battery charging etc

[Fray Bentos]

Hello all. I have a portable dvd player with a rechargeable battery pack. The mains adaptor gets red hot when in use. I mean really hot - hot enough to be uncomfortable to hold my hand on it.

Anyway, I know this is normal because I know others that have them and they get hot too.

I am not happy. I think its working right up to its limits. I am thinking of replacing it with a heavy duty supply from maplins.

now then,

The adaptor is 12V, 1.25A Player is marked as accepting 12V 1.25A battery is a 7.2V NIMh 3800 mah.

the battery connects to a different place in the player, its own dedicated connection. ( about 5 pins IIRC ), not the "dc in" socket I imagine the 12V "dc in" is designed for in car power compatibility. So, surely a 9V adaptor would do fine? I would get one that supplies 2A or more so it's not working too hard.

Would the batteries charge quicker with a bigger supply ? Would they charge too quick? I don't fancy an exploding battery pack !!!!!

don't wanna waste £20 on a shiny new supply that is no use.

thanks, all

fray bentos

[Sparks]

The unit is expecting 12v, so why give it 9v and risk it not working when you can just get a higher amperage 12v supply? I don't follow your logic here!

Just get something like CPC part number PW01656 (12V 2.1A regulated power supply with a 2.1x5.5x12mm centre positive connector on the end of a 1.8m cable.)

[Sparks]

And re your question

Possibly a little, but not a lot.

Doubtful, as this thing is probably designed to run from a car, as you suggested earlier, and there wouldn't be any current limiting between the car and the player when it is connected to the car.

Sparks...

[Fray Bentos]

I figured that the player reduces the 12v to 7.2 anyway, so give it an easy life.

You reckon the battery will charge the same rate with a higher amperage power supply ?

[Sparks]

Maybe a little higher, but probably not enough to notice! I would hope there is a limiter on the battery charging circuit, otherwise when you plug it into the car lighter socket, it would try and draw hundreds of amps (and pop the fuse, melt the wires and kill the cells!)

[Christian McArdle]

The car socket provides between 12V and 14V. Your replacement charger must do the same. 9V is not acceptable, unless the player says otherwise. I don't understand why you would want to specifically buy a charger with the wrong voltage. It will either work badly, or, more likely, not work at all. Many DVD players sense the battery running down and cut out when the voltage drops below about 10V or so, to protect the battery.

Christian.

[Fray Bentos]

all comments duly noted.

thanks for all your time

fray

[meow2222]

would be cheaper/quicker to either add a little fan or drill lots of

3mm holes in the adaptor casing, obviosuly taking care not to drill through any vitals.

NT