BajaNomad

Weird battery issues while waiting to cross the border

Santiago - 2-25-2014 at 11:20 AM

Going through the 2 hour creep getting across the border it was finally our turn; BP agent asked to look in the back. I shut the motor off in order to unlock the back and when I tried to start it again it was dead. We had to push the truck into secondary and jump start. Volt meter read 14+ for about 30 minutes and then dropped back down to the usual 12-13v. No problems after that and a week later, still no problems.
We decided that the two hours of idling and creeping with our lights on and A/C going, charging everyone's phones, iPads etc drained the battery - never happened before though. How much current would a healthy alternator generate while idling?
Anyone else have this issue?
Have not had the alternator/battery checked out yet - battery is about 3 years old.

willardguy - 2-25-2014 at 11:28 AM

your battery should charge just fine at idle, check connections.

durrelllrobert - 2-25-2014 at 11:36 AM

Quote:
Originally posted by Santiago
Going through the 2 hour creep getting across the border it was finally our turn; BP agent asked to look in the back. I shut the motor off in order to unlock the back and when I tried to start it again it was dead. We had to push the truck into secondary and jump start. Volt meter read 14+ for about 30 minutes and then dropped back down to the usual 12-13v. No problems after that and a week later, still no problems.
We decided that the two hours of idling and creeping with our lights on and A/C going, charging everyone's phones, iPads etc drained the battery - never happened before though. How much current would a healthy alternator generate while idling?
Anyone else have this issue?
Have not had the alternator/battery checked out yet - battery is about 3 years old.



An alternator, puts out amps. As the A/C accessories and electronics ask for power the alternator generates more to accomodate the load. At idle the alternator is only spinning fast enough for a basic amperage output (about 30 - 40 amps). When too much load is requested and the alternator isn't spinning fast enough, the power then starts coming from the battery and now the alternator tries to charge the battery and accomodate the electrical load. Unfortunately the battery usually gets nothing and you get an overheated alternator and failure begins.

Cliffy - 2-25-2014 at 11:37 AM

Could be low output of the alternator while at idle but maybe not. It should put out 13 to 14+ volts when the engine is running tapering down as the battery comes up to charge BUT you have no way of knowing what the amps out is without extra equipment. It's the amps that charges the battery, the volts only "push in" the amps. You might try removing the battery cables and cleaning them and the posts and re-tighten. Lots of times that solves the problem. Unlike the old generators that required lots of RPMs before they put out amps, alternators SHOULD put out some amps at idle but not their rated maximum.
With what you say the volts were my guess is the cables and the fact that you had a big draw from the battery while sitting there at idle for so long.
BTW, how old is the battery? 3 years? You could be having one cell going bad if it's old. Any parts store can do a battery capacity check for you for free. That will tell you if you have a bad cell.

weebray - 2-25-2014 at 12:00 PM

I totally agree with Clifffy. Do a very through clean up and seal of ALL connections associated with the starting/charging system. Replacement of a 3+ y/o battery may seem extreme but it's not. Modern sealed batteries tend to fail with not much warning. Your problem will return unless you deal with it now.

Hook - 2-25-2014 at 12:40 PM

And dont forget to make sure the neg ground connection to your engine block is clean and tight, too.

durrelllrobert - 2-25-2014 at 12:56 PM

Quote:
Originally posted by weebray
I totally agree with Clifffy. Do a very through clean up and seal of ALL connections associated with the starting/charging system. Replacement of a 3+ y/o battery may seem extreme but it's not. Modern sealed batteries tend to fail with not much warning. Your problem will return unless you deal with it now.

Single cell failures are common when driving on dirt roads in Baja. The vibrations can cause a separator between the plates in the battery to "fail" and cause a short between plates.

Santiago - 2-25-2014 at 01:02 PM

This is how retired guys fix it:
1. Go change into older one-piece jump suit; saving newer one for company.
2. Go get SAE tool box.
3. Get a couple of clean shop rags.
4. Throw some brewski's into the small cooler.
5. Open hood.
6. Wait a few minutes.
7. Soon other retired guys start showing up in their one-piece jump suits.
8. Go get the baking soda and water.
9. Go back and get the old toothbrush.
10. Do the baking-soda-water-toothbrush thing just like your dad showed you.
11. Yell at the wife to bring out sandwiches and more beer.
12. Take a well deserved nap.
13. Thank your lucky starts you had something to do today.

This is how I do it:
1. put all three blinking lights on hold.
2. Go to line 4 and call AAA.
3. Go back to blinking lights and finish bidness.
4. Pay AAA guy for new battery and alternator test.
5. Pi** and moan about why I'm not like the above.

DavidE - 2-25-2014 at 01:45 PM

What kind of vehicle? Year, model and engine? Did you have your headlights and AC on while waiting?

Voltmeter indicates a period of higher than normal voltage output. Definitely links a bad connection right at the battery. But if the starter loses CONTROL CIRCUIT voltage, you twist the key and nothing happens.

I agree with the folks above. Remember a HOT corroded connection and a heat soaked starter motor makes for a bad marriage.

Bob and Susan - 2-25-2014 at 03:02 PM

we just had a similar problem...

it was a battery cable from the starter to the alternator

but hook could be correct and it could be as easy as cleaning the ground

since you aren't having the problem right now...its probably loose or dirty cables...it'll happen again...just drive it to the border...

weebray - 2-25-2014 at 03:17 PM

In the charging/starting system, the pos. and neg. circuits are equal partners, speaking in relation to their importance to your end goal. Play fair give them an equal amount of love.