Fuel economy in a car: Charging battery the Arduino way: 2nd and last part

26650 LifePo4 A123 batteries (2.3 Ah)

After analyzing the advantages and disadvantages of changing the car battery for a homemade LiFePo4 one as we discussed, I've finally discharged it for the following reasons :

Home Automation: How to activate a relay via USB on Windows to control devices (blinds, lights, etc)

Although it is most economic and versatile use Arduino as a programmable electronic board, so we avoid the known unreliability of Windows, when you want to activate a equipment is sometimes easier to use a USB relay, either because we have a computer that has to be always on, or for other reasons, allowing us to theoretically control up to 8 switches for each USB connector on the same PC. 
I had to replace an old system that used the LPT1 port for controlling a time alarm (not compatible with Win XP or 7) so after investigating it I bought 2 pcs. of this USB-controlled relay  in Aliexpress.

And if we want to control multiple devices there are up to 8 channels (relays) in the same unit, with each relay 10A capacity, so the possibilities are very extended.

Fuel economy in a car: Charging the battery the Arduino way - Part One

In this post we will see what details we consider to adapt a vehicle to save fuel by switching off the alternator when we are not interested to charge the battery (and take advantage of braking, engine braking, etc. to do so), taking advantage of lessons learned in the previous post . This It is especially useful in a diesel , where power consumption is much lower than in a gasoline car.

Currently any measure is little to lower the consumption of a car, and although we are in a period of decline in fuel prices, this is transitory, because as with any commodity product high demand prices will soon go back up (or keep at the highest possible price that permits its competitors).

We can change the wheels to a eco profile ones, change the oil by other more energy efficient (as we discussed), etc. And one of the points of great savings capacity (between 1 and 5% savings) is in producing electricity, generating electricity with oil is very expensive. Some people even partially hybridized vehicle for changing the alternator motor / generator and replacing the battery with a LifePo4 (Forum GoldenMotor).

You have to evaluate the suitability of this modification, as the lead-calcium batteries do not allow more than 20% discharge without damage, so there is little room to use them with a programmed charging. Ideally mount a LiFePo4 battery, but can cost more than 200 €, only useful and profitable to people that uses them a lot in short travels in the city (taxi drivers and transport vehicles).

The most innovative engines are now including programmed battery charging, so that is only activated when the low voltage level is reached, although I do not know what kind of battery this cars uses and what the procedure in detail.

Curiously, in the following video you can see how the workload on the alternator note clearly appreciate the drop in rpm (and automatic adjustment by the control unit) of this PSA 1.6 HDI diesel engine:

The Li-ion 18650 for sale on the Internet: There are more false than legitimate

When I started acquiring Li-ion batteries 18650 back in 2012 to restore some packs, there were still no stores in Spain that had them and I started to import them through Chinese pages like DX.com, aliexpress, Ebay, etc.

Note: The reference "18650" refers to the shape and dimensions; 18 is the diameter in mm, 65 is length and 0 indicates the shape; in this case cylindrical.

At first I was confident and I trusted the ads in some extent, I knew the false capacities of some NI-MH before, where manufacturers also indicated many times more capacity than real, so I was prepared. I compared, and bought cheap, but not the cheapest, high capacity (announced) batteries, , and hoped that there would not be much difference.

This problem is very well explained in Energizes or Bateriasdelitio.net , which echo the deceptions of Chinese "smart" guys.

I was wrong. I came to ordering (ouch!) For 3 €/unit. 18 batteries "Fandy-FIRE", the "manufacturer" marked them as 3600 mAh capacity, when in fact they only had 800 or less! When they arrived the first thing that struck me was how little weighed; the larger capacity usually weigh 47 grams / unit, when these did not reach the 30 g / pc., although some manufacturers are "approaching" the weight of the good ones filling them with materials as diverse as flour!

Current state of the art LED options in H4 / H1 car bulbs

Model H4 LED high performance

Tired of changing the H4 halogen lamps of my Xsara Picasso car, I was looking for alternatives in LED, checking the state-of-the-art in H4 Led lamps, If I could find one well worth installing, so getting savings in fuel and maintenance .

Is it legal? : To carry LED lamps  outdoor legally in Spain, for now we only have the option of installing a complete approved headlamp, and that must be installed by a certified workshop to carry the certificate to the periodic Technical inspection, because the headlamps are designed for a type of lamps with which it lights the same way (lumens and openness); this could cost easily €150. These lamps in theory can not be used on public roads (although for racing/testing purposes). There is no problem changing the ambiental interior lights to Led ones.

In the following video I commented highlight of these LED lamps H4 "SunnyLight"  and installation:

DIY: Turn your bike into e-bike for yourself - Step 5/5: Final details: Active Braking, charge control and legality

This wounded wire is my brake;)

After a few months of using battery-powered bike, I am going to comment how it feels. On the one hand it does very well with the uphills, but the downhills are another thing. In my neighborhood we have slopes with between 8 and 10% drop, and the bike does not stop fast enough with his brakes (disk brake only in the back). I have found that its weight (about 30 kg) is a major handicap, and although putting many banks in each cell increases the li-ion battery life and autonomy, it makes very difficult to go upstairs with it (impossible to carry on daily to an apartment), or braking, the brakes suffer a lot (especially at low speeds when the engine brake don't work).
Although we could use engine braking to stop and derive the energy to the battery, but you can not raise too much the regeneration (engine braking); above 15 amperes (1,5C) batteries suffer much from excessive current (even without reaching 4.2V per cell), and they degrade faster, besides the Golden Motor control is proportional to speed (recovers more amperes the higher the speed), so we could be sending a damaging 40A to the batteries if the slope is steep and we go fast.

Another option is to put LiFePo4 batteries, much more tolerant, but they have less energy capacity per kg, in addition to its high prices. The A123 for example accept for each 26650 cell type up to 10A continuous recharge. For this moment I can' afford them (although they come equally profitable having more recharging cycles).

After investigating, I found a interesting solution  about using a resistance as a powerful engine braking (what  a great well of wisdom is Endless Sphere about electric behicles), ¡and they have proved that it works wonderfully!:

Example of resistance brake on a bike from a friend of Endless

Changing the hard drive of a Lacie Network Space 2

A couple of years ago I bought this super NAS (Network Storage) Lacie with Linux operating system, good performance and very low power consumption (you can set it to shut off at 20 min. without use, very convenient for longer life of your hard drive).

The disc It had got too small, so using Clonezilla, I opened the box (to do only handle in the area led out all the cover up), and I cloned the 1TB disk to another larger than 2 TB. To exploit its full capacity, we have to resize the XFS partition data to use all the free space remaining with the Gparted (free Linux program).

The Gparted allows us to do all sorts of operations on partitions (image of their web)

Avoid the discharge of the car battery when not used using a simple relay and interruptor

Relay connection scheme

An old Fiat Bravo was draining battery when not used for a couple of days, and the battery had to be recharged every time: The electronics had an excess of consumption, far surpassed the admissible 0.3 Amps.

After reviewing the possible cause (alternator regulator in poor condition, or something that was connected) by removing fuses and checking consumption every time, I did not found the source of the problem, so we decided to place a switch controlling a relay to disconnect the battery when the car was not in use.

Thus the battery, although the car is not used for 1 full year, only 30-40% is discharged (typical self-discharge at 1 year for batteries Pb / Calcium). Furthermore we lengthen the life of the Central Computer by completely disconnecting it. 

I also take the opportunity to see how these relays are for my next project, which would be programmatically control the battery charging to save fuel by turning off the alternator.

NOTE : Keep in mind that if the battery gets disconnected, you lose the date and time of the control panel (if any).

Using a relay just have to carry three thin wires into the cabin to turn the switch and voltage indicator, because power is handled as close to the battery as possible.

DIY Homemade pool water solar preheating system - by Jordi

Economic system of heating pool water

This past summer Jordi from Valencia was consulting on how to heat the pool water with economic polyethylene tube, and discussing their results, and is happy to share it with you.

Surely he noticed this post (system that does not use nearly as efficient) and was encouraged to heat his pool that way, and wanted to "removing the cold", raising its temperature from 18 to 25, a more comfortable temperature, taking advantage of the close roof surface where the sun hits well.

Jordi told me that he would use PE pipe Ø20 mm. and had doubts if it would work; the pool is quite large , 14x3 meters. I had thought to extend about 250 meters tube had calculated that fit on the roof.

Lighting by electromagnetic induction: Current best choice for high power lamps

When it is necessary to illuminate a street, building, etc, and lots of light output is required, induction lamps are more profitable than the LED because of its lower price and its durability.

Campana 250W used in warehouse

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