Hey all
I am needing to do a project but i am not too sure if it will be possible. I need to know how long it would take for an alternator to charge a 12V battery and at what speed would that be more or less?

Please e mail me you replys to [email protected]
Thanks very much

 

I assume you are talking about commonly available automotive components and SLI or deep cycle batteries. A 140 Amp alternator will charge a common size battery, say group 24, in an hour or less. It will charge to a given percentage fairly quickly and then modulate to prevent blowing the caps off or exceeding the recombination rate of "maintenance free" batteries. This is somewhat vague because there are several chemistries and it depends on temperature, etc. There is a great deal of finesse in getting a long term system to maintain optimal charge but, short term, you can dump a lot of charge into these batteries in a short period of time and get nearly fully charged before you need to slow down. This subject is much more complex and difficult than I had thought when I endeavored to design the industry's most accurate voltage regulator test equipment. I am glad to be able to share a little of what I learned.

Regards

cww