Cordless Drill Battery Care

Won't the battery alarm drain the battery over time?

Yes, it most certainly will. I've developed the habit of keeping the batteries unplugged until I'm ready to use my tools. It takes me maybe ten seconds to plug them back in and since the LiPo packs have such a low self discharge rate my tools are always ready to go.

Don't LiPo packs require special chargers/procedures?

They absolutely do. Here's a good guide to understanding LiPo packs and how to care for them- A Guide to Understanding LiPo Batteries. There is more info about Bosh power tool batteries and safety here. If you're not comfortable handling LiPo batteries and going to the extra trouble of maintaining them properly then this instructable probably isn't for you. If they are treated properly they are perfectly safe for every day use, but it's not something I would recommend if you're using tools on a construction site as they're not really practical for that application. I've been using these tools for quite some time now with absolutely no negative side effects.

If you are really worried about an overload condition (motor shorting/stalling, etc.) then you can install an automotive blade type fuse on the positive power lead from the battery connector to the tool (not on the battery pack.) These fuses will increase the load resistance so you will have to do some testing to obtain the right value but it should be below the total current capacity of the battery.

What about LiFePO4 batteries?

Yep- you can use those too. While I used a 2s Li-Ion battery in my son's drill and it works just fine ( I already had this battery pack from a broken RC helicopter that was given to me at home ) LiFePO4 batteries are a better choice. The advantage of these Milwaukee drill batteries is that they tend to be a bit more durable than LiPo packs but they can be a bit larger so they may not fit inside many power tools. If you can find a pack that fits then great- just be sure to use a pack that either has a built in protection circuit or be sure to use a low voltage cut off alarm. Again, you will need a special charger for these batteries.

Isn't the battery capacity less than the original manufacturer's?

In the case of my 14.4V Makita drill- yes. But I don't really care as I found I'm rarely trying to drive 200+ decking screws from a single battery charge. Since the batteries are so inexpensive I can also afford to keep several packs on hand.

What do I do if I have a tool that has a plug in battery but I don't have the original battery?

In this case you'll have to get creative. Two options are 3d print a suitable Craftsman battery case or vacuum form one from plastic sheet.