I am new here, but have been dreaming of doing an EV conversion for a long time.
I am a professional electronic engineer, but do not have extensive HV experience, but am happy to earn that badge.
I am starting my research with the battery, as I consider it to be the most important part of any EV conversion. Please educate me if I am wrong!
As such, I want to know if there is some kind of list of requirements. I've already found Vehicle standards bulletin 14 which contains NCOP14 Guidelines Electric Drive V2.
As I am planning to use lithium ion cells, they are class A cells and do not require venting or anything like that.
The minimum specifications seem to be
- ingress protection IP2X (against fingers), and also some level of water resistance (presumably IP22)
- fire cannot move from one battery case to the next (I am unsure if this applies to class B batteries only)
- battery restraints must withstand 20g, 15g, 10g, and 10g impacts for front, side, rear, and vertical (rollover) impacts respectively
- an impact sensing switch should (must?) be used so the traction circuit is opened in case of an impact
- labelling and marking requirements (warning labels for chemistries etc, orange wire used for HAZV)
- protection against shock (appropriate covers and ingress protection for HAZV circuits and connections)
- Hazardous voltage isolation (high voltage battery is floating with reference to the chassis and ELV, even during operation?)
- Hazardous voltage disconnect (traction circuit is controlled by a relay powered from ignition switch)
- Overcurrent protection device (fuse or relay) inside the battery enclosure for class A battery
Is NCOP14 a fairly exhaustive list of requirements for the battery pack(s) in an EV conversion?
I saw on another thread
https://forums.aeva.asn.au/viewtopic.ph ... elv#p72377
A discussion asking "Are you wanting to retain the `max ELV between any two points with the power off` criterion as well? That means a contactor every 29 cells"...
From this I can only infer that one possible method of ensuring the HAZV isolation is to break up the battery pack into smaller packs, each isolated from each other, when the car is turned off. Is this an absolute requirement? Are there other methods of ensuring the isolation (eg by simply isolating all drive electronics and using say optical isolators for communications between the drive electronics and the user interface/computer/pedals/instrument cluster etc?)
Is there any essential resource (other than NCOP14) which I should really sink my teeth into before I do any more planning?
I am in QLD, if that makes any difference

Thanks!
- Wayne