IDOC to Files Large volume

We have a large number if IDOCS being triggered from ECC and each IDOC is pushed to the target system as a separate XML files. The problem is that the target is not able to process this large number .

Assuming that there is a constraint on ECC,  what can be done from PI to batch the IDOCs and send only , say 100 files every 5 minutes . I do not want to use BPM .

Thanks!