I picked up an older Losi mini T with a Novak Spy esc from one of the members here and I wanted to wire it to take LiPos. Voltage wise I know it should work as the ESC is rated to take up to 7 cells at 1.2v (8.4v) but I want to make sure I dont over discharge the cells and wire in a cutoff at 3.4v/cell. Is there a product out there that can do this cheaply? Or is it better to just toss the ESC (and possibly motor) and buy a more modern one with that built in?

You can get voltage alarm readouts to plug into the balance port of the battery. You can set the alarm to go off at the desired "amount" of volts remaining in the pack. Costs few bucks to purchase. I got 5 for 10 bux off ebay. They won't stop the car but you will hear the alarm and know it is time to bring the vehicle in.

Novak made a product called a "smart stop" that could be programmed to turn off an ESC once the low voltage cut-off level had been reached.

You can still find them on eBay. PM me if you want one and don't want to spend what the go for on ebay.

That sounds like the right tool. I might hit you up on that later. I need check out the condition of the mini T and see if its worth it, might be smarter to just get a new ESC/Motor combo if i can get one for 20/30, since the SPY isn't waterproof and it rains 6/7 days a week here,

HobbyKing has a pretty inexpensive waterproof brushed ESC for $21 intended for 1/10th scales that would work well in a mini if you can find room for it.

https://hobbyking.com/en_us/hobbywin...-for-1-10.html