NiMH batteries from Vapextech can, for most applications, be a substitute for alkaline batteries despite their voltage differences. Alkaline batteries are rated at 1.5 volts and they will only deliver 1.5 volts when fully charged. As they start to discharge the voltage of alkaline batteries will continue to drop.
Over the course of their discharge, alkaline batteries average roughly 1.2 volts (very close to the voltage of a NiMH battery). The main difference is that an alkaline battery starts at 1.5 volts and will gradually drop to lower than 1.0 volts. NiMH batteries will stay at about 1.2 volts for most of their discharge cycle.
There are a small number of cases where their actual voltage difference is crucial. For devices such as a radio, where a higher voltage means a stronger signal, you could opt for an alkaline battery, although they are more expensive than rechargeable NiMH batteries.
Torches can also be brighter from the initial higher voltage of alkaline cells but keep in mind that this type of battery only has a higher voltage when fully charged. Once it drops to 50% capacity or less they will deliver a lower voltage than NiMH batteries.
The one time when the difference in voltage becomes important is for devices that check the voltage of a battery to estimate how much charge is left on the battery. As we have already mentioned, the voltage of an alkaline battery drops at a predictable rate you can predict the amount of capacity left in the battery based on just its voltage.
Whereas, NiMH or NiCd batteries maintain at around 1.2 volts until they are completely discharged which makes it harder to know the amount of capacity left based on just its voltage. When a device that uses NiMH batteries indicates the battery is low you will need to change the batteries immediately.
If you are looking for rechargeable NiMH batteries, contact Vapextech to find out more about the widest range available across the UK.