I just delivered a
race boat with a 3
battery Mastervolt
lithium system. The install was all Mastervolt with C-zone
remote control system to further complicate things.
I delivered the same
boat with the same system 2 years ago, and all was great. It only took one hour of
charging for every 24 hours of sailing to keep the
batteries happy. Then covid hit, and the boat sat at the
dock except for a couple of 3 hour trips to the boatyard.
This time I arrived to a dark ship. The it had gone out for a 4 hour test sail 2 weeks ago, and they had some trouble getting the
batteries on line, but then everything worked. I had been on
shore power for 24 hours prior to my arrival. The C-zone hooked all the boat systems up while on
shore power, but went dark when unplugged.
The
engine started fine on its own
battery and
alternator, and the house
alternator was putting out enough
power to run the boat. When I attempted to manually pull the relays in for the house batteries while the
engine was o, they the battery protection system tripped them off after about 60 seconds.
There was no Mastervolt
documentation on the boat. The analog multimeter on the boat was not accurate enough to determine SOC from the batteries, but I assumed they were getting a low voltage cutoff which tripped them off --even when there was a
charging source available. All of the fancy digital readouts for the house battery voltage and
current showed dashes.
I had a tight
weather window and an approaching
hurricane, and gave up on Mastervolt support after 20 minutes on hold. I did send someone out to buy jumper
cables, and left, figuring the boat could last 48 hours if I kept the engine on.
Needless to say at 0300 the first night, the house alternator stopped putting out and things went dark again. I took a jumper cable from the start battery to the back of the distribution panel, and ran on the start battery alternator the rest of the trip.
Had pretty good
weather the 360 miles of the
delivery, with no more drama. Texted the owner's rep and told him he needed a really good electrician on the boat today if he wanted to
race on Thursday. Borrowed a DVM and measured the voltage on the LiFe batteries. One was 5.6 V, one 10.8v, and one was 12.7v. The second alternator is shoehorned into a corner of a hot engine, but my guess is that it and/or its external
regulator may need replacing.
When I left the boat, we had the 12.7v battery pulled in and were attempting to charge it with the shore
power charger, but I never did figure out how to recover from a low state of charge. The battery at 6v is probably headed for the scrap heap, but they can do day races on even one battery if they fix the alternator.
Lessons learned:
Don't let them install a fancy
lithium system in your boat without providing a circuit diagram and detailed WRITTEN instructions for its care. I think that the whole problem could have been avoided or the failure(s) detected earlier.
Don't let anyone install
remote relays in place of battery off/on switches in a boat which goes
offshore. KISS.
Don't forget to pack your clamp on ammeter in your boat
delivery bag.
Does any one with Mastervolt lithium battery system know how to recover from an undervoltage cutoff? Is there a separate BMS inside each battery?