That is a safe range for the large batteries as long as the current starts to drop as the batteries start to become more charged, these are 100AH batteries, correct?At 29 volts it puts out 14.5 amps. Is that to fast to charge.
Now on to the next step.
Let the generator charge the batteries for a period of time with the caps removed so you can see if they start to bubble. Also check that the batteries do not get hot.
Make sure each cell in the batteries has the correct level of water in them. Use only distilled water to top off the level if low.
Considering the condition of the batteries and the state of charge, it may take a long while for the state of charge to come up to a point the current reading should start to drop. That is what we want to see here. The current going down.
You may even see the voltage from the generator come up a little, that is ok.
If the batteries start to get hot or boil excessively, STOP.
You want to see something like this: