A voltage question..

[MoJoMax]

Hello, i have a sony camcorder model ccd-trv46e 

which runs on 7.2 volts, even tho the power adapter outputs 8.4 volts, it works fine.

i have a 9 volt duracell battery, Will it work with the camera?
Also tried connecting crocodile clips to a USB cable connected to a phone charger but that did not work beacuse it was 5 volts.

I don't want to damage the camera.

Any help would be great! :)

 

[Windows7ge]

If you don't want to damage the camera this isn't something I would recommend trying.

 

Electronics typically have a range of voltage they operate in. This may be + or - 5%, + or - 10%. If you go too low the devices can't function properly. If you go too high. Well, R.I.P. device.

 

It may run it from a voltage perspective but I don't know how many amps a 9 volt battery can output. Most wireless electronics are based on 3.7V Li-Po batteries which can put out oodles of amps and I can't imagine it would run for all that long before depleting the battery.

 

If you want to jerry-rig your own battery I'd opt for 18650 cells. They operate within the voltage spec of the camera.

[MoJoMax]

@Windows7ge According to google a 9 volt battery has

500 milliamps,

Also by the way the battery is not full.

if i plug it to a alarm clock radio it

won't work, but i know that the battery does have charge.

 

[Unimportant]

Your typical 9V battery has too high an internal resistance. It cannot output a lot of current. Certainly not enough for such a camera.

[mariushm]

The battery is lithium based, made out of two cells.   Each cell has a nominal voltage of 3.7v but charges up to 4.2 and needs about 4.2v to charge... It's the same way with AA rechargeable batteries, which are sold as 1.2v (nominal voltage) but when fully charged they're 1.35v  and need around 1.35v to charge.

 

So that's why the power adapter is 8.4v, because the charging circuit needs at least that much to charge the batteries.

The charging circuit may support a slightly higher voltage, but without opening the camera, you have no way of knowing what's the maximum limit.  Could be the chip that manages the battery crapping out at 16v, but could be some capacitors used rated only for 10v, could be something else capable of maximum 9v or less.

 

Like Unimportant says, due to how they're made, 9v batteries have low current discharge capabilities, they're not designed for products that consume a lot of power - think of applications like smoke alarms, which sit doing nothing most of the time and just once every few seconds use a pulse of power to see if there's smoke and then go to sleep again.

 

On a random Google search, it looks like the battery for your camcorder is 7.2v 6600 mAh ... so if we assume the camera records around 2h with a full battery, we're looking at around 2000....2500mAh per hour of power consumption

 

If you download the datasheet of a regular 9v battery, you see it can hold around 450-550mA of capacity, as long as the current is low enough, because the battery (due to its chemistry) has a much higher internal resistance, which causes heat and voltage to lower.

 

Here's an example datasheet : https://data.energizer.com/pdfs/EN22.pdf

 

You can see that they only show graphs for up to 600mAh, which is possible if the current draw is low, 10mA (clocks, smoke alarms, fm radio with headphones at low volume etc)  ... if you go to 100mA  (let's say some toy with leds and sound) you're down to 400mAh at 100mA  ... you need 10-20x as much power. This type of battery just can't provide it.  

 

 

 

As an experiment, maybe, just maybe, you could have 10 such batteries in PARALLEL and you'll probably get the camera working, but for a few minutes probably.

 

It would be easier to get let's say 12 AA rechargeable batteries and make two chains of 6 batteries in series, then parallel those chains ... you'll get a battery  that's  6 x 1v..1.35v = 6v...8.1v rated for  ~ 2 x 2200-2500mAh  at low currents , but probably around 2 x 1500-1800 mAh at the amount the camera draws ... so you basically have a 7.2v battery with a capacity of around 3500-4500mAh.

AA batteries can handle continuous discharges of around 1A and if you parallel to chains, you get ~ 2A discharge for 30m-1h so a reasonable amount of recording time.

 

[MoJoMax]

@mariushm Thanks that really helped a lot