From the Tesla PowerWall and PowerPack to one-off projects like repurposing used hybrid battery packs to power a remote Ranger hut in The Yosemite National Park, it’s become something of a tradition for automakers producing significant quantities of plug-in vehicles to launch their own line of static energy products to complement their electric and plug-in cars.
And with good reason too: it gives automakers a chance to enter a new marketplace — that of static energy storage — while also allowing them to spread the cost of investing in electric vehicles and electric vehicle battery technology across a wider range of products.
In the case of Tesla Motors, announcing the Tesla PowerWall and Tesla PowerPack allowed the California automaker scale up battery production to levels simply not possible from automotive sales alone. This in turn dramatically lowered the cost of producing battery packs and by association, made it possible for Tesla to unveil its $35,000 Tesla Model 3 electric sedan.
Despite nearly every major electric automaker already producing or readying their own static energy storage products for market, the resulting products we’ve seen thus far have either repurposed used electric car batteries in a specially designed case (as in the case of second-life battery projects from BMW and Toyota) or used specially designed custom battery cells tweaked for energy storage rather than traction use (as is the case for Tesla’s energy storage products). To date, we’ve not seen an energy storage product that is designed to use an electric vehicle battery pack in its entirety without any internal modifications.
Until yesterday that is, because at the EVS29 electric vehicle symposium in Montreal, Canada, BMW unveiled a world-first in domestic energy storage systems: a wall-mounted backup power system that uses a stock BMW i3 battery pack for energy storage. Sadly, the battery storage system unveiled is still a proof of concept rather than something BMW has committed to bringing to market. And while it may not be quite as aesthetically appealing as some of the battery storage systems coming to market, it makes up for its looks with plug-and-play practicality.
Since BMW’s concept storage system is designed to make use of stock BMW i3 battery packs, it actually consists of two distinct parts: a mains power inverter and power electronics system and the battery pack itself. Joining the two is a pair of high-voltage DC power cables that plug into the existing DC power port on the BMW i3 battery pack. Since the original 22 kilowatt-hour BMW i3 battery pack as well as the new, longer-range 33 kWh i3 battery pack recently announced by BMW both use the same connections, the system can be used with either capacity battery pack.
In the single photograph shared by BMW of the concept, a BMW i3 battery pack hangs on the wall next to the external power electronics box, presumably bolted to a custom mounting plate. Despite being wall-mounted and carrying a new BMW-branded trim panel at the top of the pack where the power cables exit the battery pack, it’s clear that the battery pack itself has received no additional modifications. Indeed, we’re guessing with the right lifting equipment and workshop, it would be possible to remove a BMW i3 battery pack from a working car and then hang it on the wall to be used in this system.
BMW says that the system could easily be used with brand-new BMW i3 battery packs, or could be a great solution for those whose BMW i3 battery packs have reached a point in their life where they are no-longer capable of providing the high-currents needed to provide motive power to an electric car due to the increased internal resistance all lithium-ion battery packs suffer as they age.
While it’s unlikely any BMW i3 battery packs will reach this state for many years to come — most electric car lithium-ion battery packs will either outlive the car they are in or at worst, suffer only marginal capacity loss — it does provide BMW with an easy way to recycle electric car battery packs at the end of their life. And since BMW’s system doesn’t require any reconfiguration of the individual battery cells inside the pack, it’s a cost-effective solution that doesn’t require a large amount of reprocessing of used electric car batteries at the end of their life in a car.
Sadly, there’s no news on if or when this system will come to market, but we’d love to hear your thoughts on BMW’s concept storage system. Will it be the most cost-effective way to turn your electric car battery pack into a battery pack for your home? Do you like the design? And would you want one?
Leave your thoughts in the Comments below.
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