Voltage

[danielporsh911]

Okay so my father has a truck with a small problem with his truck his battery drains over time and by this is mean it's something wrong with the truck not the battery. He was asking me to do some research and find out how much volts it will take to charge a 12 volt battery. I am not great with electricity because I'm the programmer in the family. According to my understanding you can charge it with higher voltage but for less time and with lower voltage but for more time... am I right or wrong. Someone please help me out. He wants to use solar panels to charge his batteries but he doesn't know what voltage to charge it at as he said.

[You_are_a_cunt]

Assuming it's Lead Acid, 14.2V to 14.5V as measured right across the battery posts (which is what the alternator should be charging the battery at).

Not really a car expert of any sorts, so wait for confirmation from people that know more on the subject

[klh2000]

For a full charge, use 14.4 volts. The best way would to be a dedicated car battery charger, assuming it's a lead acid truck battery (600-1000CA) I would charge it at around 20-40 amps.

[Thunderpup]

If the battery is getting drained then there is something draining it that you should be looking into.

 

Usually the most common culprits are poorly wired security systems or upgraded car audio systems.

 

A short in a interior light that stays on even when it should be off.

[zanthros]

Generally the alternator charges @ 13.8 volts.

 

as far as finding the draw... there's the rub. You can verify that there is a draw on the system by the use of a test light used in series with either battery cable. But you already know that there is a draw, so the next step in finding the culprit is to use a test light in series with the fuses but you need to disregard the ECM fuse and the one circuit that powers the radio as at minimum those tow circuits are always drawing juice. (The radio, due to the "memory" for the preset radio stations and other functions) and the ECM (electronic control module" or "computer" for the ignition and other systems) for storing data. testing anything else in series should not produce a light on the tester...

I turned a wrench for longer that I want to admit and this is how it is done....

[danielporsh911]

34 minutes ago, Thunderpup said:

If the battery is getting drained then there is something draining it that you should be looking into.

 

Usually the most common culprits are poorly wired security systems or upgraded car audio systems.

 

A short in a interior light that stays on even when it should be off.

He says he knows what the problem is he just wants to do the battery charger.