How to Keep My Old Power Tool Kit But Use New Batteries

Do you have an old tool kit with a bunch of failing batteries? If you are not ready to give up your old tool kit, read on!

Cordless tools have improved as batteries have improved. With the invention of Lithium-Ion batteries, there have been significant improvements from the old Nickle-Cadmium and Nickle-Metal Hybride power packs.

If you feel it is time to retire your old tools instead, read “best Battery Powered Tool Kits for 2022”

Should I up-date my batteries?

Although there are some benefits to using old-school NiCd battery packs, there are also some drawbacks.

Nickle Cad batteries can handle a bit of overcharging and a bit of over-discharging. NiCd batteries can last a long time, with a recharge capacity of 1000-2000 cycles. But once they diminish in charge-life they do not come back to life.

NiCd and NiMH batteries are heavy! New Lithium-Ion batteries are the lightest and smallest for more power. New battery packs hold a charge longer in storage and have less charge memory than Nickle-Cadmium packs.

Pros of keeping your old kit as is

  • No added expense! Li-Ion batteries are the most expensive, just buy old style replacement NiCd or NiMH packs
  • Keep all my old chargers
  • The battery packs are a direct fit to my tools
  • My old tools still work

Pros of updating your batteries

  • New power tool kits are expensive
  • Nickle-Cadmium batteries are no longer made by the big brands
  • Lithium-Ion batteries have a high capacity and very low self -discharge rates
  • Most Li-Ion batteries have a power display indicator
Old tools sitting on the shelf can have a new life with new batteries.
Keep your old tools and use new batteries

How to keep your old tool kit and run new batteries

So you want to keep your old tool kit, you have decided it is just too much expense and waste to abandon all your old tools, but you want new batteries. Don’t worry we have you covered! Click on the pictures below to check out all these conversion parts on Amazon. Happy Shopping!

You can try conversion kits that come with modern Lithium-Ion in 20V with a charger and batteries. Or you can pick up the parts you need separately. You should pick up at least 2 new batteries, a new charger, and a way to use the new batteries on your old tools.

We are going to cover old 18volt tools. You can convert from NiMH and NiCd and there is no problem running the new 20volt battery packs in 18volt tools. Remember to always use a new charger for the new lithium batteries! Never use the conversion piece to charge! They are totally different and you could cause serious damage to yourself, your house, and the battery!

Using the correct type of charger is also why you should not buy converted battery packs. That is an early battery pack design with lithium inside. Unless you can find a charger that can handle the different types of batteries in one unit.

For conversions, it is better to stick with the thin battery packs. With the conversion plate and a battery, it can get a little longer on the tool and you will have to see if there is any interference on the job. By growing, and converting your batteries first, you could just replace tools as they get too old, one by one.

Conversion parts for 18Volt tools by brand

We have covered a variety of tools. Not every tool has a conversion piece. A good idea may be to take your old tools to the hardware store and see what’s up with the new batteries. Some brands, like Ryobi, have matched the new batteries to the old tools. For some brands, you will need to use a conversion battery as there are no adapter plates to go between the old tool mounts and the new battery slide-on style.

Black & Decker

Conversion piece for Black and Decker 18 Volt tools
Conversion piece for an 18V NiCad tool to 20V Ion battery
2 Amp-hour battery.

The charger must match Amp-Hours

Black and Decker Lithium Power tool battery charger

1 new 20V Li-Ion charger for Black & Decker


Bosch battery conversion piece
Bosch batteries
Two new Lithium Bosch 18V batteries 2.0Ah
Bosch battery charger
Always pick up a Lithium-Ion charger. This is a Bosch Li-Ion charger that will charge varying Ah batteries fast.


For the craftsman 19.2 tools, I am going to suggest converted batteries. This charger can handle NiCd and Li-Ion


DeWalt has an all in one kit for using your old tools with new batteries
DeWalt has an all in one kit for using your old tools with new batteries


The Makita conversion adapter
This recharge kit with two 4Ah batteries is a good deal to get your old tools converted


This slide-on converter is ready for your old Milwaulkee Nicad tools
When you have to replace your Milwaulkee tools, you will have a nice new carry bag with your new charger and new batteries.

Porta Cable

Conversion part for 18V to 20V batteries
A Porta Cable Conversion 18V NiCd to 20V Li-Ion
Porta cable charger with two batteries
Nice Porta Cable Charger with 2 Li-Ion batteries and bonus bag with a USB port and room to hold more batteries and tools!


The Ryobi kit is a straight conversion on old blue tools! They made the new battery in the same design as their old 18v tools. It is a great way to bring your old tools back to life!
Check out this video of using new batteries in old Ryobi tools

The best thing about keeping your old tools

When you can save your old tools by using new batteries, it is like getting free tools! You can put your old tools back into service. For odd jobs around the house, you can spend a lot less than buying new tools to do a small job.

Don’t forget to triple check the charger is the right one for the job! Do not be tempted to use an old Nicad charger on your new lithium-ion batteries.

The best thing about keeping your old tools, is now you have time. Time to decide which tool you want to replace first. You can keep using your old tools till they fail. And if you already have an extensive set of old tools, it’s like bringing them all back to life with new batteries!

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