I’ve got a 2018 F150 with 120,000 miles. Over the summer, it started having trouble starting now and then, so I replaced the battery under warranty at NTB. Afterward, the issue still popped up here and there. It would start fine if it sat for a while, but if I stopped and started it a few times, it struggled and sometimes needed a jump.
Took it to a mechanic who found out both the alternator and starter were bad, so he replaced them. He also mentioned that the alternator had been overcharging and causing the battery to ‘sweat,’ and now he thinks the battery might need replacing to avoid damaging the new alternator.
The battery was only a few months old, so I went back to NTB to have it checked. They said the battery was fine and the sweating might just be condensation. I also had O’Reilly’s test it, and they said it was fine too.
My question: Could the battery have a problem that these tests didn’t catch? Is my mechanic just being cautious, or is this something I should worry about? If the battery checks out fine, can I leave it as is without hurting the new alternator?
Appreciate any advice! Attached a pic from NTB’s test for reference.
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Sounds like your battery is fine. It might’ve been just bad luck with the alternator. Sometimes shops only test the battery and not the whole charging system, so the alternator issue could’ve gone unnoticed at first.
From what I see, your battery is fine based on the tests. Sometimes a weak battery can strain an alternator because it forces it to work harder than it should, and that might’ve caused the alternator to fail.
Your old weak battery may have put extra wear on the alternator, shortening its life. That’s probably why your mechanic is being extra cautious. If the alternator is tricky to replace, they might just be trying to avoid future problems.
If the labor to replace the alternator is more expensive than the battery, it could be worth swapping it. Otherwise, I’d keep the battery if it’s testing well.
@Presley
Appreciate the breakdown. Is there any risk with the ‘sweating’ the mechanic mentioned? Or should I be good with the current setup since the battery tests fine?
Quince said: @Presley
Appreciate the breakdown. Is there any risk with the ‘sweating’ the mechanic mentioned? Or should I be good with the current setup since the battery tests fine?
Battery sweating can happen, especially with a flooded battery like yours. It’s usually not a big deal. Unless the sweating gets excessive, I don’t think it’s something to worry about.
Congrats on getting the repairs done! Since NTB and O’Reilly’s both confirmed the battery is fine, I think you’re good there. If you do decide to replace it, you’ll probably have to pay out of pocket unless NTB’s warranty covers something specific.
Next steps: I’d have your mechanic check the charging system while the engine is running and also check for any electrical draws when it’s off. A multimeter can help with that.
Also, newer vehicles like yours might need the battery management system reset when parts are replaced. This could explain why your mechanic is being cautious.
