To put it mildly, the battery test on the previous pages presented a recharging nightmare. Ideally, what we needed was an intelligent multi-bank battery charger that could independently recharge any combination of battery chemistries at the same time – with speed, accuracy and temperature compensation. Consider a common recharge sequence that we carried out during our test:
• Battery No. 1 is an absorbed glass mat (AGM) battery requiring 50-plus amps of bulk recharge current,
• Battery No. 2, also an AGM battery, needs a .5-amp float charge
• Battery No. 3, a gel battery, needs 20 amps of absorption charge.
This, and many other variations of this recharging sequence would need to be repeated 24 hours a day for more than 20 days.
To our good fortune, in the fall of 2005, Xantrex Technologies Inc. formally introduced its line of XC battery chargers, which featured new multiplex charging capability, just the technology that we needed. Xantrex sent us the XC 5012, a 50-amp, three-bank multiplex charger for our evaluation.
Once you program the charger and tell it what type of battery chemistry that you have connected to each of its three independent banks, the charger will check each battery bank and then start a recharging profile on the battery bank with the lowest state of charge.
Once this particular battery bank responds to the XC’s charge profile, the charger will put that battery’s charge profile on hold and switch its recharge energy over to the next battery bank in numeric sequence and apply a new charge profile.
The charging sequence is repeated for the third battery bank, and then charging switches back to the very first battery bank and picks up where it left off. This rolling recharge sequence allows the charger to briefly focus all of its energy into one particular battery bank.
Our experience with Xantrex’s XC5012 convinced us that this is the best battery charger in its class that we have tested to date. The XC5012 regularly delivered 53 amps in the initial bulk charge phase (more than its rated output) in stone silence. And silence is something that any sailor can appreciate.
Bearing in mind that the fastest way to ruin a VRLA battery is to recharge it without a temperature compensated charge, we fitted each battery bank with a Xantrex battery temperature probe (each unit ships standard with one probe). We scrutinized the XC’s recharge voltages during each of its charging phases for each type of battery chemistry. All parameters measured across the board were in range for a safe and fast recharge without a hint of over- or under-charging.
It was apparent that this new charger was powerful and capable, but was it durable? The XC series is rated for true reverse polarity protection, so we reverse-connected one set of the battery output leads (on purpose), stepped back a few feet and plugged the charger in. The result was uneventful, to say the least. No sparks, no smoke, no Gabriel’s horn. All that happened was that a fault message was displayed on the unit’s LCD display.
Costing about $335, the XC 30-amp charger (approximately $100 more for the 50-amp XC5012) is one serious battery charger that will finally allow a vessel with perfectly functioning lead acid start batteries to upgrade the house battery bank to AGM or gel technology without having to add a second battery charger to the system.
Contact – Xantrex Technologies Inc., 800/670-0707, www.xantrex.com.
