I have been using this car battery for the past 15 months. Recently, it starts the car very well in the morning but, after driving around for some minutes/hours, it fails to start the engine almost immediately. Although, after two or more hours rest, it starts the engine very fine again, very symbolic of a weak battery.

I performed a DIY on the alternator while engine was running and got 14 volts, which means my alternator is working well. I proceeded in testing the battery and always get 12.7 volts (perhaps OK). A battery charger also checked the battery and confirm that, there is nothing wrong with it.

I am actually confused with the phenomenon where I will stop my car and it wont start almost immediately till I will have to wait and made up my mind to go for a new battery. I therefore, need candid advise/opinion from this esteemed forum before I will hastily conclude to buy a new battery.

Kind advise please.

Thanks.

jimmy74:
I have been using this car battery for the past 15 months. Recently, it starts the car very well in the morning but, after driving around for some minutes/hours, it fails to start the engine almost immediately. Although, after two or more hours rest, it starts the engine very fine again, very symbolic of a weak battery.

I performed a DIY on the alternator while engine was running and got 14 volts, which means my alternator is working well. I proceeded in testing the battery and always get 12.7 volts (perhaps OK). A battery charger also checked the battery and confirm that, there is nothing wrong with it.

I am actually confused with the phenomenon where I will stop my car and it wont start almost immediately till I will have to wait and made up my mind to go for a new battery. I therefore, need candid advise/opinion from this esteemed forum before I will hastily conclude to buy a new battery.

Kind advise please.

Thanks.

That is a wrong method for checking for a defective alternator. U will need to load the alternator(switch on all accessories ) and check the alternator voltage again .A good alternator voltage shouldn't fall below 13v.
The issue is most likely alternator not battery ,I am sure you are running your fan direct .
Folks that run their fan direct always get their alternator regulator fried easily.

@ Honmusa, Thanks for that input. My fan actually run direct and I am correcting that within the week. For the wrong testing method, I will check test again with my full lamps and other loads on.
Hope to get back when am done.

Thanks.