How to calculate the duration of a car battery needed to be fully charged?

Question

Lets say i have a alternator which produces 100 amp 12v and the battery is 50 amphr. Thank you guys

Answer 1

This will more than likely fry the battery, if it is connected to 100 amp for any amount of time. Usually, any amperage over 50 is used for jump starting, not charging.
Using a 10% rule, I would not charge the battery with more than 5 amps for 5-6 hours. (Charge times/voltages/amps vary on types though).

The alternator's output is based on the load it sees from the battery. A low battery may only prompt the alt. to boost output to <20 amps. Rpm's are a factor too. Alternators will have full output after 2000rpm's. Idling may charge a battery, but th best bet is driving. Usually, an hour or two of driving can charge a battery enough.

Answer 2

Hi you need more info on the battery capacity. There is a number called reserve capacity. This number tells you how many hours your battery can supply 25 amps (25 amps/hr x RC) will give you the amount of charge it can hold then you divide that by the alternator output. But remember a lot of variables come into play, the voltage regulator, the battery condition, the temperature ambient and the temp of the charging battery as it gets hot the charging rate will reduce. Also make sure the electrolytes are well suspended via correct water level.

Finally there are a few different technologies of car batteries out there and each type of battery takes different charge rates and characteristics.

Hope that helps. Grufly speaking if your rpms are up there and your drain rate is negligable a dead battery becomes fully charged in 15 to 30 mins of driving at 2k plus rpms.

Answer 3

charge time of the battery is determined by the regulator circuit in the alternator and how low the battery is. . the alternator rating of 100 amps at 12v is at full load and the battery rating of 50 amp/hrs is discharge rating. the battery can supply 50 amps for 1 hour or 1 amp for 50 hours. no connection on charge time between the two. an alternator can charge a battery in about 15 minutes (enought to start the car)

Answer 4

if the battery is down then it,s no longer completely charged. it may start up with jumper cables as long as a results of fact the battery continues to be solid. however the starter can save it from beginning additionally if the solenoid is undesirable.you may go away the fan on or the radio on and it gained,t run the battery down yet leaving the lights on will drain the battery. as quickly as you close up the swap off then the radio or fan don,t artwork however the lights nonetheless will shine. you be attentive to while your tires choose changing once you may,t see any tread on them.

Answer 5

you can't calculate the duration

Answer 6

I THINK NOT LONGER THAN 6-8 HOURS.