[bennelson]

I have been having some problems with charging lately.

The charger starts off at full amperage, but drops down to a lower amperage rather quickly. It SHOULD act like that if the batteries are mostly full, but this is happening when the pack is discharged!

I threw the car on charge today, cranked up the amperage setting, and let it run a few minutes. Then I checked over the wiring. One thing that I did notice was that the charger wires running to the batteries was warm.

I have always known that the charger wires I was using were a little undersized. I think that perhaps there has been some corrosion or something that has exasterbated the problem, because I never really remember the wires getting warm before.

The battery charger itself has fairly thick leads coming out of it, but they are only a few inches long, so additional wire is wire-nutted onto it. I really didn't have any extra-thick cable around. The only real, new-on-a-spool, cable I have is 14ga. The next thicker size I have around is 2/0, with nothing in between.

The positive end of the pack is in the rear battery box, and the negative end is at the single traction pack battery that's under the hood. That means it's a real short path from the charger to the positive, and a much longer one to the pack negative.

I strung together two of the 14 ga wires and put BOTH pieces into a crimp-on ring terminal to go to pack positive. The other end of both wires went to the wire nut on charger positive.

I have three pieces of extension cord that run through the conduit under the car from under the hood to the rear battery box and spare tire wheel well (where the charger is.)
One conductor of one of those extension cords is the charger negative lead that goes to the front battery. Double-checking the markings on the cord jacket, it listed 16-3, or three conductors, each 16 guage. That's pretty thin to pump any amount of amperage to the front of the car!
The other two conductors of that cable originally had purposes, but are currently free.
So, I stripped all three conductors on both ends, and ran all three into a single ring terminal. That way, I now have three times as much copper connecting the charger to the front of the car.

Still "seat-of-the-pants" science, but the charger seems to be working better now. It has been charging for a couple hours and the ammeter display is dropping slowly, the way it aught to.

PS.
I also had been using my 100'/14ga extension cord from the wall outlet to the car for at home charging. Mostly just for convenience/out of habit, as it reaches wherever I park so easily.
I dug out a 25'/12GA cord, and am using that between the outlet and car now.