Using Different Types Of Batteries

[DaleSwanson]

I have a bathroom scale which uses a 3v CR2016 battery. The battery only lasted about a month before needing to be changed. I thought that perhaps I was getting old batteries from stores, so I bought from a variety of stores and they all died quickly. My solution was to find the wires going to battery, and splice in a 2 AA battery holder from some old device I had. So I replaced the 3v CR2016 with 2 1.5v AAs in series. This worked quite well.

My question is if this is safe to do in other places. I didn't really care about the scale, but I may do this with some more expensive electronics. Is this fine to do as long as I match the voltages? I plan on replacing anything that can take AAs or AAAs that currently takes watch batteries and doesn't need to. Also I may think about running some devices I want longer battery life out of on Ds instead of AAs. So would all this be fine? I won't be doing anything crazy like trying to start a car from 8 AAA batteries.

 

[mgb_phys]

Watch batteries have low capacity and low maximum current because they are small
Replacing them with AA/AAA will be fine, the other way around probably wouldn't be!

Watch batteries also tend to get used in places where the device is only going to be used occasionally so if you used NiCad/NiMh rechargeables you might have a problem with them going flat from self discharge.

 

[david90]

Some device have build in charging circuit for the battery. If this is the case then it's best to stick with factory recommended battery.

 

[mgb_phys]

Not for CR2016 style batteries - they aren't rechargeable.
Any built in rechargeable lithium battery is going to be either tagged and soldered to the board, or in equipment expensive enough that you aren't going to play with it.

 

[DaleSwanson]

Thanks for the help. I was fairly sure it was ok, I just wanted to make sure there wasn't something I was missing before I tried it on anything else.