Ohmmeter
A. ohmmeter B. voltmeter C. ammeter D. wattmeter
You can get one that uses it's own battery and not worry about that.
Tissot belongs to The Swatch Group. Swatch Group owns 'Renata Batteries' a Swiss company specializing in high quality button cells for Swatch Group's own watches. Tissot PRC 200 with Quartz movement uses button cell battery of the following specifications:- Battery type: button-type zinc-silver oxide primary battery cell, 1.55 V Battery, No. 394, SR 936 SW
A Griffin itrip transmitter uses the power supply provided by your Ipod, so you are using that battery. There is no battery source in the Itrip I own.
You can get a car alarm that uses it's own battery so wont drain the car.
A Brio Battery Train requires a 1.5 volt AA battery. This type of battery does not come included with the train and you will need to purchase one on your own.
A phone uses energy to function, which is provided by its battery. The phone does not produce energy on its own, but it can be charged using external sources such as electricity from a power outlet or a portable charger.
Ohm meter
ohmmeter has it's own power supply
RADAR
Not a 'discharging' battery. Depends on the type of battery. A lead acid battery gives off Hydrogen when 'charging', which could be hazardous to health, if a spark causes it to explode. A 'discharged' battery can have an impact on it's own health. Best to keep them charged.
You answered your own question. Sealed dry or gel type battery need no maintenance other than keeping a full charge on them