It's hot. Damned hot. Fox in a forest fire hot.

I have a 2018 F150 and am the original owner. Replaced the first battery about 15 months ago with a 3 year guaranteed battery from Auto Zone.

Lately, the truck has sometimes been 'laggy' on starting. A bit of hesitation when I turn the key, sometimes slow cranking. On the other hand, sometimes it's fine. Like today. Ran errands, 5 separate stops, cranked like a champ every time, and started quickly.

What is going on here? Do I have a cell that is starting to fail, but isn't consistent? I don't have any corrosion on any terminals or the ground strap, so it isn't that.

Any ideas would be appreciated.

Thanks.

A

Swing by an auto parts store. They can test the battery and let you know if it has a bad cell.

Have it tested, it will tell you the most info.

You said no corrosion on the terminals, but did you check to make sure they are tight? I went to swap the battery in my then 2-year old truck because it was doing similar & when I touched the negative post with the wrench, it spun. Tightened it up & went another 2 years before the battery croaked.

Starter motor maybe (or connections to it)? I had one that was "iffy" on my Mercedes 240D, and I kept blaming the battery.

Have the battery tested at an auto parts store first. Next check connections while testing it (clean and tight). Then if both of those check out, start ( NOT alternator) is probably getting a weak spot.

Corrected.

This message has been edited. Last edited by: jimmy123x,

Put a meter on it and see how many volts you have with the car off. I have found that most car batteries have 6 cells. If one is bad you get about 2 fewer volts than you should. A fully charged battery will be about 12.6 volts.

You can also start the car put a meter on the battery. You should see 13.5 to 14.something if the charging system is working correctly.

I would take it back to Autozone and let them test it.

If the battery checks out, take a look at the starter. The last one I replaced, the starter would hesitate/cut out before starting, you would turn the key, it would turn over once, then stop, turn the key off and on again and it will start up, but sluggish and chugging. Some days would start right up like you mentioned.

When I took the bad starter out, the armature/pinion had significant wobble play.

Potentially could be a loose ground strap as well. Follow the big ground wire from the negative battery post to where it grounds out and verify that it is tight and corrosion free.

I have a 2013 F150 that still has the OE battery in it.

It’s been a long time, and I can’t recall if a solenoid can cause the slow crank issues you describe. I know that when failing it can “click,” then turn over.

Taking it back to Auto Zone is the best idea though. I’ve got a volt meter, but they can test it under a load.

The laggy cranks are on a cold start first thing in the morning? Then you run around, the motor warms up, the battery voltage is higher because the alternator charges at a little more than 14v, and it seems to start fine? If that’s the case, that’s a sign that the battery is on it’s last legs. That’s the battery that won’t start the car up north when the first cold snap hits, but seems to be fine during Indian summer.

First thing I’d do is put it on a charger overnight. If this is a vehicle that gets infrequent use and only does short trips, you may not be running it enough to charge the battery fully.

Next thing I’d do is get it checked at the autoparts store.

Laggy crank is usually when I stop during the trip. Cold crank is typically, but not always ok.

quote:

Originally posted by ArtieS:
Laggy crank is usually when I stop during the trip. Cold crank is typically, but not always ok.

My opinion it sounds like your battery is heating up and may be going bad. I suggest getting it checked by AutoZone and make sure the battery is heated up and used when you have them check it. God Bless

quote:

Originally posted by ArtieS:
Laggy crank is usually when I stop during the trip. Cold crank is typically, but not always ok.

I had that problem on my farm truck a few months ago. The starter was bad.

I have a 2012 F150. Sixteen months ago, I had a bad battery that Costco replaced because it still had one month of warranty remaining. A few weeks ago, the replacement battery was dead and wouldn't take a charge. I took it back to Costco and they said the warranty only applies to the original battery so I had to buy a new battery. I mentioned to the cashier that this battery didn't last very long and they must not be making them as good as they used to. He agreed with me and also said that the new warranty on batteries is prorated instead of a full replacement.

Batteries are weird sometimes. Some can crank the engine OK, but leave the ignition/accessory position on for 5 minutes and it dies. Others only last ~18-24 months, while another, even one produced consecutively in the same factory, might last 5-7 years or even longer. Have it tested, preferably with a load.

Also, many vehicles produced in the last ~5-7 years have load/current-based charging systems. These alternators only put out according to the electrical load at a given moment and are not meant to actually charge the battery. This is done because an alternator puts a slight drag on the engine and they want to squeeze that extra one-tenth of a mile per gallon. If you have one of those, there will be a three-wire sensor attached to or encircling the negative battery cable.