How to determine the voltage level in Lithium Ion battery

Lithium Ion batteries are now widely used in Mobile phones, Power banks, Digital cameras and other devices that requires 3.6 V . Lithium Ion batteries are long lasting since its current rating is very high above 2300 mAh.It is very important to maintain Lithium Ion batteries since, both over charging and poor charging may completely destroy the battery.Some have the habit of plugging the Mobile phone in charger overnight. Mobile battery needs to be charged only when its charge goes below 50 %.Proper charging and discharging increases the life of Mobile battery and its efficiency. Let us see its voltage levels
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How to set the Re trigger Jumper in PIR sensor Module

The PIR sensor module has a Jumper arrangement to select single trigger and re trigger modes. Let us see how it works Continue reading

How to connect PIR sensor Module

It is important to know the connections of PIR sensor module. It is easy to connect it with alarms, relay to drive AC load etc. Let us see Continue reading

Laptop Battery Power supply. Start Up Project 38

12ADon’t throw away old Laptop battery; it can be reused for other purposes. I hacked one Laptop battery and salvaged six high efficient Samsung Lithium Ion batteries each rated 3.6V, 4300 mAh. It is worth Rs. 1000. Few days before, I found that, my Laptop is not getting enough back up and shutdown immediately when the charger is removed. So I replaced the battery at the cost of Rs.1200. Due to curiosity, I just opened the case of the old battery pack and found that, the batteries inside can be reused. After testing, I found that only one battery out of the six is damaged. All the other five are in good condition. That damaged battery created the problem in the battery pack and prevented the remaining five batteries from their work. So actually this is happening in our Laptop. If one battery fails, we have to replace the battery pack. If the good batteries are salvaged from the old pack, we can reuse them for many different applications like LED lighting, Mobile charging, making power supply etc. So I spend Rs.1200 for the new battery pack but I salvaged 5 good batteries worth Rs. 1000 from the old battery pack. So my actual expense is only Rs.200. So do not discard the old Laptop battery. Tear it, salvage the individual batteries and reuse. You can save money and can reduce the e-waste.
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Peltier Joule Thief. Start Up Project 37

13AYou know, we can light a 1 watt LED without a battery! Peltier will give “Free Electricity” for that. When we heat the Peltier with flame, hot water or a hot object, it starts to generate current. Its voltage can be around 1.5V when the heat is above 60 degree. But this 1.5V is not sufficient to light even an ordinary LED that requires 1.8V minimum. 1 watt White LED requires 3.6V. Then how? We can add a Joule Thief circuit for that. A Joule Thief circuit is a self oscillating circuit that increases the input voltage as low as 700 mV to 4-5V. So if the Peltier is connected to a Joule Thief and heated, Joule thief will amplify the voltage to light the 1 watt LED. Let us check this.
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Peltier Electricity. Start Up Project 36

12APeltier is the Fantastic device used to make cooling devices. When a current of more than 500 mA passes through the Peltier, its one side cools while the other side turns hot. This is due to the transfer of heat from one side of the Peltier semiconductor to the other. As the current increases above 1 Amps , the cooling effect increases and the temperature of the cold side of Peltier drops below 0 degree. But if we reverse the function of Peltier, it generates electricity. For example, if we heat one side of Peltier above 60 degree using a hot object, hot water or flame, Peltier generates around 1.6V DC and around 350mA current. Let us make one circuit of “Free energy “generation using a Peltier Module. Since the 1.5V from the Peltier is not sufficient for lighting an LED, we have to add a voltage booster to increase the Peltier voltage sufficient to light the LED. If 5 Peltier are serially connected, we can even charge our Mobile phone using a Candle flame.

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Servicing a Maintenance Free Battery. Start Up Project 29

6BI found that my UPS is not giving sufficient back up as expected for 20 minutes. I thought that I have to spend Rs. 800 to replace the battery. But I was not in a hurry. Want to find out the reason. After 5 minutes, the PC shutdowns. Why so? The UPS battery is not giving sufficient power (Ampere Hour) to run the load. The UPS battery is a 12 volt 7 Ah (Ampere hour) Maintenance free Sealed LeadAcid battery (SLA). That means, it is “Maintenance free” and can be used for long time without any attention. But what happens is, the cells dry out due to heat generation. This happens after 6 months to 1 year of use . It is a Lead Acid battery that requires Electrolyte in the cells. So water is necessary inside. It has 6 individual cells giving 2V each. After removing the battery from the UPS, I found that it is very easy to rejuvenate the battery through “Hydration”. The battery will become top, if the dry cells are filled with battery water. Hydrated the battery and charged. Well, now it is giving more than 15 minutes back up. Saved Rs. 800 and reduced an e-waste. You can also rejuvenate the 6V Emergency lamp battery like this. So do it yourself. It is only a 10 minutes job.

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