A fine-spot welder is one of the few equipment where building yourself is cheaper than buying. There are already published a lot of DIY spot welders, this one has some unique features:
It can be used in 2 welding applications: opposed and series configuration.
The construction is kept very simple.
Accurate electrode force adjustment.
It has a solid electrode holder, made of a radiator earthing clamp.
An Arduino microcontroller is used to set the weld time accurately.
Creates a double pulse which improves clamping.
The current can be reduced for welding sensitive parts.
DIY battery tab resistance fine-spot welder - [Link]
by pinomelean @ instructables.com:
Lithium based batteries are a versatile way of storing energy; they have one of the highest energy density and specific energy(360 to 900 kJ/kg) among rechargeable batteries.
The downside is that, unlike capacitors or other kinds of batteries, they can not be charged by a regular power supply. They need to be charged up to a specific voltage and with limited current, otherwise they turn into potential incendiary bombs.
And that’s no joke, storing such a high amount of energy in a small and normally tight packaged device can be really dangerous.
Li-ion battery charging guide - [Link]
We all know lithium-ion batteries need careful monitoring to prevent over-charging and ensure cell temperature remains within limits. We all thought we knew the best way to replace the charge as well: trickle charge, take it nice and gentle to keep the cell temperature down and prolong cell life. Turns out we may have got that last one wrong! New findings published in the Nature Materials Journal by a team of researchers at Stanford University indicate that by tweaking the battery design it may be possible to get faster charge/discharge rates and also increase the number of charge cycles.
Better lithium-ion Charging - [Link]
A USB port is a great power source for charging a single cell Lithium-Ion battery. It is capable of supplying a maximum of 5.25V and 500 mA. The circuit above is a USB powered single cell Li-Ion battery charger. LM3622 is used as the controller. This special purpose IC has a precise end-of-charge control and low battery leakage current about 200nA. S1 and S2 select the low voltage detect enable/disable. The low voltage detection is handy for conditioning a deeply discharged battery with a low current stage, to prepare it for the full charge cycle.
LM3622 Li-Ion USB Battery Charger - [Link]
This Arduino Nano controlled solar battery charger can charge a standard lead acid 12V battery and runs with 90% efficiency under 70ᵒC (158ᵒF). The circuit can take up to 24V input from the solar panels. The maximum power point tracking is implemented in the circuit by measuring the output voltage and current from the solar panel to get the maximum possible power from it.
Solar battery charge controller - [Link]
Alan Parekh of Hacked Gadgets writes:
Thanks to GearBest for sending in this Opus BT-C3100 V2.0 Intelligent Battery Charger for review. at a quick glance this charger might look like any other charger that you see at the grocery store. Your generic store bought brand probably also has 4 charging bays for AA and AAA batteries, it probably has 2 charging circuits which places 2 cells in series to charge them, it most likely has 2 charging lights which just turns off when charging is done. If you leave the batteries in your generic charger you will most likely have batteries that have been overcharging or running down. Also your generic charger can probably just charge one chemistry of battery.
When you have a closer look at the Opus BT-C3100 V2.0 Intelligent Battery Charger you can see how this system differs from your every day generic battery charger. It can auto detect and charge NiCd, NiMH and Li-ion batteries. It charges each cell independently preventing bad cells from interfering from other cells from charging properly. Forget charging lights, this has a full LCD display that provides tons of status. It will monitor batteries that are left in the charger and keep them topped up and ready to go. From here the features go on and on. Don’t let the small package fool you, there is a ton of smarts and features built into this small package.
Have a look at the pictures below and in the video for a look inside the charger. The construction is a dual sided SMD load, the construction looks very professional. The battery contact spring tensioners work well and the connection to the PCB has been beefed up with a thick metal bar…
BT-C3100 intelligent battery charger teardown - [Link]
Here’s an Instructable about a DIY charger for car’s battery with an analog DC ammeter in the front panel. A PIC12F683-based control circuit is enclosed inside which adds some intelligence to this charger. The PIC MCU checks the terminal voltage of the battery being charged in every ten minutes using one of its analog inputs, and if it is found above a set threshold, the charging process is stopped. A relay switch is included into the circuit to connect/disconnect the charger output and the battery terminals.
PIC12F683 based battery charger - [Link]
Perhaps the most frequently used rechargeable batteries on the market nowadays – Lithium-Polymer (Li-Po) can be found also in our offer.
From the beginning of electronics, the world searches for an “ideal” rechargeable battery. So far such a battery doesn´t exist (maybe supercapacitors in the future), but Li-Po (Li-Pol) cells are quite near to an ideal in some aspects.
Very low self-discharge (approx. 5% / month), high voltage of a cell (3,7-3,8V average), high energy density and a low weight, considerably stable discharge voltage and a possibility to recharge anytime are one of the main advantages of Li-Po cells. Another benefits are advantageous flat shape, high variability in dimensions and a long lifetime. No wonder, that Li-Po cells have become no. 1 in consumer electronics, hand tools and in many industrial devices.
Perhaps the only drawback of these cells is their lower chemical stability at overcharging (in a corner case ending up with a fire). But that´s the case which is practically eliminated at a common operation with a suitable charging circuit (chip or a charger intended for Li-Po).
Basic principle at usage is not to exceed approx. 4.25V charging voltage and the battery is almost discharged at a voltage below approx. 3.0V (2.75V). On the very end of a discharge cycle, the inner resistance slightly increases, what can cause a slight heating of a battery at higher currents – it is a normal behavior. Charging is usually based on a method constant voltage/ limited current. In principle it´s possible to use the same chargers and charging circuits for Li-Ion as well as Li-Po cells.
At a usual usage and discharging to say 20-80%, Li-Po cells will reward you by a reliable operation and a long lifetime. Flat shape is ideal for various handheld equipment, as well for usage in flat enclosures. In respect to a low self-discharge it´s possible to use Li-Po cells even as a backup energy source.
In our offer can be found several several Li-Po types from company EEMB with a capacity of 130 mAh to 2000 mAh. Exact list of available types and datasheets can be found below this article. Upon request, we´re able to provide you also many other types.
Try the most favorite type of batteries - [Link]
Jianan Li made this LiPo Booster project, that is available at Github:
LiPo Booster is a breadboard-friendly boost converter board based on the TPS61230 IC from Texus Instrument. It has an output voltage of 5V, and is designed to be used with a single cell LiPo battery.
LiPo Booster, a breadboard-friendly boost converter board based on TPS61230 - [Link]
Rechargeable batteries save us a lot of money but take a lot of time. What if you could recharge a battery in seconds instead of hours?
Rechargeable batteries save us a lot of money these days but for the savings, we give up some of our time, waiting for them to recharge. What if though. What if there was a rechargeable battery that took seconds to recharge instead of hours? That is exactly what I’ve invented and I need your help to bring this to the masses and show the world that we no longer need to waste hours of or lives waiting for a battery to charge.
With the leaps and bounds being made today with capacitors, they’ve gone from being able to store a tiny potential of energy to now, being able to store enough energy to be considered a power source. These high Farad capacitors are known as super capacitors and aside from providing electricity for an extended period of time, they can also be charged very quickly. Recently, there’s been another development, combining the technology of super capacitors with lithium ion batteries. The usually downside to super capacitors from batteries is that they don’t provide electricity for nearly as long. However, with the advent of the lithium ion capacitor, that is quickly changing.
30 Second Charging, Rechargeable Battery - [Link]