Tesla’s Latest Patent Is For A “Methodology For Charging Batteries Safely”


Tesla Model S

One of Tesla’s latest patents focuses on a topic that we had thought was already taken care of…safely charging batteries.

Apparently, Tesla thinks charging can be done more safely with the use of a fault-detection apparatus.

Here’s the brief from the patent filing (which contains a wicked run-on sentence):

Methodology for charging batteries safely

“An apparatus and method for identifying a presence of a short circuit in a battery pack.

A fault-detection apparatus for a charging system that rapidly charges a collection of interconnected lithium ion battery cells, the safety system includes a data-acquisition system for receiving a set of data parameters from the collection while the charging system is actively charging the collection; a monitoring system evaluating the set of data parameters to identify a set of anomalous conditions; and a controller comparing the set of anomalous conditions against a set of predetermined profiles indicative of an internal short in one or more cells of the collection, the controller establishing an internal-short state for the collection when the comparing has a predetermined relationship to the set of predetermined profiles.”

Safety is always priority #1, so it makes sense to focus on charging as safely as possible, but with only a few documented incidents with electric vehicle while charging, we had thought a high level of safety had already been achieved.

However, Tesla believes there’s room here to increase safety to the next level and we applaud the automaker for its efforts.

Source: Fresh Patents

Categories: Charging, Tesla


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12 Comments on "Tesla’s Latest Patent Is For A “Methodology For Charging Batteries Safely”"

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Robert Weekley

How would they lab test this idea? Design a Pack with some specific known flaw coditions, and test the data monitoring to see if it caught the known flaws & stopped charging?

For example: a pack built with some substandard cells, built that way on purpose, to test the new data monitoring system?

Or, a pack built normally, but subjected to a test rig that applied physical damage to the pack in both slow a rapid types of force applications?

Or a test rig that applied localized external heating or cooling (Acetylene Torch Flame / Liquid Nitrogen Flow ), to determine if such conditions could: a) be detected and stop charging, b) be identified as occurring at a specific location in the pack?


Sure. I’m sure they have enough substandard cells they ran across. You can make worn out cells by abusing them or just using them to near destruction.

You can create cells with opens and shorts mechanically (specific construction to be bad) too.

Kim Jorgensen

Not so long ago Elon Musk commented on a competitors claim to be able to charge at higher rates than the Tesla supercharger and Musk’s reply was; … amps, a children’s toy! This could be related to much faster charging on the way from Tesla.


It’s amazing to me that patents like this get approved.

Smart chargers have been checking cells against expected profiles (including impedance) for over a decade now. They already uses these profiles to change between charging methods (CC, CV, etc.).

It shouldn’t be possible to get a non-specific patent of this sort on this process since it is common use already. Its a failure in the system.


If battery electrical vehicles had to meet OBD-II requirements, this would be a boilerplate requirement for the battery.

Electrical fault detection on most components is pretty standard stuff in order to meet OBD regulated requirements for a vehicle with a more traditional power train.

Realistically, this should already be mandated per the right to repair laws. Faults are supposed to be easily detected so that the owners and service community can readily repair vehicles.

“It shouldn’t be possible to get a non-specific patent of this sort on this process since it is common use already. Its a failure in the system.” First of all, this is a partial description from a patent filing. Nothing in the article says the patent was approved by the USPTO. Secondly, and more to the point: If you follow the link for the source of this article, you see the full patent runs to 16 pages. What is quoted above is just the description of what the patented technology is intended to achieve; effectively, it’s just an abstract of the full patent application. The details of exactly how that would be achieved will be detailed later in the patent application; apparently detailed at great length, since the entire document runs to 16 pages, altho it’s possible a large part of that length is figures (i.e., schematics and circuit diagrams). And I’m no patent expert, but I think you’ll find that it’s the method of implementation that would be protected by a patent; as you say, Unlucky, the description of the purpose is so broad that it never would stand up to a challenge, because there are already numerous systems… Read more »

This the internet. The whole thing is available and I read it.


Although you’d do better to look at a version with pictures.

I don’t really get your comment about the method. The patent lists several embodiments and says it is not intended to be limited to the embodiment shown.

‘Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein.’

This is ridiculously broad and I can’t see how anything like this would be approved in a reasonable system.

I don’t really care whether Tesla has put it into production. If they haven’t they should, because other companies already have this kind of monitoring. I’d be surprised if Tesla didn’t have it.

Maybe you’re right, it won’t be approved.


Good Idea.
Now you also have all your Easter Eggs, in one basket.


Who said, biting off the chocolate ears on an Easter Bunny never Tesla-tasted so Good? The Easter Basket can have all the eggs!

Bill Howland

Well, at least they are thinking about safety. I haven’t heard of any car other than an “S” that has safety issues while charging. The one car in Norway totally melted down, and the Chinese car put a hole in the door of an adjacent “S”.

Rav4EV also had trouble with heating connectors, but they were Tesla electronics. Not sure who made the J1772 but the connector was made concurrent with the “S”.

I never had any heating issues/safety issues with my Tesla Roadster while charging, nor have I heard of any other trouble other than with the 40 amp S or X portable wallbox. They partially addressed the problem first with a software kludge, and then more permanently with a fuse in the 14-50 adapter which positively prevented fires..


Looks like there has been at least one fire reported from a non-Tesla battery pack charging. According to Wikipedia:

“The lithium-ion battery of an i-MiEV caught fire at the Mizushima battery pack assembly plant on March 18 [2003] while connected to a charge-discharge test equipment.”

However, since test equipment was involved, it’s possible the i-MiEV pack was being charged at a higher current rate than it was designed for; this may have been a “test to destruction” situation. Without more details, it’s impossible to tell.


Mister G