There’s a buttload of them at Home Depot.
Do they stock the electric vehicle batteries at Home Depot now?
NiCd, nickel–metal hydride, lithium-ion, Li-ion polymer,
I have heard a few companies are making replacement battery packs for hybrids like the Prius at a drastically reduced price but you have swap out the cells or have a mechanic do it. It's not complicated but the bat pack is heavy.