Repurposing EV batteries for energy storage

NiHaoMike · 05-21-18, 12:54 AM

Nissan Leaf battery modules are already $200/kWh.

oil pan 4 · 05-21-18, 07:30 AM

I see them on ebay, modules are 2 cells, I'm assuming 24ah and people want $90 to $100 for them.
That's still $700 for 1 useable KwH if the cells actually hold 24ah and they are 24ah.

Now if you bought an entire used battery that would be $200 to $400 KwH then you still have to take it apart and rearrange the cells for normal useable voltage unless you have a lead on an inverter that will convert leaf 400vdc to single phase AC?

NiHaoMike · 05-21-18, 10:18 AM

Each module is 2S2P for about 62Ah.

jjackstone · 05-21-18, 11:57 AM

I can buy a used Leaf pack locally for $3000. That's $125/kwh. Of course there's no telling what level of charge ability the pack has remaining until tested. I have seen wrecked Leafs go for around $2000 on auction sites. But then you'd have to transport the car, pull the pack, and get rid of the rest of the vehicle. On the other hand if you were doing a conversion and the motor was still intact you could swap out the Leaf parts into your own build. JJ

oil pan 4 · 05-22-18, 08:47 AM

That still leaves you with a battery with 400vdc potential to take apart.
It doesn't bother me one bit.
When I replace the battery in my leaf I was going to eat the deposit and harvest the modules for my projects and sell the rest individually.

NiHaoMike · 05-22-18, 10:26 AM

This girl will show you how to tear down a Nissan Leaf pack to get at the modules:

https://www.youtube.com/watch?v=oWNnnIHVsCU

She kind of shows off how strong she is:

https://www.youtube.com/watch?v=AHLjdjAaMj4

oil pan 4 · 06-16-18, 10:44 AM

That actually looks pretty easy.

Take the leaf battery when it loses 2 or 3 bars of battery life, replace it then harvest the leaf modules out of the old battery and repurpose them for 48v.
The first 4 cell LiFePO4 charge controller came out about 2013 and I believe the first 48v LiFePO4 charger is out already.

NiHaoMike · 06-17-18, 10:07 AM

The Leaf cells are not LiFePO4 but LiMn. 4.1V full charge is not a common voltage for a BMS so I ended up designing my own for my project.

05-21-18, 12:54 AM	#1
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Repurposing EV batteries for energy storage Nissan Leaf battery modules are already $200/kWh. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

05-21-18, 10:18 AM	#3
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Each module is 2S2P for about 62Ah. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

06-17-18, 10:07 AM	#8
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	The Leaf cells are not LiFePO4 but LiMn. 4.1V full charge is not a common voltage for a BMS so I ended up designing my own for my project. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

05-21-18, 07:30 AM	#2
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	I see them on ebay, modules are 2 cells, I'm assuming 24ah and people want $90 to $100 for them. That's still $700 for 1 useable KwH if the cells actually hold 24ah and they are 24ah. Now if you bought an entire used battery that would be $200 to $400 KwH then you still have to take it apart and rearrange the cells for normal useable voltage unless you have a lead on an inverter that will convert leaf 400vdc to single phase AC?

05-21-18, 11:57 AM	#4
jjackstone Helper EcoRenovator Join Date: Mar 2009 Location: Sacramento,Ca Posts: 88 Thanks: 5 Thanked 32 Times in 23 Posts	I can buy a used Leaf pack locally for $3000. That's $125/kwh. Of course there's no telling what level of charge ability the pack has remaining until tested. I have seen wrecked Leafs go for around $2000 on auction sites. But then you'd have to transport the car, pull the pack, and get rid of the rest of the vehicle. On the other hand if you were doing a conversion and the motor was still intact you could swap out the Leaf parts into your own build. JJ

05-22-18, 08:47 AM	#5
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	That still leaves you with a battery with 400vdc potential to take apart. It doesn't bother me one bit. When I replace the battery in my leaf I was going to eat the deposit and harvest the modules for my projects and sell the rest individually.

06-16-18, 10:44 AM	#7
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	That actually looks pretty easy. Take the leaf battery when it loses 2 or 3 bars of battery life, replace it then harvest the leaf modules out of the old battery and repurpose them for 48v. The first 4 cell LiFePO4 charge controller came out about 2013 and I believe the first 48v LiFePO4 charger is out already.