Rehabilitating one Metabo screwdriver with a Li-ion 4400 mAh 12.6V

Metabo BZ 12 SP with DIY Li-Ion Battery

As a gift, I was given an old screwdriver that was going to go to waste. It used the old Ni-MH battery technology or Ni-CD, and you know me ... I love those tools that works wirelessly, so I started to build for it a more economical, durable and powerful li-ion battery than the original, as there are no li-ion batteries for this screwdriver.

Note : Adapting these instructions you will be able to build batteries for any wireless device that you have at home and that, for its price or quality of their batteries, you are considering to throw away.

This requires using Li-ion batteries that allow discharge at 2C at least, or they could be damaged quickly. Lipo could be used but these have half life than other liIon chemistries. The Li-Mn (manganese) allow faster discharging without damage, but are quite expensive, and LiFePo, A123 manufacturer would be ideal, but pricy too.

I found a middle ground in Lico of  Boston Power-shaped like two 18650 united , but actually is a single battery, ovalish format, making better use of the space, and with very good capacity for cases where two batteries are used in parallel (such as laptop batteries), and they have a very good chemistry that is not damaged by 8Ah instantaneous demands such as a screwdriver, retaining its capacity better than others between uses:

See below Load controller chip

The humidity at home: Origins and possible solutions

Typical grid to beautify vents

When moisture appears in our house, the most important thing is to find out its origin , since it depends on the applied correctly and lasting solution, avoiding wasted expenditure of time, energy and money.

Moisture not only spoils the walls and all kinds of organic material (mold on leather, wood, etc), but their lack of treatment can be a source of health problems ;fungi, breathing problems (asthma, allergy), etc. While a definitive solution can not locate, we try to keep it in a healthy range (45 to 65% saturation) with a dehumidifier for example.

Designing a wood stove: simple, convenient and efficient combustion: Understanding the process of combustion of wood (3)

Picture: Hergóm 

To find an optimal design in an oven, we must analyze and understand the process of combustion of wood; variables involved, phases, each phase processes, better combustion conditions, etc., a theme to spare studied by engineers and encompasses knowledge of different subjects: thermodynamics, fluid dynamics, chemical dynamics, mechanical properties and thermal properties of various materials etc.

When designing an effective, safe and easy to build homemade stove, we find the following dilemma:

As the efficiency of the stove grows, so the complexity of it.

However we must look for a committed performance and simplicity and ease of construction that fits the overall needs in burning wood design , and our goal should be that, later to be implemented improvements (also easy to implement if possible ) that can increase performance.

Wood stoves with secondary combustion: Less smoke and more performance

In this blog we have been analyzing the benefits of using biomass to heat our home for profitability and ecology.

In this post I will discuss something even more beneficial for our pocket and nature: The technology of double combustion wood stoves. With this system, lacking the vast majority of wood stoves, get even greater performance avoiding much maintenance to avoid the generation of smoke, which the outlet tubes accumulate less soot and tar with use, produced by imperfect combustion of the gases expelled by the timber to catch high temperatures.

Soot particles are carbon that failed to burn and did not pass gas as CO and CO2.

Philips vs Braun Shavers, what is technically better?

As you can see in the video, while most Braun afeitaduras use their own proprietary system, in which the blades cut hair using a reciprocating, and is actually the floating plate moving under a thin steel sheets the which makes the cut, in Philips shavers have 2 or 3 discs that cut the hairs that pass between the slots, cutting more effectively and accurately.

The SmartTouch XL; a marvel of Philips

Repairing an LCD screen: Replacing blown capacitors

The capacitors are famous for electrolytic fail when subjected to long time of use, temperature and stress, swelling and bursting the top cover where release of the electrolyte liquid inside. Many basis of old computers that had this type of capacitor plates ended up failing after 2 years, and now they are substituted for polymer electrolytic capacitors aluminum, stronger and more durable.

IMPORTANT : Before you throw a screen away because you think beyond repair, ask before budget in an electronic workshop , it may be a small thing (every day are cheaper and sometimes costs more to repair, but still not worth more than a new repair, convenient repair, you are recycling, less waste and investing in local labor).

In this case I was left a screen which two seconds to light the lamps emitting a like a very low "zzzzz" buzzing sound turned off. The sound was probably the vibration of capacitors stage transformation frequency of 50 Hz which is the AC, that being in poor condition that sound emitted.

How to heat a home with an open fireplace: Adding a cupper coil, by Rafa

Fireplace coil made of copper by Rafael, with added doors

The people are so rigged. Rafa, a Seville plumber of 52 years, residing in Gerona has been kind enough to share with us their system , very similar to mine , which  for heating radiators leverages the built-in fireplace (yes, those that turn you on ahead and I grow cold by behind), achieving a more than worthy result to save wood and heat the house. 
He was not aware of these pots (used in villages of the Basque Country for decades), and their parents save money and gave googled my page, went looking for and found Lacunza, in whose  assembly schemes relied for connecting pumps, thermostats , etc., which sells kits pumps and thermostats ready for its chimneys, and the coil was based on the they have for sale Fireplaces Sierra , but made ​​with 15 mts. welded copper tin / silver . Detail thermometer, thermostat at 45 ° C to activate pumps and sensor of the safety valve 90 (not visible in the picture, touching the tube) which triggers a valve that ejects the last water this temperature outside and in turn enter cold water from a faucet automatic filling (in another photo) set to 1.5 bar:

Detail shot regulating door, right thermostat, thermometer and safety valve sensor

The best choice for heating your home (updated 2014)

How do I heat my house cheaply and with greater comfort? This same question I became in the summer of 2006. And now I discuss in this article that will update as circumstances change.

Before heating, is 10 times cheaper and more effective to isolate; in this post or  this one's more information on this topic.

Having analyzed and changed the heating my house I have acquired some knowledge that I share with my readers, since heat your home is a major expense that if we do not choose it may prevent us to make ends meet during the cold winter months ; - ). Nor find myself in possession of absolute truth, so take my advice and reasons for yourself.

Building a wood-optimal, safe, efficient and easy firewood: Continuation

Example stove with vermiculite plates and air intake to improve combustion

I keep turning the issue of simple and efficient stove burning (low CO2), my goal before automate with Arduino and complicate thing is to seek simplicity.

Everything should be made ​​as simple as possible, but not simpler. Albert Einstein

First of all I will discuss a couple of important things in any boiler or fireplace:

• Pressure of fumes (sub-Atmospheric): It depends on the height of the chimney, caudal (diameter) and flue gas temperature rising by it; more value for any of these three variables shot improvement. If too much heat recovered from combustion, the fireplace is narrow and low rise in output has no anti-wind cap, going to have problems in your smoke fire under; the combustion chamber will be filled with smoke and even put a door will not improve much the problem and the fire may drown in their own CO2. It is important a good shot if you do not want to fill with smoke every time you load wood burning stove.

Repair closing system from a door from an AEG Lavamat 5011 washer: The door does not open

In this post we will see how to repair the tab closing the door of a washing machine

At this AEG Lavamat 5011 stopped suddenly open the door . At first I thought it was the next piece, control door lock, but after releasing it, I checked stuck and moved as expected, so it could not be the problem.

We will have to act on the inner part (across) the closing of the door open