Battery Pack on ORDER!!

Battery pack design - It's starting to get serious

With the motor decided upon, I know I need a pack that is 400V. Gardner Douglas Factory is 100 miles each way from my house so a range of 200 miles seems reasonable. 

Again going back to my earlier post on watt hours per mile this is only an educated guess but I have to start somewhere. We will start with 250wh/mile and go from there.

I won't write about all the battery modules I researched and disregarded, there were a lot.. But here are the main considerations I had throughout the process.

Like with the motors second hand Tesla packs are extremely good bang for your buck, but the same problems apply. Although currently battery packs are not one of the key items that have to be new for the IVA, however I can see that changing quite quickly as EV kit cars become more popular. 

Zero EV seem to be the best source in the UK of reputable modules. 

So now It's a game of module voltages and amperages, how many in series, how many in parallel, till you get the voltage and range you need.

I settled on their 4S3P CABL 2.55kw module. With a nominal voltage of 14.6V 28 of these in series will give 408V.

Here is a link to the calculator I made if anyone finds it useful. Please let me know if you spot an issue with the calculations. 

My battery pack is set!
I have ordered the modules and lots of other bits from Zero EV and will hopefully be going to collect them soon. 

I should be getting a useable range of around 230 miles. Only real world driving will be a way to test, I look forward to my first bout of range anxiety..

The modules have no internal cooling built into them so I will have to make this. 
You can buy cooling plates per battery but this is a very expensive way of doing it. I'm going to investigate having 3 layers of aluminum laser cut. A solid base, a finned middle and then a solid top to have screws holding all 3 together. 
Cooling the battery pack is key to sustained performance and good battery life. 

Here is a very crude mock up of what I plan to do. Only on a much bigger scale. 

I hope this will work, its only under very low pressure so fingers crossed it won't leak, I'll try some form of sealant between the plates and a pressure test first, I'm going down this route as this will be able to form the structural portions of the battery pack. 

I need 28 modules in my pack to get the range I need.
I have the CAD model from GD for the body and chassis. I'm trying to do minimal changes to the chassis, GD have it well dialed in so the fewer changes the better. 
Also I'd hope that potentially maybe this could be used as a retrofit chassis in the future if people would like to convert their ICE GD's to Electric. 

Looking at the cad model so far I can fit 8 modules in the tunnel and 20 in the engine bay. The beady eyed might notice the motor poking out at the back more on that next time.