8 replies to this topic

[CamperSam]

Hi
I bought a new F150 last month. I bought from dealer stock and given the little bits of mould they didn’t clean from the bed, I think this has sat in the lot for a few months.

I bought a voltage meter which goes in the cigarette plug to get an idea of battery health.

It’s generally 12.2v with the ignition on before I go to start it (air-con off) after sitting for 12-24hrs. Is this normal or a bit low (ie battery is bad).

I want to check this before we go on some big trips later this summer.

Sam

[Vic Harder]

Sounds low.  

https://www.emarinei... 12.9 and 13.1.

 

 

Vic

[PaulT]

Because of all the electronics that remain live with the ignition off in modern vehicles & the lousy job of charging done by the alternator especially on short trips, try putting on a real smart charger until it indicates full charge before making a decision. I charge my truck once or twice a month to be sure that the battery sees full charge regularly.

 

Keeps the battery happier.

 

Paul

[Vic Harder]

Because of all the electronics that remain live with the ignition off in modern vehicles & the lousy job of charging done by the alternator especially on short trips, try putting on a real smart charger until it indicates full charge before making a decision. I charge my truck once or twice a month to be sure that the battery sees full charge regularly.

Keeps the battery happier.

Paul

And if you really are seeing only 12.2 and that is the “resting” voltage, that’s not good. 12.2 resting is only 50%, or basically discharged.

[CamperSam]

That’s what I’m wondering - if the truck sat on the lot for ~6 months? (It’s a 2019) then it’s entirely possible the battery has been killed (my theory anyway)

[fish more]

It's called "Lot Rot". Should have them replace the battery before it leaves you stuck somewhere. You can also look at the label on the inside of the driver's door jam and find the build date of the vehicle. That would tellyou about the history of the battery.

[Beach]

After driving let sit for a couple hrs then check voltage. Voltage should be 12.6-12.8, if not get them to replace that battery if there is a warranty.

[ntsqd]

Bare in mind that you can also be seeing voltage drop in the wiring. Best to check it right at the battery.

[CamperSam]

Ok update - the F150 smart alternator doesn’t charge the battery full.
I had the battery tested at Ford and they said it’s all good.
I then also disconnected the battery sensor on the negative terminal so that on road trips I get full alternator output 14.5V to my FWC Hawk.