A BMS is a required component of any lithium battery installation. The BMS monitors the individual cell voltages and prevents any cell from entering a dangerous over-voltage or under-voltage state. It also balances the pack (brings the cell voltages closer together) which can increase capacity.
We’ll be using Thunderstruck’s Dilithium BMS. The main BMS Controller supports up to 24 cells, and can be connected to up to 3 expansion (satellite) modules, each supporting an additional 24 cells, for a maximum cell capacity of 96. In the XJ-S we’ll be using 40 Chevy Bolt Cells (4x 10s modules), so we only need 1 BMS Controller and 1 BMS Satellite
Leaf: They’re affordable ($50/ea), have fairly good energy density (64Ah per module when new, probably around 40-50Ah used), and due to the exposed terminals as well as the 5/16″ mounting holes, are easily re-arranged to suit any voltage/amperage requirements. If you have a larger budget and care more about range (higher Ah capacity), used 2nd Gen Nissan Leaf Modules are also available, at a 25% price premium over 1st Gen.
LG Chem (Chevy Bolt): The modules are much larger and heaver (about 10x) than a single leaf module, but they’re much more energy dense. They can’t be broken up into smaller modules, so you have to make room for the 72 pound 19″ x 14″ x 4″ modules. On the upside, you won’t have to make custom bus bars, and the BMS wiring will be easier if you can source a Chevy Bolt BMS harness.
More battery building coming soon! Example Leaf packs below:
One of the main objectives in this conversion was keeping the front engine, rear wheel drive configuration, without modifying the Jaguar Independent Rear Suspension.
Update: I’ve had a significant amount of trouble with the CanEV hub adapter for the Hyper 9. Initially it was too small to fit onto the Hyper 9, and now that it’s finally on, the flywheel bolt spacing isn’t correct, with two holes not lining up.
CanEV adapter on the XJ-S’s Chevy T56 transmission.Misaligned flywheel bolt holes. (Two bottom left)
When converting a car to electric, sometimes the little details like power steering and vacuum boosted brakes get overlooked. Here we’ll explore some solutions for keeping those systems working.
Vacuum Boosted Brakes
Summit Racing® Electric Vacuum Pump SUM-760152
There are plenty of 12v vacuum pumps on the market, but not all of them are designed to provide enough hg for brakes (they’re intended for misc controls like HVAC or motorized headlights) or require separate sensors/switches to prevent them from running continuously and burning out.
My search for a self regulating pump that was suitable for brakes resulted in this: Summit Racing Vacuum Pump. This pump is designed for brakes and is self regulating; activating and increasing brake vacuum to 20 hg whenever the vacuum level drops below 15 hg. Note: You should still use a vacuum canister to reduce the duty cycle of the pump.
Electric Power Steering
Mechanical Electric Power Steering
Oh boy, how far down the rabbit hole of electric power steering do you want to go?
There are some mechanical solutions like EVWest’s Kit. However, these systems involve cutting and welding your steering column and installing a controller that’s basically just a potentiometer that you have to install somewhere reachable to adjust the level of assist. (I greatly admire EVWest, but it’s a gross solution.)
Since I wanted to maintain the factory Jaguar rack/column and steering feel, I decided electro hydraulic was the only way to go. Unfortunately there really aren’t any aftermarket solutions for this, and unless you know what you’re looking for, good luck finding a compatible pump.
Bosch Automotive KS01000120 Remanufactured Electro Hydraulic Power Steering Pump (EHPS) for Mini Cooper
My requirements:
12v powered
Self regulating (no controller or canbus required)
Readily available
Not outrageously expensive
This list seems simple, but there are almost no electric pumps that meet all of those requirements, except one, the Bosch OEM Mini Cooper Pump. The only connections are 12v and the hydraulic lines! Note: This pump runs hot and requires significant air flow to prevent overheating.
