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Discussion Starter #1
I have a few gripes with my cts. When starting the car the radio switches off and the lights flicker. This annoys me big time; I am thinking something like a capacitor could bridge the lack in current for the few seconds it takes to start the car thereby keeping the radio on and sorting the flicker.

Is this feasible and if so how would one make this happen?
 

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more torque than the mrs
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I have a few gripes with my cts. When starting the car the radio switches off and the lights flicker. This annoys me big time; I am thinking something like a capacitor could bridge the lack in current for the few seconds it takes to start the car thereby keeping the radio on and sorting the flicker.

Is this feasible and if so how would one make this happen?
How about starting the car then turn on the Radio.?
 

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Discussion Starter #3
Hey I am all for non invasive and low tech solutions but that doesn't really solve the problem. Maybe replacing the car might work
 

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Discussion Starter #5
The MRS has a Ford focus and hers keeps the beats pumping when starting. Even the Fiat van at work doesn't have the same issue.
 

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A capacitor will not fix your problem.

This is not a fault with the car, just an annoyance.

Either get over it or get a new car.

There is no quick fix to this.
 

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Have you a weak battery maybe?
 

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I dont think you understand what a capacitor is and how it holds a charge.

In order to power a radio you will need a bloody large assed capacitor and i mean large like high of your car battery and 1/5 the width and you will need 6 of them.
 

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Discussion Starter #11
I don't think it would have to power the radio entirely but large enough to bridge the shortfall in current/to compensate or top up during starting of the car. Guys with massive audio systems tend to install capacitors to compensate for the power used on high load.
 

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a capacitor in a dc circuit acts as a current blocker, once full nothing is going anywhere, you would need to work out the current being drawn and the correct capacitance needed so it never actually fills up completely.
 

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Discussion Starter #14
I assume I could measure the initial draw. I also assume resistance would need to factored in.
 

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You will need supercaps to do the job due to them having large enough capacitance
Since their voltage is only 2.7 at the most you will need get 6 and wire them up in series to get more than 14.3v as the max voltage, but wiring in series reduces capacitance a.

Each Super cap is roughly the size of can of coke and costs about £400
 

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Discussion Starter #16
Yeah I think this idea is dead in the water. I might look into yellow top batteries instead. Thanks for all your help though
 

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Does the radio in your wife's ford work even without the key in the ignition?
I think the reason it turns off for a brief moment is because it is connected to a circuit that is only closed on ignition, which is a good thing as you can easily forget the radio on and drain your battery.
 

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Does the radio in your wife's ford work even without the key in the ignition?
I think the reason it turns off for a brief moment is because it is connected to a circuit that is only closed on ignition, which is a good thing as you can easily forget the radio on and drain your battery.
My mums focus has "1 Hour Mode" which allows the radio to be on for 1 hour without the keys being in the ignition.
 

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The electrical charge equations Q = CV and Q = IT are relevant and can be combined to give CV = Q = IT (where C is capacitance in Farads, V is volts, Q is electrical charge in coulombs, I is current in amps and T is time in seconds).

The lights are too big a current draw to solve using a capacitor (a small battery might solve this problem though) but the radio cutting out could be fixed using a capacitor...

So, CV = Q = IT can be simplified to CV = IT.

V is 12
I drawn by the radio would be around 3
T where the capacitor has to supply power would be around 2

So CV = IT becomes C x 12 = 3 x 2, algebraically reordered becomes C = 6/12 or 0.5 Farad. So you need a capacitor bigger than 1/2 Farad... Bass Face CAP2.1 2 Farad Car Audio Power Cap Capacitor Amp Digital Display 12v | eBay
 

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Discussion Starter #20
Thanks pal, I am confused though as I always thought 1 coulomb is equal to 1 ampere. The number of electrons across a point per second. With that being said at the price of that capacitor I am willing to give it a try.
 
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