Lithium battery for EZip Eco Ride 2 needed.

I bought a used EZip for lightweight riding. It had Life PO4 Lithium Ion printed in the frame so I assumed it was. Turns out is is lead acid and dead in the water. I would like to upgrade to a 36v (I've read its ok to run that on the 24v motor based on an article by Ron/Spinning magnets). I have absolutely no idea how to do this or what parameters I should ask for other than 36v (how many amps>). I assume the lead acid batteries would be replaced inside the existing battery case, with 2 18 volts? Is there any off the shelf items for this bike? I can't find any. My tentative plan is to hire someone to build this for me. In LA a shop called laebike.com offers this but I don't know what to ask for. Or, that being said can someone suggest a builder close to Pomona, CA

DrkAngel has written a lot about eZips & battery conversions. See his index to all his posts:
Homemade Battery Packs
https://endless-sphere.com/forums/viewtopic.php?f=14&t=26383#p381104
in particular the "eZip - iZip Specific Threads" section at the bottom.

From there it looks like some eZip controllers can take 36V but others won't:
eZip-iZip Usable Controller Voltages
https://endless-sphere.com/forums/viewtopic.php?f=2&t=50979

Here's a google search link to other E-S posts about this subject:
https://www.google.com/search?q=site:endless-sphere.com/forums+ezip+36v+-750

You could use a couple of $99 Lowes Kobalt 24V 6Ah tool batteries to power your bike at 24V.