Battery management at Tesla cars

Battery management at Tesla cars


There's something I want to learn.

A few days ago on a TV show, a rival manufacturer said that Tesla was not able to control every battery cell. But in their vehicles, each battery's voltage, amperage, temperature is controlled, he said. It was necessary because each cell he said it was their own character.

Why doesn't Tesla control every cell in this way?


Frank99 | April 25, 2019

If each cell has their own character to the extent that they need to monitor voltage, current, and temperature of each cell, I'd say the "rival manufacturer" needs to improve the quality of their battery supplier.

There are a dozen ways to build a 400 Volt, 200 Amp-Hour battery pack. Tesla has chosen a couple of different methods, Chevy chose a method, BMW chose a method. The engineers involved had to make many tradeoffs to decide how they would do it - tradeoffs involving manufacturing cost, customer safety, ability to control temperatures and balance battery cells, etc. It's not clear to me that Tesla's approach will be what EV design converges on 20 years from now - but it's a danged good one to jumpstart the EV industry. | April 25, 2019

The easy answer is Tesla is a lot smarter than such rival manufacturer!

The main reason is expense - it requires costly electronics to do this for each cell, and is unnecessary when you have reliable production that makes each cell repeatable as Frank points out. The problem occurs when you start using much larger cells, as some other EVs companies use. It becomes almost impossible to manufacturer the cells to be identical to each other, forcing you to control each cell's charging and discharging independently of other cells. There is nothing wrong electrically with this approach (other than being more costly).

The one downside, as Boeing found out in the 787, large cells have a much higher risk of an extreme thermal event if an internal short occurs. All cells have similar risk, but using small cells greatly reduces the heat generated and risk to the pack. A large cell failure is very hard to stop and will clearly take out the entire pack or you need to isolate each cell, adding more costs and weight.

This is unrelated to crash damage, which is quite different situation and likely all types of packs have a latent risk of a thermal event depending the severity. Still better than a gas fire in an ICE vehicle that erupts immediately.

Yodrak. | April 25, 2019

"A few days ago on a TV show, a rival manufacturer said ..."

What TV show and what manufacturer?

reed_lewis | April 25, 2019

Just because another company does something does not make it either necessary or better. For example with FSD other companies are doing lots of simulations because they do not have the fleet already driving.

And I would trust Tesla battery management over any other manufacturer. The longevity of Tesla batteries in the cars has been proven to be excellent.

jordanrichard | April 25, 2019

From what I have seen, Tesla has the best thermal management than any other company. From what I saw in a video of a tear down of the Bolt and i3 battery packs, the cooling of the batteries is only done one side of the module of batteries sort of in a heat sink manner. Tesla has a ribbon “tube” running between all of the individual batteries, providing IMHO a far superior method of cooling the cells.

neset.ozeren | April 26, 2019

Rival manufacturer was

It is not a serious company to be taken seriously.
Still, I was curious about the claim.

Thanks for the descriptions.

I couldn't find a record of the TV show that I watched

Company responsible also said; In the position of the battery cells in the car, there are different characters depends the temperature and humidity differences there, it is necessary to control each cell.
According to these differences, the life span of each is different. etc.

bp | April 26, 2019

Tesla vehicles have THOUSANDS of small batteries in the battery pack, arranged in "bricks".

The remaining range measurements are an estimate of available charge across all of those batteries.

Tesla's charging hardware is designed to charge the batteries safely - and manage the batteries to minimize long term degradation.

Musk stated this week the current packs should have a lifetime of 300,000 to 400,000 miles, and that a new pack will be released next year that will extend that to 1,000,000 miles - or around 4,000 full charge cycles.

They've already developed and deployed packs capable of 4,000 full charge cycles for the industrial PowerPacks and consumer PowerWalls and will be bringing that technology to their EVs next year.

Even if Tesla isn't able to control individual batteries, based on the experience with the huge number of battery packs they've deployed (in EVs since 2012) and power storage devices, they've proven their strategy works very well - and likely puts them at least several years ahead of any other vehicle manufacturer.

Earl and Nagin ... | April 26, 2019

in EVs since 2008 -- when the Roadster first went into production.