The difference is all current, load and charging, should enter the batteries BALANCED. Positive on one batt, neg on the other, NOT both batteries grounded separately. Impossible for both to have same charge/discharge action. Negative lead could go to one starter mount bolt for better cranking with cable to now vacated (of batt neg leads) ground junction in center of crossmember to pick up rest of the smaller loads. Pictures and numbers to follow after I get air leaks solved.
Battery cables
- Thread starter nostrokes
- Start date
This is what the actual charging circuit looks like. (Most basic drawing.)
Current from alt goes to the positive side of the solenoid, then to the positive side of one battery. Then from there to the positive side of the other battery, via a cable straight between them.
Negative goes out through the alt case. To the engine block. From there it goes straight to BOTH battery negatives.
I fail to see how a dedicated cable between the two battery negatives will change the charge properties. Let alone improve them.
If anything, for an improvement, or at least an equalization... You should be running a cable from the solenoid positive, to the secondary battery positive.
But I don't think even that would make much of a difference if any at all.
Current from alt goes to the positive side of the solenoid, then to the positive side of one battery. Then from there to the positive side of the other battery, via a cable straight between them.
Negative goes out through the alt case. To the engine block. From there it goes straight to BOTH battery negatives.
I fail to see how a dedicated cable between the two battery negatives will change the charge properties. Let alone improve them.
If anything, for an improvement, or at least an equalization... You should be running a cable from the solenoid positive, to the secondary battery positive.
But I don't think even that would make much of a difference if any at all.
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His point is that the passenger side battery should NOT be grounded to the block and the ground should ONLY go to the drivers side battery and then from the drivers battery to the passenger.
This way the electricity basically goes out the passenger side and back in the drivers side. This way the passenger side battery is not getting more load than the driver side (being the passenger side is the "shorter" circuit).
So, in essence you guys are saying that the path to ground should be made longer for the driver side battery.
I still fail to see the improvement. I still think an equal path for the positive would give better benefits.
And I don't think either one is needed. I think you'll see more benefit in the older trucks like we have, just in new cables all around, and all connections cleaned up and sealed.
I still fail to see the improvement. I still think an equal path for the positive would give better benefits.
And I don't think either one is needed. I think you'll see more benefit in the older trucks like we have, just in new cables all around, and all connections cleaned up and sealed.
IDIBRONCO
IDIBRONCO
I believe that they're saying that the path to ground for the passenger's side battery should be made longer. The two batteries should be connected by the ground cable. The ground should run from the block, to the driver's side battery, and then to the passenger's side battery. In my mind, this seems like overcomplicating things. If you have two containers that are connected by a hose toward the tops and you fill one with water, then the other will also be filled. It may be slower, but it will still be filled to the top with water.
I would agree with this.
Pat Tavelli
Registered User
The improvement in charging is overshadowed by major improvement in battery life due to high current cranking equally supplied by both batteries. Slightly longer ground cable to starter will be larger cable (sum of circular mills of both existing neg cables). If it starts on first rev with no extended cranking sessions, mod maybe not necessary. Just measure cranking current each batt negative cable to see difference.
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Analogy is correct. The second, battery, will charge slower and discharge less current. First will probably die sooner depending of which is more damaging, slower charge or higher current share. Small differences in measured charge/discharge battery voltage equate to large current differences due to small internal resistance, damn Ohm's Law again.
This, might, slightly improve charging only with very little cranking effect. Highest load is cranking, that should be balanced with pos and neg cables to STARTER, with smaller cables to frame ground and solenoid/alternator. Almost the only designs like our trucks are done by manufacturers saving a few cents per vehicle. Check out how the rest of the world connects parallel batteries. For a hoot, check out 3 or more in parallel.
https://www.impactbattery.com/blog/tutorials/how-to-charge-marine-and-rv-batteries-in-parallel/
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79jasper
Chickenhawk
Picture is worth a thousand words.
Now I see what you are saying. We have a few dump trucks setup that way.
Sent from my SM-N960U using Tapatalk
Now I see what you are saying. We have a few dump trucks setup that way.
Sent from my SM-N960U using Tapatalk
If you really want to maximise the efficiency of the cranking system, put both the batteries on the frame and make all the cables to the starter just a couple feet long.
I wasn't thinking about cranking.This, might, slightly improve charging only with very little cranking effect. Highest load is cranking, that should be balanced with pos and neg cables to STARTER, with smaller cables to frame ground and solenoid/alternator. Almost the only designs like our trucks are done by manufacturers saving a few cents per vehicle. Check out how the rest of the world connects parallel batteries. For a hoot, check out 3 or more in parallel.
https://www.impactbattery.com/blog/tutorials/how-to-charge-marine-and-rv-batteries-in-parallel/
And as Jasper said, the pictures and reference are invaluable!
You are correct.
Agreed. I did exactly that in my 97 E350 (powerstroke) because the engine always had starting issues. #2/0 from each battery (mounted side-by-side) combining to #4/0 for the leg to the starter.
In these cases you need every volt and amp for as long as possible... meanwhile the automatic GP system happily drags your system below the IDM's 10volt starting threshold.
Starter is 'technically' closer to the passenger side battery, right?Agreed. I did exactly that in my 97 E350 (powerstroke) because the engine always had starting issues. #2/0 from each battery (mounted side-by-side) combining to #4/0 for the leg to the starter.
In these cases you need every volt and amp for as long as possible... meanwhile the automatic GP system happily drags your system below the IDM's 10volt starting threshold.
I believe the GPs draw from there, as well, right?
How about moving the GP system to draw more from the driver's side battery?
