question

@dmac The voltage jumps to 14.6 or 14.7 momentarily then falls back to 14.3 or so before the charger sends another pulse

Sounds normal if you have selected "recondition" charge cycle.

Have you read the IP 67 manual?

Unless the battery manufacturer specifies a custom charge profile you should be alright. However, to prevent damage, AGM and GEL batteries should NOT be charged with the recondition mode enabled.

It would be beneficial to read the owner manuals before using the charger.

I have read the manual. I am using the default settings - which do NOT include the recondition mode. Recondition mode is NOT selected and never was.

If you do read the manual, this is not how the reconditioning mode is described anyway: "RECONDITION Optional reconditioning for deeply discharged lead-acid batteries. Reconditioning is applicable to the charge algorithms NORMAL and HIGH and can be selected with the App on your smartphone. When in RECONDITION mode the battery will be charged with low current up to a higher voltage at the end of the absorption phase. "

In fact, there is also this bit in the manual as well: "Some battery charger manufactures recommend pulse charging to reverse sulfation. However, most battery experts agree that there is no conclusive proof that pulse charging works any better than constant voltage charging. This is confirmed by our own tests."

So, recondition, even if it was on - which it is not - does not pulse, it applies low current but just takes the battery up to a higher voltage than usual (16.2 or higher depending on other settings, per the manual.

Why would I see this behavior then?

If you have doubts about your battery charger you should have it examined and tested by your Victron dealer.