Alternator output

[Td12327]

My battery compartment has four red + wires. My first question is: does it matter which battery I connect to, if the two batteries are connected in parallel. My second question is which red wire is coming from the vehicle alternator? I am guessing it’s the one that is showing 1.5 amps when the engine is running. I was surprised that the amount of amps is so low. Does that seem to be a typical amount from a Ram sprinter chassis on my 2016 Dynamax rev.

[kcmusa]

Connect all red top one battery in parallel, all negative to other battery that’s in parallel with first battery.
Use a volt meter, with engine running the wire should be the one with 13+ volts .

[Td12327]

Thanks for your response. I should mention that I have two cables that are not in the picture, a positive and negative cable I use to put the batteries in parallel. So are you saying that after putting the batteries in parallel with those cables I should connect all the coach red cables to the positive post on one battery and the negative cables on the other battery? Also, I am guessing that I would test the voltage on the red cables when they are disconnected, while the alternator is charging?

[TitanMike]

Originally Posted by Td12327

Thanks for your response. I should mention that I have two cables that are not in the picture, a positive and negative cable I use to put the batteries in parallel. So are you saying that after putting the batteries in parallel with those cables I should connect all the coach red cables to the positive post on one battery and the negative cables on the other battery? Also, I am guessing that I would test the voltage on the red cables when they are disconnected, while the alternator is charging?

Yes.

When you connect two batteries in parallel you want to connect charge/load wires to opposite corners so the resistance, even though very small, is evened out as current flows within the battery bank.

If you connect both positive and negative cables to one side then the other battery has the connector cables causing load/charging currents to be unbalanced, again by a small amount usually but significant when high currents are applied (Microwave on Inverter, etc). If you look at the top of a connection diagram, load wires connected to the same battery will draw from the closest battery and the jumpers will have a slight resistance that will cause the second battery to deliver slightly less current to the system. "Diagonal" connections equalize the resistance in connectors negating this effect.

Not so much a big deal when only using two batteries in parallel to run low current devices like lights, a fan, the furnace. Also not so much of an issue if connecting wires are oversized for the loads applied.

It's just a good practice so both batteries discharge at the same rate as well as charge at the same rate.

[kenandterry]

Originally Posted by Td12327

My battery compartment has four red + wires. My first question is: does it matter which battery I connect to, if the two batteries are connected in parallel. My second question is which red wire is coming from the vehicle alternator? I am guessing it’s the one that is showing 1.5 amps when the engine is running. I was surprised that the amount of amps is so low. Does that seem to be a typical amount from a Ram sprinter chassis on my 2016 Dynamax rev.

I hope things go okay when hooking back up. Pictures BEFORE and AFTER are always best. While you’ve got the compartment empty, do a good cleaning and inspection for any rusting or corrosion. It may be awhile before you get the chance again.
Just sayin’.

[kcmusa]

Originally Posted by Td12327

Thanks for your response. I should mention that I have two cables that are not in the picture, a positive and negative cable I use to put the batteries in parallel. So are you saying that after putting the batteries in parallel with those cables I should connect all the coach red cables to the positive post on one battery and the negative cables on the other battery? Also, I am guessing that I would test the voltage on the red cables when they are disconnected, while the alternator is charging?

You are exactly right.