I have a drill drive which is quite old the battery is 9.6v and 1.25 ah with nicd batteries.. I want to replace the batteries to li ion.. I am a layman and don't know much about circuits...
Need help if someone guide me
1. What value batteries /ampere to use.
2. I had lost the charger, so need recommendations for charger as well.
Obliged

 

Lithium ion batteries are not good replacement because you will either get 7.4V with 2 cells or 11.1V with 3 cells. If you must, use 3 cells along with a buck converter. I have a drill driver with similar batteries and it draws about 5 or 6A, so you need ti allow for that when choosing the batteries and buck converter. You might be better off opening up the batteries and replacing the Nicad cells with new ones. I did this successfully with mine.

 

Plus the issue of charging the lipo

 

LI ion are much less resistant to charge problems,
they tend to explode and / or catch fire if you get the charging wrong.
or at the minimum, refuse to take any more charge.

NiCad are much more resistant to charge problems,

Believe me, an exploding AA LiIon cell, flying across the room, on fire, and burnt through bench top, is a very memorable event, CO2 extinguishers did not seem to make any difference.
And the smoke is horrendous,

 

I get it, I hate the throw-away society we've become but what you are trying to do is extremely challenging even for experienced.
The difference between NiCd and Li is great with Li being very compilcated electronically when it comes to charging. Most Li power tools have electronic circuits inside the battery to control drain and charge to protect you and the battery.
By the time you're done with just parts and supplies (not counting labor), it is more efficient to buy a new drill.
If in the US, buy one of these from Home Depot fo $60.
https://www.homedepot.com/p/RYOBI-O...-1-5-Ah-Battery-and-Charger-PDD209K/312462410

This is what can happen when Li batteries are messed with....
https://liveandletsfly.com/laptop-b...ptop battery caught,were sent to the hospital.

 

Or maybe replace with a lifepo4.

 

You could try to see how the drill operates with 7.2V from two 3.6V Li-ion rechargeable in series.
There are also 1.5V rechargeable AA or AAA Li-ion batteries, which would require 6 cells for 9V.

What size cells are in the battery package and what are its internal dimensions?

 

9.6V drills work REALLY well from 12V. 3S or 3S2P lithium-ion should be fine, providing you include a protective "BMS" module
(this one is on the expensive side, but it does appear to have balancing)
https://www.ebay.com/itm/404162642332?hash=item5e19f8819c
and charge it with a 12.6V lithium-ion charger, not the 9.6V nicad charger. Like this:
https://www.ebay.com/itm/234576409412?hash=item369dd7f344

 

9.6V drills work REALLY well from 12V. 3S or 3S2P lithium-ion should be fine, providing you include a protective "BMS" module
(this one is on the expensive side, but it does appear to have balancing)
https://www.ebay.com/itm/404162642332?hash=item5e19f8819c
and charge it with a 12.6V lithium-ion charger, not the 9.6V nicad charger. Like this:
https://www.ebay.com/itm/234576409412?hash=item369dd7f344

You didn't clarified what type and Volts of li ion battery

 

You didn't clarified what type and Volts of li ion battery

And you haven't answered my question about how much room there is in the battery case for batteries, so we are kind of at a standoff.

 

You didn't clarified what type and Volts of li ion battery

Actually he dd if you know what 3S and 3S2P mean. The both have 3 in series , so 3 x 3.7 = 11.1V. You also have to look at the discharge current soec. You are going to need at least 5A.

 

Lithium ion batteries are not good replacement because you will either get 7.4V with 2 cells or 11.1V with 3 cells.

I get it, I hate the throw-away society we've become

9.6V drills work REALLY well from 12V. 3S

In accordance with all three quotes: I have an older deWalt set of tools that run on 18V. Few years ago wife bought me a complete set of deWalt tools with 20V arrangements. I found an adapter that plugged into the 18V tool and accepted the 20V battery. Since these tools are powered by motors - motors are quite tolerant of differing voltages. If your tool operates on 9.6V, buying new 12V Li-Ion batteries and finding an existing battery adapter you can probably continue to use your tools long after the Ni-Cad's go bad. My Ni-Cad's in the 18V arrangement went bad after years of service. Rather than buy new and very expensive replacement batteries I just found an adapter that fits my new batteries and old tools. You might try Amazon.

As for motors tolerating varying voltages, since yours is designed for 9.6V I would not recommend 20V batteries. That'd probably blow your motor out. Or burn it up. But 12V should be just fine.

 

I have a drill drive which is quite old the battery is 9.6v and 1.25 ah with nicd batteries.. I want to replace the batteries to li ion.. I am a layman and don't know much about circuits...
Need help if someone guide me
1. What value batteries /ampere to use.
2. I had lost the charger, so need recommendations for charger as well.
Obliged

I ran my 9.6v Ryobi drill off of a 12v battery for many years. Just need a wire and a 12v lead acid battery.

Li-ion batteries are a bit more complicated then other batteries. That's because they have limitations that MUST be observed or some really nasty things can happen. There are videos of these cells catching on fire you can check them out.

One of the important limitations for a high current device like a power drill is the max current spec for the cell. Li-ion cells are made for different things so they come in various ratings even though they may be all the same exact size like the 18650.
You can find some that are good at 2 amps, and others that are good at 20 amps, but you cant use a 2 amp device in an application that demands 20 amps.
When you buy the cells from a place that cells good cells, they will have the rating shown when you go to look at them. You can then decide.
I had to get some high ampere Sony cells when i got my very high powered flashlight. It's made with several high powered white LEDs so it draws a lot of current on high.
They also make cells with button tops or flat tops or tabs. For a drill you'd have to get tabs so you can connect them together.

Charging is a challenge though because you need to have the charge balanced in each cell. You usually need a circuit to do that.

After all is said and done it's much simpler and maybe even cheaper just to go out and buy a new drill and can the old one or save it for a conversation piece. Go with a good brand and you will be happy i can tell you from experience. I put up with that Ryobi drill for years until i finally went out and got a Mikita. End of problems. Some of the even newer drills have better technology too because they did evolve over the years. Mine is a few years old already but it even has a battery pack with a test button on the side that you press to check the remaining charger. Newer ones have brushless motors also. You can also get super fast charge, like 30 minutes to full charge, and i think that is kind of common now.

Sometimes you do have to embrace the future.

 

Jump on Amazon and check if someone is already manufacturing LiIon batteries for that drill, and a matching charger. This is by far the best way to go if you must keep the drill.

If you must do it yourself, the drill part will likely be OK with LiIon batteries, but as mentioned above you need to protect the batteries with a battery manager circuit that will prevent both over and under charging. There are some pre-made boards available, you'll need to dig in and match the specs to the cells you choose. But if you're not knowledgeable about electronics, I would not try it. Lithium battery fires are nothing to fool with. The fumes are toxic and the fire is self-oxidizing which means you cannot put them out until the fuel is burned up. And a damaged battery can seemingly burst into flames at any time, including the middle of the night when everyone is sleeping.

 

18 volt and 20 volt lithium ion are the same thing; it's just marketing. You can make or buy adapters to mix batteries and tools from different brands, or convert an 18V nicad drill to lithium-ion. That's far easier than trying to stuff cells into a case that wasn't made for them. https://www.ebay.com/itm/314064131219?hash=item491fae5493
Making your own requires a dead donor battery for the connector and a broken/useless tool for the socket; cut them down to the essentials and fit them together with glue. It seems that few if any cordless tools communicate with the brains (or temperature sensor) on the battery, they just want + and -.
Junked drills are worth stripping for the chuck, the speed control trigger (as-is or to salvage a power MOSFET); and the planetary gears are a good size for steampunk jewelry.

 

18 volt and 20 volt lithium ion are the same thing

My old 18V battery was Ni-Cad
My new 20V battery is Li-Ion