Devices operated by both rechargeable battery and mains

In summary, the arrangement is that the batteries are always in parallel with the mains power supply.
  • #1
epenguin
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This may be in the 'you were afraid to ask' category.

There are many devices which work on batteries or alternatively when plugged into the mains. You can recharge the batteries. Obviously when you are using batteries alone they have to have been charged.

Now I am finding that while some devices (e.g. a radio) when attached to mains work equally well whether the battery is charged or not and think the charging goes on while you are using it, but others, particularly shavers and trimmers do not work, or hardly, on the mains until the battery is recharged which can take hours at least and can be inconvenient. I have just verified this experimentally. I do not remember that this ever used to happen.

Is my impression that things have changed in this respect accurate, or is my memory at fault? And in any case why are things like this now? What is the arrangement and principles? And if it has changed, why?

I would have thought it natural to put battery in parallel with mains supply (reduced and rectified in the device, the motor working with DC) and that is how it is done, but maybe I have some egregious misconceptions?
 
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  • #2
epenguin said:
This may be in the 'you were afraid to ask' category.

There are many devices which work on batteries or alternatively when plugged into the mains. You can recharge the batteries. Obviously when you are using batteries alone they have to have been charged.

Now I am finding that while some devices (e.g. a radio) when attached to mains work equally well whether the battery is charged or not and think the charging goes on while you are using it, but others, particularly shavers and trimmers do not work, or hardly, on the mains until the battery is recharged which can take hours at least and can be inconvenient. I have just verified this experimentally. I do not remember that this ever used to happen.

Is my impression that things have changed in this respect accurate, or is my memory at fault? And in any case why are things like this now? What is the arrangement and principles? And if it has changed, why?

I would have thought it natural to put battery in parallel with mains supply (reduced and rectified in the device, the motor working with DC) and that is how it is done, but maybe I have some egregious misconceptions?

It mainly depends on how strong the recharger is. If it is using a trickle charge, then that is not usually enough to run the device.

A good example is the two charging devices that I have for my hand-held HAM radio. The home charger is a "wall wart" style transformer that is strong enough to charge the batteries and allow the radio to work in receive mode. But if you try to transmit (which takes a couple of amps), the wall charger is not strong enough, and the radio will not transmit.

The other charger that I have for that radio is a car cigarette lighter based unit. It passes power through from the car battery (with appropriate voltage regulation), and is easily strong enough to allow transmitting while charging up the radio's battery.
 

Related to Devices operated by both rechargeable battery and mains

1. What is a device operated by both rechargeable battery and mains?

A device operated by both rechargeable battery and mains is a type of electronic device that can be powered by either a rechargeable battery or by plugging it into a power outlet. This allows for both portability and consistent power supply.

2. How does a device operated by both rechargeable battery and mains work?

These devices typically have a switch or setting that allows you to choose between using the rechargeable battery or mains power. When using the rechargeable battery, the device will draw power from the battery. When using mains power, the device will charge the battery while also powering the device.

3. What are the advantages of a device operated by both rechargeable battery and mains?

The main advantage of these devices is their versatility. They can be used anywhere, even without access to a power outlet, as long as the rechargeable battery is charged. They also eliminate the need for constantly replacing disposable batteries, which can be costly and harmful to the environment.

4. Are there any downsides to using a device operated by both rechargeable battery and mains?

One potential downside is that these devices may be more expensive than those that only use disposable batteries. Additionally, the rechargeable battery may lose its ability to hold a charge over time, requiring it to be replaced.

5. How do you know when to use the rechargeable battery or mains power on a device?

It is generally recommended to use the rechargeable battery when you need portability or are away from a power outlet. Use mains power when the device will be used for an extended period of time or when you want to ensure a constant power supply for the device.

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