hard start/ battery indicator needle bouncing

[darkstar66]

Trying to get my 2006 E350 6.0 back to long road trip worthy. Have had some issues since returning from Mexico in 2021 that have kept me to close to home. Fortunately is was mostly aging parts needing to be replaced and not cooler/ turbo related. The issue I am having was supposedly fixed about 2 months ago. In that time I drove to MT and back with no issues. The symptoms I will list are exactly what happened before. A couple of days ago I noticed I was having hard starts. Sometimes it fired right up and other times it would take several cranks. Sometimes it would fire but not catch causing me to crank a second time. This morning when I fired it up my power locks activated and then it took longer than normal to turn over. My battery indicator needle was low and then after a few seconds of running it moved up but bounces up and down. I recognized these symptoms and knew that when I turned off the engine, I would not be able to start it again. When I try to start it, it clicks as if the batteries are dead. Batteries are at 12.4 so it should at least crank the engine, yes? Once again these are the exact same symptoms as last time. I am hoping someone smarter than I will recognize these symptoms and have some input. Thanks so much for taking the time to read this. Fyi. SCT tuner shows running battery at 10.8 - 12.

[boywonder]

General rule of thumb.....fully charged battery 12.8V 50% charged 12.2V.

When cranking the voltage can sag much lower like 11V...or less......

It takes lots of amps to crank a 6.0......enough to warrant 2 starter batteries.

[Twoxentrix]

I’m thinking starter batteries as well - when mine reached end-of-life a couple years ago, I too had some odd stuff taking place (one of the issues was door locks doing funky things).

[darkstar66]

Thank you for your reply. I have two batteries that are about seven months old. I will place them on the charger but I tried this the time before.

[darkstar66]

The two starter batteries are less than seven months old. I had them replaced, had starting issues. Took them in and they said they were bad so they replaced them again. When I had this issue three months ago my diesel mechanic said they held charge just fine.

[Twoxentrix]

Originally Posted by darkstar66

Thank you for your reply. I have two batteries that are about seven months old. I will place them on the charger but I tried this the time before.

That’s exactly what I did - it kept my Van batteries happy for a day or two, and then issues started back up.
You can have the batteries ‘tested’ to see if in fact they are good - I would hope so if they are only 7 months old - but then I’ve bought a bad battery (another car) in the past which they ended out replacing after only two months in the car.

[boywonder]

^^^^have the batteries load tested....

If lead-acid chemistry batteries sit around discharged for long periods of time they suffer from sulfation

https://batteryuniversity.com/articl...-to-prevent-it

https://www.power-sonic.com/blog/wha...ou-prevent-it/

Depending on the severity of the sulfation, the battery may be recoverable or not. Sulfation reduces the available plate area in the battery to emit electons/current, so the battery capacity is reduced......eventually to being unusable.

Same thing happens when a lead-acid battery reaches the end of it's life ...the anode (plates) get so corroded there's just not much plate surface left to provide electrons/current, and the oxides formed on the plates don't conduct electricity so the battery is kaput.

Oxides don't conduct much at all, that's why rusty connections don't flow much current and why you have to scrape anodizing off of aluminum to get it to conduct. Anodizing is a electroplating process that oxidizes the aluminum surface in a controlled manner to provide corrosion protection.

[REF]

Right…..so it’s possible for a battery to show normal operating voltage, but the available cranking amps are compromised due to sulfation buildup.
What brand and kind are the batteries? AGM or flooded? Also worth checking to see if your alternator is putting out. Clean and inspect all connections including ground wires.

[darkstar66]

The batteries are from les schwab, a company here in the NW. Regular auto batteries but supposedly the largest they carry. They came out to try to jump start the van but it did not even register. My SCT scanner showed the batteries to be at 8.9 volts. Obviously to low to crank. The weird things is that I didn't try to turn it over so much that I would have drained the batteries. I knew it would not work since this happened a couple of months ago so I tried once or twice and that is it. I am wondering if there is something intermittently drawing from my batteries. I have no clue to what that could be. I have it set up so that my alternator is suppose to charge my solar batteries while driving although I do not think that is happening at all. Could there be something with that? Dang, I just have no clue.

[1der]

Be VERY careful with low voltage and a 6.0. We do not have a 6,0 but have read where low voltage can really F up the ECM / FICM. I solid crank it over until new batteries are in.

The batteries could be internally shorted at this point.