After a volatile four-day run for Tesla Motors (TSLA 12.06%) stock, shares wrapped up the short trading week with a roughly 3% gain, trading near $191 at the time of this writing. Here's a review of some of this week's key events and commentary related to Tesla stock.

Model S. Source: Tesla Motors.

Is China a problem, or not?
When the week began, Tesla stock was trading only a few dollars off its 52-week low of $177.22. The stock has been pressured by pessimism regarding the company's ability to sustain high demand for its Model S sedan, particularly in China. Last Friday, Tesla CEO Elon Musk told the news agency Xinhua that China was "the only place on Earth" where Tesla has excess inventory.

But Musk added that sales are steadily improving in China. On Twitter this week he said he remains "very optimistic about Tesla's long term future in China." 

A "major new Tesla product line" is coming
On Monday, Musk tweeted that the company would reveal a "major new Tesla product line" on April 30. The new product, he said, is "not a car."

Speculation quickly turned to the "home battery" Musk referred to during the company's fourth-quarter earnings call. Tesla has said it plans to unveil the battery within a few months and begin producing this summer. On Tuesday, Musk all but confirmed that speculation about a home battery unveil was correct.

Tesla has already worked with SolarCity (SCTY.DL) to provide energy storage in a small-scale pilot program. SolarCity plans to install battery energy storage systems in 430 homes by early 2015.

SolarCity details the current pilot program on its website:

SolarCity is making the latest advancements in battery technologies available to you through our partnership with Tesla Motors. Only SolarCity's home backup system uses technology engineered by Tesla, leveraging their expertise in developing battery technologies for premium electric vehicles.

Tesla's long history of research and development has enabled a cost-effective, wall-mounted storage appliance that is small, powerful and covered by a long lasting full 10 year warranty.

The actual battery unit is about the size of a solar power inverter, and will be mounted on the wall in your garage or near your electrical panel.

While SolarCity has filled all the spots in its battery storage pilot program, the company's website says it will share a "new and improved offering" in mid-2015, timing that coincides with Tesla's home battery talk.

SolarCity has said it eventually wants to install home batteries with every home energy system it sells; Tesla has said it will provide at least some of these batteries.

The home battery Tesla mentioned in its fourth-quarter earnings call would likely be a more complete and widespread solution than the current pilot program for storing energy generated by solar panels.

Tesla plays the April Fool's game
Tesla joined in with other tech companies for the April Fool's fun. Seeming to poke fun at the rumors of Apple building an electric car, Tesla said it was launching the Model W.

See the full Tesla Model W blog post here. Image source: Tesla Motors.

"This incredible new device from Tesla doesn't just tell the time, it also tells the date," read the company's blog post. "Studies have shown the Model W will dramatically improve your health. If you work out."

At the end of the post, Tesla nudged Apple: "This is in no way a competitive response to what some other company is doing."

Tesla also announced a new feature for the Model S, which the company claimed it would push to its fleet via an over-the-air software update.