# simple Lead acid battery conversion

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#### Anafam

##### New Member
hi guys, I have a 6v 4AH Lead acid battery . I am using this to power a small portable dvd player which requires at least 8v to 12v dc power.

My question is how can I convert the power from the 6v 4AH Lead acid battery to give at least 9v to power the portable dvd player ?

I need a really simple cheap solution without any complex circuits.....

Any help would be greatly appreciated.

#### Hero999

##### Banned
How much current do you require?

There are plenty of ICs that can be used to boost 5V to 7V and give 12V out, all that's needed is a couple of resistors, capacitors and an inductor.

If you you don't have the time/skill to assemble a circuit then you can buy modules that don't require any external components.

#### Anafam

##### New Member
I need at least 1.5 ampere of current.

#### MikeMl

##### Well-Known Member
Buy a second 6V battery to put in series with the one you already have or a new 12V battery. If you try to use a switcher to step up 6V to 9 or 12 at 1.5A, the current draw from the 6V battery would be ~3A, so the run time would be short.

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#### Anafam

##### New Member
I only have one 6v battery at the moment.

Im sorry I don't know what a switcher is? I'm sort of a noob when it comes to electronics.I'm not a complete noob, I know a lot more than the basics, I can solder and do small things like that, but I'm really bad at ic's and stuff.

Is there anyway to convert from 6v using a few resistors and transistors?

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#### Hero999

##### Banned
Did you check out the links?

The websites are really easy to use, simple input the requirements and you'll be pointed to a datasheet which will have an application circuit one it.

Here's a simple circuit using a couple of transistors but you'll need to find a ferrite core and it's more complicated than using a regulator from one of the suppliers I linked above.

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#### Willbe

##### New Member
You can do it with a capacitor and DPDT relay that switches the cap so it is alternately in series with the batt. and in parallel with the batt.
If you switch at 1/2 Hz you need 1.5F for 1v P-P ripple. 5 Hz, 0.15F. 50 Hz, 15,000 uF. You're trading off relay contact life for cap. size.
I = C (ΔV/Δt), C = I (Δt/ΔV).
Three 4700 uF caps from Hosfelt.com is ~$1.50 total. Last edited: #### duffy ##### Well-Known Member Just go to Digikey or someplace and buy a DC-DC converter module rated for 1.5A. Cost like$30-\$100, but saves you a lot of headaches.

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