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1995 F-150 Flareside with the 4.9L. Been working through a starting issues over the past couple of days. Found that my battery was running down over night.
Yesterday it turned over slowly, but still started. I checked the voltage at the battery with the engine running and it measured 14.3V, so seems to be charging OK. I turned on all the accessories I could and it only dropped to ~ 14.25V.
Battery was dead again this morning, so I pulled it and put on the charger. Charger showed it was fully charged after a couple hours. I took a voltage reading ~ 11:20 am.
Here is the second reading 2 hours later.
Is this battery toast? It's roughly 2.5 years old. I took it to Pep Boys where I purchased it earlier this week and they put it on their tester. They said it was showing ~ 900 CCA (it's rated at 750 CCA if I remember correctly). So they said it was good to go and handed it back to me.
Just wondering what to do at this point. I think it is still covered under at least a partial warranty. Thanks in advance.
Was it hooked up to the truck from when it was charged at 12.60 and then dropped to 11.90?
I almost did that, but then thought I would pull it out in case there was a draw on it from the truck. So it was on the bench during charging and when I took the readings.
Willing to bet Pepboys didn't select AGM on the battery tester. An AGM battery is charged at capacity at 12.85v not 12.6v like a flooded battery. The battery needs to be tested again, its most likely a failed battery.
Willing to bet Pepboys didn't select AGM on the battery tester. An AGM battery is charged at capacity at 12.85v not 12.6v like a flooded battery. The battery needs to be tested again, its most likely a failed battery.
Appreciate that, should I take it in as is? Last time I took it to them, I think it was closer to a full charge.
Check for excessive current draw when the truck is supposed to be off. The battery may be fine, it's the truck that is drawing it down overnight.
Yeah, I think I will do that also.
Does it strike you as odd that it would drop nearly a volt in a couple hours on the bench? Or could that just be a result of parasitic draw beating this battery down?
Normally I would agree the battery may be weak, but only two hours on a charge after being discharged enough to not start the engine may contribute focusing on it as the root cause. I have been down this path before on my first 1993 F150 Lightning.
Just like you, I started having the overnight dead battery symptom. I took the battery in and they found it was failing so I purchased a new one. There was no warranty. I installed it and everything was good for a few days then the symptom started again. Ended up being a chafed wire for the power lumbar seat. It took awhile to track it down. After repairing the wire and re-routing it so it would not happen again I found there was a TSB from Ford on this very issue.
If you have any aftermarket amps, radios, etc. they are common causes of excessive parasitic drain. Use a clamp on current probe if you have one or install your meter set to amps inline between the negative battery terminal and the the negative cable. I believe the current draw should be less than 50 mA. Whatever you do...do not try to start the engine, you will blow the internal fuse on your meter.
Took the battery back to Pep Boys this morning. They put it on there charger and were able to see how quickly the voltage dropped following a full charge and gave me a replacement.
If you have any aftermarket amps, radios, etc. they are common causes of excessive parasitic drain. Use a clamp on current probe if you have one or install your meter set to amps inline between the negative battery terminal and the the negative cable. I believe the current draw should be less than 50 mA. Whatever you do...do not try to start the engine, you will blow the internal fuse on your meter.
I made sure there was nothing on and tried this test. My multimeter showed 0.07 on the 10A scale. I might try and see if I can get it lower, but that doesn't seem too bad.
