Victron Centaur Charger


The only thing that wasn't "smart" about my old battery charger
was the decision to install it in the first place. The old unit was
definitely undersized for maximizing the health and well being of my
two banks of Rolls lead-acid batteries. One long winter weekend at a
dock in the south sound was enough to alert me that a few 12-volt cabin
lights and the fan in my diesel furnace were drawing the batteries down
faster than the inadequate old charger could replenish them. As the
weekend wore on, our cabin lights grew dimmer, the heater fan lost
speed, and the need for a better charging system became increasingly
obvious.

With the addition of a new electric bow thruster last spring, an
improved battery charger became even more critical. Even after sitting
on shorepower for a week or more between uses, the alternator was still
working at maximum output for the first hour or so of operation to
bring the batteries up to an optimal state of charge. It was almost
impossible to keep the bow thruster battery charged up. The physics of
lead acid batteries are such that it is important to give them a fairly
hot charge once in a while, and I was not certain at all that the
batteries were ever receiving enough energy from the charger to be
properly desulfated..

Clearly aware of the specific cranial flatulence that led to the
selection of an undersized charger a few years ago, I was determined
not to make the same mistake again. I did what any reasonable person
should have done the first time around and sought out some expert
advice. I had purchased my Rolls batteries from Boat Electric in
Seattle, and I approached Jeff Ericson and Lori Hogan to ask about a
recommended charger to maintain them.

After evaluating my battery capacities and charging needs, Boat
Electric recommended a 30-amp Centaur Charger by Victron Energy. There
are a number of appealing characteristics associated with the Victron
Centaur.

Victron's Centaur has been specifically designed to fit into almost
any 12-volt or 24-volt DC system on any boat, anywhere in the world. It
would be exceptionally unusual to find a boat that would have an
electrical system incompatible with the Centaur. While it isn't of
specific importance to my use, one of the notable advantages of the
Victron Centaur is that it will automatically sense the input voltage.
Some chargers require that a manual switch is thrown to prevent
damaging the unit if switching from 110 to 220-volt AC, but the Victron
Centaur is truly a world-wide circuit.

The Centaur is designed so that AC input is electronically corrected by
the first power stage and the second stage has built-in galvanic
islolation. Many of the more typical concerns about the "quality"
of AC power delivered by a marina's shorepower system are addressed
by Victron's internal technology. The electronic correction of the
input current allows the Centaur to function normally even if current
on the dock drops to as low as 90-volts. Advanced technology assures a
perfect DC voltage at the output terminals, while drawing up to 30%
fewer amps than similarly rated chargers. (This can be critical when
trying to recharge batteries at a dock with only 15-20 amps of
shorepower available for the combined AC needs of the vessel). All of
the internal parts are protected by a special coating resistant to dirt
and moisture.

Centaur chargers are available in eight different 12-volt ratings,
ranging from 20-200 amps. There are six different 24-volt chargers in
the series, rated from 16-100 amps.
My new 30-amp Centaur charger has three DC output terminals. The house
battery, the starting battery, and the bow thruster battery each have a
dedicated charging circuit. The 30-amp DC output is divided among the
three terminals, but if there were only one or two batteries connected
the DC output would be reapportioned to allow the full power to be
delivered to the terminal(s) actually in use. Additionally, the Centaur
can direct up to the entire 30-amps of charging current to a single
terminal if it detects that one of the connected batteries is badly
discharged relative to the others.

There was a time when a lot of batteries were boiled to death. Old time
battery chargers poured a constant supply of power into the batteries,
and if left connected on a permanent basis (a typical practice aboard
most boats) the batteries' electrolyte would boil away and damage to
internal plates would be inevitable. Like all of the better chargers
available today, the Victron Centaur charges the battery with a 3-stage
process that is ideal for continuous connection. The first stage, bulk
charging, introduces a lot of energy to the battery to blow sulfates
off the lead plates and bring the battery back toward a fully charged
condition. The second stage, absorption, reduces the amount of power
being pumped into the battery and completes the charging cycle. The
third stage, float charging, applies only enough power to the batteries
to keep them in a fully charged, ready to serve, condition.

The Centaur is shipped with a series of dip switches preset for gel
batteries, but the instructions are easily followed to configure the
settings for lead-acid or AGM.

Installation was very simple. A three-screw bracket is included from
which to hang the housing, and two more screws at the bottom of the
unit secure it in place on the bulkhead or other mounting surface. The
assembly has a respectable "heft" to it; certainly enough to foster
confidence that it is built to a commercial duty specification. After
disconnecting the positive connections to all of the batteries, it was
simple enough to connect the AC service used for the previous charger
to the Victron. The DC connections feed into the case through
waterproof rubber seals, and with a DC ring connector crimped onto the
terminal end of each cable the connections are made fast with nuts
tightened onto DC outlet lugs. (Each of the three +DC connections has
its own lug, while there is a common lug for all three -DC leads).

The instruction booklet has a chart to illustrate the proper position
of the dip switches for various battery types, and the switches are
located in the lower left hand corner of the battery connection area of
the charger.

With everything hooked up to the charger, I reconnected the battery
cables and then switched on the AC current. If there had been any doubt
whether my old charger was inadequate, watching the DC output meter on
the Centaur's case peg itself on the high side for the first several
minutes of the charge cycle would have confirmed that my batteries were
not fully or properly charged. I became concerned that perhaps I had
made some error in hookup that caused the charger to be putting out at
a high, fixed rate- but after a short time the needle began moving
slowly to the left and eventually indicated only a couple of amps being
doled out to my batteries.
The Victron Centaur charger was an ideal fit for my boat. The
alternator no longer begs for mercy during the first several miles of a
cruise, the cabin lights are brighter, the bow thruster responds
reliably, and I am more confident of realizing the extremely long
service life for which my Rolls batteries are renown.