EDIT: TLDR build
Parts;
Ryobi Battery Adaptors x2 - $16
https://www.amazon.com/dp/B0C5QQHKG7...t_details&th=1
Power Connector - $9
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
18v Speed Controller - $26
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Throttle Pedal - $14
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Ignition Switch - $10
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
~$70 total to add a variable throttle, speed controller, Ryobi battery adaptors, and key ignition switch. Various tools, connectors, wire, solder, etc not included in the build inventory, as I already had these items.
Here's most of what I used in the build;
Here's the ignition switch, which fit perfectly without modification.
I've got a Jeep Wrangler EV now.
Considering a sealed lead acid battery is a poor choice for a traction battery since discharging them rapidly degrades capacity, I was keen to replace it with a lithium ion battery.
My garage has Ryobi 18v batteries aplenty since I'm a collector of those tools. I bought a cheap battery adaptor that adds leads and a fuse so I could attach it to other devices.
With just this modification, it adds 50% more power/speed. Max speed goes from 5 MPH up to 8 MPH.
The problem is, the plastic wheels have low grip and the throttle is on/off, meaning the thing spins the wheels and then takes off quickly, with no speed control at all.
I bought an 18v speed controller for $25, and a hall effect throttle pedal for $14.
Last night I finally got a round tuit. Decided to leave the original throttle pedal and mount the new one next to it.
I used a shorter retention bolt in the stock pedal which keeps it "on" all the time. I swapped the top and bottom wires so that the original pedal is normally "on" and pressing it engages the brake. The floor plate was difficult for me to modify since there was no template that came with the throttle. It requires a hole in the middle because depressing the pedal extends it through the floor.
Wired 2x Ryobi adaptors in parallel using Wago connectors. The stock battery is 144 watt/hours (12v x 12 Ah). My batteries are 18v x 3 Ah each for 108 watt/hours. Not quite as much energy, but 1.5x the power. If I swap out for 4Ah Ryobi batteries, that would equal the energy of the stock battery. Ryobi makes all the way up to 12Ah, meaning I could potentially have up to 432 watt/hours, or 3x the stock range. Of course, you would never want to run a lead acid battery flat to get all of the range, so already it has more practical range.
Not factoring in the batteries, the project cost about
$60 $70.
Here's a test of 18v speed prior to adding speed control
Maiden voyage this evening.