charging lipos

[Brushless55]

sounds like the one getting hotter is a little hurt..

[785boats]

As far as I know, the current flow is exactly the same on the negative side of a circuit as the positive side.
The next time you give the packs a good run check each individual cell voltage of both packs. See if the suspect pack has differing voltages & by how much. All 4 cells should be pretty close. If the suspect pack voltages are a lot different it's probably not in the best condition.
If your charger can charge at 5A why not start the charge of your 5000mah packs at 5A? That's a perfectly acceptable 1C charge rate. The first part of the charge would be a bit quicker until the voltage starts to drop.
Just a thought.
Paul.

[domwilson]

Good explanation of circuits here... http://www.electronics-lab.com/artic...y/parallel.htm

[NorthernBoater]

It sounds like one of your packs has a higher internal resistance then the other pack. The same amount of current will go through both packs. A higher resistance means it will get hotter.