Alternator or Battery Problems

[ncgoblin]

Hey Guys,

When I first started removing the parts of the donor I purchased a T5 Everstart Battery it was off a charger for a month. I add a tender on the battery especially this winter. Last week I was driving for about an hour and noticed when I went WOT the car would cut power and backfire. I remember in the past having this same issue when the battery would not be charged fully this would cause the throttle body to not open all the way. When I got home I put the battery on the tender and noticed it was only 50% charged. I have a USB plug with a digital voltage meter and it was reading 13.9 to 14.0v while the car is running. So my first thought is that the alternator is functioning but the battery is not holding a charge. I have a Schumacher BT-100 100A Battery Load Tester and Voltmeter that I can put on the battery do you think this will give me an accurate reading of if the battery is faulty? Is there a test I can do on the alternator?

I am fine with buying new parts just want to make sure I don't remove the battery for a warranty replacement and they say its fine and then also buy an alternator when it too is fine.

Thanks

 

[ctuinstra]

While running, your alt should be able to provide all the voltage (and current) the car needs to function. If it doesn’t or can’t, it will drain the battery over time while driving it.

Now if your car is running fine and then you park it for a month and the battery is dead, either you have a parasitic draw on the battery or the battery has a shorter cell.

Most of the testers test the internal resistance of the battery by loading it heavily and calculating the drop.

I tend to wonder if you have another issue. You might want to get an OBD reader and monitor the voltage if you suspect it, but the alt should be able to provide enough assuming the battery is not a dead short.

 

[Desert Sasqwatch]

Most auto parts stores can test the battery for a shorted cell and some (like NAPA) can test the alternator if you bring it in. Hope it is not a wiring issue as Chad alluded to. A quick check for the alternator is to pull the positive cable on the battery while the car is running - if it keeps running the alternator should be okay.

 

[ctuinstra]

Most auto parts stores can test the battery for a shorted cell and some (like NAPA) can test the alternator if you bring it in. Hope it is not a wiring issue as Chad alluded to. A quick check for the alternator is to pull the positive cable on the battery while the car is running - if it keeps running the alternator should be okay.

I would be very careful about pulling the battery while running. Without the battery, it's very difficult for the alt to regulate the voltage. I made this mistake on a motorcycle once. Blew every bulb and darn near a few other things along with it. The battery is it's foundation, good or bad.

Checking the voltage at the battery while running and with load such as headlights should tell you if the alt and regulator are working well. You should have 13.8v roughly.

 

[G Atsma]

One way to put it is, even with the alternator charging, everything runs off the battery. The battery is the "reservoir" of electricity that the alternator refills if needed, as dictated by the voltage regulator.

 

[BaltimoreHokie]

Hey Guys,

When I first started removing the parts of the donor I purchased a T5 Everstart Battery it was off a charger for a month. I add a tender on the battery especially this winter. Last week I was driving for about an hour and noticed when I went WOT the car would cut power and backfire. I remember in the past having this same issue when the battery would not be charged fully this would cause the throttle body to not open all the way. When I got home I put the battery on the tender and noticed it was only 50% charged. I have a USB plug with a digital voltage meter and it was reading 13.9 to 14.0v while the car is running. So my first thought is that the alternator is functioning but the battery is not holding a charge. I have a Schumacher BT-100 100A Battery Load Tester and Voltmeter that I can put on the battery do you think this will give me an accurate reading of if the battery is faulty? Is there a test I can do on the alternator?

I am fine with buying new parts just want to make sure I don't remove the battery for a warranty replacement and they say its fine and then also buy an alternator when it too is fine.

Thanks

The first time I took out my goblin for a test drive (which also had to be jumped to start) it also back fired on me. I cannot say for sure about the WOT now, as I have not been able to take it out for any pulls. But, I haven't had any issues since.