Confirmed: 30 kWh Nissan LEAF Battery Packs Incompatible With Older Nissan LEAFs

Yesterday morning, Nissan confirmed long-running rumors that suggested the 2016 Nissan LEAF SL and SV electric cars would go on sale with a larger-capacity battery pack to extend the real-world EPA-approved range of the popular family hatchback to 107 miles per charge.

All 2016 Nissan LEAF SV and SL models come with an expanded 30 kWh battery pack.

All 2016 Nissan LEAF SV and SL models come with an expanded 30 kWh battery pack.

Fitted with the latest lithium-ion battery cell technology, the new 30 kilowatt-hour battery packs are physically the same size as the 24 kilowatt-hour battery packs found in previous model year LEAFs and the entry-level 2015 Nissan LEAF S. While 46 pounds heavier in weight, the larger packs require no special modification to the LEAF’s six-year old body design in order to accommodate them.

This lead us to theorize that owners of the 2011 through 2015 Nissan LEAF models might be able to purchase a new 30 kWh battery upgrade for their electric cars in much the same way that Nissan has allowed owners early-model LEAFs to upgrade their car’s battery pack to the latest-generation, more robust 24 kWh packs under Nissan’s official battery replacement program.

But while the physical exterior pack dimensions of the new 30 kWh LEAF battery packs are identical to the battery packs found in every LEAF that has rolled off the production line since late 2010, internal differences in the way the packs are wired and connected to the car means that a 30 kWh upgrade path for existing cars isn’t possible.

Existing owners wont be able to upgrade to the 30 kWh pack, says Nissan.

Existing owners won’t be able to upgrade to the 30 kWh pack, says Nissan.

 

From the technical specifications provided by Nissan when it announced the 2016 Nissan LEAF, we’re able to piece together what those differences are.

While both the new 30 kWh pack and old 24 kWh pack have contain 192 individual cells for a total nominal battery voltage of 360 volts, the old pack is made up of a string of forty-eight modules, each containing four cells per module. The new 30 kWh pack contains twenty-four modules, each containing eight cells per module.

While that gives the same nominal voltage as the old pack, we’d guess the way in which the on-board battery management system manages and monitors individual cells and modules is different, meaning that a new power management unit is required for the 30 kWh battery pack.

For new vehicles rolling off the production line, that change is fairly simple to make. But in order to use the 30 kWh pack in an older Nissan LEAF that originally shipped with a 24 kWh pack, we’d guess multiple components in addition to the battery pack would need to be replaced.

That would be a costly and somewhat complex process.

We should reiterate at this point that what we’ve just said is our own theory, based on what we know of the 2011-2015 Nissan LEAF family and what we’ve learned about the new 30 kWh Nissan LEAf battery pack from Nissan’s own technical briefing material. We haven’t been able to confirm that theory with Nissan.

The new battery packs are physically the same size as the old ones -- but are differently wired.

The new battery packs are physically the same size as the old ones — but are differently wired.

Because the technical requirements are not the same, the 30 kWh cannot be used to replace a 24 kWh battery,” Nissan said in response to our query about theoretically fitting a 30 kWh battery to an older 24 kWh Nissan LEAF. 

This doesn’t mean Nissan intends to keep current owners out in the cold however. Nissan will continue to offer its existing battery replacement program for owners of 2011 through 2015 Nissan LEAFs, allowing customers to either lease or purchase a brand-new 24 kWh battery pack for their cars, depending on where they live in the world.

Those battery packs, while still limited to 24 kWh in capacity, will be built using the latest generation of lithium-ion cell chemistry, but won’t feature the extra capacity.

In addition to answering our question about replacement battery packs for existing owners, Nissan also clarified that the all-new NissanConnect EV telematics which will debut on the 2016 Nissan LEAF SV and SL will replace Carwings as Nissan’s default telematics system.

“Existing CARWINGS users will have the opportunity to transition to the NissanConnect EV system,” we were told. “They should receive communications shortly.”

It’s not clear what functionality will be available to existing Carwings customers who transition to the new telematics, but we’d guess doing so will equate to a new mobile phone app and improved website functionality. As existing Carwings users will know, that should be a welcome upgrade after struggling with the buggy, unreliable carwings system LEAF owners have been using for the past five years.

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