question

Hello Ricco,

That would have been shocking to see 26 volts incoming, especially when the max output for that unit is supposed to be 15 volts! I’d do some testing with the Victron units and batteries alone, to make sure everything is working properly, then move on to the alternators, then the whole system. If possible, have your current alternator output checked when removed. The source of that high voltage needs to be identified, for sure.

Not to be stating the obvious, but make certain your Victron gear is set correctly for the batteries you have. They work with a wide range of batteries, and the charge profile needs to be right for your situation.

Good luck!

Hi RickP

Thank you for your reply!

Tomorrow I will get the new start batteries and the two new alternators, we are kinda dead here in the water at a anchorage.

There is not much setup I can do on the start batteries I can only control the output and that is setup to lithium iirc, note the 26v was at the input of the Orion, charging was disabled onto my lithium bank, because I was suspecting that the Orion was drawing power from the start batteries onto the lithium even tho the engines was not running. I got plenty of power from solar and a genset so it was only secondary for me to charge from the engines, and during this specific sail I choose to disabled the charging from the alternators.

/Ricco

I go with alternators damaged by current draw with sustained low voltage at low idle.

If your Orions were discharging starter batteries the voltage setting when to stop was too low. Possibly because it otherwise didnt work with the small alternators otherwise and they would not come online at low idle or were on off in quick successsion.

A 60A alternator can likely not provide 30A sustained plus charging a discharged battery at low rpm in any case. Alternator will heat up into destruction. And depending on the alternator it cannot up the voltage above battery voltage without a squirt of throttle of high idle after start up. So maybe your original starter batteries were not discharged by the orions but they were discharged by several starts and never recharged because the voltage never came up high enough again. The second set died of a malfuntioning regulator possibly because of it being sick and tired trying to get the voltage up and never getting there, eventually you opened the throttle, voltage finally did go up but was not regulated anymore.

It will likely happen again. Switch on the Orions manually only at lots of throttle, decrease Orions power draw if possible while watching temp of alternator and voltage at starter battery, change to big alternators, change reduction ratio to existing alternators if possible is what I would look for.

Also: Now that the Orions have seen severe overvoltage at the input, I'd disconnect from big Li battery and make sure they still provide the correct output voltage on the new set of 12V equipment. I had a water damaged 12V- 12V DCDC which then provided over 30V at the output destroying all electronics. With the big Li battery behind the overvoltage can only be recognized with a long time delay resulting in BMS shutting down or shooting it through if worse comes to worst.