What is the voltage needed to recharge a battery.

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Dumindu
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My tercel:: 1987 Toyota tercle 4wd DX Wagon 1452CC
Location: Sri Lanka
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What is the voltage needed to recharge a battery.

Post by Dumindu »

My car is a Toyota Tercel 1987 4WD 1452CC DX Wagon.

I had a Exide battery used in my car. I had to recharge it.

My regular Battery charger had a problem. So I have to use an another.

I have a 240V AC to 12V DC 10A converter. Its output is just 12V. I know that the battery voltage must be 12.4V or higher.

Can I use this converter to recharge the battery ?

Or should I get a new one ?
teranfirbt
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My tercel:: '86 SR5 4WD, 5AFE, lifted rear, 195/70/14 tires
Location: Seattle, WA

Re: What is the voltage needed to recharge a battery.

Post by teranfirbt »

To fully charge a battery you need ~14.5 VDC (which is what your alternator puts out when working correctly).
A lot of modern battery chargers have smart charge modes that can restore some of the capacity of older lead acid batteries, but if it has been abused it might be time for a new one. Starting batteries don't like to be discharged below ~80% capacity.
If you need to charge your battery you'll want to get a proper charger. Slower trickle chargers are better for them since it won't heat up the internals as much.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: What is the voltage needed to recharge a battery.

Post by Petros »

terafirbt is correct, to charge the battery the alternator must put out over 14 volts. a fully charged battery is 6 cells, x 2.2 voltes each, that makes 13.2 volts when fully charged. Most cars will usually start when as low as about 11.6 volts.

I once had one bad cell, so down to 11.0 volts: it barely rotated a warm engine after a fuel stop. I had to roll start it out from the pump island (fortunately it slight down hill slope from there and was able to roll and bump start with the clutch). And drive it home without stopping the engine, to look for the problem.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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