Improving the Ebike with Arduino to monitorize battery and add anti-theft alarm 2/2

As discussed in the previous post, my goals to put a microcontroller programmed with Arduino on electric bike they were:

• With an RGB LED display the charge / status of the battery monitoring one of the (weaker if possible) cells, to avoid surprises of not having enough charge for the trip the next day, showing orange when needed recharging (between 20 and 40%).
• With an accelerometer and a powerful piezoelectric speaker  (and a mosfet to activate) we can add an anti-theft alarm, easy disabled with a button hidden from view, which is very handy against foreign's friends.
• And even (this slope time), add light automatic brake  using the accelerometer (which changes from low intensity to high intensity when the accelerometer receives a deceleration in the axis of the fly), to keep usage statistics (number of refills, airtime, or adding small OLED display to show instant consumption in Ah with  a Hall sensor  (such as Allegro ACS75x, etc), battery charging, etc.

So this Christmas I could get down to work, and start to test in a breadboard to get something functional:

Extending the range and power of the bike by adding two cells in the luggage carrier

Before this project, the battery of my bike consisted of 8 cells in series of 6 batteries LiFePo4 A123 in parallel each, and I realized that I could have some more top speed and range by adding two cells with the previously left over LiFePO4 A123 batteries, and changing the BMS for the one I found of 10S and 60A (much better than the previous 15Ah only):

BMS / Control LiFePo4 charging battery cells 10 and 60A  maximum.

I will not cease repeating that if ye ride yourselves a Lithium Ion battery, you must put always a BMS, as this is essential prottection for the battery, cutting the flow of current in both overload and over - discharge in any of the cells.

One important note: This only works if you use the SAME type and state of cells for the additional cells (or you will get an unballanced battery fast, or worse, damaged cells that can't cope with the current).

On the other hand, increasing only 6V maximum load, I can still use the configuration of the motor control for 24V (having automatic cut if they drop too low voltage with the BAC-281P ebike controller, we cut prematurely the current if we use 33V battery with a 36V configuration). 

Features of BMS 10S LifePo4 60A load balancing ref. BMS-10SQZ6060LF375 :

Important data:

• 10 Cells LiFe 3.6V, 36V full.
• Maximum peak current: 90A
• Constant current approx. without sink: 30A
• Standby power consumption: 0.1 mAh (100 microamperes / hour).
• For the rolling is effective with only 70mAh per cell balancing, the load should be as slow as possible (depending on the difference of load cells), recommended < 500 mAh.

As  I noted, the 12 could fit on a damaged old hard drive enclosure aluminum made. 

Installation and improvements over an Hephestos Prusa i3 3D Printer from BQ

Those who follow me will have seen that I have uploaded some videos with the assembly of the i3 Prusa BQ, plus reducing vibration and the last has been adding LED light, adapting for printing flexible filament and isolating the extruder with silicone (spanish voice):

Improving cooling a powerful notebook graphics with a transistor and Arduino

Laptops that come with powerful graphics have an usually badly designed thermal control; This is the case of my dear Acer 5930G (already I spoke above ) wearing a removable Geforce graphics card.

Engineers Acer believed it was enough to regulate the fan with the processor temperature, since the sink joins both, but the graphics consume more, which can reach 70 easily while the CPU is 40 and the fan medium gas.

We'll see how we regulate the fan directly 5V , depending on the temperature of the area that interests us, with the advantage of being able to use any fan that can be coupled to our team, plus you can customize the level of cooling in the Arduino code. 

The result : I got him down more than 20 to the graph regarding the regulation of factory, from 70 to about 45 ° C at rest. And in 90 games at maximum 70 ° C. You hear more, because almost constantly is 100% , but if that win in durability, I welcome the resulting hiss. Another advantage is that by taking the power from the USB port, turn it off when no temperature peaks but still cooling off while connected to the grid, until it cools completely and stops. 

Materials Needed:
- Chip ATtiny85 
- Transistor NPN 50V typical and 5Vgs ( 2N4401 I used myself). 
- Capacitor 220uF 6V and min. 
- Diode 5V and minimum hold 200mAh. 
- Tubing.

Drivers for Windows 10 ATI RV370 (X300)

Here you have the direct download, without advertising, of drivers that work for this card in Windows 10 (64 - bit and I think also 32 bits).

If it gives you an error with the installation, you have to install them manually (by going to Device Manager -> Select Display driver (right mouse button) -> Update Driver, select it manually on the system, locate the driver directory).

I've gone crazy looking for them ... getting no more than incorrect drivers for it (Ati no longer supports it) so if I hope will save more than one headaches... :).

Reusing power sources to power devices of different voltages: voltage converters

42V DC Power 19V 2A regulated DC to charge a laptop that spends 3A

In this post we will see how to feed these appliances we have at home, whose power supplies had stopped working and left, forgotten, in a drawer.

For example, that portable power supply can have a second life and continue feeding any device that requires a power exceeding the capacity (watts) of the transformer. While we maintain the amps equal or exceeding the needings by the apparatus we want to power, we just have to make sure that the voltage output is the same or little less of your device needs.

If for example we need an  e-bike charger, or need a charger of a given voltage, we can adapt economically the output voltage: This is where the boosters and converters come into play modifying voltage DC to DC.

Improving the Ebike with Arduino to monitorize battery and other info 1/2

It is the second time it happens; I pick up the bike, and after the trip to work, the ebike left me without power in the middle of a slope... with the hassle of having to carry their 30 kgs. on a slopes over 14% (and the damage it does to the battery the depth discharge, fortunately are pretty well LiFePo that support this). 

I have no charging indicator (the handle that provided me is to 48V) to calculate if you have enough power for 4 km I have to do, and also the LiFePo4 have a very small voltage variation between 20% and 80% of capacity (between 3,15V and 3,35V), which is easily neglected. And make it load every day is not practical or the best for the battery (ideally recharge when you reach the 20% to maximize battery life). And the battery charge indicators seem to me too "greedy" energy. So...

A solution for every need ...

01/09/17: In the end I finished using a Nano and MPU-6050 accelerometer for burglar alarm functions and voltage indicator, in the 2/2 post from january 2017 you can see the details.

Types of Batterie Management Systems (BMS); building new batteries for our equipment

Complementing the already abundant information on this blog about batteries, recycling and repair, and BMS, I will analyze the types of BMS and qualities that we can find among Chinese BMS. The main reason for the short life of batteries any type is often their poor maintenance ; either because they remain flat or that are downloaded more than convenient (both lead as Li-ion do not tolerate discharges well below a certain level). To protect the batteries (particularly lithium dangerous if overloaded or short -circuited), the " battery Management Systems " or BMS come into play to good use and long battery life.

How to Choose the BMS we need

Solar thermal collector configuration supporting gas/oil boiler

Antonio from Orense had a solar panel with a deposit of 150 lts connected to the same circuit ACS but separately, so that when it was sunny had to walk opening and closing keys to harness this energy and save fuel in the oil boiler.

With solar thermal energy (pre - heat the water with a solar collector) all are advantages. This renewable energy system is today the fastest amortized, usually in two years the installation is amortized, and lasts up to 30 years , with minimal maintenance. It's easy money, and who have not it installed, properly sized, they are throwing money to the trash, literally.

After analyzing your installation of ACS (ignoring the heating pipes), I advised him to use solar thermal as we do; supporting boiler  (gas in our case).

The method is simple; it provides warm water tank directly to the boiler, so that it only has to provide sufficient energy to bring it to the temperature (usually 60 °), and so you forget.

DIY: Avoid overheating problems on your PS3 with a chip and sensor for 5 bucks

With a small chip Digispark ATtiny85 will see how to regulate the fan of the PS3 (or any PWM-controlled fan) depending on temperature, avoiding wear and tear prematurely. 

Engineers PS3 gave priority to the silence of the PS3 , since it is intended to be a center of games and multimedia, so the processors can reach damaging temperatures for the welds thereof, and within a few years ends up breaking down by poor contact welding (reparable only with reflow or reballing).

The PS3 has a pulse PWM controlled fan, Atmel ATtiny85 and can be easily programmed with the Arduino IDE.

There are examples on Youtube and internet people that has regulated the fan fixedlyto go ever faster (with a resistance in the gray wire connected to the 12V, regulating 1V approx., Or with a potentiometer to do it manually) but is not the best solution because it does not consider the processor temperature (which can vary greatly depending on ambient temperature), and although it works, having to cover all cases, there isusually noisier.  and with this solution we have the advantage that if we hear the very loud fan, you will surely have a problem of lack of ventilation dust or other problem.

materials