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).

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0
votes
1answer
15 views

Number of cycles for AGM battery with an inverter

I have an AC system which has a continuous load of 7 amps at 120 volts. To run this system, I need a set of AGM battery and an Inverter system (power factor- 0.8). The inverter is 24 volts and rated ...
3
votes
1answer
26 views

Multiple charge controllers on the same solar panel

I have two 12v lead acid batteries on my boat. One at the front for the trolling motor (~80 AH) and 2 smaller batteries in parallel at the rear for electronics (~30-35 AH combined). I want to put a ...
0
votes
2answers
38 views

Can I charge two small batteries of different voltage using one solar panel and two diodes?

If I use diodes to direct power to each of two small batteries (old NiMH laptop packs), will both charge properly from a single solar panel at the same time if one pack is 11 Volt (9 NiMH cells in ...
0
votes
2answers
67 views

What is the deal with input voltage?

Let me tell you right off the bat that I am new to electronics, more specifically the creating of electronics. I recently discovered a project that I would like to make, a pocket power supply(link at ...
-4
votes
2answers
48 views

Connecting a 20 amps battery charger to an 18 amps source

I have an inverter with a 20 amps DC battery charger (AC to DC ). I need to a connect the ac Generator output to the ac input of the inverter. The thing is that the generator can provide a maximum ...
0
votes
2answers
100 views

How could a rechargeable battery charge itself without an external source?

While I was working on my graduation project I had to charge a rechargeable battery then discharge it and so on.I was shocked when the battery charged itself without any other external sources for ...
0
votes
1answer
28 views

Charging Indicator for any battery (Charge Monitor)

We see in all today electronic devices like mobile a Visual battery charging indicator,that a graphical Container composed of bars that increases one by one when the battery is charged for long, and ...
0
votes
0answers
31 views

How does charging a lithium ion battery work? [on hold]

I want to charge a lithium ion battery, but knowing the risks of lithium I want some additional information on the principles of battery charging (can't seem to find this info). I would like some ...
1
vote
1answer
71 views

How to calculate solar panel setup?

I have an equipment which draws 550W at a constant level, no peaks. I want to power this unit with solar cells only during the day when there is light using a simple car battery. Because I don't want ...
0
votes
0answers
6 views

Question about Solar Panel and Lithium charging board

I have a 6V 4.5W solar panel which I would like to use to charge my Lithium-Ion batteries. The battery chargin board accepts 4.5-5.5V. Would it still be safe to use it with 6V? If not, should I just ...
2
votes
1answer
42 views

How do you protect a Li-ion / Li-polymer battery from over-dishcharge?

I'm setting up a power regulation system for a lithium polymer battery, but I'm aware that my LDO will continue to draw current from the battery even after it's fallen below an acceptable level of ...
0
votes
0answers
39 views

simple USB charging

I have a battery project that i want to charge via USB at around 300mA. If just using a wall wart then everything is easypeasy, but I want to make it compatible with a computer as well. What I've done ...
0
votes
0answers
27 views

Switching between batteries while charging

Let's say I have a 4 A current source and two 12 V car batteries, connected in series (with a tap in the middle). What in your opinion is the simplest MOSFET switching circuit, that would allow me to ...
0
votes
0answers
88 views

How do I prevent a bulb from dimming?

I am powering a 4W bulb from a 12v lithium-ion 9.8Ah battery. My problem is the bulb dims after a couple of hours. Is there a component I could introduce to the circuit that would keep the bulb ...
3
votes
2answers
536 views

Will the lower frequency of 50Hz AC affect overall charging time? [closed]

I'm using a voltage converter to go from 220V to 110V to charge a small appliance. The recommended charging time is 6-8 hours. However, this is specified for US AC voltage 110V@60Hz, whereas the ...
0
votes
0answers
14 views

(Battery Charging) What voltage / A charger I can use to charge 18650 [closed]

I bought Shenzhen Ferei Lighting Co.,Ltd (18650) battery. It is 2600mAh 3.7V. I'm wondering which charger I can use to charge it. I have Kangertech e-cigarette and it has a micro-usb plug integrated ...
0
votes
1answer
27 views

PV cell output calculation, when a charging limiter is involved

I need to the charging rate of a battery connected to a 20w PV panel. Due to the regulator on the board though the maximum rate the battery can be charge at is 1A, 12V , due to how this is setup, ...
1
vote
0answers
57 views

Can AC/DC conversion losses from solar panels be avoided with a Tesla Powerwall?

(background: I'm just playing with numbers, trying to estimate how many solar panels would be needed to fully supply the energy for a home and 2 Tesla cars) I've been reading up on solar panels and ...
0
votes
2answers
42 views

Arduino remove power if battery voltage is too low

I want to power my Arduino using a Lithium-Ion battery. When the battery is below 3.0V, the power to the Arduino should be disconnected, and when it rises high enough again is should be reconnected ...
-1
votes
0answers
25 views

What Charger do I need to charge my lipo batteries? [closed]

I have two lipo batteries First: capacity: 5000mha max voltage per cell: 4.2V max voltage per pack: 12.6V charge rate: 1C Wwtt Hours: 55.5 configuration: 25C cells: 3 Second: Battery capacity: ...
-2
votes
2answers
56 views

Charging 2 different age batteries using a battery isolator in my vechicle [on hold]

I am interested in using a battery isolator, specifically this battery isolator, in my van to charge a deep cycle auxiliary battery using the vans alternator. I would then like to use that auxiliary ...
0
votes
0answers
36 views

How to slightly modify this circuit for a lower charging current?

I have mosfet controlled transistor charger circuit for Li-ion battery as picture below. So when 5V presents on VCHG, the processor(with power management) will control VDRV for a Vgs(VCHG-VDRV) ...
1
vote
1answer
56 views

Discharge and Recharge of a battery [on hold]

Under which value it is not recommendend to discharge a Li-Ion battery? How fully discharging battery affects a battery life? What happens if we leave a battery on charger, even battery is fully ...
0
votes
0answers
61 views

Building a solar powered USB charger

Can some one please help me ! I'm new to electronics and I have been building my own basic ones, but I have decided to step it up a little and design this. Could you tell me if it would work ? If ...
0
votes
1answer
55 views

12V Battery charger voltage - cycle use

I need to charge 12V e-scooter battery with DC-DC converter. Specification of the battery charging voltage is: Standby use - 13.5V - 13.8V Cycle use - 14.4V - 15.0V Can I charge the battery in ...
0
votes
0answers
43 views

Charge a Li-Ion battery from a anemometer

I am trying to charge this Li-Ion battery (https://www.sparkfun.com/products/339) with a small dc generator. It is attached to an anemometer and i can get 100 mV and 20 mA in a normal windy day. I ...
-2
votes
1answer
70 views

How come portable phone chargers tend to use USBA?

How come most portable phone chargers use USBA rather than Micro USB for the output port? Is USBA supposed to be more tolerant? If they use Micro USB for the output (as well), the user could just use ...
-1
votes
3answers
61 views

Electricity needed to maintain power for camera [closed]

I am not an electrical engineer by any means and do not even know the terms I should use to ask this question but basically I am trying to determine which solar panel I can use to power my camera. ...
1
vote
2answers
155 views

How come 2 MOSFET chips are needed in protection circuits?

Like those here, the protection boards have at least 2 MOSFET chip (AO8814). Does anyone know why so many (4 fets) are needed?
0
votes
0answers
32 views

How to make a Lithium-Ion battery sub-zero proof

I'm planning to use 2 Lithium-Ion batteries in parallel to power my arduino via a step up converter. The batteries get charged using 5W a solar panel during the day. The problem iy, temperatures can ...
0
votes
1answer
45 views

Charge Lithium-Ion batteries using a solar panel in parallel

I want to charge some Lithium-Ion batteries using a solar panel with this loading circuit found on ebay here. Apparently it works fine with just one Li-Ion battery, but I would like to extend the ...
0
votes
1answer
47 views

Laptop battery not working after cells replacement

I have a Sony VGP-BPS21A battery that I use to power my laptop on. It is really old, like 5-6 years now and its cells have lost more than 50% of their capacity. As a new OEM is very expensive, hard to ...
0
votes
0answers
29 views

Using Lithium-Ion batteries for arduino

I want to know a couple of question regarding my upcoming project of powering a arduino using solar power. I want to use 2 5.5V 2.5W solar panels which charge Lithium Ion batteries. On this site here ...
0
votes
1answer
52 views

Build a solar panel nimh charger

Today I found this tutorial on how to build a battery/solar power supply for an arduino here. The tutorial explains on how to use NIMH or Lithium-Ion batteries for this. Step 4 explains how to use ...
2
votes
1answer
61 views

Solar powered single cell LiFePo4 charger circuit

As a follow-up to this question I've come up with this schematic for a solar powered battery charger: Subcircuits, from left to right: Solar cell (just a voltage source), 12V, 10W. Buck regulator ...
0
votes
1answer
56 views

Materials required to convert NiMH rechargeable 24V/6Ah circuit (20 C-cell) to Li-Ion rechargeable circuit

Below is a picture of a battery shell for a NiMH circuit for a power assist wheelchair battery. I'm taking a guess that each of the 20 batteries is 1.2V because the entire circuit is 24V. These are ...
0
votes
1answer
70 views

Why is the 1uF capacitor needed in this load-sharing circuit?

Consider the following circuit that describes a MCP73831 battery charger with a load sharing circuit: Why is the 1uF capacitor needed? I realize that the 4.7uF are there to reduce "noise", but why ...
-1
votes
0answers
51 views

How to make a robot charger?

I would like to equip my robot with a docking base to charge its batteries. My problem is that I do not want to turn off the Arduino in the robot during charge. I don't think we can use and charge a ...
0
votes
2answers
55 views

Making a simple solar-powered lighting system, a few concerns

I'm building a fairly simple solar-powered lighting system to use at home, which charges up a battery by day and then the battery powers a few bulbs at night, switching automatically. So far, I got ...
0
votes
1answer
26 views

Lead Acid Battery Charge C/20Ah

I need to charge a lead acid battery, I will be manually developing a program to set the current. Its the "US 12V XC2" Deep Cycle battery. Here is a link to the datasheet: ...
0
votes
0answers
46 views

Adding a regulating circuit to supply 3.3v

Background I wish to power my circuit with a 18680 battery. My circuit actually has two parts: 1) a 18650 charger and power booster for USB at 5V, and 2) a Bluetooth LE module (running at 3.3v with ...
-2
votes
1answer
49 views

Show charge state of a car battery [closed]

I'm building a mobility music box, powered by a car battery (12v, 74Ah). What can I build into this box to show the current charge state (read somehow from a display if the battery should be changed)? ...
-1
votes
1answer
76 views

Portable 1A battery phone charger

I want to make a little battery-powered portable phone charger with 2x AAs that outputs 1A. I have seen similar USB powered battery chargers such as the Mintyboost but it only outputs 500mA. For 1A ...
2
votes
1answer
58 views

Solar powered charger circuit for a single LiFe cell

I'm looking for a solar powered charger circuit for a single LiFePo cell. The load is a low power MCU with some sensors attached, and when sufficient solar power is available, it should be used to ...
-1
votes
2answers
64 views

how long charge li- ion battery [closed]

I have \$3.7V\$ Li-ion battery \$3800mAh\$ and Solar panel \$U=5.5V, I_{max}=290mA\$. Battery will supply arduino with sensors taking \$100mA\$ current. How long will it take to charge the battery ...
0
votes
0answers
38 views

SLA charging circuit design

I got one more question about my car-dynamo-connected-to-bike project. My dynamo needs some juice to energize the electromagnets inside, so that's why I will include a small 12V 1.2Ah SLA battery ...
-1
votes
3answers
83 views

What happens when gadget gets 100% charged

We see that when our mobile phones, laptops, i-pads, or any other electronic gadget requiring charging, gets completely charged it starts displaying that it has stopped charging like in my HTC phone ...
2
votes
0answers
63 views

piezoelectric vibration energy harvesting

Recently i'm working on a project aims to convert the vibration of sound waves into electricity to charge batteries using piezoelectric material ( MFC type ) , i was trying to use the human voice as ...
-5
votes
1answer
105 views

How many hours would a 38000 mAh powerbank will last? [closed]

i bought a 38000 mAh powerbank and to my surprise when I could only use it for a total of 6 hours and then I have to recharge it again. My battery's capacitu is 1 700 mAh. By the way I'm taking up ...
3
votes
4answers
910 views

How do I design a 2A or more power supply for my consumer USB devices?

I understand that many of my consumer devices charged by USB ports can charge at higher rates than 0.5A. However, in testing, I've found they don't consume more than this. Test Setup I have a ...