powering 400 LEDs
I have WS2812B LED strips, that has 144 LEDs per meter. The ratings are:
43W/M .3W/LED
.06A per LED
Input Voltage of 5V DC
The recommended power supply stated by the website is 5V DC and 10A for 1 ...
- 13
2
votes
3
answers
3k
views
Why is my buck converter emitting smoke and fire?
I am powering my router from a 24 V battery, but the power requirement of router is 12 V/1 A, so I am using an LM2596 buck converter.
The specification for this buck converter is as follows:
Input ...
- 123
0
votes
1
answer
661
views
Inductor and Capacitor for Bidirectional DC-DC Converter with Battery
I have to design a bidirectional converter to regulate a DC bus at 250 V with a battery bank at 144 V. My question is how to do it optimally, because I do not know the maximum ripple allowed in the ...
- 157
1
vote
1
answer
107
views
Is there any risk in leaving a Li-ion connected to a solar panel with only step-down converter?
I have a 18V solar panel which is connected to a step-down buck converter, which drops the voltage from 18V to 3.5V. When clouds block the sun, the voltage drops to less than 3.1V. I have added a ...
- 573
2
votes
0
answers
371
views
Any specific precautions should be taken when using 2x AA LiSOCL2 batteries in parallel?
I am working on the wireless sensor design and one of the sensor is such that it needs to be kept ON through out the operation and it takes supply of 3V and current of about 100uA, which I think is ok ...
- 358
1
vote
1
answer
617
views
Synchronous buck converter in parallel with linear regulator
I'm looking at designing a circuit to provide power to a USB charging port (500 mA charge rate max) in a 12V battery-powered application.
I'd like the buck converter to be "off" when there isn't any ...
- 1,420
0
votes
3
answers
236
views
DC Buck Converter for more than 3A
I want to use an Arduino Nano to controll an LED strip using an WS2812B IC. The strip takes 5V at 3.6A. I want to power the arduino and the strip using two 18650 Li-ion batteries (LGDBHE41865), which ...
- 101
1
vote
1
answer
2k
views
Calculating Amperage After Boost In DC-DC Circuit
To keep this simple, I am trying to figure out what happens to the amperage when having the voltage boosted in a DC-DC circuit.
For an example here, Lets assume that the power source is a 26650 ...
- 11
3
votes
2
answers
2k
views
How to convert 48V to 5V in this system?
I have built a prototype for monitoring the battery voltage of my off-grid PV system. The prototype is as shown in the clumsy schematic drawing below, and it uses 24 V battery. I use an OKI-78SR-5 to ...
- 65
2
votes
4
answers
10k
views
Battery Charger using a buck converter
I'm designing a Lead Acid battery charger with 3 stages. For the 2nd stage (constant voltage stage) as it is written in literature: the voltage applied on the battery must be dependent on temperature. ...
- 63
2
votes
1
answer
599
views
Extending battery life: Calculating advantage of adding more batteries
I have a small 3 volt device with an MCU and 8 LEDs that I'm currently powering by two AAA batteries connected in series. With fresh batteries, I start out with about 3.2-3.3 volts and get very good ...
- 1,835
0
votes
1
answer
1k
views
Current output of a solar panel when connected to battery and load
I am trying to build a microgrid (final year project) where a 100-250 W 48V solar array will charge a 24V battery bank and a couple of 24V loads (40W lights, 60W fan).
Batteries used (7 of this in ...
- 11
0
votes
3
answers
142
views
Getting closer to figuring out my battery requirements
I have been doing research for at least a week and am still a bit confused, but think I am getting to the point where I am close.
I need to power 5V 3-5A. Some days this power source will hook up to ...
- 165
11
votes
4
answers
3k
views
Boost or buck regulator for battery life?
I want to make a wireless sensor node that will run at about 2.5v. I am trying to decide between running 3 alkaline batteries in series with a buck converter or in parallel with a boost converter. I ...
- 1,202
2
votes
2
answers
530
views
Powering DSLR with buck/boost convertor
I've been experimenting a bit with time-lapse photography lately. Still basic stuff. Right now I have to change batteries every so often which is a pain because it's hard not to move the camera when ...
- 123
2
votes
4
answers
27k
views
Charging 2 Li-Ion Batteries via a single charger
I'm currently building a portable USB charger. It uses 2 Li-ion batteries in series connected to a USB port via a 5V regulated buck converter. While a single Li-ion battery would suffice for most ...
- 567
1
vote
2
answers
8k
views
How to adjust output current on a buck converter?
I 'm planing to use a zinc–carbon 9 V battery to power up:
the circuit that battery belongs to
BeagleBoard-xM
I 'm thinking of using a breadboard, in order to power up both circuits. Beagleboard-xM'...
- 659
2
votes
2
answers
2k
views
Building a low-power solar/wind buck-boost converter
Using a 18V(max) solar panel, I'd like to charge a 12V lead-acid battery. I'm working from the basic inverting buck-boost circuit. My main question is, being a relatively low-power circuit, can I ...
- 127
3
votes
5
answers
8k
views
How to power a GSM Modem from a Li-Po battery?
I want to integrate an AirPrime SL6087 GSM modem into a design, this is my first try at working with a GSM module. The datasheet states that the modem draws 2A for 1mS every 4mS (max) at 3.6V, the ...
- 2,525