Jason Hughes is the Tesla hacker extraordinaire who first discovered the P100D logo embedded deep in a software update 6 months before the Tesla 100 kWh battery became available  in the Model S P100D and Model X P100D. Rather than being miffed that his secret had been revealed ahead of time, Elon Musk tweeted at the time, “Good hacking is a gift.”

Tesla 100 kWh battery

Now Hughes has latched on to a Tesla 100 kWh battery from a salvaged P100D and dug into it to learn its secrets. The P100D has only been available for less than 6 months, so finding a salvage car probably means someone with more money then brains was unable to handle the awesome power available and crashed the car the battery came from.

One of the discoveries Hughes made is that Tesla seems to have taken the trouble to make the 100 kWh battery backwards compatible with older Tesla automobiles. Hmmmm….what is Elon up to now? Hughes notes this newest battery uses the same high and low voltage connectors as other Tesla batteryu packs. He says, “the pack itself has the same high voltage connection, the same low voltages connectors, and the same cooling connector.” There is one change, however. The P100D battery pack requires one new part in order to connect to an older car — a plastic ring.

“The [P100D] pack has the newer ring around the high voltage connector. So, it’s plug-and-play (for the most part, firmware and config changes needed) on the Model X and refreshed Model S, however it would require a different spacer ring on the high voltage connector.” No problem, Hughes says. “Tesla even has a part number for it, so it should be pretty simple to put into any Model S/X,” he reports.

Tesla already is taking steps to keep the number of battery packs it produces to a minimum. In the Model S, a customer can order a a car with a 60 kWh battery, but it will come with a 75 kWh battery pack that is software limited to 60 kWh. The owner or subsequent purchaser can unlock the extra capacity at any time upon payment of a fee to Tesla. Apparently having to manufacture and stock only one battery pack that serves the needs of two different sets of customers saves the company money.

Battery packs are expensive items. Is it likely that anyone would ever actually pay the money to have a whole new battery installed in a Tesla? It would probably be cheaper to just order a new car in the long run. But things are moving swiftly in the world of electric cars. If nothing else, backward compatibility would make it easier to fit a used battery to an older car if the original car is destroyed in a collision. Maybe Tesla wants to keep its options open, just in case.

Hughes also uncovered some interesting technical tidbits after poking around the salvaged battery. He found that Tesla had crammed a total of 8,256 18650 battery cells into the 16 individual modules inside the battery. It found space for the extra cells by making the cooling coils shorter and thinner. But the connection to car’s external cooling system is identical to the one used by all other Tesla battery packs. He also found the battery had a total of 102.4 kWh of capacity.

Elon Musk has said Tesla probably won’t be building a battery larger than 100 kWh any time soon, even though competitors like Faraday Future and Lucid are claiming to use larger batteries with up to 135 kWh of capacity. But neither of those cars have gone beyond the prototype stage and may never actually go into production.

Tesla meanwhile has made the 100 kWh battery its new top of the line power source for both the Model S and Model X, replacing the 90 kWh pack that was the top selection previously. The Model S 100D has an EPA certified range of 335 miles, making it the longest range electric car you can buy. Tesla seems to think if you need more range than that, its network of Superchargers will be just what its customers need for long distance travel.

Source: Teslarati  Photo credit: Justin Hughes