# 6V/0.5A flashlight bulb

Discussion in 'General Electronics Chat' started by Lightfire, May 10, 2011.

1. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
Hello,

I found and purchased a new flashlight bulb which I think will meets my exact standard.

The flashlight bulb ratings are 6volts/0.5 amperes so 3 watts.

Now, I am going to ask if it can be operated by a 6 volt/6AH lead-acid battery.

Thanks~~~

2. ### tom66 Senior Member

May 9, 2009
2,613
214
Yes, although when charged the lead acid battery could be as high as 7.2V. Do not let the battery discharge below 6V.

3. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
Okay.

But for example I have connected two bulb (same specs/6v 0.5a) in series. Is the voltage I needed is 12 volts? How about the amperes? How many amperes it will pull in the battery? 0.5 ampere?

Thanks....

4. ### iONic AAC Fanatic!

Nov 16, 2007
1,420
68
The current is the same, but you will need 12V.
If in parallel, you can run them on 6V, but the current will be 1.0A

Lightfire likes this.
5. ### Audioguru New Member

Dec 20, 2007
9,411
896
A little 6V 6Ah battery is rated at 1/20th its rating which is only 0.3A for 20 hours.

6. ### DerStrom8 Well-Known Member

Feb 20, 2011
2,428
1,328
Keep in mind that the battery may be "depleted" before 30 minutes, simply because it no longer has enough power to light the bulb. The longer the bulb is connected to the battery, the dimmer it will get.

Jan 5, 2011
43
1
If you connect two lamps in series (aka two resistors in series) you will need to have 12 volts to maintain same brightness. If you will use 6v, the brightness will drop due to decreased voltage between each lamp (so each lamp will run on 3 volts) while the current will be the same!

Anything (any resistance) in series has same current going through (because there is only one way for current to go but voltages will be different.
While anything in parallel will have same voltage but different current across each branch.

If you want to have same brightness, you need to do parallel connections to maintain voltage, but that will increase current consumption by the factor of two (1 amp).

8. ### Lightfire Thread Starter Well-Known Member

Oct 5, 2010
690
21
Huh?

For example, I had 6 volt / 6 AH lead acid battery

And I got two 6 v / 0.5 A connected in parallel. And I connect it to that battery. Is there any possibility that the battery will be dead instantly? If not, how many hours/minutes does the battery can operate the bulb?