Thanks whz1234 for those information. You are right the battery

acts like a huge capacitor to smooth the DC voltage in ca system. There is DC regulator inside alternator. It's output is not a pure DC voltage. Of course pure DC voltage is better than unstable DC for car system. But I do not think DC from alternator without battery connected will damage any module in car. Any module used in car should meet a standard, like reverse protection, high voltage protection (2-3 times working voltage for 60 seconds, from 60 up to 300 voltage spike from ms. to us. etc. Otherwise automotive company will not accept your module. The unstable DC from alternator is just like piece of cake for the module.

My company makes lot of automotive module for cars. I believe alternator output will not damage other module in car even without battery connected, no matter older or newer car. But with battery connected, whole car system will work better, more efficiency.

所有跟帖： 

• 回复：Thanks whz1234 for those information. You are right the batte -whz1234- ♂ (150 bytes) () 05/24/2009 postreply 20:49:05

• Believe or not, it's up to you ... -Happy-DIY- ♂ (467 bytes) () 05/24/2009 postreply 22:29:40