Xantrex RV2012 charger doesn't do bulk?

[Kenpimentel]

I think my charger is out-smarting itself?

Setup:
- Xantrex RV2012GS, 2kW inverter, 100A charger, 2009
- RC7 remote display
- Northern Lights, 6kW generator, 2009
- Lifeline AGM 4D batteries (3), 630Ah, new
- Linklite monitor, shows current in/out

Problem:
I turn the generator on, I watch my Linklite go from negative current to positive current (about 40A into the batteries). The problem is that I do not see the the bulk stage charging. The voltage is only 13.4v, so the charger has gone straight to the final float stage. Why?

More info
- Before I turn the genset on, the batteries are showing 12.5V with a 20A load
- According to the Linklite, the batteries have been discharged by 125Ah, which is what I'm trying to replace with the genset
- If the batteries are more drained, such that the voltage is 12.2V with a load, then I do see the bulk stage kick in and I do see 80-90A flowing into the batteries
- For whatever reason, the Xantrex "charge" LED is not lit on the RC7 panel even though it is obviously charging - just not the bulk mode like I expect or want. The RC7 also used to tell me which mode it is in, but that is no longer displayed on the panel. It just shows me the bar graph with the charge capacity.

Why this matters
I obviously want to maximize my generator hours and get faster charging. Instead of a 3-stage charger, I seem to have a 1-stage charger when the batteries are only drawn down by 1/3rd. I assume that the charger is sensing that the battery voltage is high enough that it skips the other stages?

[senormechanico]

Check both positive and negative leads for a bad connection from the charger to the batteries.
If you measure the voltage at the charger terminals and battery during operation, you will probably see enough difference to make the charger think the battery is full.
All it takes is a few tenths of a volt.

[Kenpimentel]

I will check. I think the RC7 also has a measurement of what it thinks the voltage is, so I'll check that too.