LVC device

I've heard some issues regarding the LVC of VXL esc's. I have just bought a 2s and 3s packs for my Rustler and Stampede. I don't want to ruin these lipos because of faulty LVC. My first choice is a Novak but I think they are "s"-specific so I need to buy one for 2s and one for 3s. Then I came across with
Li-saver and lipo shield and both are not "s"-specific.
Please help me decide on what to buy.
Thank you.