They all can but rarely freeze solid but cold temp does reduce power
As long as you keep them charged you do not have to remove them. A fully charged battery will not freeze, but a dead battery will.
A fully charged 12 volt automotive battery should have 12.68 volts.
Normally, no it should be fully charged if it is a fresh battery.
A fully charged 12 volt battery will read about 12.6 volts, or 2.1 volts per cell.
Depends how flat it is and the capacity of the charger and also capacity of the battery. A 6 volt battery fully charged should read about 6.5 to 7 volts when fully charged.
6.4
Usually from being discharged in below freezing weather. The water will freeze in a dead battery, expand, & swell the battery. This won't occur with a fully charged battery.
When it is charging the screen reads: Battery Charging. When it is fully charged it reads: Battery Charged.
If the charger has a ammeter on it then it should show close to zero which means the battery is no longer pulling any current from the charger which would mean the battery is fully charged. If it has only a voltmeter then it should show 12.5-13.5 vdc
With a fully charged battery (12.68 volts) and engine running at idle with no accessories on, 14.5 volts. You will not get a accurate reading if the battery is not fully charged.
there should be an battery sign and there look at it. there is probably a white part in the battery then that is the amount of battery you have left.
Fully charged battery should have 12.6 volts. 75% charged 12.4 volts, 50% charged 12.2 volts, & 25% charged 12.0 volts.