[Raynor]

So I would like to build an external battery back for my 2011 Nissan Leaf but I don’t know anything about EV’s. I have some mechanical knowledge but that it’s all. If some one is willing to share some knowledge that would be nice.

 

[OR-Carl]

Before people can help you, you will need to learn a little bit more about EVs. If you are going to modify a leaf, start with doing some research about the leaf battery. There is loads of information online, so come back with some specific questions and people will hopefully have some answers for you.

 

[john61ct]

Where will the battery be carried?

 

[Raynor]

Where will the battery be carried?

I was thinking about building a 10 kilowatts battery and placing it in the trunk. I would like to build something similar to what they are building in EU (manxun) but I am finding it hard to find information on how to put it together and installation.

 

[OR-Carl]

Honestly, the best I think you will be able to hope for is to cart around a 10kwh battery wired up to say 48volts, and then running a 2kw inverter and plugging your car into like it was a charging station. I sort doubt the leaf will allow you to drive around while "charging" so even that would be pretty limited. Adding a battery that seamlessly integrates into the leafs existing traction battery is going to be a heavy lift. It would not be impossible, I am sure it could be done, but it would be a very involved project.

 

[john61ct]

Serious engineering chops required, not something to follow a cookbook howto from the internet

 

[john61ct]

Plus the coolant circulation to regulate temperatures, heating or cooling as needed

and shutting down the engine in the event of thermal runaway.

Boom bad

 

[brian_]

Plus the coolant circulation to regulate temperatures, heating or cooling as needed...

The Leaf doesn't use active thermal management for its own battery (other than a set of module heaters for extremely cold conditions), so the add-on pack presumably wouldn't have it, either.

 

[john61ct]

that is active, and critical.

passive design measures are just as critical.

As are monitoring and shutdown failsafes

 

[brian_]

that is active, and critical.

The Leaf heating is active, but only needed in low enough temperatures; it's not even included in the Leaf in warmer climates. The Leaf has no circulating coolant, and no active cooling at all (even with air).

passive design measures are just as critical.

As are monitoring and shutdown failsafes

Yes, although there is little if any attention paid to passive cooling in the Leaf pack. A BMS is important but it only monitors temperature and responds to it, not moving any heat; perhaps you would consider that response to be thermal management. I was only commenting on the lack of active cooling in the Leaf.

 

[Doc Smith]

Why? More range? I'm a EE and have done one conversion, a VW bug. I would not attempt what you are contemplating.