In May 2015, Ilon Mask presented beautiful home Powerwall units to store energy from solar panels from the roof – and provide free electricity The whole house day and night. Even in the absence of solar panels, such backup power for the house is especially valuable if electricity is cut off in the quarter. The computer and all the equipment will continue to work quietly.
The second version of the Powerwall stores up to 13.5 kWh, which should be enough for several hours (standard power of 5 kW, and at a peak of 7 kW). The only problem is that the original version of Tesla costs as much as $ 5500 (plus $ 700 for related equipment, total $ 6200, plus installation works cost from $ 800 to $ 2000) – very expensive. DIY makers solved this problem with the help of battery batteries that lie free in discarded laptops.
With their hands, it is possible to assemble a unit with better characteristics than Tesla (for example, 30-100 kWh) – and much cheaper.
Enthusiasts of DIY-assemblies share their experience at specialized forums DIY Powerwalls, in a group on Facebook and on YouTube. A special section on security forums is an important aspect when you collect such a powerful thing that can also catch fire on the street (they are usually installed outside the house so as not to break the law and out of security).
For builders, the assembly And connecting such a power supply is not only an interesting occupation and saving money, but also an opportunity to understand how an electrician works in the house.
Almost all enthusiasts in the comment Motherboard noted that their own systems Are much more shey capacity than the Tesla. Probably, the company has sacrificed capacity for the sake of beautiful fine design of the power unit and for greater efficiency of cooling and safety. One of the French makers from the forum under the nickname Glubux assembled a block for 28 kWh. He says that this is enough for the whole house, and he even had to buy an electric oven and an induction cooker to consume surplus energy somewhere.
Australian maker Peter Matthews assembled a 40 kWh unit that is powered by 40 solar panels On the roof, the blessing in Australia is no shortage of sunny days.
The largest homemade unit found Motherboard assembled from 22,500 cells from laptops and has a capacity of more than 100 kWh. From this block a small house can work for several months – for example, throughout the winter – even if the solar panels are completely out of order or inactive.
A Californian blogger Jehu Garcia intends to assemble from batteries Laptop system at 1 megawatt, the largest similar system of private energy storage in the US
Most enthusiasts use the 18650 lithium-ion batteries when assembling. They are usually packaged in colored plastic cases and installed in laptops and other electronics. The new 18650 batteries cost about $ 5 apiece, so the system will be a little cheaper than the Tesla model. Therefore, assemblers usually buy up batteries and remove batteries from discarded broken laptops. Unfortunately, many people just throw out the batteries together with a broken laptop, although they are still quite working. According to the director of the largest US recycling company Call2Recycle, about 95% of the batteries are not reused, and finish their way in the dump, although all types of batteries can be re-used in one form or another in the mail.
Finding a sufficient amount of discarded technology is not so simple, and recently it has become even more difficult, because many people began to collect their own power systems like Powerwall from them, and laptop manufacturers do not encourage the reuse of their batteries at all In 1945. They were tested after the discovery of batteries, and then "updated" through cycling with a full discharge. Then the batteries are combined into "packages". Such boxes for hundreds of batteries can be bought on the market or collected independently. Attached to the top are electrically conductive copper busbars, and battery contacts are soldered to them.
The entire structure is attached to the inverter and mounted in a rack, which is usually installed on the street. It is possible to set up a monitoring system for temperature monitoring with automatic shutdown of energy banks that are too hot.
A whole community of makers from all over the world has already formed that build such "cordless home farms" from old laptop batteries to store electricity from solar Batteries. The community unites enthusiasts from around the world, they share experience and advice on safety, engineering systems, compatibility of different types of batteries, etc. Success and safety Powerwall has proven that these are truly safe systems suitable for permanent long-term use (Powerwall warranty 10 years ).