Diesel truck battery issue

Hads930 · 11-24-2018, 09:06 AM

Friend of mine has one of those $75K diesel trucks with 2 batteries like the ones mentioned in the expensive truck thread and called this morning w a question. It’s a 17 or 18 F350 and will not start unless jumped. He is about 2 hours away at his ranch and can only find 1 battery local. He wants to jump it and drive back tomorrow, he’s not a car guy and has no patience trying to run down batteries, would not be surprised if he traded it Monday, that impatient. I am not an electrical guy and know even less about 2 battery systems, question is can he damage anything worse by driving it? Damage to alternator? I assume that voltage regulator keeps it from frying itself?

speeder · 11-24-2018, 09:15 AM

It's probably having a charging issue, easy to diagnose w a simple multimeter on the battery cables while running. If a battery issue, most likely connected to the truck sitting for periods of time or something draining the batteries while parked.

Does he leave it on the ranch when he is away at other locations for periods of time? If I was local, I'd come by and help but unfortunately, I'm not. Good luck.

speeder · 11-24-2018, 09:19 AM

Also, 2 battery systems are exactly like 1 battery systems in those trucks. They are wired in circuit, so not 24V. Only 12V. It should start fine w one battery charged. It is extremely unlikely that both batteries "went bad" in that new truck. Something is draining it or he has a charging failure. The truck is under full warrantee if it's a 2017 or '18, just have it towed to the dealer and say, "fix it."

Hads930 · 11-24-2018, 09:44 AM

Thanks appreciate the response. The truck is his daily and does not sit and does not have any accessories that would drain the batteries outside of the original equipment. No meter so I can walk him through any sort of diagnostics. Driven a ton so it is probably out of warranty due to mileage. I agree that towing to dealer would be ideal but dealer is an hour away in a small town and not open today. Would take batteries to him but had surgery Monday and not 100%. He’s impatient and wants immediate fixes, he’d hire a tow truck out of Houston if he could. Pretty sure no matter what I tell him he is driving home.

speeder · 11-24-2018, 09:53 AM

Diesel powertrain warrantee is 100k miles/5 years so if it's a 2017 or newer and he has more than 100k miles, you're right--no warrantee. Still, the dealer would fix it.

If he's going to trade it, PM me and I'll buy it for cash. Forget everything I wrote in the other thread 20 minutes ago, lol...

Hads930 · 11-24-2018, 10:09 AM

Sent me a pic of dash, 58K miles, I’ll let him know. Thanks again.

911boost · 911boost's Garage

My stock batteries are almost 7 years old and still work just

Does it run once it is jumped?

CurtEgerer · CurtEgerer's Garage

If one battery is weak, it may not start. At least, that's what happened to me. 2 year old battery, replaced under warranty. I was able to start it with one of those tiny electronic jump starters connected to the weak battery.

Can't explain it, other than to say that this is way more complicated than just 2 batteries hooked together. All sorts of electronics in between.

John Rogers · 11-24-2018, 12:20 PM

I had a 2000 Ford F350 and about a year after I bought it in 2003 one of the batteries went weak and according to the F350 forums they said to replace both with the largest capacity that would fit in the battery space. I did just that and they lasted until I sold the truck 6 years later. It does take a lot of amps to turn over one of those engines, that is why engines with very high compression sometimes use air starters.

908/930 · 908/930's Garage

Never had a dual battery system but I thought that the two are not directly connected and somehow isolated, if so it could be just a bad connection on the one battery.

Can he run cables between the two batteries and try to start it? Otherwise sounds like the alternator or a connection to the alternator, if he drives it like that he might get left on the side of the road.

Sebscst · 11-24-2018, 12:29 PM

Yeah I currently have 7.3 f350 dual battery. I’ve owned 4 of these trucks through the years and if one battery goes bad it will not start. Also never replace just the bad one always replace both. I have only had a dead battery twice with over 20 years of owning the different trucks.

Arizona_928 · 11-24-2018, 02:42 PM

it comes down to cca. They are wired in parallel to get the cca to turn over the engine.
Shouldn't be a problem to run it short term until he gets a pair of new batteries.
If you're in Texas. I wouldn't be surprised if one battery is bad by year two or three that it is now.

Also to sell a truck over a dead battery is astonishing.

911boost · 911boost's Garage

Why would the battery be dead in Texas as opposed to a cold climate?

Arizona_928 · 11-24-2018, 04:09 PM

Heat kills batteries. Especially if the battery used recycled Pb instead of virgin metal. Sulfated plates, shorted out plates, etc ect.

In phoenix, the most I can get out of a battery is two years ( I should note lead acid batteries). Even German oem batteries in diesel application. I average 1 year or so on the autozone. A little bit longer on the Costco Interstate. The best I have used have been the Optima red top AGM with the spiral cells. However, they cost about 3 times as much as an Interstate battery.

cabmandone · cabmandone's Garage

If the truck runs after jumping, the alternator is charging IMO. If the alternator wasn't charging the truck wouldn't run because the computer wouldn't be seeing the voltage it needs. My money is on bad batteries. If he has access to one, have him put it in alone (what I mean is don't connect the other battery). The truck shouldn't need two batteries to start in a warm climate and if the other battery would have a bad cell it might drain the one new battery installed.
BTW, if it's like most Ford trucks it has a system check feature. If he gets it started he can run the system check and if the truck is seeing normal voltage, drive it home.

Zeke · 11-24-2018, 04:30 PM

Quote:

Originally Posted by cabmando

If the truck runs after jumping, the alternator is charging IMO. If the alternator wasn't charging the truck wouldn't run because the computer wouldn't be seeing the voltage it needs. My money is on bad batteries. If he has access to one, have him put it in alone (what I mean is don't connect the other battery). The truck shouldn't need two batteries to start in a warm climate and if the other battery would have a bad cell it might drain the one new battery installed.

Best post yet. But, he needs a charger to get one of the batteries topped off. Sounds like this guy has trouble putting fuel in the tank and doing simple maintenance.

chapo · 11-24-2018, 04:41 PM

My 7.3 only needed batteries once in 10 years. Bosch are available at PEP Boys. Always replace them in pairs. My 6.0 Ford diesel was Very sensitive to low voltage, wouldn't start below 11.6 volts. New batteries don't seem to last very long. My 2012 F150 needed a battery when it was only two years old, My Passat made it to three before needing replacement

cabmandone · cabmandone's Garage

Went over the OP again and if he's jumping and running on bad batteries it is possible to burn up the alternator. Like I said above, i'd have them put in the one good battery and drive it.

Zeke · 11-24-2018, 04:49 PM

Hopefully it has a big amp alternator.

speeder · 11-24-2018, 05:15 PM

Quote:

Originally Posted by AZ_porschekid

it comes down to cca. They are wired in parallel to get the cca to turn over the engine.
Shouldn't be a problem to run it short term until he gets a pair of new batteries.
If you're in Texas. I wouldn't be surprised if one battery is bad by year two or three that it is now.

Also to sell a truck over a dead battery is astonishing.

You are correct, I should have typed "parallel" above. At least I got the principle right, IOW, still 12V.