# 6 Volts - 7 volts

Discussion in 'General Electronics Discussion' started by raymondht, Apr 26, 2010.

1. ### raymondht

6
0
Apr 26, 2010
Hello, just want to ask if we can increase 6V to 7.2V by just adding somthing..

2. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
another battery?

3. ### Mitchekj

288
0
Jan 24, 2010
Beat me... I was going to say "Oh, about 1.2V."

4. ### davennModerator

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Sep 5, 2009
hahaha good responses steve and Mitchekj

but in all seriousness, raymondht, we need a bit more info from you of the circuit involved

If for example the cct in question was being supplied via a 7806 voltage regulator, the
input to the regulator is likely to be ~ 10 - 12V and yes with a couple of resistors
you can jack up the output of the regulator a bit ( up to a couple of volts or so)
is being supplied from say a 6V battery then not much you could do and still keep the
current ratings.
There are voltage multiplier ccts, and I have used voltage doublers, but current supplied
is the big sacrifice

cheers
Dave
VK2TDN

Last edited: Apr 29, 2010
5. ### ElectronWorks

28
0
Aug 20, 2009
or failing that, try Googling 'boost converter' These circuits use the back emf of an inductor to boost the voltage. They are used in pretty much all portable devices from laptops to mobile phones

6. ### raymondht

6
0
Apr 26, 2010
its a battery lead acid battery, its only 6V, but my device needs 7.2v...

7. ### 55pilot

434
3
Feb 23, 2010
What exactly is your device? How much current does it need?

---55p

8. ### raymondht

6
0
Apr 26, 2010
Its a hand held video camera. JVC Everio

9. ### chejian6

2
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Apr 29, 2010
a boost converter, a charge pump, a battery...

10. ### davennModerator

13,676
1,892
Sep 5, 2009
ok forget the 6V battery, get a 12V sealed lead acid or similar battery and use a voltage regulator to produce the required voltage needed for the video cam there are a number of good hi current adjustible V-regs out there that would be able to handle the current required by your camera eg ... my favourite the LM338 5 Amp TO-3 casing
I have used for so many projects over the years

with a 6V battery and using any sort of boost converter is going to run into probs
as the battery drops in voltage out as it discharges.

with a 12V battery you are going to have several volts of discharge "headroom" without
affecting the output of the regulator.

cheers
Dave
VK2TDN

11. ### 55pilot

434
3
Feb 23, 2010
Using a linear regulator to go from 12V to 7.2V, you are wasting 40% of power. If the 12V was coming from a wall outlet, that would not be a big deal. But if it is coming from a battery that you need to lug around, it does become a big deal. A 12V to 7.2V step down DC-DC converter, or a 6V to 7.2V step up DC-DC converter is more appropriate (in that order).

But for some people, a linear regulator is the extent of their capabilities.

---55p

Last edited: Apr 30, 2010
12. ### 55pilot

434
3
Feb 23, 2010
Let me repeat the question: How much current does it need?

---55p

13. ### raymondht

6
0
Apr 26, 2010
problem is 12V lead acid is huge!... its like 5in wide 4in ht and 2in thick and its heavy While 6V half of it.

14. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
Lead acid batteries come in all shapes and sizes. It's almost certain that you can get a 12V lead acid battery that is very close to the size, shape, and weight of the 6V one.

15. ### raymondht

6
0
Apr 26, 2010
oh isee ok i'll check if theairs available lead acid 12 v small size... by the way what type of charger I cam use... Can I use my regular charger?

16. ### 55pilot

434
3
Feb 23, 2010
Only if it is a lead acid battery charger.

---55p

17. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
*and* suited to the Ah rating of your battery.

18. ### raymondht

6
0
Apr 26, 2010
ok it means much Hugher ah right? ill gor look for one.

19. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
No, not necessarily higher, just appropriate.

If it's a 1.3Ah battery, then you need a charger that can charge this capacity. Say 1 to 7 Ah. A charger suited for 20 to 200 Ah would NOT be appropriate.