Are parallel batteries worthwhile?

[SteveK]

It may or may not be a power problem. Diesels are compression ignition, so if one is cranking slower it makes sense that it would crank longer before building enough heat to fire. But if it's cranking just as strongly, then I agree, it's not a battery problem.

 

[Kuncicky]

It may or may not be a power problem. Diesels are compression ignition, so if one is cranking slower it makes sense that it would crank longer before building enough heat to fire. But if it's cranking just as strongly, then I agree, it's not a battery problem.

I thought I had stated it clearly, but apparently not. The starboard engine turns over very fast and starts without any problem. The port engine turns over slowly, and does that for awhile before it will finally start. Once it starts, it runs just fine. As stated by others, I suspect corrosion, either at an attachment point or in the battery cable itself. And in fact have bought a new battery cable, and now if I could just lose about 150 pounds and become a wraith, then I could somehow wiggle in there and replace the cable at the starter. That is on the agenda.


Bill

 

[backinblue]

I thought I had stated it clearly, but apparently not. The starboard engine turns over very fast and starts without any problem. The port engine turns over slowly, and does that for awhile before it will finally start. Once it starts, it runs just fine. As stated by others, I suspect corrosion, either at an attachment point or in the battery cable itself. And in fact have bought a new battery cable, and now if I could just lose about 150 pounds and become a wraith, then I could somehow wiggle in there and replace the cable at the starter. That is on the agenda.


Bill

Thanks that is clearer now and I agree that it sounds like a connection or battery problem. I think you said it's the same bank for both engines? If so, cables to the starter is a good place to start. Could also be the starter motor itself. I had a motorcycle that was slow to turn over as it got older even with a new battery. Funny, but it was worse of a problem when the engine was hot, not cold. I rebuilt the starter, the old brushes were very worn. After that it was never a problem. For whatever reason, the starter motor being hot became worse. BTW, I also cannot crawl around the engine easily. Not my size as much as lack of flexibility. I now get great satisfaction from paying someone younger to do the crawling.

 

[koliver]

We seem to be getting close to the answers here.
We know that one engine cranks fast, the other slow.
Which is tried first doesn't change that scenario.
That description eliminates battery capacity as the issue. It may be connections, cabling, starter, or something as yet unidentified, all wrt the port engine, as the stb is fine.