We have gone 100% rechargable batteries like AAA, AA and so on. The chargers for Lithium will not accept a Nicad or NIMH battery for charging. Each takes their own charger.With lithium ion batteries and storage, it's optimal to run them down to under 40% charge then recharge them to about 60% and store then store them like that. Don't try to charge one that at freezing or below, it'll damage it. Same goes for LifeP04 batts which I don't think are used in portable tools yet.
OP you will probably need a new charger for the lithium batteries, but I'd swap them to your tools too vs. buying all new tools. Lithium batteries are a huge step up in all ways from NICad and NIMH batteries.