Hi All
I have recently experienced broken stud terminals on the Mulitplus-II 8kVA and 10kVA 48V 230V units. When tightening the nuts with a torque wrench the AC studs break almost with no force.
I see there is a lot about this in the old forum:
https://communityarchive.victronenergy.com/questions/42235/multiplus-ii-battery-terminal-bolt-snapped-sheared.html
Any else seeing this?
Yes. Just happened too me on a 48v/8k. What was your resolution please?
Had to pay to have it repaired.
@munga It could be that the torque wrench is not properly calibrated. Did you check before first use and depending on frequent use do so once in a while?
It happened to me just yesterday as well.
I’m wondering if there’s a DIY fix for this issue.
My problem looks exactly the same as in the pictures shown in the community archive (see the first post in this thread).
Is it correct that the threaded section of the M6 screw — the part that shears off — is simply screwed into an M6 nut that’s glued to the board?
If so, it should be possible to unscrew and replace it fairly easily, right?
Or is there actually a screw head on the reverse side of the board that needs to be removed instead?
Thanks in advance for any input!
It is really do you have the tooling. 100w soldering iron won’t be able to remove the stud. It is well soldered at the back of the pcb. Also the stud is not the normal one you can get from a hardware store.
Not glued unless something has changed from the last one i looked at
I had the same problem with a MultiPlus-II 12/3000/120-32.
First time in June 2022, tightening the nuts with a torque wrench 12Nm. Broked direct at the PCB. Luckily I had warranty at this time and I get a new one.
Second time a week ago (April 2026), tightening the nuts with a torque wrench 12Nm. (+) broken 7mm below tip of the screw. 
(120mm² cable/ 8mm cableshoes. Torque wrench Gedore red with calibration certificate.)
Now I fix it by myself.
Here is a - howto repair broken stud terminals …
Dissemble the whole MultiPlus-II.
For soldering we use a 2000W heatgun with 650°C and a lot of time. Copper area (heatsink) at the pcb is big.
Turn pcb soldering side down, so that screws can fall down when tin is warm/ liquid.
(Be very careful, next to the Screws at the PCB soldering side/ downside are two SMD resistors. Don’t un-solder them.)
I directly remove all 4 M8 18mm screws (they are not magnetic but no VA, maybe brass with tin coated. This might be the problem, depending on brass alloy 8 - 10Nm for M8 screws - not 12Nm.)
New screws I take are zinc coated M8 8.8 20mm screws. (It’s in a camper so I don`t expect problems with corrosion.)
Datasheed M8 8.8 max. 24Nm so I hope they will never broke again with 12Nm. I wont use more torque before soldering or pcb will be damaged.
For tinning the new screw heads we use “Felder Weichlot- und Verzinnungspaste Sn97Cu3” (Felder Lead-Free Soft Soldering & Tinning Paste Sn97Cu3).
and later for soldering on the pcb "Felder Lötdraht ISO-Core “EL” " (Solder wire ISO-Core “EL”).
Turn around pcb, downside/ soldering side up, put the screws in the wholes, parallel to the edge.
For soldering we use again the 2000W heat gun with 650°C and a loooot of time. Copper area (heatsink) at the pcb is big and must get warm until tin at the pcb liquid.
When ist was cold we use “LR, Leiterplattenreiniger Spray” (pcb cleaner spray) to get rid of brown flux/ Kolophonium rests at the PCB
Finally I use “NO-OX-ID Electrical Contact Grease” on the cable shoes contact surfaces and bolts.
In the first post I forgot to mention keep in mind to reduce torque at screws witch grease “off-the-cuff rule of thumb is 25% to 30%. Torque values given in the manuals are dry torque,” - sry. - thank you Justin for the hint.
Re assemble the whole stuff.
For a first test run under high load we let the hood open (Dangerous, high voltage!) and still use an IR-camera module to check if we generate hot spot/ overheating problems at the inner busbars by resitors.
After that final test we close the MultiPlus-II. And remount it on it`s place.
Good luck.
Keep in mind that if you’re using a grease on the threads of a fastener, you have to decrease your torque value. By how much will depend on the type of grease, but an off-the-cuff rule of thumb is 25% to 30%. Torque values given in the manuals are dry torque, not wet torque. So, if the manual of X says that torque should be 12Nm, if you’ve lubricated the threads of the bolt you should lower your torque wrench setting to around 8.4 to 9.6Nm.
@Justin,
thank you for the hint.
In my posting I forgott some more points, I will correct my posting.