About to leave, truck batteries are dead question

[mattyj]

Hello everyone, I loaded the camper last night packed everything up had the truck running idling for a while no problem. Today I go to start truck batteries are dead and I can’t figure why the meter is saying the camper battery is OK, lights work.Can anybody help me with this? Thanks

[mattyj]

joerg68 wrote:
Re. Airbags: the airbag compressor is not continous duty. I doubt it will survive running long enough to pull down two batteries.

some more thoughts: I checked the voltage of the batteries and they kept dropping even know the The truck was running so I am bringing it to the shop I think it is the alternator, I am annoyed this happened but it could’ve been worse I could’ve been on the road. Thank you for your responses thank you sir
What voltage does the camper battery show?
There are not many electrical consumers in a truck or camper that can run down two (or possibly even three, with the camper battery) fully charged 70-something Ah batteries in one night. Leaving the truck lights on, or the fridge on 12V, might. A single dome light won't do this.
Do you know if you have a battery separation switch of sorts between truck and camper?
Having the camper on shore power does not necessarily guarantee that the fridge is running on shore power, though it normally should. But it may have been inadvertently set to 12V, or something may have gone wrong.
15 minutes is not long (enough) to charge the batteries. You'd need to know what their voltage was before the jump start.
In any case you need to find out if the problem is with the truck or the camper.

[rexlion]

I would use a standalone charger to recharge the truck batteries while the cables are off the terminals, then check their voltages a few times over the next several hours. If the voltage falls off quickly on one or both with nothing hooked to them, one or both have gone bad (unlikely for both at once, but not impossible). If they stay at a reasonably high voltage, hook them back into the truck (camper line disconnected) and check their voltage again in an hour or so. Then if need be, hook the camper back to the truck and again test battery voltage in an hour or so. I think most likely it's a drain from the camper, but the other possibilities must be eliminated first.

[joerg68]

Re. Airbags: the airbag compressor is not continous duty. I doubt it will survive running long enough to pull down two batteries.

some more thoughts:
What voltage does the camper battery show?
There are not many electrical consumers in a truck or camper that can run down two (or possibly even three, with the camper battery) fully charged 70-something Ah batteries in one night. Leaving the truck lights on, or the fridge on 12V, might. A single dome light won't do this.
Do you know if you have a battery separation switch of sorts between truck and camper?
Having the camper on shore power does not necessarily guarantee that the fridge is running on shore power, though it normally should. But it may have been inadvertently set to 12V, or something may have gone wrong.
15 minutes is not long (enough) to charge the batteries. You'd need to know what their voltage was before the jump start.
In any case you need to find out if the problem is with the truck or the camper.

[mattyj]

bighatnohorse wrote:
You need to check the battery fluid with a hydrometer.
A hydrometer is easy to use, inexpensive and available at all or most auto parts stores.
If the battery has a dead cell then it is toast - it won't charge up again. It's toast.

these are seal batteries

[bighatnohorse]

You need to check the battery fluid with a hydrometer.
A hydrometer is easy to use, inexpensive and available at all or most auto parts stores.
If the battery has a dead cell then it is toast - it won't charge up again. It's toast.

[mattyj]

I’m wondering if the airbags on the truck which I was using last night could have been the culprit, I don’t know if there’s a switch to turn them off or you just leave them and turn the ignition key off and they’re off

[mattyj]

Both truck batteries totally disconnected read 11.35

[mattyj]

I will disconnect each battery on the truck and test again when I tested the first time they were connected thanks

[mattyj]

joerg68 wrote:
I amended my first reply, pse re-read if you haven't yet.

. I had to camper plugged in to AC at my house and I just jump started the truck and it started and I shut it down 15 minutes later it won’t start again

[mattyj]

The truck batteries are 11.38 volts and the camper battery is 12.56 if anyone can help me.

[NRALIFR]

Yeah, start with checking the battery’s voltage. Disconnect one of the cables on each battery and check each one separately.

Are there any accessories connected directly to either battery?

Normally on Ford’s, the 12v charging circuit from the truck is running through a relay that isolates the camper from the truck when the engine isn’t running. It’s not hard to defeat that though of you want to. As joerg said, make sure it’s not the camper that ran the truck batteries down.

:):)

[joerg68]

I amended my first reply, pse re-read if you haven't yet.

[mattyj]

Correction I am now going to test the batteries

[mattyj]

Thanks for responses the battery in the camper is new in the truck batteries are new I am not going to go get a tester and try to check the voltage

[Dick_B]

Not much to go on but we had battery problems with our Suburban due to electronics using juice overnight even tho we supposedly had everything else turned off.
How old is the truck battery? Did you accidentally leave a dome light on overnight?
Better to get the battery tested by a pro. My auto dealer told me that they find bad batteries in the new cars just off the truck 😞