Hi Everyone,

I am sure this is a simple question, but the 3rd question maybe harder.

Can I power a 18 volt cordless drill from a 20 volt battery of the same make?
Can I power a 20 volt drill from a 18 volt battery?

If I take a dead battery and strip out it’s insides, and wire up a 18volt circuit to put inside the battery case, then connect this to the mains electric, will it power the drill ok?
Any ideas?

The reason I ask this question is that I have a dead batteries for this drill, and it would be useful to have something so when the others go flat I have something just to finish the job off with.

Thanks for the help.

 

The simple answer is yes, yes, and yes, depending on the maximum current the drill motor demands when loaded.

 

The simple answer is yes, yes, and yes, depending on the maximum current the drill motor demands when loaded.

Yes, providing the three alternative power sources can supply whatever current the drill motor requires.

 

Yes to all, but your drill current dictates how long these cells last.

You can strip down the battery and replace cells ok.

 

Yes to all, but your drill current dictates how long these cells last.

You can strip down the battery and replace cells ok.

Nickel chemistry can have a high casualty rate. The chargers are usually pretty crude and shorted cells due to overcharging isn't exactly rare. Each failed cell gives the diminishing number of survivors more stress.

Its generally worth replacing with all new cells, the ones that look OK are probably just being brave...….

Last time I looked - a new battery was more than just buying a whole new drill. A good deal on cells can make repair worthwhile.

 

Thanks guys.

I will definitely look into buying new cells for the dead ones, are they just rechargeable batteries with a high rating or are they special cells for power drills.

I might try modding a old battery into something I can plug into the mains, even if it just for a small project to do.
Any ideas on how to make up a circuit board for a 18volt drill?
Thanks again

 

If they're ordinary Nicads, they're just Sub C type 1.2V, 2Amp rated or higher.

https://m.reichelt.com/gb/en/sub-c-...yq-KG3gIVEed3Ch2iJQc-EAkYDSABEgKmcvD_BwE&&r=1


Lithium-ion is a different matter.

 

If they're ordinary Nicads, they're just Sub C type 1.2V, 2Amp rated or higher.

https://m.reichelt.com/gb/en/sub-c-...yq-KG3gIVEed3Ch2iJQc-EAkYDSABEgKmcvD_BwE&&r=1


Lithium-ion is a different matter.

You beat me to the sub-C bit.

Start showing the TS how to fill out a Darwin award if its lithium.

Lithium stimulates adrenaline production - the batteries make half decent rocket motors too...……..

 

I have a few words about 18 and 20 volt drills.

A 5 cell Li/Ion battery drill can be sold as an 18 Volt machine on the European market, and as a 20 Volt machine in the United States.

 

“A 5 cell Li/Ion battery drill can be sold as an 18 Volt machine on the European market, and as a 20 Volt machine in the United States.”

How can that happen? Surely a 18 volt battery can’t make up two volt on a trip to the USA?

Any ideas on a 240 volt to 18 volt circuit yet? ( I am in Ireland and we have real electric here!!)

Great information as always, thanks everyone.

J

 

It's probably something about marketing, and that a Li / Ion cell can measure both 3.6 and 4.0 volt, depending on the charge status.

 

It's probably something about marketing, and that a Li / Ion cell can measure both 3.6 and 4.0 volt, depending on the charge status.

The not lower than voltage is somewhere around 2.75 ish. Very early cells had a 4.1 maximum, most common now is 4.2 and I see the occasional 4.3.