Trying to determine if the M18 Red Lithium batteries for my Milwaukee tools can be overcharged or if the charger shuts off when fully charged. The batteries are expensive, so I'm wanting to prolong the battery life to the extent possible. Thanks.

I'm pretty sure it shuts off when fully charged. Also be mindful to store batteries in climate controlled areas since extreme heat or cold will degrade the batteries.

How to Charge the Battery Pack.....
The charger will keep the battery pack fully charged if it is left on the charger.

https://www.milwaukeetool.com.au/on/demandware.static/-/Sites/en_AU/v1595534460623/ProductResources/Powertools/Battery%20&%20Chargers/M12-18C_Product_Manual.pdf

Thank you for the replies.

Home Depot is having some awesome deals on m18 right now if looking to expand your lineup.
I'll be picking up the inflator with two batteries for $199 soon (need to find my HD CC to use a coupon they sent in the mail).

Id

Any other good package deals that might include a weedeater, edger and a pole saw?

If you buy the 2-pack 5.0ah battery kit there are a bunch of free tools to choose from. I might pick up the blower as well. Last year this kit went to $179 in November/December with the free tool options so I might just see if that happens again. Link below.
https://www.homedepot.com/p/Milwaukee-M18-18-Volt-Lithium-Ion-XC-Starter-Kit-with-Two-5-0Ah-Batteries-and-Charger-48-59-1852B/320379720?irgwc=1&cm_mmc=afl-ir-10451-483420-&clickid=V23VhXRUWxyKWJ%3AWgB1D4ydtUkCWxnTaEQqaWU0

I came across the stringer kit (in-store only) at Ace Hardware last month for $149 and bought it to try it out. I was impressed - I can cut my yard (1 acre) within two batteries. You might try to see if you can find some still in stores (it is 199 online right now) - I got the display model in Cypress. They might also start clearing them out at other stores since the word is they are coming out with new models. Link below.
https://www.acehardware.com/departments/lawn-and-garden/outdoor-power-equipment/trimmers-and-edgers/7017486?irclickid=S7N1GwRUWxyKTpwz901KTQ5ZUkCWxi0KEQqaWU0&irgwc=1&utm_medium=Affiliate&utm_source=Impact&utm_campaign=10451&utm_term=664353

This 8" pruning saw also looks interesting for $279
https://www.acehardware.com/departments/lawn-and-garden/outdoor-power-equipment/trimmers-and-edgers/7017486?irclickid=S7N1GwRUWxyKTpwz901KTQ5ZUkCWxi0KEQqaWU0&irgwc=1&utm_medium=Affiliate&utm_source=Impact&utm_campaign=10451&utm_term=664353

Id
Where are these special deals posted? Thanks for all the information. The free items make sense if you will need additional batteries anyway.

slickdeals.net is my go-to

He's right. Wait a few more weeks for the Black Friday deals.

Picard
I'll keep monitoring Slick Deals to find out when the Black Friday deals are online. Seems tog as that they start early November in some stores and the true " Black Friday" after Thanksgiving Day is not much of a thing anymore. Thanks guys.