NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Secondary Use of PHEV and EV 

Batteries – Opportunities & Challenges

The 10th Advanced Automotive Battery Conference 

Orlando, Florida 

May 19-21, 2010

Jeremy Neubauer 

Ahmad Pesaran

National Renewable Energy Laboratory 

David Howell*

U.S. Department of Energy

NREL/PR-540-48872

Funded by Energy Storage R&D (David Howell), 

Vehicle Technologies Program U.S. Department of Energy
National Renewable Energy Laboratory 2 Innovation for Our Energy Future

Background – Battery Secondary Use

• It is a common belief that batteries in PHEVs and EVs expect to reach the 

end of their useful life when their capacity, energy, and/or power capabilities 

drop by 20% to 30%. 

– The reason is to have a vehicle that performs roughly the same at the beginning 

and end of the life of the battery.

• At the end-of-life, the “retired” PHEV or EV battery may still have reasonable 

energy capabilities for other applications such as stationary use.

• Secondary use of EVs (mostly NiMH) batteries was briefly studied in the 

past, but no implementation occurred

– 1997 ANL study sponsored by USABC 

– 2002 Sentech study sponsored by SNL/DOE

– “Electric Vehicle Battery 2nd Use Study” by Southern California Edison 

• Due in part to the limited market of PHEV/EVs at the time, no second use 

programs have been implemented yet

– Sensitivity to uncertain degradation rates in second use

– High cost of battery refurbishment and integration

– Low cost of alternative energy storage solutions

– Lack of market mechanisms and presence of regulation

– Perception of used batteries
National Renewable Energy Laboratory 3 Innovation for Our Energy Future

New Interest in Battery Secondary Use

• New opportunities and dynamics for secondary use of 

“retired” electric drive vehicle batteries

– Recent strong interest in PHEVs and EVs for reducing 

emissions, energy security, peak oil, and high price of oil. 

– Improved performance and life Li-Ion batteries, but still with 

high cost 

– Growing use of renewable solar and wind electricity; increased 

market penetration may benefit from energy storage

– New trends in utility peak load reduction, energy efficiency, and 

load management

– Smart grid, grid stabilization, low-energy buildings, and utility 

reliability has the need for energy storage such as batteries

– Large investment in battery manufacturing for green economy

– Reducing the initial cost of batteries by the value obtained in 

second use applications. 
Current Second Use Activities

• AEP & EPRI... considering a Community Energy Storage (CES) appliance, 

which they’ve stated is “the ideal secondary market we have been seeking for 

used PHEV batteries”

• UC Davis... with funding from CEC has released an RFP titled “Second Life 

Applications and Value of Traction Lithium Batteries” to investigate profitable 

second use strategies and develop a Home Energy Storage Appliance (HESA)

– The California Center for Sustainable Energy and its partners were selected for an Award

• UC Berkeley/CEC... investigated strategies to overcome the battery cost of 

plug-in vehicles by the value of integrating post-vehicle battery to grid 

• Rochester Institute of Technology... funded by NYSERDA to investigate the 

second use of lithium ion batteries

• Nissan... has partnered with Sumitomo to initiate a business plan centered on 

recovering and reselling used automotive batteries

• Enerdel ... is working with Itochu to develop energy storage systems for 

apartment buildings to “help develop a secondary market” for used batteries

• Better Place... is “evaluating ... second life applications for used batteries” in 

partnership with Renault-Nissan

• NREL... funded by DOE to investigate the potential and value of PHEV/EV 

battery in second use and obtain data on performance of used batteries

National Renewable Energy Laboratory 4 Innovation for Our Energy Future
NREL: Uniquely Positioned to Investigate Second Use

National Renewable Energy Laboratory 5 Innovation for Our Energy Future

Utilities & Grids Solar Energy Wind Energy

Hybrid & Electric Vehicles Energy Efficient Commercial & Residential Buildings

Energy

Analysis

Li-Ion Batteries
National Renewable Energy Laboratory 6 Innovation for Our Energy Future

NREL Battery Secondary Use Project

Objective

• Evaluate the merits and value of end of vehicle life 

batteries for use in other applications – address challenges

Potential Benefits

• Reducing the (first) cost of batteries for PHEV and EV 

applications

• Reducing the cost and environmental impacts of recycling 

and disposal of batteries before their “true” end of life.

• Providing advanced inexpensive batteries for nonvehicle 

applications such as renewable electricity and home use

Approach

Phase 1:

Assess 

Merit

Phase 2:

Verify 

Performance

Phase 3:

Facilitate 

Implementation
Phase 1: Assess the Merit

Some Second Use Applications

• Grid-Based Stationary 

– Energy Time Shifting

– Renewables Firming

– Service Reliability / Quality

– Home Energy Appliance

National Renewable Energy Laboratory 7 Innovation for Our Energy Future

• Off-Grid Stationary

– Backup Power

– Remote Installations

• Mobile

– Commercial Idle Off

– Utility & Rec. Vehicles

– Public Transportation
Phase 1: Assess the Merit

Application Identification

• All applications are considered, but highvalue / high-impact ones are most 

desirable

• Accurate use profiles and economic data 

are needed

• Application value and impact will be 

estimated before progressing to a 

detailed investigation

National Renewable Energy Laboratory 8 Innovation for Our Energy Future

• For each application, consider...

– How does a battery retired from automotive service 

perform when subjected to the second use profile?

– What are the projected revenues and costs?

– What are the safety concerns and liabilities?

– How do the performance, life, and cost of a second 

use battery compare with those of competing 

technologies?

– What are the regulatory issues or other barriers 

specific to this application?

– Is the scale of this application well suited to the 

expected availability of retired PHEV/EV batteries?
Phase 1: Optimizing Use Strategies

• For a given second use 

application, there can be many 

different ways to implement it

• Changing these variables can 

have a significant impact on 

total lifetime value and general 

feasibility

• In this segment, the use 

strategy of the battery is 

optimized via the developed 

tools and practical 

considerations

National Renewable Energy Laboratory 9 Innovation for Our Energy Future

Manufactured & Installed 

in Automobiles

Employed in Automotive 

Applications

Refurbished for Second 

Use Applications

Employed in

Second Use Applications

Recycle
Phase 1: Optimizing Use Strategies

• For a given second use 

application, there can be many 

different ways to implement it

• Changing these variables can 

have a significant impact on 

total lifetime value and general 

feasibility

• In this segment, the use 

strategy of the battery is 

optimized via the developed 

tools and practical 

considerations

National Renewable Energy Laboratory 10 Innovation for Our Energy Future

Manufactured & Installed 

in Automobiles

Employed in Automotive 

Applications

Refurbished for Second 

Use Applications

Employed in

Second Use Applications

Recycle

How should the 

battery be used and 

retired?

How do you collect, 

screen, refurbish, certify, 

& distribute the batteries?

How do you manage 

ancillary systems, the 

use of multiple packs, 

and servicing needs?

What design and 

manufacturing practices 

should be employed?

Who owns 

the battery at 

each stage?
Phase 2: Verify Performance 

Conduct Long-Term Testing

• Subject the aged batteries to the expected use profile and 

conditions of the second use application to verify performance 

and degradation predictions and lifetime valuations

• Lab testing for precise 

control of conditions

• Field testing for final 

demonstration

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NREL’s Distributed 

Energy Resources Test 

Facility could serve as a 

venue for this phase
Phase 3: Facilitate Implementation

of Second Use Projects

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– Disseminate study findings to inform the market of the 

potential profitability of the second use of traction batteries

– Provide validated tools and data to industry

– Develop design and manufacture standards for 

PHEV/EV batteries that facilitate their reuse

– Propose regulatory changes to encourage the reuse of 

retired traction batteries in other applications

Phase 1:

Assess 

Merit

Phase 2:

Verify 

Performance

Phase 3:

Facilitate 

Implementation
Planned Work – Battery Second Use

National Renewable Energy Laboratory 13 Innovation for Our Energy Future

• NREL is currently seeking partners to investigate the reuse of retired 

PHEV/EV traction batteries to reduce vehicle cost and emissions as well 

as our dependence on foreign oil.

• A Request for Proposal (RFP) was issued in April 2010 seeking a 

subcontractor to accomplish the aspects of this effort. 

– You can find RFP No. RCI-0-40458 at www.nrel.gov/business_opportunities

- current solicitations. 

– Proposals are due near the end of May 2010 (extended to early June 2010). 

– If you have questions regarding the RFP, please contact Kathee Roque at 

Kathee.Roque@nrel.gov.

• A workshop to solicit industry feedback on the entire process is also 

being planned.

• Aged batteries will be tested in 2-3 suitable second-use applications.

• Hope to answer the questions, “Do PHEV/EV batteries have any value 

for other application? What are the barriers?”
Concluding Remarks

• Secondary Use of PHEV and EV Batteries

– DOE is supporting efforts to evaluate the second use of retired 

lithium ion batteries to identify if second use batteries could 

reduce the initial cost of PHEV and EV batteries.

– NREL is involved technically and will collaborate with partners.

• NREL has issued an RFP for collaboration

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